Dissolution Media Simulating Conditions in the Proximal Human Gastrointestinal Tract: An Update

Helicobacter pylori γ-glutamyltransferase is linked to proteomic adaptions important for colonization

Helicobacter pylori γ-glutamyltransferase (gGT) is a virulence factor that promotes bacterial colonization and immune tolerance. Although some studies addressed potential functional mechanisms, the supportive role of gGT for in vivo colonization remains unclear. Additionally, it is unknown how different gGT expression levels may lead to compensatory mechanisms ensuring infection and persistence. Hence, it is crucial to unravel the in vivo function of gGT. We assessed acid survival under conditions mimicking the human gastric fluid and elevated the pH in the murine stomach prior to H. pylori infection to link gGT-mediated acid resistance to colonization. By comparing proteomes of gGT-proficient and -deficient isolates before and after infecting mice, we investigated proteomic adaptations of gGT-deficient bacteria during infection. Our data indicate that gGT is crucial to sustain urease activity in acidic environments, thereby supporting survival and successful colonization. Absence of gGT triggers expression of proteins involved in the nitrogen and iron metabolism and boosts the expression of adhesins and flagellar proteins during infection, resulting in increased motility and adhesion capacity. In summary, gGT-dependent mechanisms confer a growth advantage to the bacterium in the gastric environment, which renders gGT a valuable target for the development of new treatments against H. pylori infection.

Improving accuracy in food effect predictions: Application of in-vitro absorption experiments as a useful tool for the evaluation of ten drug products

Predicting the magnitude and direction of food effects on oral drug delivery can be challenging, especially for compounds with absorption limited by changes in the permeation rate. Currently available in-vitro tools assess the impact of increased bile flow and food on drug solubilization, potentially leading to increased absorption under fed conditions. However, the presence of bile can sequester the drug within bile/food colloids, reducing free drug availability and resulting in unanticipated absorption. The aim of this study is to explore the application and outcome of a combined dissolution/permeation (MacroFLUX™) assay of ten drug products for a more accurate prediction of clinical food effects in the context of given dose and formulation. The ratio of the fed-to-fasted dissolution and Flux were used to correlate each experimental model to clinical food effect in humans. Assessing the flux across a biomimetic artificial membrane provided superior predictability over dissolution alone. Food effects were predicted accurately for 60% of compounds within 1.25-fold based on flux analysis, while dissolution analysis only predicted 30% of compounds evaluated. The most interesting outcome is that dissolution did not pick up on any of the negative food effects. Notably, the study revealed that the common assumption of compounds exhibiting a positive food effect due to increased dissolution/solubility from fasted to fed state does not always hold true. This in-vitro absorption experiment proved to be a valuable in-vitro biopharmaceutic tool that can predict clinical food effects, support (pre-)formulation development, and guide the design of dedicated clinical pharmacology studies.

Development of 3D-Printed Captopril Mini-Tablets with customized release profiles for paediatric hypertension therapy

Hypertension, defined as a sustained increase in resting systolic and/or diastolic blood pressure (BP), represents a modifiable risk factor for cardiovascular and renal diseases that affect 5-10 % of paediatric patients. Captopril (CPT) is widely used for treating paediatric arterial hypertension; however, the smallest commercially available dosage form (25 mg) often necessitates off-label use, as paediatric doses range from 0.3-0.5 mg/kg. This study explores the development of immediate-release Mini-Tablets (MTs) of CPT for paediatric use via direct powder extrusion (DPE) 3D printing. The DPE technique enables precise control over dosage, shape, and size, facilitating personalized therapy. CPT-loaded MTs were fabricated using a 3DForMe® DPE 3D printer, incorporating polyvinyl alcohol (PVA) as a carrier polymer and hydroxypropyl methylcellulose (HPMC) as a co-polymer to ensure structural integrity and enhance drug encapsulation. MTs were produced with consistent size but varied infill percentages, allowing the formulation of immediate and sustained-release profiles from a single polymer mixture. Characterization of the MTs (weight uniformity, content uniformity both inter- and intra-batch, etc.) was performed to evaluate the effectiveness of the printing protocol and equipment in producing MTs. Dissolution and drug release studies were conducted in simulated gastric conditions (fasted and post-prandial states). MTs with 50 % and 75 % infill exhibited rapid dissolution and immediate drug release in fasted media, while other formulations demonstrated prolonged release in both gastric environments. These findings underscore the potential of DPE 3D printing to create flexible, precise, and customizable paediatric pharmaceutical formulations, addressing critical needs in personalized medicine and optimizing therapeutic outcomes.

Self-Emulsifying delivery systems for oral administration of exenatide: Hydrophobic ion pairs vs. Dry reverse micelles

This research provides a comparative analysis of two innovative strategies - hydrophobic ion pairing (HIP) and dry reverse micelles (dRM) - to enhance the oral bioavailability of exenatide, a GLP-1 receptor agonist, as a diabetes treatment. These techniques were integrated into self-emulsifying drug delivery systems (SEDDS) featuring a lipid matrix composed of propylene glycol dilaurate and salicylic acid methyl ester (32.5 %:32.5 %; v/v) with polyethoxylated-35 castor oil (35 %; v/v) as surfactant. HIP enhances the lipophilicity of exenatide through ion-pairing with cationic surfactants, thereby promoting efficient incorporation into the lipid matrix of SEDDS. In contrast, dRM forms stabilized micellar structures using sorbitan monooleate, improving safety and compatibility. The droplet sizes for SEDDS were analyzed via dynamic light scattering and varied from 95 to 110 nm, with a polydispersity index of approximately 0.25, and zeta potentials between -1 mV and -6 mV. The maximum log DSEDDS/AQ values were 2.13 ± 0.31 for exenatide-loaded HIPs (ExeHIP) and 2.05 ± 0.08 for exenatide-loaded dRM (ExedRM), indicating sufficient lipophilicity, which is crucial for effective absorption and bioavailability. Toxicological assessments showed low toxicity levels. In vivo studies indicated a relative bioavailability of 18.08 % for ExeHIP and 17.06 % for ExedRM compared to intravenous injection. Both strategies demonstrated a similar potential in relative bioavailability, reflecting a significant increase in bioavailability compared to the control. Notably, the HIP formulation provided better control over exenatide release and ensured stable GLP-1 levels, while dRMs are preferable for safety reasons as all excipients have GRAS status and are therefore FDA approved.

Artificial gut Simulator. A scheme to predict intestinal and plasma concentration-time profiles of a weakly basic BCS-II drug, dipyridamole

The objective of this study was to develop a scheme to predict intestinal and plasma concentration-time profiles of the weakly basic BCS-II drug, dipyridamole (DPD), using an Artificial Gut Simulator (AGS) integrated with a compartment-based disposition model. In vivo data for this study was obtained from previously published literature. A 3-compartment disposition model was developed using the plasma concentration-time profile of DPD following an intravenous bolus dose. The AGS, consisting of a donor cell and a hollow fiber-based absorption module, was tuned to absorb DPD saturated solution at a physiological rate constant, 0.0402 min-1, based on the measured Caco-2 cell monolayer permeability coefficient. The dose dumping technique commonly used during dissolution testing can generate excessively high initial supersaturation and precipitation which is not physiologically relevant. In this study, fractions of DPD dose were added incrementally every 15 min to the AGS donor to simulate an overall first-order gastric emptying process. The concentration absorbed by the hollow fiber receiver media was input into the central compartment of the disposition model. The predicted plasma concentration-time profile matched the human in vivo profile of DPD obtained after oral administration of a 50 mg dose. For 30 and 90 mg oral doses, time profiles of concentration and fraction precipitated in the AGS donor agreed well with human duodenal measurements. This study demonstrates the significance of simulating physiological rate of absorption in vitro to accurately predict the bioavailability of a BCS-II compound.

Predicting and Confirming Bioequivalence of Alpelisib Oral Granules and Tablets for Patients With PIK3CA-Related Disorders

Alpelisib, an oral α-specific phosphoinositide 3-kinase (PI3K) inhibitor, has been shown to be safe and effective for some patients with gain-of-function mutation in the PIK3CA oncogene. Alpelisib has received US FDA accelerated approval as Vijoice® film-coated tablets to treat severe PIK3CA-Related Overgrowth Spectrum (PROS). PROS typically displays clinical manifestations in the first year of patient life. Therefore, oral granules were developed as an age-appropriate pediatric dosage form. Bioequivalence between alpelisib granules and tablet and the effect of food on granules pharmacokinetics were assessed in a single-center, randomized, three-treatment, six-sequence, three-period, crossover study among 60 healthy adults. Participants were randomly assigned to receive a single 50-mg alpelisib dose as: (i) tablet following a meal, (ii) granules following a meal, and (iii) granules while fasting. Statistical analysis of non-compartmental pharmacokinetic parameters demonstrated bioequivalence between the 50-mg alpelisib granules and tablet forms when administered with food: estimated geometric mean ratios (90% confidence interval) for granules-versus-tablet area under the curve (AUC) from time zero to infinity (AUCinf), to the last measurable concentration (AUClast) and maximum observed concentration (Cmax) were 0.984 (0.952, 1.02), 0.980 (0.946, 1.02), and 0.947 (0.891, 1.01), respectively. No clinically relevant food effect on 50-mg alpelisib granules pharmacokinetics was observed. These results were accurately predicted using physiologically based biopharmaceutical modeling. Alpelisib granules provide a bioequivalent alternative to tablets for patients prescribed a 50-mg dose and have difficulty swallowing tablets, an important consideration for convenience and compliance of this standard-of-care chronic therapy for patients with PROS. This study was registered in ClinicalTrials.gov on January 4, 2022 (NCT05195892).

Highly increasing solubility of clofazimine, an extremely water-insoluble basic drug, in lipid-based SEDDS using digestion products of long-chain lipids

Clofazimine (CFZ) is a highly effective antibiotic against leprosy and drug-resistant tuberculosis and is on the WHO List of Essential Drugs. However, no CFZ product with optimal bioavailability is available worldwide. The manufacturer withdrew its only marketed product, presumably due to poor and erratic bioavailability because of extremely low aqueous solubility in the gastrointestinal pH range. We developed a self-emulsifying drug delivery system (SEDDS) using a lipid digestion product (LDP) containing glyceryl monooleate and oleic acid at ∼1:2 molar ratio to increase drug solubility and ensure rapid dispersion into microemulsion. While solubilities of CFZ in glyceryl monooleate, glyceryl trioleate, and two common surfactants (Tween 80 and Kolliphor EL) were comparatively low (<15 mg/g), oleic acid provided a very high solubility of ∼500 mg/g. Because of the presence of oleic acid, the clofazimine solubility in SEDDS containing a 50:50 w/w mixture of LDP and surfactants increased to 130 mg/g. Two formulations having 50 or 100 mg CFZ in one gram of SEDDS were developed. They dispersed rapidly and almost completely in simulated intestinal fluid and in the USP pH 6.8 phosphate buffer containing 3 mM sodium taurocholate. There was some precipitation of CFZ as the HCl salt at low gastric pH during dispersion testing, but the effect could be avoided using enteric-coated capsules. Thus, an enteric-coated lipid-based formulation for CFZ with as high as 100 mg/g drug loading was developed, providing complete drug release and producing microemulsions under intestinal pH conditions.

Simulated Media for Mimicking the Human Environment In Vitro

The phrase 'All models are wrong but some are useful' spoken by George Box in 1976 is as relevant today as ever. Modern research relies heavily on models and the use of in vitro models is the cornerstone of developing novel treatments for various infectious diseases. Simple growth media have been, and still are, heavily used when performing research involving biofilms and infectious pathogens. However, using modern technologies, large discrepancies are now being revealed between bacteria grown in simple media versus those grown in more authentic media. These discrepancies can lead to significant differences in bacterial tolerances, growth patterns, biofilm formation abilities, etc. Hence, if the aim is to replicate the in vivo situation in a laboratory setting, the creation of realistic simulated bodily fluids should be prioritised. This paper presents a range of simulated human fluids from various body sites where infections often occur. Bacterial behaviour has been evaluated in all these media and is often compared to a simple growth medium counterpart. In all instances, significant differences are observed which might lead to important discrepancies, particularly in potential treatment efficiency. We hope this may serve as inspiration for any researcher doing in vitro work, attempting to mimic reality.

Mucin Mimics and Impacts the Function of Polymeric Inhibitors in Stabilizing Drug Supersaturation

Many drugs entering clinical trials today are poorly water-soluble and rely on supersaturating formulations, such as amorphous solid dispersions (ASD) to enhance their bioavailability. The in vivo performance of these formulations is often investigated through biorelevant dissolution testing using simulated intestinal fluid. Often overlooked in biorelevant dissolution is the presence of mucus within the intestinal environment and its possible role in affecting the formulation performance. In this study, the impact of mucins, the main structural glycoproteins of mucus, on the precipitation of two model compounds, carvedilol and nifedipine, from supersaturated solutions was investigated. The presence of mucin within the supersaturated environment was demonstrated to significantly alter the rate of drug precipitation in vitro. The impact of mucin on precipitation was then compared to commercially available polymer precipitation inhibitors hydroxypropyl methylcellulose (HPMC) and Kollidon VA 64, which are commonly used in ASD formulations. Surprisingly, when present at the same concentration (0.2% (w/v)), mucin reduces drug precipitation to an extent comparable to that of polymer precipitation inhibitors. Additionally, we observed that the presence of mucin in the supersaturated environment altered the precipitation inhibitory effects of HPMC and Kollidon VA64, suggesting that mucin could play an important and complicated role in formulation performance in the intestine.

In Vitro-In Vivo Correlation Of Amorphous Solid Dispersion Enabled Itraconazole Tablets

PURPOSE

There are scarce reports on in vitro-in vivo correlation (IVIVC) model development of immediate-release (IR) formulations, and few investigations of the impacts of formulation and process of spray-dried solid dispersions (SDD)-based tablets on human pharmacokinetics (PK), despite commercial product successes. The goal of this study was to investigate the formulation and process factors that impact bioavailability enhancement of IR itraconazole SDD tablets; and to develop an FDA level A IVIVC that would predict in vivo PK performance from in vitro dissolution testing.

METHODS

A direct, differential-equation-based IVIVC model approach was employed, using an oral solution for post-dissolution disposition and Fast-, Medium-, and Slow-release tablets.

RESULTS

The IVIVC met FDA internal predictability for level A IVIVC requirements. The in vitro dissolution employed USP simulated intestinal fluid (phosphate buffer), adjusted pH 6.4, and tablets were triturated into particles prior to their immersion into dissolution media to mimic the attenuated disintegration difference between Medium and Slow in vivo. Credibility assessment of the FDA level A IVIVC model was performed, including model verification and validation considerations in light of the question of interest, the context of use, and model risk.

CONCLUSION

To our knowledge, this is the first and only study that successfully developed an FDA level A IVIVC of an amorphous solid dispersion, which assessed the impact of grades of the same polymer, disintegrant level, and dry granulation processing on the performance of SDD tablets in humans.

Simulation of Antral Conditions for Estimating Drug Apparent Equilibrium Solubility after a High-Calorie, High-Fat Meal

The simulation of antral conditions for estimating drug apparent equilibrium solubility after a high-calorie, high-fat meal is challenging. In this study, (1) we measured the apparent equilibrium solubility of two model lipophilic drugs, ketoconazole and danazol, in antral aspirates collected at various time points after a minced high-calorie, high-fat meal and a glass of water 30 min after initiation of meal administration, and we designated one point estimate for ketoconazole and one point estimate for danazol; (2) we evaluated the usefulness of FeSSGF-V2 and FEDGAS pH = 3 in reproducing the two point estimates; (3) we evaluated potential compositions of FeSSGF-V3 that simulate the pH, the buffer capacity toward both less acidic and more acidic values, and the antral lipid and protein contents with easily accessible, commercially available products, and (4) we identified the most useful composition of FeSSGF-V3 for reproducing the two point estimates. For both model drugs, apparent solubility in FeSSGF-V2 and in FEDGAS pH 3 deviated substantially from the corresponding point estimate. For FeSSGF-V3, hydrochloric acid, acetates, and FEDGASbuffer pH 3 were evaluated for regulating the pH and buffer capacity, FEDGASgel was used for simulating the lipid content, and Régilait skimmed milk powder was used for simulating the protein content. Level III FeSSGF-V3 prepared with hydrochloric acid, 6.1% (w/v) Régilait, and 2.83% (w/v) FEDGASgel, i.e., one-sixth of FEDGASgel concentration in FEDGAS pH 3, was comparatively the most useful medium for point estimating ketoconazole and danazol apparent solubility in antral contents after water administration in the fed state, induced as requested by regulatory authorities in oral drug bioavailability studies. Level III FeSSGF-V3 prepared by using hydrochloric acid as the principal pH controlling species could be useful in the evaluation of food effects on drug absorption with in silico physiologically based biopharmaceutics modeling approaches and, also, with biorelevant in vitro methodologies.

The impact of volume of dissolution medium for biopredictive dissolution/permeation studies of enabling formulations: A comparison of two brands of telmisartan / amlodipine tablets

For compendial dissolution testing of solid dosage forms, media volumes of 500 to 900 mL are used in apparatus I and II to ensure sink conditions. However, these volumes are considerably larger than those in the gastrointestinal tract. Thus, the experiments are not biomimetic and possibly not suitable for biopredictive dissolution testing. The present study investigates the influence of volumes of dissolution media in non-compendial dissolution/permeation settings. Dissolution/permeation studies of two commercial bilayer tablets (Twynsta® and Arrow) containing the active pharmaceutical ingredients telmisartan (40 mg) and amlodipine (10 mg) were evaluated using the MacroFlux tool with various biomimetic media mimicking fasted and fed states as well as biological variability ("biorelevant"). Particularly, the two-stage dissolution process of telmisartan from the tablets is interesting because the compound has a pH-dependent solubility, and 2-stage dissolution leads to supersaturation and precipitation upon pH shift. For telmisartan, lower dissolution volumes significantly induced precipitation, leading to lower permeation, while no precipitation was observed in the larger volume. The permeation of telmisartan was overly sensitive to both pH and micelle concentrations in the biomimetic media. Amlodipine showed complete dissolution under any conditions, which correlates with its known complete absorption in vivo. In conclusion, volumes of dissolution media (and their compositions) are key parameters and play a significant role for designing relevant biomimetic experiments used to predict the bioavailability of supersaturating systems.

Structure-Based Discovery and Development of Highly Potent Dihydroorotate Dehydrogenase Inhibitors for Malaria Chemoprevention

Malaria remains a serious global health challenge, yet treatment and control programs are threatened by drug resistance. Dihydroorotate dehydrogenase (DHODH) was clinically validated as a target for treatment and prevention of malaria through human studies with DSM265, but currently no drugs against this target are in clinical use. We used structure-based computational tools including free energy perturbation (FEP+) to discover highly ligand efficient, potent, and selective pyrazole-based Plasmodium DHODH inhibitors through a scaffold hop from a pyrrole-based series. Optimized pyrazole-based compounds were identified with low nM-to-pM Plasmodium falciparum cell potency and oral activity in a humanized SCID mouse malaria infection model. The lead compound DSM1465 is more potent and has improved absorption, distribution, metabolism and excretion/pharmacokinetic (ADME/PK) properties compared to DSM265 that support the potential for once-monthly chemoprevention at a low dose. This compound meets the objective of identifying compounds with potential to be used for monthly chemoprevention in Africa to support malaria elimination efforts.

Thymoquinone loaded lipid nanocapsule dispersion: two methods of preparation, characterization and in vitro evaluations for oral administration

This work explores two methods to encapsulate Thymoquinone (TQ) into lipid nanocapsules (LNCs) for oral administration. TQ was added during the phase inversion temperature method (TQ-LNCs-1) or to unload LNCs dispersion (TQ-LNCs-2). LNCs were evaluated for mean diameter, polydispersity index (PDI), ζ-potential, drug loading (DL), drop tensiometer, storage stability, in vitro stability in simulated gastrointestinal fluids (SGIF), and intestinal permeability across Caco-2 cells. TQ-LNCs-1 and TQ-LNCs-2 produced NPs (58.3 ± 3.7 nm and 61.5 ± 3.5 nm, respectively), with a DL of 8.7 ± 0.2 and 7.7 ± 0.6 mg/mL of suspension, respectively. For both, less than 14% of TQ was released in SGIF, and a minor increase in TQ intestinal permeability with LNCs compared to free TQ was observed. TQ-LNCs represented a promising formulation for oral delivery of TQ. Encapsulation of TQ by adding it at LNCs dispersion can be extended for further drugs.

Chemistry and ionization of HPMCAS influences the dissolution and solution-mediated crystallization of posaconazole amorphous solid dispersions

Hydroxypropyl methyl cellulose acetate succinate (HPMCAS) is one of the polymers of choice in formulating amorphous solid dispersions (ASDs) and helps to sustain high levels of drug supersaturation by delaying drug crystallization. Herein, the impact of HPMCAS chemistry on the solution crystallization kinetics of a fast-crystallizing lipophilic drug, posaconazole (PCZ), from the aqueous bulk phase and the drug-rich phase generated by liquid-liquid phase separation (LLPS), was studied. Three grades of HPMCAS: L, M, and H, which differ in the degree of acetyl and succinoyl substitution (A/S ratio), were compared. The influence of the polymers on the nucleation induction time, and LLPS concentration of PCZ, as well as the size, ζ-potential and composition of the nano-sized drug-rich phase was determined. An increase in the nucleation induction time was observed with an increase in the polymer A/S ratio. A blue shift in the fluorescence emission spectrum of PCZ suggested a greater extent of interaction between PCZ and HPMCAS with an increase in the A/S ratio. More polymer partitioning into the drug-rich phase was also observed with an increase in the A/S ratio, resulting in smaller droplets. A greater extent of ionization of HPMCAS upon increasing the pH from 5.5 to 7.5 decreased the hydrophobicity of the polymer resulting in shorter nucleation induction times. The phase behavior of PCZ in ASD release studies was consistent with these observations, where the shortest duration of supersaturation was observed with the L grade. Although the H grade provided the best inhibition of crystallization, complete release was only observed at higher pH. HPMCAS grade thus influences the kinetics of PCZ crystallization following release from an ASD, as well as the extent of release at physiologically relevant pH conditions. This study provides insights into the role of HPMCAS chemistry and ionization as factors influencing its ability to act as a crystallization inhibitor.

Characterization of macrocyclic peptide drug interactions with bile salts and biorelevant colloids via single amino acid mutations and 1H nuclear magnetic resonance (NMR) spectroscopy

There is growing interest in the oral delivery of poorly permeable peptide drugs; however, the effect of biorelevant colloids found in the aqueous gastrointestinal environment on peptide drug solution behavior has been largely understudied. In this work, we detail the molecular level interactions between octreotide, a water-soluble macrocyclic peptide drug, and biorelevant colloids, i.e. bile salt micelles and bile salt-phospholipid mixed micelles, via dialysis membrane flux experiments and proton nuclear magnetic resonance (1H NMR) spectroscopy. A modified alanine scan was employed to generate eight mutated octreotide analogs; the impact of individual amino acid mutations on peptide dialysis membrane flux rates in micellar (trihydroxy and dihydroxy) bile salt solutions as well as fasted state simulated intestinal fluid (FaSSIF) and fed state simulated intestinal fluid (FeSSIF) was evaluated and compared against the parent peptide, octreotide. We show that octreotide interacts more strongly with dihydroxy bile salt micelles than trihydroxy bile salt micelles in solution, and in FaSSIF/FeSSIF media, octreotide mainly interacts with the phospholipid component. These interactions are largely mediated by hydrophobic interactions of octreotide's aromatic residues as well as electrostatic interactions between octreotide's basic Lys residue and terminal amine.

Understanding the Impact of Lipids on the Solubilizing Capacity of Human Intestinal Fluids

Lipids in human intestinal fluids (HIF) form various structures, resulting in phase separation in the form of a lipid fraction and a micellar aqueous fraction. Currently used fed state simulated intestinal fluids (SIF) lack phase separation, highlighting the need for a deeper understanding of the effect of these fractions on intestinal drug solubilization in HIF to improve simulation accuracy. In this study, duodenal fluids aspirated from 21 healthy volunteers in fasted, early fed, and late fed states were used to generate 7 HIF pools for each prandial state. The apparent solubility of seven lipophilic model drugs was measured across these HIF pools, differentiating between the micellar fraction and the total sample (including both micellar and lipid fractions). The solubilizing capacities of these fluids were analyzed in relation to their composition, including total lipids, bile salts, phospholipids, total cholesterol, pH, and total protein. The solubility data generated in this work demonstrated that current fed state SIF effectively predicted the average solubility in the micellar fraction of HIF but failed to discern the considerable variability between HIF pools. Furthermore, the inclusion of a lipid fraction significantly enhanced the solubility of fed state HIF pools, resulting on average in a 13.9-fold increase in solubilizing capacity across the seven model compounds. Although the average composition of the fluids was consistent with previous studies, substantial variability was observed in micellar lipid concentrations, despite relatively stable total lipid concentrations. This variability is critical, as evidenced by the strong correlations between the solubilizing capacity of the micellar fraction and its micellar lipid concentrations. Additionally, this study identified that fluctuations in bile salt concentrations and pH contributed to the observed variability in micellar lipid concentration. In summary, the influence of the lipid fraction on solubility was 2-fold: it enhanced the solubility of lipophilic drugs in the total fluid, and contributed to the variability in the solubilizing capacity of the micellar fraction.

Single-Dose Drug Development Candidate for Schistosomiasis

Aryl hydantoins were identified in the early 1980s as a promising antischistosomal chemotype. However, as exemplified by Ro 13-3978, this compound series produced antiandrogenic side effects on the host, a not unexpected outcome given their structural similarity to the antiandrogenic drug nilutamide. The two key advances in our optimization of Ro 13-3978 were swapping the aryl trifluoromethyl substituent with a difluoroethyl to abolish antiandrogenic effects and replacing the hydrogen atoms of the gem-dimethyl substructure with deuterium atoms to increase metabolic stability. Combining these two structural changes led to the discovery of single-dose drug candidate AR102, a compound with potent, selective, and broad-spectrum activity against schistosomes, a long pharmacokinetic half-life in preclinical species, and an acceptable safety profile.

Physiologically based in vitro - in vivo correlation of modified release oral formulations with non-linear intestinal absorption: A case study using mirabegron

Establishing an in vitro - in vivo correlation (IVIVC) for oral modified release (MR) formulations would make it possible to substitute an in vitro dissolution test for human bioequivalence (BE) studies when changing the formulation or manufacturing methods. However, the number of IVIVC applications and approvals are reportedly low. One of the main reasons for failure to obtain IVIVCs using conventional methodologies may be the lack of consideration of the dissolution and absorption mechanisms of drugs in the physiological environment. In particular, it is difficult to obtain IVIVC using conventional methodologies for drugs with non-linear absorption processes. Therefore, the aim of the present study was to develop a physiologically based biopharmaceutics model (PBBM) that enables Level A IVIVCs for mirabegron MR formulations with non-linear absorption characteristics. Using human pharmacokinetic (PK) data for immediate-release formulations of mirabegron, the luminal drug concentration-dependent membrane permeation coefficient was calculated through curve fitting. The membrane permeation coefficient data were then applied to the human PK data of the MR formulations to estimate the in vivo dissolution rate by curve fitting. It was assumed that in vivo dissolution could be described using a zero-order rate equation. Furthermore, a Levy plot was generated using the estimated in vivo dissolution rate and the in vitro dissolution rate obtained from the literature. Finally, the dissolution rate of the MR formulations from the Levy plot was applied to the PBBM to predict the oral PK of the mirabegron MR formulations. This PB-IVIVC approach successfully generated linear Levy plots with slopes of almost 1.0 for MR formulations with different dose strengths and dissolution rates. The Cmax values of the MR formulations were accurately predicted using this approach, whereas the prediction errors for AUC exceeded the Level A IVIVC criteria. This can be attributed to the incomplete description of colonic absorption in the current PBBM.

Assessing solubility of meloxicam in age-specific gastric and intestinal media relevant to adults and pediatric populations: implications for optimizing dosing in patients for postoperative pain

BACKGROUND

Oral dose formulations must be soluble in gastrointestinal fluids for systemic absorption. The solubility of meloxicam was determined in 16 different age-specific simulated gastric and intestinal media that mirrored the microenvironments in pediatrics and adults.

METHODS

The solubility of meloxicam in the 16 different age-specific simulated gastric and intestinal biorelevant media was assessed using the standard US pharmacopeial method. The molecular descriptors of meloxicam were used to assess its intestinal permeability.

RESULTS

Meloxicam exhibited low solubility in the age-specific simulated gastric media for fasted and fed states and in pediatrics and adults. Similarly, meloxicam exhibited low solubility in the age-specific simulated media that mirrored neonates fed cow milk-based formula. On the other hand, meloxicam exhibited high solubility in the rest of the age-specific pediatric and adult intestinal media that simulated the fasted and fed states. The pediatric-to-adult solubility ratios were outside the 80-125% range in 7 (58.3%) and was borderline in 1 (8.3%) out of the 12 calculated ratios. These findings indicated that the solubility of meloxicam showed clinically significant differences in 8 (66.7%) of the compared media.

CONCLUSION

Meloxicam exhibited low solubility in the age-specific simulated gastric media and high solubility in the simulated intestinal media for adults and pediatrics. Moreover, the pediatric-to-adult solubility ratios may have clinically significant implications. These differences can be translated into a higher likelihood of failing to demonstrate bioequivalence of different formulations containing meloxicam and variabilities in the performance of these formulations.

Advancing the Harmonization of Biopredictive Methodologies through the Product Quality Research Institute (PQRI) Consortium: Biopredictive Dissolution of Dipyridamole Tablets

Biorelevant dissolution and its concept have been widely accepted and further developed to meaningfully predict the bioperformance of oral drug products. Biorelevant methodologies have been applied to design and optimize oral formulations, to facilitate formulation bridging, and to predict the outcome of bioperformance by coupling the results with modeling. Yet, those methodologies have often been independently customized to align with specific aspects of the oral drug products being developed. Therefore, the evolution of biorelevant dissolution methodologies has taken slightly diverse pathways rather than being standardized like compendial quality control (QC) methodologies. This manuscript presents an effort through the Product Quality Research Institute (PQRI, https://pqri.org) consortium entitled: the standardization of "in vivo predictive dissolution methodologies and in silico bioequivalent study working group" to find the key parameters for biorelevant dissolution, to identify the best practices, and to move toward standardization of biorelevant dissolution methodologies. This working group is composed of members from 10 pharmaceutical companies and academic institutes. The consortium project will be accomplished in five phases, whereby the first two phases have already been completed and published. In this paper, the next two phases are addressed by reporting the biorelevant dissolution profiles of dipyridamole, a weak base model drug, then incorporating the dissolution results into physiologically based biopharmaceutics modeling (PBBM) to determine whether they would lead to bioequivalence (BE) or non-BE.

Characterization of luminal contents from the fasted human proximal colon

To treat colonic diseases more effectively, improved therapies are urgently needed. In this respect, delivering drugs locally to the colon is a key strategy to achieve higher local drug concentrations while minimizing systemic side effects. Understanding the luminal environment is crucial to efficiently develop such targeted therapies and to predict drug disposition in the colon. In this clinical study, we collected colonic contents from an undisturbed fasted proximal colon via colonoscopy and characterized their composition with regard to drug disposition. Colonic pH, osmolality, protein content, bile salts, lipids, phospholipids and short-chain fatty acids were investigated in 10 healthy volunteers (8 male and 2 female, age 19-25). The unique environment of the proximal colon was reflected in the composition of the sampled luminal fluids and the effect of the microbiota could be observed on the pH (median 6.55), the composition of bile salts (majority deconjugated and secondary), and the abundance of short-chain fatty acids. At the same time, an increase in phospholipid concentration, osmolality and total protein content compared to reported ileal values was seen, likely resulting from desiccation. Lipids could only be found in low quantities and mainly in the form of cholesterol and free fatty acids, showing almost complete digestion and absorption by the time luminal contents reach the colon. All characteristics also displayed the considerable intersubject variability found in different regions of the gastrointestinal tract. This study contributes to an improved understanding of the luminal conditions in the proximal colon and facilitates the development of new predictive tools to study colonic drug absorption.

Impact of Physiological Characteristics on Chylomicron Pathway-Mediated Absorption of Nanocrystals in the Pediatric Population

Nanocrystals exhibit significant advantages in improving the oral bioavailability of poorly soluble drugs. However, the complicated absorption properties of nanocrystals and the differences in physiological characteristics between children and adults limit pediatric applications of nanocrystals. To elucidate the absorption differences and the underlying mechanisms between children and adults, the pharmacokinetics and tissue distribution of aprepitant crystals with different particle sizes (NC200, NC500, and MC2.5) in rats and mice at different ages were studied, and their absorption mechanisms were investigated in Caco-2 cells, mice, and rats. It was found that childhood animals demonstrated higher bioavailability compared with adolescent and adult animals, which was related to higher bile salt concentration and accelerated drug dissolution in the intestine of childhood animals. The majority of nanocrystals were dissolved and formed micelles under the influence of bile salts. Compared with intact nanocrystals, the bile salt micelle-associated aprepitant was absorbed through the chylomicron pathway, wherein Apo B assisted in the reassembling of the aprepitant micelles after endocytosis. Higher bile salt concentration and Apo B expression in the intestines of childhood animals are both responsible for the higher chylomicron transport pathways. Elucidation of the chylomicron pathway in the varied absorption of nanocrystals among children, adolescents, and adults provides strong theoretical guidance for promoting the rational and safe use of nanocrystals in pediatric populations.

Nanomaterial-assisted molecularly imprinted polymer strategies for highly sensitive and selective determination of cefdinir and its validation using computational approach

In this study, the first nanomaterial-supported molecularly imprinted polymer (MIP)-based electrochemical approach was proposed to achieve the successful detection of cefdinir (CFD). Here, p-amino benzoic acid (p-ABA) was used as the monomer and the photopolymerization method was chosen to form MIP on a glassy carbon electrode (GCE). ZnO nanoparticles (ZnO NPs) were added to the MIP sensor to increase sensitivity and create high porosity. Through the use of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), characterization investigations confirmed the alterations at each stage of the MIP production process. Electrochemical (cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS)) and scanning electron microscopy (SEM) methods were used for study the characterization studies of the MIP-based nanocomposite sensor. The measurement of MIP parameters, such as the addition of nanoparticles, the removal procedure, the rebinding period, the monomer ratio, etc., was done using the differential pulse voltammetry (DPV). The findings showed that when ZnO NPs were added, the signal was three times higher than when MIPs were used alone. Under the optimized conditions, CFD/4-ABA@ZnONPs/MIP/GCE showed a linear response in the concentration range between 7.5 pM and 100 pM with LOD and LOQ values of 2.06 pM and 6.86 pM, respectively. Anions, cations, and substances including uric acid, ascorbic acid, paracetamol, and dopamine were all used in the selectivity test. In addition, the imprinting factor (IF) study was carried out using compounds such as cefuroxime, cefazolin, cefixime, ceftazidime, and ceftriaxone, which have structural similarities with CFD, as well as impurities such as thiazolylacetyl glycine oxime (IMP-A), thiazolylacetyl glycine oxime acetal (IMP-B), and cefdinir lactone (IMP-E). The results showed that the proposed sensor was selective for CFD, as evidenced by the relative IF values of these impurities. The recovery studies of CFD were successfully applied to tablet dosage form samples, and the developed sensor demonstrated significant sensitivity and selectivity for rapid detection of CFD in tablet dosage form.

Preclinical proof of principle for orally delivered Th17 antagonist miniproteins

Interleukin (IL)-23 and IL-17 are well-validated therapeutic targets in autoinflammatory diseases. Antibodies targeting IL-23 and IL-17 have shown clinical efficacy but are limited by high costs, safety risks, lack of sustained efficacy, and poor patient convenience as they require parenteral administration. Here, we present designed miniproteins inhibiting IL-23R and IL-17 with antibody-like, low picomolar affinities at a fraction of the molecular size. The minibinders potently block cell signaling in vitro and are extremely stable, enabling oral administration and low-cost manufacturing. The orally administered IL-23R minibinder shows efficacy better than a clinical anti-IL-23 antibody in mouse colitis and has a favorable pharmacokinetics (PK) and biodistribution profile in rats. This work demonstrates that orally administered de novo-designed minibinders can reach a therapeutic target past the gut epithelial barrier. With high potency, gut stability, and straightforward manufacturability, de novo-designed minibinders are a promising modality for oral biologics.

Application of a Novel Dissolution Medium with Lipids for In Vitro Simulation of the Postprandial Gastric Content

Food can change various physiological parameters along the gastrointestinal tract, potentially impacting postprandial drug absorption. It is thus important to consider different in vivo conditions during in vitro studies. Therefore, a novel dissolution medium simulating variable postprandial pH values and lipid concentrations was developed and used in this study. Additionally, by establishing and validating a suitable analytical method, the effects of these parameters on the dissolution of a model drug, cinnarizine, and on its distribution between the lipid and aqueous phases of the medium were studied. Both parameters, pH value and lipid concentration, were shown to influence cinnarizine behavior in the in vitro dissolution studies. The amount of dissolved drug decreased with increasing pH due to cinnarizine's decreasing solubility. At pH values 5 and 7, the higher concentration of lipids in the medium increased drug dissolution, and most of the dissolved drug was distributed in the lipid phase. In all media with a lower pH of 3, dissolution was fast and complete, with a significant amount of drug distributed in the lipid phase. These results are in accordance with the in vivo observed positive food effect on cinnarizine bioavailability described in the literature. The developed medium, with its ability to easily adjust the pH level and lipid concentration, thus offers a promising tool for assessing the effect of co-ingested food on the dissolution kinetics of poorly soluble drugs.

The bile salt/phospholipid ratio determines the extent of in vitro intestinal lipolysis of triglycerides: Interfacial and emulsion studies

This study focused on the protein-stabilised triglyceride (TG)/water interfaces and oil-in-water emulsions, and explored the influence of varying molar ratios of bile salts (BSs) and phospholipids (PLs) on the intestinal lipolysis of TGs. The presence of these two major groups of biosurfactants delivered with human bile to the physiological environment of intestinal digestion was replicated in our experiments by using mixtures of individual BSs and PLs under in vitro small intestinal lipolysis conditions. Conducted initially, retrospective analysis of available scientific literature revealed that an average molar ratio of 9:4 for BSs to PLs (BS/PL) can be considered physiological in the postprandial adult human small intestine. Our experimental data showed that combining BSs and PLs synergistically enhanced interfacial activity, substantially reducing oil-water interfacial tension (IFT) during interfacial lipolysis experiments with pancreatic lipase, especially at the BS/PL-9:4 ratio. Other BS/PL molar proportions (BS/PL-6.5:6.5 and BS/PL-4:9) and an equimolar amount of BSs (BS-13) followed in IFT reduction efficiency, while using PLs alone as biosurfactants was the least efficient. In the following emulsion lipolysis experiments, BS/PL-9:4 outperformed other BS/PL mixtures in terms of enhancing the TG digestion extent. The degree of TG conversion and the desorption efficiency of interfacial material post-lipolysis correlated directly with the BS/PL ratio, decreasing as the PL proportion increased. In conclusion, this study highlights the crucial role of biliary PLs, alongside BSs, in replicating the physiological function of bile in intestinal lipolysis of emulsified TGs. Our results showed different contributions of PLs and BSs to lipolysis, strongly suggesting that any future in vitro studies aiming to simulate the human digestion conditions should take into account the impact of biliary PLs - not just BSs - to accurately mimic the physiological role of bile in intestinal lipolysis. This is particularly crucial given the fact that existing in vitro digestion protocols typically focus solely on applying specific concentrations and/or compositions of BSs to simulate the action of human bile during intestinal digestion, while overlooking the presence and concentration of biliary PLs under physiological gut conditions.

Protium spruceanum Extract Enhances Mupirocin Activity When Combined with Nanoemulsion-Based Hydrogel: A Multi-Target Strategy for Treating Skin and Soft Tissue Infections

The treatment of skin and soft tissue infections (SSTIs) can be challenging due to bacterial resistance, particularly from strains like MRSA and biofilm formation. However, combining conventional antibiotics with natural products shows promise in treating SSTIs. The objective of this study is to develop a nanoemulsion-based hydrogel containing Protium spruceanum extract and mupirocin and evaluate its potential for the treatment of SSTIs. The nanoemulsion was obtained by phase inversion and subsequently characterized. The antibacterial activity was evaluated in vitro against S. aureus MRSA, including the synergism of the combination, changes in membrane permeability using flow cytometry, and the anti-biofilm effect. In addition, the irritative potential was evaluated by the HET-CAM assay. The combination exhibited synergistic antibacterial activity against S. aureus and MRSA due to the extract enhancing membrane permeability. The hydrogel demonstrated suitable physicochemical properties, inhibited biofilm formation, and exhibited low irritation. The formulation was nanometric (176.0 ± 1.656 nm) and monodisperse (polydispersity index 0.286 ± 0.011). It exhibited a controlled release profile at 48 h and high encapsulation efficacy (94.29 ± 4.54% for quercitrin and 94.20 ± 5.44% for mupirocin). Therefore, these findings suggest that the hydrogel developed could be a safe and effective option for treating SSTIs.

In Vitro Simulation of the Fasted Gastric Conditions and Their Variability to Elucidate Contrasting Properties of the Marketed Dabigatran Etexilate Pellet-Filled Capsules and Loose Pellets

Variability of the gastrointestinal tract is rarely reflected in in vitro test protocols but often turns out to be crucial for the oral dosage form performance. In this study, we present a generation method of dissolution profiles accounting for the variability of fasted gastric conditions. The workflow featured 20 biopredictive tests within the physiological variability. The experimental array was constructed with the use of the design of experiments, based on three parameters: gastric pH and timings of the intragastric stress event and gastric emptying. Then, the resulting dissolution profiles served as a training data set for the dissolution process modeling with the machine learning algorithms. This allowed us to generate individual dissolution profiles under a customizable gastric pH and motility patterns. For the first time ever, we used the method to successfully elucidate dissolution properties of two dosage forms: pellet-filled capsules and bare pellets of the marketed dabigatran etexilate product Pradaxa. We showed that the dissolution of capsules was triggered by mechanical stresses and thus was characterized by higher variability and a longer dissolution onset than observed for pellets. Hence, we proved the applicability of the method for the in vitro and in silico characterization of immediate-release dosage forms and, potentially, for the improvement of in vitro-in vivo extrapolation.

Efficiency of single pharmaceutical surfactants to mimic intestinal biorelevant media solubilization and dissolution of etravirine: Comparison of intrinsic and film dissolution models

We understand that quality control dissolution media may best anticipate in vivo product performance by mimicking in vivo media, but preferably involve at most a single pharmaceutical surfactant for routine laboratory use. The objective here was to estimate the concentrations of six pharmaceutical surfactants to mimic etravirine solubility and intrinsic dissolution rate, as well as dissolution rate from a film model, in each Fed State Simulated Intestinal Fluid Version 2 (FeSSIF-V2) and Fasted State Simulated Intestinal Fluid Version 2 (FaSSIF-V2). Solubility studies and colloid sizing measurements were conducted. Results indicate that all six surfactants were more efficient than FeSSIF-V2 or FaSSIF-V2 at solubilizing drug, and also exhibited higher micelle diffusivities than FeSSIF-V2 and FaSSIF-V2 mixed-micelles. The rank-order potency (on mM basis) of the six pharmaceutical surfactants to mimic etravirine solubility in each FeSSIF-V2 and FaSSIF-V2 was: polysorbate 80 (PS80) > polysorbate 20 (PS20) > polyoxyethylene(23) lauryl ether (POE23) > POE10 > hexadecyltrimethylammonium bromide (HEX) > sodium lauryl sulfate (SLS). This rank-order potency was almost the same to mimic drug dissolution rate into each FeSSIF-V2 and FaSSIF-V2, except POE10 > POE23. For the most potent surfactant, PS80, 0.461 mM and 0.140 mM PS80 was estimated to mimic etravirine's solubility and dissolution rate into FeSSIF-V2, respectively, using the intrinsic dissolution model. The low PS80 concentration to mimic dissolution rate reflects the relatively high diffusivity of PS80 micelles, compared to FeSSIF-V2 mixed-micelle diffusivity, which was the case for all six pharmaceutical surfactants. Results are also presented in terms of a film dissolution model for surfactant-mediated dissolution, where dissolution enhancement was less than that in the intrinsic dissolution model, and the film model required lower surfactant concentration than in intrinsic dissolution model to mimic FeSSIF-V2-enhanced dissolution. Findings have promised to identify single pharmaceutical surfactant concentrations that mimic key performance attributes of biorelevant media.

Development of lipid-based SEDDS using digestion products of long-chain triglyceride for high drug solubility: Formulation and dispersion testing

A self-emulsifying drug delivery system (SEDDS) containing long chain lipid digestion products (LDP) and surfactants was developed to increase solubility of two model weakly basic drugs, cinnarizine and ritonavir, in the formulation. A 1:1.2 w/w mixture of glyceryl monooleate (Capmul GMO-50; Abitec) and oleic acid was used as the digestion product, and a 1:1 w/w mixture of Tween 80 and Cremophor EL was the surfactant used. The ratio between LDP and surfactant was 1:1 w/w. Since the commercially available Capmul GMO-50 is not pure monoglyceride and contained di-and-triglycerides, the digestion product used would provide 1:2 stoichiometric molar ratio of monoglyceride and fatty acid after complete digestion in gastrointestinal fluid. Both cinnarizine and ritonavir had much higher solubility in oleic acid (536 and 72 mg/g, respectively) than that in glyceryl monooleate and glyceryl trioleate. Therefore, by incorporating oleic acid in place of glyceryl trioleate in the formulation, the solubility of cinnarizine and ritonavir could be increased by 5-fold and 3.5-fold, respectively, as compared to a formulation without the fatty acid. The formulation dispersed readily in aqueous media, and adding 3 mM sodium taurocholate, which is generally present in GI fluid, remarkably improved the dispersibility of SEDDS and reduced particle size of dispersions. Thus, the use of digestion products of long-chain triglycerides as components of SEDDS can enhance the drug loading of weakly basic compounds and increase dispersibility in GI fluids.

An Artificial Gut/Absorption Simulator: Understanding the Impact of Absorption on In Vitro Dissolution, Speciation, and Precipitation of Amorphous Solid Dispersions

Upon dissolution, amorphous solid dispersions (ASDs) of poorly water-soluble compounds can generate supersaturated solutions consisting of bound and free drug species that are in dynamic equilibrium with each other. Only free drug is available for absorption. Drug species bound to bile micelles, polymer excipients, and amorphous and crystalline precipitate can reduce the drug solute's activity to permeate, but they can also serve as reservoirs to replenish free drug in solution lost to absorption. However, with multiple processes of dissolution, absorption, and speciation occurring simultaneously, it may become challenging to understand which processes lead to an increase or decrease in drug solution concentration. Closed, nonsink dissolution testing methods used routinely, in the absence of drug removal, allow only for static equilibrium to exist and obscure the impact of each drug species on absorption. An artificial gut simulator (AGS) introduced recently consists of a hollow fiber-based absorption module and allows mass transfer of the drug from the dissolution media at a physiological rate after tuning the operating parameters. In the present work, ASDs of varying drug loadings were prepared with a BCS-II model compound, ketoconazole (KTZ), and hypromellose acetate succinate (HPMCAS) polymer. Simultaneous dissolution and absorption testing of the ASDs was conducted with the AGS, and simple analytical techniques were utilized to elucidate the impact of bound drug species on absorption. In all cases, a lower amount of crystalline precipitate was formed in the presence of absorption relative to the nonsink dissolution "control". However, formation of HPMCAS-bound drug species and crystalline precipitate significantly reduced KTZ absorption. Moreover, at high drug loading, inclusion of an absorption module was shown to enhance ASD dissolution. The rank ordering of the ASDs with respect to dissolution was significantly different when nonsink dissolution versus AGS was used, and this discrepancy could be mechanistically elucidated by understanding drug dissolution and speciation in the presence of absorption.

Importance of Considering Fed-State Gastrointestinal Physiology in Predicting the Reabsorption of Enterohepatic Circulation of Drugs

PURPOSE

The purpose of this study was to develop a simulation model for the pharmacokinetics (PK) of drugs undergoing enterohepatic circulation (EHC) with consideration to the environment in the gastrointestinal tract in the fed state in humans. The investigation particularly focused on the necessity of compensating for the permeability rate constant in the reabsorption process in consideration of drug entrapment in bile micelles.

METHODS

Meloxicam and ezetimibe were used as model drugs. The extent of the entrapment of drugs inside bile micelles was evaluated using the solubility ratio of Fed State Simulated Intestinal Fluid version 2 (FeSSIF-V2) to Fasted State Simulated Intestinal Fluid version 2 (FaSSIF-V2). Prediction accuracy was evaluated using the Mean Absolute Percentage Error (MAPE) value, calculated from the observed and predicted oral PK profiles.

RESULTS

The solubilization of ezetimibe by bile micelles was clearly observed while that of meloxicam was not. Assuming that only drugs in the free fraction of micelles permeate through the intestinal membrane, PK simulation for ezetimibe was performed in both scenarios with and without compensation by the permeation rate constant. The MAPE value of Zetia® tablet, containing ezetimibe, was lower with compensation than without compensation. By contrast, Mobic® tablet, containing meloxicam, showed a relatively low MAPE value even without compensation.

CONCLUSION

For drugs which undergo EHC and can be solubilized by bile micelles, compensating for the permeation rate constant in the reabsorption process based on the free fraction ratio appears an important factor in increasing the accuracy of PK profile prediction.

Drug solubility in biorelevant media in the context of an inhalation-based biopharmaceutics classification system (iBCS)

An inhalation-based Biopharmaceutics Classification System for pulmonary drugs (iBCS) holds the perspective to allow for scientifically sound prediction of differences in the in vivo performance of orally inhaled drug products (OIDPs). A set of nine drug substances were selected, that are administered via both the oral and pulmonary routes. Their solubility was determined in media representative for the oral (Fasted State Simulated Intestinal Fluid (FaSSIF)) and pulmonary (Alveofact medium and Simulated Lung Fluid (SLF)) routes of administration to confirm the need for a novel approach for inhaled drugs. The complexity of these media was then stepwise reduced with the purpose of understanding the contribution of their components to the solubilizing capacity of the media. A second reason for varying the complexity was to identify a medium that would allow robust but accurate dissolution testing. Hence, Hank's balanced salt solution (HBSS) as a medium used in many in vitro biological tests, non-buffered saline solution, and water were included. For some drug substances (salbutamol sulfate, tobramycin, isoniazid, and tiotropium bromide), no significant differences were observed between the solubility in the media used. For other drugs, however, we observed either just small (rifampicin, budesonide, salmeterol) or unexpectedly large differences (beclomethasone dipropionate). Based on the minimum theoretical solubility required for their common pulmonary dose in 10 ml of lung lining fluid, drug solubility was classified as either high or low. Two high solubility and two low solubility compounds were then selected for refined solubility testing in pulmonary relevant media by varying their content of phospholipids, surfactant proteins and other proteins. The solubility of drug substances in simulated lung lining fluids was found to be dependent on the physicochemical properties of the drug substance and the composition of the media. While a pulmonary dissolution medium that would fit all drugs could not be established, our approach may provide guidance for finding the most suitable dissolution medium for a given drug substance and better designing in vitro tests for predicting the in vivo performance of inhalable drug products.

Molecular dynamics study on micelle-small molecule interactions: developing a strategy for an extensive comparison

Theoretical predictions of the solubilizing capacity of micelles and vesicles present in intestinal fluid are important for the development of new delivery techniques and bioavailability improvement. A balance between accuracy and computational cost is a key factor for an extensive study of numerous compounds in diverse environments. In this study, we aimed to determine an optimal molecular dynamics (MD) protocol to evaluate small-molecule interactions with micelles composed of bile salts and phospholipids. MD simulations were used to produce free energy profiles for three drug molecules (danazol, probucol, and prednisolone) and one surfactant molecule (sodium caprate) as a function of the distance from the colloid center of mass. To address the challenges associated with such tasks, we compared different simulation setups, including freely assembled colloids versus pre-organized spherical micelles, full free energy profiles versus only a few points of interest, and a coarse-grained model versus an all-atom model. Our findings demonstrate that combining these techniques is advantageous for achieving optimal performance and accuracy when evaluating the solubilization capacity of micelles. All-atom (AA) and coarse-grained (CG) umbrella sampling (US) simulations and point-wise free energy (FE) calculations were compared to their efficiency to computationally analyze the solubilization of active pharmaceutical ingredients in intestinal fluid colloids.

Improved Therapeutic Efficacy of MT102, a New Anti-Inflammatory Agent, via a Self-Microemulsifying Drug Delivery System, in Ulcerative Colitis Mice

MT-102 is a new anti-inflammatory agent derived from Juglans mandshurica and Isatis indigotica. Its therapeutic potential is hindered by low aqueous solubility, impacting its in vivo efficacy. Therefore, this study aimed to develop a self-microemulsifying drug delivery system (SMEDDS) for MT-102 to enhance its oral efficacy in treating ulcerative colitis. Solubility assessment in different oils, surfactants, and cosurfactants led to a SMEDDS formulation of MT-102 using Capmul MCM, Tween 80, and propylene glycol. Based on a pseudoternary phase diagram, the optimal SMEDDS composition was selected, which consisted of 15% Capmul MCM, 42.5% Tween 80, and 42.5% propylene glycol. The resulting optimized SMEDDS (SMEDDS-F1) exhibited a narrow size distribution (177.5 ± 2.80 nm) and high indirubin content (275 ± 5.58 µg/g, a biomarker). Across an acidic to neutral pH range, SMEDDS-F1 showed rapid and extensive indirubin release, with dissolution rates approximately 15-fold higher than pure MT-102. Furthermore, oral administration of SMEDDS-F1 effectively mitigated inflammatory progression and symptoms in a mouse model of ulcerative colitis, whereas pure MT-102 was ineffective. SMEDDS-F1 minimized body weight loss (less than 5%) without any significant change in colon length and the morphology of colonic tissues, compared to those of the healthy control group. In addition, oral administration of SMEDDS-F1 significantly inhibited the secretion of pro-inflammatory cytokines such as IL-6 and TNF-α. In conclusion, the SMEDDS-F1 formulation employing Capmul MCM, Tween 80, and propylene glycol (15:42.5:42.5, w/w) enhances the solubility and therapeutic efficacy of MT-102.

A toolbox for mimicking gastrointestinal conditions in children: Design and evaluation of biorelevant dissolution media for mimicking paediatric gastric- and small intestinal conditions

The goal of the present work was to develop an in vitro toolbox to evaluate the oral administration of dosage forms to children of different age groups and under different administration conditions (fasted/fed). Based on current data on the gastrointestinal physiology of children, a set of new biorelevant media was designed to mimic the composition and physicochemical properties of resting gastric and resting small intestinal fluid in children of different age groups. In addition, guidelines were developed on how to generate fasted and fed state gastric and small intestinal fluids by combining these media with age-specific drinking volumes or portions of already established simulated paediatric breakfast meals, respectively. These fluids can simulate the conditions in the paediatric stomach and small intestine after administration of a dosage form in the fasting state or after a breakfast. The in vitro toolbox was evaluated using the example of pre-school children with a total of five paediatric medicines. Results from the corresponding set of in vitro studies highlight the importance of addressing patient-specific characteristics rather than downscaling existing adult in vitro models.

Structured solubility behaviour in fed simulated intestinal fluids

Intestinal drug solubility is a key parameter controlling absorption after the administration of a solid oral dosage form. The ability to measure fed state solubility in vitro is limited and multiple simulated intestinal fluid recipes have been developed but with no consensus which is optimal. This study has utilised nine bioequivalent simulated fed intestinal media recipes that cover over 90% of the compositional variability of sampled fed human intestinal fluid. The solubility of 24 drugs (Acidic; furosemide, ibuprofen, indomethacin, mefenamic acid, naproxen, phenytoin, piroxicam, valsartan, zafirlukast: Basic; aprepitant, atazanavir, bromocriptine, carvedilol, dipyridamole, posaconazole, tadalafil: Neutral; acyclovir, carbamazepine, felodipine, fenofibrate, griseofulvin, itraconazole, paracetamol, probucol) has been assessed to determine if structured solubility behaviour is present. The measured solubility behaviour can be split into four categories and is consistent with drug physicochemical properties and previous solubility studies. For acidic drugs (category 1) solubility is controlled by media pH and the lowest and highest pH media identify the lowest and highest solubility in 90% of cases. For weakly acidic, basic and neutral drugs (category 2) solubility is controlled by media pH and total amphiphile concentration (TAC), a consistent solubility pattern is evident with variation related to individual drug media component interactions. The lowest and highest pH × TAC media identify the lowest and highest solubility in 70% and 90% of cases respectively. Four drugs, which are non-ionised in the media systems (category 3), have been identified with a very narrow solubility range, indicating minimal impact of the simulated media on solubility. Three drugs exhibit solubility behaviour that is not consistent with the remainder (category 4). The results indicate that the use of two bioequivalent fed intestinal media from the original nine will identify in vitro the maximum and minimum solubility values for the majority of drugs and due to the media derivation this is probably applicable in vivo. When combined with a previous fasted study, this introduces interesting possibilities to measure a solubility range in vitro that can provide Quality by Design based decisions to rationalise drug and formulation development. Overall this indicates that the multi-dimensional media system is worthy of further investigation as in vitro tool to assess fed intestinal solubility.

Crushing the Contents of Valbenazine Capsules for Potential Addition to Soft Foods or Administration via Gastrostomy Tube

PURPOSE

One-capsule, once-daily valbenazine is approved for tardive dyskinesia and under evaluation for chorea associated with Huntington's disease, conditions in which patients often experience dysphagia. In vitro studies were conducted to assess the suitability of crushing the contents of valbenazine capsules (40 and 80 mg) for mixing with soft foods or liquids or administration via a gastrostomy tube (G-tube).

METHODS

In study 1, the dissolution of whole valbenazine capsules and crushed capsule contents were measured serially for 1 hour. In study 2, valbenazine recovery was evaluated after crushed contents were mixed with soft foods, buffer solutions (pH range, 1.2-6.8), and fed-state simulated gastric fluid. In study 3, valbenazine recovery was evaluated after crushed contents were dispersed in water and delivered via a G-tube. In studies 2 and 3, acceptable valbenazine recovery was 90% to 110%.

FINDINGS

Study 1 indicated rapid and complete drug release for whole valbenazine capsules and crushed capsule contents, with similar release at 10 minutes (whole, 94%-99%; crushed, 98%-100%) and 60 minutes (whole, 101%-103%; crushed, 101%-102%). Study 2 found acceptable valbenazine recovery within 2 hours of adding crushed capsule contents to tested foods, buffers, or fed-state simulated gastric fluid (recovery, 92%-102%). Study 3 found acceptable valbenazine recovery when crushed contents were added to cold or hot water and delivered via G-tube, with a water cup rinse to capture residual contents (recovery, 91%-97%).

IMPLICATIONS

These studies indicate the potential viability of valbenazine formulation(s) that can be added to soft foods or liquids or delivered via G-tube. Such formulations will be important for individuals who require treatment with a vesicular monoamine transporter 2 inhibitor but cannot swallow whole pills.

Surface functionalization affects the retention and bio-distribution of orally administered mesoporous silica nanoparticles in a colitis mouse model

Besides the many advantages of oral drug administration, challenges like premature drug degradation and limited bioavailability in the gastro-intestinal tract (GIT) remain. A prolonged residence time in the GIT is beneficial for enhancing the therapeutic outcome when treating diseases associated with an increased intestinal clearance rate, like inflammatory bowel disease (IBD). In this study, we synthesized rod-shaped mesoporous silica nanoparticles (MSNs) functionalized with polyethylene glycol (PEG) or hyaluronic acid (HA) and investigated their bio-distribution upon oral administration in vivo. The negatively charged, non-toxic particles showed different accumulation behavior over time in healthy mice and in mice with dextran sulfate sodium (DSS)-induced intestinal inflammation. PEGylated particles were shown to accumulate in the lower intestinal tract of healthy animals, whereas inflammation promoted retention of HA-functionalized particles in this area. Overall systemic absorption was low. However, some particles were detected in organs of mice with DSS-induced colitis, especially in the case of MSN-PEG. The in vivo findings were connected to surface chemistry-related differences in particle adhesion on Caco-2/Raji and mucus-producing Caco-2/Raji/HT29 cell co-culture epithelial models in vitro. While the particle adhesion behavior in vivo was mirrored in the in vitro results, this was not the case for the resorption results, suggesting that the in vitro model does not fully reflect the erosion of the inflamed epithelial tissue. Overall, our study demonstrates the possibility to modulate accumulation and retention of MSNs in the GIT of mice with and without inflammation through surface functionalization, which has important implications for the formulation of nanoparticle-based delivery systems for oral delivery applications.

Solubility of lamotrigine in age-specific biorelevant media that simulated the fasted- and fed-conditions of the gastric and intestinal environments in pediatrics and adults: implications for traditional, re-formulated, modified, and new oral formulations

BACKGROUND

Lamotrigine is an effective antiseizure medication that can be used in the management of focal and generalized epilepsies in pediatric patients. This study was conducted to quantify and compare the solubility of lamotrigine in age-specific biorelevant media that simulated the fasted and fed conditions of the gastric and intestinal environments in pediatrics and adults. Another aim was to predict how traditional, re-formulated, modified, and new oral formulations would behave in the gastric and intestinal environments across different age groups.

METHODS

Solubility studies of lamotrigine were conducted in 16 different age-specific biorelevant media over the pH range and temperature specified by the current biopharmaceutical classification system-based criteria. The age-specific biorelevant media simulated the environments in the stomach and proximal gastrointestinal tract in both fasted and fed conditions of adults and pediatric sub-populations. The solubility of lamotrigine was determined using a pre-validated HPLC-UV method.

RESULTS

Lamotrigine showed low solubility in the 16 age-specific biorelevant media as indicated by a dose number of > 1. There were significant age-specific variabilities in the solubility of lamotrigine in the different age-specific biorelevant media. Pediatric/adult solubility ratios of lamotrigine fell outside the 80-125% range in 6 (50.0%) and were borderline in 3 (25.0%) out of the 12 compared media. These ratios indicated that the solubility of lamotrigine showed considerable differences in 9 out of the 12 (75.0%) of the compared media.

CONCLUSION

Future studies are still needed to generate more pediatric biopharmaceutical data to help understand the performances of oral dosage forms in pediatric sub-populations.

Integration of Biorelevant Pediatric Dissolution Methodology into PBPK Modeling to Predict In Vivo Performance and Bioequivalence of Generic Drugs in Pediatric Populations: a Carbamazepine Case Study

This study investigated the impact of gastro-intestinal fluid volume and bile salt (BS) concentration on the dissolution of carbamazepine (CBZ) immediate release (IR) 100 mg tablets and to integrate these in vitro biorelevant dissolution profiles into physiologically based pharmacokinetic modelling (PBPK) in pediatric and adult populations to determine the biopredictive dissolution profile. Dissolution profiles of CBZ IR tablets (100 mg) were generated in 50-900 mL biorelevant adult fasted state simulated gastric and intestinal fluid (Ad-FaSSGF and Ad-FaSSIF), also in three alternative compositions of biorelevant pediatric FaSSGF and FaSSIF medias at 200 mL. This study found that CBZ dissolution was poorly sensitive to changes in the composition of the biorelevant media, where dissimilar dissolution (F2 = 46.2) was only observed when the BS concentration was changed from 3000 to 89 μM (Ad-FaSSIF vs Ped-FaSSIF 50% 14 BS). PBPK modeling demonstrated the most predictive dissolution volume and media composition to forecast the PK was 500 mL of Ad-FaSSGF/Ad-FaSSIF media for adults and 200 mL Ped-FaSSGF/FaSSIF media for pediatrics. A virtual bioequivalence simulation was conducted by using Ad-FaSSGF and/or Ad-FaSSIF 500 mL or Ped-FaSSGF and/or Ped-FaSSIF 200 mL dissolution data for CBZ 100 mg (reference and generic test) IR product. The CBZ PBPK models showed bioequivalence of the product. This study demonstrates that the integration of biorelevant dissolution data can predict the PK profile of a poorly soluble drug in both populations. Further work using more pediatric drug products is needed to verify biorelevant dissolution data to predict the in vivo performance in pediatrics.

Enteric coating of tablets containing an amorphous solid dispersion of an enteric polymer and a weakly basic drug: a strategy to enhance in vitro release

Recent work has highlighted that amorphous solid dispersions (ASDs) containing delamanid (DLM) and an enteric polymer, hypromellose phthalate (HPMCP), appear to be susceptible to crystallization during immersion in simulated gastric fluids. The goal of this study was to minimize contact of the ASD particles with the acidic media via application of an enteric coating to tablets containing the ASD intermediate, and improve the subsequent drug release at higher pH conditions. DLM ASDs were prepared with HPMCP and formulated into a tablet that was then coated with a methacrylic acid copolymer (Acryl EZE II®). Drug release was studied in vitro using a two-stage dissolution test where the pH of the gastric compartment was altered to reflect physiological variations. The medium was subsequently switched to simulated intestinal fluid. The gastric resistance time of the enteric coating was probed over the pH range of 1.6-5.0. The enteric coating was found to be effective at protecting the drug against crystallization in pH conditions where HPMCP was insoluble. Consequently, the variability in drug release following gastric immersion under pH conditions reflecting different prandial states was notably reduced when compared to the reference product. These findings support closer examination of the potential for drug crystallization from ASDs in the gastric environment where acid-insoluble polymers may be less effective as crystallization inhibitors. Further, addition of a protective enteric coating appears to provide a promising remediation strategy to prevent crystallization at low pH environments, and may mitigate variability associated with prandial state that arises due to pH changes.

Formulation of benznidazole-lipid nanocapsules: Drug release, permeability, biocompatibility, and stability studies

Benznidazole, a poorly soluble in water drug, is the first-line medication for the treatment of Chagas disease, but long treatment periods at high dosages cause several adverse effects with insufficient activity in the chronic phase. According to these facts, there is a serious need for novel benznidazole formulations for improving the chemotherapy of Chagas disease. Thus, this work aimed to incorporate benznidazole into lipid nanocapsules for improving its solubility, dissolution rate in different media, and permeability. Lipid nanocapsules were prepared by the phase inversion technique and were fully characterized. Three formulations were obtained with a diameter of 30, 50, and 100 nm and monomodal size distribution with a low polydispersity index and almost neutral zeta potential. Drug encapsulation efficiency was between 83 and 92% and the drug loading was between 0.66 and 1.04%. Loaded formulations were stable under storage for one year at 4 °C. Lipid nanocapsules were found to protect benznidazole in simulated gastric fluid and provide a sustained release platform for the drug in a simulated intestinal fluid containing pancreatic enzymes. The small size and the almost neutral surface charge of these lipid nanocarriers improved their penetration through mucus and such formulations showed a reduced chemical interaction with gastric mucin glycoproteins. LNCs. The incorporation of benznidazole in lipid nanocapsules improved the drug permeability across intestinal epithelium by 10-fold compared with the non-encapsulated drug while the exposure of the cell monolayers to these nanoformulations did not affect the integrity of the epithelium.

Engineering Escherichia coli for diagnosis and management of hyperuricemia

Uric acid disequilibrium is implicated in chronic hyperuricemia-related diseases. Long-term monitoring and lowering of serum uric acid levels may be crucial for diagnosis and effective management of these conditions. However, current strategies are not sufficient for accurate diagnosis and successful long-term management of hyperuricemia. Moreover, drug-based therapeutics can cause side effects in patients. The intestinal tract plays an important role in maintaining healthy serum acid levels. Hence, we investigated the engineered human commensal Escherichia coli as a novel method for diagnosis and long-term management of hyperuricemia. To monitor changes in uric acid concentration in the intestinal lumen, we developed a bioreporter using the uric acid responsive synthetic promoter, pucpro, and uric acid binding Bacillus subtilis PucR protein. Results demonstrated that the bioreporter module in commensal E. coli can detect changes in uric acid concentration in a dose-dependent manner. To eliminate the excess uric acid, we designed a uric acid degradation module, which overexpresses an E. coli uric acid transporter and a B. subtilis urate oxidase. Strains engineered with this module degraded all the uric acid (250 µM) found in the environment within 24 h, which is significantly lower (p < 0.001) compared to wild type E. coli. Finally, we designed an in vitro model using human intestinal cell line, Caco-2, which provided a versatile tool to study the uric acid transport and degradation in an environment mimicking the human intestinal tract. Results showed that engineered commensal E. coli reduced (p < 0.01) the apical uric acid concentration by 40.35% compared to wild type E. coli. This study shows that reprogramming E. coli holds promise as a valid alternative synthetic biology therapy to monitor and maintain healthy serum uric acid levels.

Development of Low-Cost, Weight-Adjustable Clofazimine Mini-Tablets for Treatment of Tuberculosis in Pediatrics

Clofazimine (CFZ) is an important component of the World Health Organization's (WHO) recommended all-oral drug regimen for treatment of multi-drug resistant tuberculosis (MDR-TB). However, the lack of a dividable oral dosage form has limited the use of the drug in pediatric populations, who may require lowering of the dose to reduce the likelihood of adverse drug events. In this study, pediatric-friendly CFZ mini-tablets were prepared from micronized powder via direct compression. Rapid disintegration and maximized dissolution in GI fluids was achieved using an iterative formulation design process. Pharmacokinetic (PK) parameters of the optimized mini-tablets were obtained in Sprague-Dawley rats and compared against an oral suspension of micronized CFZ particles to examine the effect of processing and formulation on the oral absorption of the drug. Differences in maximum concentration and area under the curve between the two formulations were non-significant at the highest dosing level tested. Variability between rats prevented bioequivalence from being determined according to guidelines outlined by the Food and Drug Administration (FDA). These studies provide an important proof-of-concept for an alternative, low-cost formulation and processing approach for the oral delivery of CFZ in manner that is suitable for children as young as 6 months of age.

Harmonizing Biopredictive Methodologies Through the Product Quality Research Institute (PQRI) Part I: Biopredictive Dissolution of Ibuprofen and Dipyridamole Tablets

Assessing in vivo performance to inform formulation selection and development decisions is an important aspect of drug development. Biopredictive dissolution methodologies for oral dosage forms have been developed to understand in vivo performance, assist in formulation development/optimization, and forecast the outcome of bioequivalence studies by combining them with simulation tools to predict plasma profiles in humans. However, unlike compendial dissolution methodologies, the various biopredictive methodologies have not yet been harmonized or standardized. This manuscript presents the initial phases of an effort to develop best practices and move toward standardization of the biopredictive methodologies through the Product Quality Research Institute (PQRI, https://pqri.org ) entitled "The standardization of in vitro predictive dissolution methodologies and in silico bioequivalence study Working Group." This Working Group (WG) is comprised of participants from 10 pharmaceutical companies and academic institutes. The project will be accomplished in a total of five phases including assessing the performance of dissolution protocols designed by the individual WG members, and then building "best practice" protocols based on the initial dissolution profiles. After refining the "best practice" protocols to produce equivalent dissolution profiles, those will be combined with physiologically based biopharmaceutics models (PBBM) to predict plasma profiles. In this manuscript, the first two of the five phases are reported, namely generating biopredictive dissolution profiles for ibuprofen and dipyridamole and using those dissolution profiles with PBBM to match the clinical plasma profiles. Key experimental parameters are identified, and this knowledge will be applied to build the "best practice" protocol in the next phase.

Characterizing interspecies differences in gastric fluid properties to improve understanding of in vivo oral drug formulation performance

An in-depth understanding of the properties of gastric fluid(s) prior to an in vivo pharmacokinetic investigation can vastly improve predictions of in vivo performance. Previously, properties of animal and human gastric fluids have been characterized with varying methods. Unfortunately, characterization has often not been thorough, and some properties, such as density and viscosity, have not been reported. Here, human, porcine and canine gastric fluids were harvested and characterized for pH, viscosity, surface tension, density, and osmolarity. We found that the variability of pH and surface tension between dogs was significantly higher than the variability between pigs, and, furthermore, gastric fluids collected from the same canine species (beagles) housed in two different countries (Denmark and China) had surprisingly different pH values. Next, an in vitro dissolution study in diluted gastric fluids from each species was performed using minitablets containing ibuprofen. Human gastric fluids and porcine gastric fluids showed similar dissolution profiles and corroborated well with biorelevant human Fasted State Simulated Gastric Fluid (FaSSGF). In contrast, differences in canine gastric fluids caused highly variable dissolution results. We systematically compared our findings to those in the literature and based on this evaluation, propose obtaining aspirates from the animals used for in vivo studies to ensure knowledge on the fluid properties affecting the performance of the formulated drug in question.

Assessment of food effects during clinical development

Food-drug interactions frequently hamper oral drug development due to various physicochemical, physiological and formulation-dependent mechanisms. This has stimulated the development of a range of promising biopharmaceutical assessment tools which, however, lack standardized settings and protocols. Hence, this manuscript aims to provide an overview of the general approach and the methodology used in food effect assessment and prediction. For in vitro dissolution-based predictions, the expected food effect mechanism should be carefully considered when selecting the level of complexity of the model, together with its drawbacks and advantages. Typically, in vitro dissolution profiles are then incorporated into physiologically based pharmacokinetic models, which can estimate the impact of food-drug interactions on bioavailability within 2-fold prediction error, at least. Positive food effects related to drug solubilization in the GI tract are easier to predict than negative food effects. Preclinical animal models also provide a good level of food effect prediction, with beagle dogs remaining the gold standard. When solubility-related food-drug interactions have large clinical impact, advanced formulation approaches can be used to improve fasted state pharmacokinetics, hence decreasing the fasted/fed difference in oral bioavailability. Finally, the knowledge from all studies should be combined to secure regulatory approval of the labelling instructions.

LC-MS/MS method for quantification of raspberry ketone in rat plasma: application to preclinical pharmacokinetic studies

Background: Raspberry ketone (RK), derived from red raspberry fruit (Rubus idaeus, family Rosaceae), is a reported potent antiobesity agent. This study aims to investigate method development, validation, and in vitro and in vivo pharmacokinetics in rats. Materials & methods: LC-MS/MS was used to conduct method development, validation, stability, and oral PK samples of RK in plasma analyses. Results: RK was highly soluble in Tris buffer and stable in gastrointestinal fluids as well as plasma. Rat liver microsomal stability of RK in phase I and II studies was 84.96 ± 2.39 and 69.98 ± 8.69%, respectively, after 60 min. Intestinal permeability was 4.39 ± 1.37 × 10^-5 cm/s. Maximal concentration was 1591.02 ± 64.76 ng/ml, which was achieved after 1 h (time to maximal concentration), and absolute oral bioavailability was 86.28%. Conclusion: Pharmacokinetic data serve as a keystone for preclinical and clinical adjuvant therapy.