Food, gastrointestinal pH, and models of oral drug absorption

Comparative Pharmacokinetics and Bioequivalence of 2 Formulations of Bosentan Dispersible Tablets in Healthy Chinese Volunteers Under Fasting and Fed Conditions

Bosentan is a dual endothelin receptor antagonist widely used in the treatment of pulmonary artery hypertension. However, there are few reports on the pharmacokinetics (PK) and bioequivalence of bosentan dispersible tablets (32 mg) in the Chinese population. This study aimed to evaluate the PK characteristics and bioequivalence of the test and reference formulations of bosentan dispersible tablets in healthy Chinese volunteers under fasting and fed conditions. A randomized, single-dose, 2-sequence, 2-period crossover study (fasting) and a 4-period replicate crossover study (fed) were conducted with 48 and 30 healthy volunteers, respectively. The bosentan plasma concentrations were measured by a validated ultra-performance liquid chromatography coupled with a tandem mass spectrometry method, and PK parameters were analyzed using noncompartmental methods. The bioequivalence statistical analysis showed that 90% confidence intervals for the geometric mean ratios of peak plasma concentration, area under the concentration-time curve (AUC) from time zero to the last measurable concentration, and AUC from time zero to infinity for the test and reference formulations were within the bioequivalence range of 80%-125% under both fasting and fed conditions. After the administration of bosentan dispersible tablets under fed conditions, the systemic exposure (based on AUC from time zero to infinity) was increased by approximately 15%-20%. These findings confirm the bioequivalence of the 2 formulations, and both formulations were well tolerated, with no safety-related adverse events reported. Given the wide therapeutic dose range of bosentan dispersible tablets for the treatment of pulmonary artery hypertension in children, the impact of food on its PK is not considered clinically significant.

Enhanced ex vivo skin retention of bicalutamide using a nano-in-micro composite: Drug-loaded lipid vesicles in a dissolving microarray patch

Antiandrogens are a family of drugs that block the biological effects of androgens, which are commonly used to treat a plethora of androgen-dependent conditions. However, their effectiveness highly depends on treatment compliance and their use is not exempt from side effects. Bicalutamide (BIC) is a testosterone blocker that, due to its peripheral tissue selectivity, offers the advantage of fewer side effects compared to other antiandrogens such as finasteride or dutasteride. In this study, BIC-loaded lipid vesicles (LVs) were developed and incorporated into a PVP/PVA-based Dissolving Microarray Patches (BIC-LVs@DMAPs) for BIC skin local delivery. First, the mechanical and insertion properties of the BIC-LVs@DMAPs were assessed. Then, the in vitro biocompatibility of the formulation was determined in keratinocytes. Finally, the effectiveness of the formulation to deliver BIC through skin was explored ex vivo using murine skin. BIC-LVs@DMAPs exhibited optimal mechanical and insertion properties to effectively perforate the stratum corneum and facilitate the passage of BIC-LVs. Ex vivo studies demonstrated the efficacy of BIC-LVs@DMAPs to improve the skin retention of BIC, while in vitro cytotoxicity results ensured their safety profile. Overall, these results pave the way for further in vivo studies and clinical application to improve the current early stages androgenetic alopecia topical treatments.

Mechanistic Advances in the Therapeutic Application of Bixin for Lung Inflammation In Vitro and In Vivo

Background: Nrf2 plays a key role in regulating the antioxidant response against oxidative stress. Therefore, it is imperative to examine the advantages of Nrf2 activation by new small molecules capable of inhibiting the Nrf2-Keap1 protein interaction that do not present electrophilic sites, since electrophilic compounds have intrinsic toxicity. The bixin pigment has been used as a form of treatment and prevention of several pathological conditions in animal models since it was described as an Nrf2 activator without electrophilic sites. This study aims to synthetize a soluble derivate KBx (potassium bixinate) and evaluate its ability to activate Nrf2/ARE in a model of exposure to cigarette smoke extract (CSE; in vitro) and intranasal LPS administration (in vivo). Methods: In the in vivo study, C57BL/6 mice were pretreated with 200 mg/kg of KBx (gavage) during 5 consecutive days and then challenged with 60 µg of LPS i.n. for 16 h. Bronchoalveolar lavage was collected to examine cytokines dosage. In the in vitro study, RAW 264.7 macrophages were exposed to CSE and post-treated with KBx to evaluate their ability to revert the redox imbalance caused by the stressor. Results: KBx was characterized using mass spectrometry (433.1778 m/z). KC levels were increased in the LPS group (p = 0.021), and KBx inhibited this (p = 0.001). IL-10 levels were decreased (p = 0.055) in the LPS group that was prevented when pretreated with KBx (p = 0.037). The in vitro study showed KBx to be a more potent derivate of bixin through its ability to intercept ROS formation with three-fold more potency, and it showed an anti-inflammatory propriety by reducing the nuclear translocation of p65 (p < 0.001). Conclusions: In conclusion, these data suggest that KBx was able to activate the Nrf2/ARE pathway and intercept ROS formation induced by CSE and LPS in both in vivo and in vitro studies.

Effect of Food on the Pharmacokinetic Characteristics of a Single Oral Dose of D-1553, a Selective Inhibitor of KRASG12C, in Healthy Chinese Subjects

BACKGROUND AND OBJECTIVE

D-1553 (garsorasib) is a novel and selective oral KRASG12C inhibitor. This study aims to evaluate the effect of food on the single-dose pharmacokinetics (PK) of D-1553 tablet in healthy Chinese subjects. Also the safety and tolerability of single-dose D-1553 in subjects are also evaluated.

METHODS

A randomized, open-label, single-dose, two-intervention (fed vs fasting), two-period, two-sequence crossover study was performed on 14 healthy Chinese subjects. Plasma concentrations of D-1553 were determined by the liquid chromatography-tandem mass spectrometry method. Safety evaluations were carried out during the study period. The main PK parameters of the two formulations of D-1553 were calculated by non-compartmental analysis using Phoenix WinNonlin (Version 8.3) software.

RESULTS

The geometric mean ratios (90% confidence interval [CI]) of AUC0-t and AUC0-∞ in the high-fat meal condition versus the fasting condition were 86.19% (78.30%, 94.87%) and 83.30% (75.77%, 91.58%), respectively. The geometric mean ratio (90% CI) of Cmax values in high-fat meal condition to that observed in fasting condition were 109.74% (100.22%,120.15%). The p value of Tmax was 0.1484 (fed vs fasting). Two subjects (14.3%) reported 4 treatment-emergent adverse events (TEAEs) in the fasting condition, and no subjects reported TEAEs in the fed condition. All adverse reactions were mild and had recovered by the end of the study.

CONCLUSION

The study indicated that a high-calorie and high-fat meal has no clinically relevant impact on the PK and bioavailability of D-1553 in healthy Chinese subjects. D-1553 was generally safe and well-tolerated under both fasting and fed conditions. The findings suggest that D-1553 could be administered orally with or without food.

CLINICAL TRIALS

ClinicalTrials.gov Identifer CTR20212761; registered on 4 Nov 2021.

Effect of High-Fat Diets on the Pharmacokinetics of Bedaquiline Fumarate Tablet: A Trial in Healthy Chinese Participants

Bedaquiline is employed to treat multidrug-resistant and extensive drug-resistant tuberculosis by inhibiting the proton pump of adenosine triphosphate synthase in Mycobacterium tuberculosis. This study aims to investigate the effect of high-fat diets on the pharmacokinetics of bedaquiline through a single-center, open-label, randomized trial in healthy Chinese participants. Bedaquiline fumarate tablets were administered at a dosage of 100 mg under both fasted conditions and high-fat diet conditions. The concentrations were determined using liquid chromatography-tandem mass spectrometry, and the pharmacokinetic parameters were calculated using a noncompartmental model. The high-fat diet group showed a maximum plasma concentration that exceeded that of the fasted group by more than 4-fold and an area under the concentration-time curve from time 0 to the last measurable point that was more than twice as high. Moreover, compared to the fasted group, the high-fat diet group exhibits significantly lower levels of apparent clearance, indicating that the high-fat diet markedly enhances the rate and extent of gastrointestinal absorption of bedaquiline. To optimize drug bioavailability and absorption and ensure safety, the administration of bedaquiline with food is recommended in accordance with clinical usage guidelines and expert consensus.

Targeting Neuroinflammation in Central Nervous System Diseases by Oral Delivery of Lipid Nanoparticles

Neuroinflammation within the central nervous system (CNS) is a primary characteristic of CNS diseases, such as Parkinson's disease, Alzheimer's disease (AD), amyotrophic lateral sclerosis, and mental disorders. The excessive activation of immune cells results in the massive release of pro-inflammatory cytokines, which subsequently induce neuronal death and accelerate the progression of neurodegeneration. Therefore, mitigating excessive neuroinflammation has emerged as a promising strategy for the treatment of CNS diseases. Despite advancements in drug discovery and the development of novel therapeutics, the effective delivery of these agents to the CNS remains a serious challenge due to the restrictive nature of the blood-brain barrier (BBB). This underscores the need to develop a novel drug delivery system. Recent studies have identified oral lipid nanoparticles (LNPs) as a promising approach to efficiently deliver drugs across the BBB and treat neurological diseases. This review aims to comprehensively summarize the recent advancements in the development of LNPs designed for the controlled delivery and therapeutic modulation of CNS diseases through oral administration. Furthermore, this review addresses the mechanisms by which these LNPs overcome biological barriers and evaluate their clinical implications and therapeutic efficacy in the context of oral drug delivery systems. Specifically, it focuses on LNP formulations that facilitate oral administration, exploring their potential to enhance bioavailability, improve targeting precision, and alleviate or manage the symptoms associated with a range of CNS diseases.

Harnessing the Potential of Human Breast Milk to Boost Intestinal Permeability for Nanoparticles and Macromolecules

The intricate interplay between human breast milk, nanoparticles, and macromolecules holds promise for innovative nutritional delivery strategies. Compared to bovine milk and infant formula, this study explores human breast milk's role in modulating intestinal permeability and its impact on nanoparticle and macromolecule transport. Comparative analysis with bovine milk and infant formula reveals significant elevations in permeability with human breast milk, accompanied by a decrease in transepithelial electrical resistance, suggesting enhanced paracellular transport. Mechanistically, human breast milk reduces Zonula occludens-1 levels, suggesting a regulatory role in intestinal barrier function. Through in vitro and ex vivo evaluations, we aim to understand better the mechanisms behind enhanced permeability and how human breast milk affects nanoparticle physicochemical properties, potentially modulating their behavior. Specifically, human breast milk improves the intestinal permeability of liposomes in a porcine intestinal model, with associated changes in the composition of milk proteins corona related to liposome charge. These findings underscore the unexploited potential of human breast milk in facilitating transport across the intestinal barrier, offering novel avenues for human nutritional delivery and therapeutic interventions.

In silico exploration of cholinergic activity and neuroprotection of novel caffeine analogues

Alzheimer's disease (AD) is characterized by a cholinergic deficit, prompting conventional therapies to elevate acetylcholine levels as a compensatory measure. Two main strategies involve the inhibition of acetylcholinesterase (AChE) and/or the stimulation of acetylcholine receptors (AChR). Caffeine (CFF), known as a partial agonist of nAChR and an AChE inhibitor, acts as a cholinergic enhancer. Additionally, it is suggested that CFF may exhibit neuroprotective capabilities through the inhibition of the human adenosine receptor type 2A (hA2AR) in the brain's striatum, potentially preventing cellular apoptosis. This study explores on the design and prediction of the bioactivity of CFF analogues with the aim of enhancing cholinergic signaling and providing neuroprotection to improve their therapeutic potential. We employed tools to predict pharmacokinetic and bioactivity properties, molecular docking, molecular dynamics, and target prediction to identify potential candidates among the designed CFF analogues capable of enhancing neurotransmission and providing cellular protection. In a novel approach, a normalized index is proposed for the combined analysis of the pharmacokinetic parameters and molecular docking binding affinities, which facilitates the systematic evaluation and comparison of the synthesized analogues and minimizes subjectivity in the selection of promising candidates. Results indicated that some analogues show promise in improving cholinergic activity and providing neuroprotection. These findings instill optimism, encouraging further research to corroborate their effects, while also representing a significant step towards the development of new therapeutic agents for AD.

Exploration of Abiraterone acetate loaded Nanostructured lipid carriers for bioavailability improvement and circumvention of fast-fed variability

Abiraterone acetate (ABA), a biopharmaceutical class IV drug suffers from solubility and permeability pitfalls resulting in limited oral bioavailability and positive food effect, i.e. multi-fold enhancement in drug absorption in the presence of food. This poses difficulties to physicians towards the estimation of dose and dosage regimen required for efficacious therapy of prostate cancer (PCa). Nanostructured lipid carriers (NLC) have demonstrated tremendous outcomes in enhancing the oral bioavailability of various entities along with food effect attenuation. In this study, Quality by design and multivariate analysis was employed for optimization of ABA loaded NLC (ABA NLC). The optimal size, PDI and zeta potential obtained using QbD were 134.6 nm, 0.163 and -15.7 mV respectively. Ex vivo qualitative and quantitative intestinal permeability studies demonstrated improved traversion of NLC through the intestinal segments. In vitro dissolution profile in biorelevant fast and fed gastric and intestinal media revealed minimal differences for ABA NLC compared to ABA. In vivo pharmacokinetics was performed to decipher the efficacy of ABA NLC in mitigating the food effect of ABA. The studies demonstrated 14.51-fold and 1.94-fold improvement in oral bioavailability during fasted and fed state respectively as compared to free ABA. The absorption mechanism of ABA NLC using chylomicron flow blocking approach conveyed lymphatic uptake as the major mechanism. Cmax fast/fed ratio was 0.9758 whereas, AUC fast/fed ratio was 0.9386, which being nearly equivalent, confirmed the food effect attenuation. Therefore, the results of the study demonstrate optimal pharmacokinetics of ABA NLC and its utility in circumventing the fast fed variability.

An electroadhesive hydrogel interface prolongs porcine gastrointestinal mucosal theranostics

Establishing a robust and intimate mucosal interface that allows medical devices to remain within lumen-confined organs for extended periods has valuable applications, particularly for gastrointestinal theranostics. Here, we report the development of an electroadhesive hydrogel interface for robust and prolonged mucosal retention after electrical activation (e-GLUE). The e-GLUE device is composed of cationic polymers interpenetrated within a tough hydrogel matrix. An e-GLUE electrode design eliminated the need for invasive submucosal placement of ground electrodes for electrical stimulation during endoscopic delivery. With an electrical stimulation treatment of about 1 minute, the cationic polymers diffuse and interact with polyanionic proteins that have a relatively slow cellular turnover rate in the deep mucosal tissue. This mucosal adhesion mechanism increased the adhesion energy of hydrogels on the mucosa by up to 30-fold and enabled in vivo gastric retention of e-GLUE devices in a pig stomach for up to 30 days. The adhesion strength was modulated by polycationic chain length, electrical stimulation time, gel thickness, cross-linking density, voltage amplitude, polycation concentration, and perimeter-to-area ratio of the electrode assembly. In porcine studies, e-GLUE demonstrated rapid mucosal adhesion in the presence of luminal fluid and mucus exposure. In proof-of-concept studies, we demonstrated e-GLUE applications for mucosal hemostasis, sustained local delivery of therapeutics, and intimate biosensing in the gastrointestinal tract, which is an ongoing clinical challenge for commercially available alternatives, such as endoclips and mucoadhesive. The e-GLUE platform could enable theranostic applications across a range of digestive diseases, including recurrent gastrointestinal bleeding and inflammatory bowel disease.

Colorimetric pH-sensing of artificial gastric fluid using naphthalimide-based CH acids

In this study, we introduce novel colorimetric pH-sensing probes based on naphthalimide malonate derivatives. These probes were synthesized by reacting 4-bromo-1,8-naphthalimide with various malonates, including malononitrile, ethyl cyanoacetate, and diethyl malonate. Each derivative exhibited distinct pH-sensing characteristics due to their differing CH acidities. The malononitrile-based probe, NPI-N2, demonstrated pronounced chromogenic pH-signaling behavior, transitioning from colorless to red-violet, accompanied by a decrease in fluorescence intensity. Notably, NPI-N2 retained its pH-sensing capability in the presence of common metal ions, anions, and pepsin, a key component of gastric fluid. The pKa of NPI-N2 was determined to be 3.08 through pH-dependent absorbance curve fitting. To modulate the pH-sensing range, ester-nitrile (NPI-EN) and diethyl ester (NPI-E2) subunits were incorporated into the naphthalimide framework, resulting in increased pKa values of 6.73 and 10.76, respectively. The pH-signaling mechanism of NPI-N2 was elucidated by 1H and 13C NMR spectroscopy, revealing deprotonation of the malononitrile moiety and subsequent resonance extension through the naphthalimide structure. To facilitate practical pH determination, NPI-N2 was integrated into a paper-based test strip, enabling convenient and reliable pH measurement of artificial gastric fluid.

Efficacy and in vitro pharmacological assessment of novel N-hydroxypyridinediones as hepatitis B virus ribonuclease H inhibitors

We previously reported N-hydroxypyridinedione (HPD) compounds with mid-nanomolar efficacy and selectivity indexes around 300 against hepatitis B virus (HBV) replication. However, they lack pharmacological evaluation. Here, we report in vitro anti-HBV efficacy, cytotoxicity, and pharmacological characterization of 29 novel HPDs within seven subgroups. The best two compounds had EC50s of 61 and 190 nM and selectivity indexes of 526 and 1,071. Compounds with one halogen on the major R group were most effective and compounds with large ether R groups were most cytotoxic. Compounds were not cytotoxic in primary human hepatocytes. All compounds were freely soluble in pHs reflecting plasma (7.4) and the gastrointestinal tract (5 and 6.5). Almost all highly soluble compounds were passively permeable at pH 5.0 and 7.4. Only 2 of 11 compounds tested were likely to be effluxed by p-glycoprotein. The most potent HPDs inhibited HBV replication over human ribonuclease H1 activity by 10-fold. Four of 19 compounds inhibited CYP2D6 >50%, but their CYP2D6 IC50s were >8× higher than their anti-HBV EC50. No compound substantially inhibited CYP3A4. Thirteen of 15 compounds had human microsomal half-lives >30 min with medium to low rates of intrinsic clearance. Eleven of 12 compounds bound plasma proteins by ≥80%; however, effects against HBV replication for only one would likely be physiologically relevant. These results identify two lead candidate HPDs with pharmacological characteristics resembling commercially available drugs that are suitable for in vivo pharmacological and efficacy studies.

Dietary content and eating behavior in ulcerative colitis: a narrative review and future perspective

Ulcerative colitis (UC) has experienced a steady increase in global incidence and prevalence recently. Current research into UC pathogenesis focuses on the complex interplay of genetic and environmental factors with the immune system and gut microbiome, leading to disruption of the intestinal barrier. Normally, the microbiome, intestinal epithelium, and immune system interact to maintain intestinal homeostasis. However, when this equilibrium is disturbed, a harmful cycle of dysbiosis, immune dysregulation, and inflammation emerges, resulting in intestinal barrier dysfunction and UC progression. Among various risk factors, diet significantly influences epithelial barrier integrity and architectural stability through both direct and indirect mechanisms, shaping the entire UC continuum from pre-clinical prevention to active phase treatment and remission maintenance. This review provides insights into the impact of dietary content and eating behaviors on UC, focusing on specific food, food groups, nutrients, and intermittent fasting, while providing a detailed explanation of why the gut microbiota may mediate the sustained effects of diet across all stages of UC. Additionally, it addresses the limitations of current studies, explores underexamined areas in UC dietary research and proposes potential directions for future research and expansion.

Impact of Food Physical Properties on Oral Drug Absorption: A Comprehensive Review

Food-Drug Interaction (FDI) refers to the phenomenon where food affects the pharmacokinetic or pharmacodynamic characteristics of a drug, significantly altering the drug's absorption rate or absorption extent. These Interactions are considered as a primary determinant in influencing the bioavailability of orally administered drugs within the gastrointestinal tract. The impact of food on drug absorption is complex and multifaceted, potentially involving alterations in gastrointestinal physiology, increases in splanchnic blood flow rates, and shifts in the gut microbiota's composition. Up to now, extensive research has focused on the interactions between food composition (such as proteins, fats, and vitamins) and drug absorption. In contrast, the impact of food physical properties (such as viscosity, volume, and pH) has received less attention in drug development. This article reviewed the impact of food properties on oral drug absorption based on a comprehensive literature search, focusing on the influence of food volume and food viscosity. From the perspective of pharmacokinetics, we examined interaction trends between food properties and drugs across different classification based on the Biopharmaceutics Classification System (BCS). In addition, we introduced the practical application of physiologically based pharmacokinetic (PBPK) modeling in predicting oral drug absorption under the influence of food Properties.

Microencapsulation of broccoli sulforaphane using whey and pea protein: in vitro dynamic gastrointestinal digestion and intestinal absorption by Caco-2-HT29-MTX-E12 cells

Sulforaphane, an organosulfur phytochemical, has been demonstrated to have significant anticancer potential in both in vitro and in vivo studies, exhibiting mechanisms of action that include inducing apoptosis, inhibiting cell proliferation, and modulating key signalling pathways involved in cancer development. However, its instability presents a major obstacle to its clinical application due to its limited bioavailability. This study aimed to improve the stability and thus the bioavailability of sulforaphane from broccoli by microencapsulation with whey (BW) and pea protein (BP) by freeze-drying. BW and BP were characterised by particle size measurement, colour, infrared spectroscopy, scanning electron microscopy, thermogravimetry, and differential scanning calorimetry. Dynamic in vitro gastrointestinal digestion was performed to measure sulforaphane bioaccessibility, in BP, BW and dried broccoli. A Caco-2-HT29-MTX-E12 intestinal absorption model was used to measure sulforaphane bioavailability. The in vitro dynamic gastrointestinal digestion revealed that sulforaphane bioaccessibility of BW was significantly higher (67.7 ± 1.2%) than BP (19.0 ± 2.2%) and dried broccoli (19.6 ± 10.4%) (p < 0.01). In addition, sulforaphane bioavailability of BW was also significantly greater (54.4 ± 4.0%) in comparison to BP (9.6 ± 1.2%) and dried broccoli (15.8 ± 2.2%) (p < 0.01). Microencapsulation of broccoli sulforaphane with whey protein significantly improved its in vitro bioaccessibility and bioavailability. This suggests that whey protein isolate could be a promising wall material to protect and stabilise sulforaphane for enhanced bioactivity and applications (such as nutraceutical formulations).

Role of Posaconazole Drug in the Treatment of Invasive Fungal Disease: A Review

Posaconazole is an antifungal medication used primarily to treat invasive fungal infections caused by various organisms, such as Aspergillus, Candida, and certain molds. It belongs to the class of drugs known as triazole antifungals. Clinical studies have reported posaconazole to be effective in treating various invasive fungal infections, especially in patients who are immunocompromised, such as those with weakened immune systems due to conditions like HIV/AIDS, undergoing chemotherapy, or having received an organ transplant. It has effectively treated invasive candidiasis, aspergillosis, zygomycosis, and other serious fungal infections. The effectiveness of the drug varies based on factors, such as the type of infection, the patient's immune status, and the site of infection. This review describes the types of infection, the drug's safety profile, the development of resistance to posaconazole, and strategies to manage or prevent resistance.

Potential and challenges in application of physiologically based pharmacokinetic modeling in predicting diarrheal disease impact on oral drug pharmacokinetics

Physiologically based pharmacokinetic (PBPK) modeling is a physiologically relevant approach that integrates drug-specific and system parameters to generate pharmacokinetic predictions for target populations. It has gained immense popularity for drug-drug interaction, organ impairment, and special population studies over the past 2 decades. However, an application of PBPK modeling with great potential remains rather overlooked-prediction of diarrheal disease impact on oral drug pharmacokinetics. Oral drug absorption is a complex process involving the interplay between physicochemical characteristics of the drug and physiological conditions in the gastrointestinal tract. Diarrhea, a condition common to numerous diseases impacting many worldwide, is associated with physiological changes in many processes critical to oral drug absorption. In this Minireview, we outline key processes governing oral drug absorption, provide a high-level overview of key parameters for modeling oral drug absorption in PBPK models, examine how diarrheal diseases may impact these processes based on literature findings, illustrate the clinical relevance of diarrheal disease impact on oral drug absorption, and discuss the potential and challenges of applying PBPK modeling in predicting disease impacts. SIGNIFICANCE STATEMENT: Pathophysiological changes resulting from diarrheal diseases can alter important factors governing oral drug absorption, contributing to suboptimal drug exposure and treatment failure. Physiologically based pharmacokinetic (PBPK) modeling is an in silico approach that has been increasingly adopted for drug-drug interaction potential, organ impairment, and special population assessment. This Minireview highlights the potential and challenges of using physiologically based pharmacokinetic modeling as a tool to improve our understanding of how diarrheal diseases impact oral drug pharmacokinetics.

The Pharmacokinetic Changes in Cystic Fibrosis Patients Population: Narrative Review

Cystic fibrosis (CF) is a rare genetic disorder commonly affecting multiple organs such as the lungs, pancreas, liver, kidney, and intestine. Our search focuses on the pathophysiological changes that affect the drugs' absorption, distribution, metabolism, and excretion (ADME). This review aims to identify the ADME data that compares the pharmacokinetics (PK) of different drugs in CF and healthy subjects. The published data highlight multiple factors that affect absorption, such as the bile salt precipitation and the gastrointestinal pH. Changes in CF patients' protein binding and body composition affected the drug distribution. The paper also discusses the factors affecting metabolism and renal elimination, such as drug-protein binding and metabolizing enzyme capacity. The majority of CF patients are on multidrug therapy, which increases the risk of drug-drug interactions (DDI). This is particularly true for those receiving the newly developed transmembrane conductance regulator (CFTR), as they are at a higher risk for CYP-related DDI. Our research highlights the importance of meticulously evaluating PK variations and DDIs in drug development and the therapeutic management of CF patients.

Integrating environmental, ecological and human health risk assessments for heavy metals in tropical ultramafic soils

Ultramafic soils are a natural source of metals such as Ni, Co and Cr that can pose ecosystem and human risks. Here, we assessed the environmental, ecological, and human health (carcinogenic and non-carcinogenic) risks from exposure to ultramafic soils through an integrated approach using petrographic and soil mineralogical assessments together with total, available, bioaccessible, and soil fractions analyses of Ni, Co and Cr in ultramafic soils from Brazil. The metal concentrations were similar or up to 5-fold higher for Ni than other studies worldwide in ultramafic soils. Soil sequential extraction showed Co and Ni predominantly bound to Fe and Mn oxides, while Cr was mostly in residual fractions. Medium environmental risks were found for Ni (RAC = 13.0), but no environmental risks were associated with Co and Cr in soils. Ecological risks were high (PERI = 522.8) and significantly high (PERI = 1759.9). Low metal bioaccessibility led to acceptable carcinogenic and non-carcinogenic risks for all routes of human exposure to soil, but consuming vegetables grown in these soils posed unacceptable cancer risks (> 10-3). Our results reinforce the need to monitor ultramafic areas regarding the mobility and availability of metals in the soil to ensure food safety and human health.

Development of intestinal colonic drug delivery systems for diverticular disease: A QbD approach

This study aimed to advance the development of intestinal colon-coated sustained-release matrix tablets of metronidazole for diverticulitis treatment, employing the Quality by Design (QbD) methodology. Comprehensive Risk analysis and Risk evaluation were conducted to assess the potential risks associated with Critical Material Attributes (CMA) and Critical Process Parameters (CPP). Ishikawa diagram, color-coded risk classification and the Risk Priority Number (RPN) were used as tools for risk evaluation. A Design of Experiments (DoE) was executed using a fractional factorial design, incorporating five key factors derived from the Risk analysis and Risk evaluation. Two levels and a central point were established for each factor, resulting in 28 batches of coated tablets. The manufacturing process involved direct compression, followed by a coating process using pH-dependent or time-dependent polymers. Characterization and dissolution studies were conducted on all batches, and the obtained results underwent analysis of variance (ANOVA). The findings demonstrated the robustness and reproducibility of both the direct compression and coating processes. Statistical analysis identified HPMC/chitosan ratio, blending time, coating polymer, and coating weight gain as factors significantly impacting drug release. A Design Space was established to delineate the interplay of these factors, offering insights into various combinations influencing drug release behavior. Thus, the design space for 10 % weight gain formulations includes a range of HPMC/CH ratios between 2.7-3 and mixing times between 10 and 12 min; for 20 % weight gain formulations it includes a range of HPMC/CH ratios up to 2 and mixing times between 10 and 16 min. Multiple Linear Regression between technological and biopharmaceutical variables were optimized facilitating scale-up operations. Batches with a 10 % weight increase and varied HPMC viscosity grades and coating polymers achieve ∼50 % drug release at 24 h; however, batches with a 20 % weight increase along, with either high proportions of HPMC and short blending times or low proportions of HPMC and longer blending times, achieve slow release of metronidazole. This study contributes to optimizing metronidazole colonic delivery systems, enhancing their potential efficacy in diverticulitis treatment.

An integrated population pharmacokinetic model of febuxostat in pediatric patients with hyperuricemia including gout and adult population of healthy subjects and patients with renal dysfunction

The study objective was to validate febuxostat dosage and administration in pediatric patients with hyperuricemia including gout, using an integrated population pharmacokinetic (PopPK) analysis in the Japanese population. Integrated PopPK analysis of febuxostat used a nonlinear mixed-effects modeling (NONMEM) program on plasma febuxostat concentration data for 2611 samples from Japanese pediatric patients with hyperuricemia including gout (n = 29) and from adult subjects who are healthy or have renal dysfunction (n = 113). We described febuxostat pharmacokinetics using an integrated PopPK model applicable both to pediatric patients and to the adult population. The covariates of body weight and eGFR were identified for CL/F and the covariate of fasted/fed status for bioavailability. The range of steady-state exposures (Cmax,ss and AUCτ,ss) for 5, 10, 20, and 30 mg of febuxostat in fed pediatric patients weighing 20 to 40 kg was within that for 10, 20, 40, and 60 mg of febuxostat in fed pediatric patients and adults weighing 40 to 120 kg. Post hoc estimates of CL/F, adjusted by body weight, differed little between pediatric patients and the adult population in the renal function categories of normal, mild dysfunction, and moderate dysfunction. We successfully validated the febuxostat dose that provided the same level of exposure in pediatric patients as in the adult population: half the adult dose for pediatric patients weighing <40 kg and the full adult dose for pediatric patients weighing ≥40 kg. As in adults, the results support the use of febuxostat without dose adjustment in pediatric patients who have mild to moderate renal dysfunction.

Nutraceutical tablets: Manufacturing processes, quality assurance, and effects on human health

Consumers are increasingly focused on food products' nutritional content and health aspects. Nutraceutical tablets containing nutritional supplements have seen remarkable progress and are well-known for their precise dosage, which can improve consumer health by increasing the intake of bioactive compounds and vital nutrients. Oral nutraceuticals are frequently used to enhance consumer well-being, with around 80% of products being in solid form. This manuscript aims to thoroughly analyze and summarize the gathered literature using various search engines to investigate key trends in the market, the components involved, and the functional impact of nutraceutical tablets. Furthermore, the manuscript explores various nutraceutical tablets such as chewable tablets, gelling capsules, vitamin tablets, spirulina tablets, and bran tablets. A perspective is provided on multiple production and manufacturing methods of nutraceutical tablets, along with comparing these processes. Following this, evaluating quality characteristics and enforcing quality assurance procedures have been emphasized. The manuscript discussed the physiological breakdown of ingestible nutraceutical tablets in the human body and the possible toxic effects of the components found in these tablets. Furthermore, the focus is on producing nutraceutical tablets in a more environmentally friendly manner, tackling sustainability issues, offering solutions, and delving into potential opportunities. This manuscript will create a significant platform for people from the research, scientific, and industrial fields seeking novel and inventive projects.

Investigating Strategies to Enhance the Aqueous Solubility of Ketamine HCl for Intranasal Delivery

Background: Ketamine HCl, an FDA-approved therapeutic, is administered through various routes, including intranasal delivery. Administering an adequate therapeutic dose of intranasal ketamine HCl is challenging due to the limited volume that can be delivered intranasally given the current commercially available concentrations. Objectives: This study investigates solubilizing strategies to enhance the aqueous solubility of ketamine HCl for intranasal administration. Methods: We assessed the solubility profile of ketamine HCl by evaluating factors such as pH, co-solvents, and surfactants. Additionally, we developed and validated a UV-Vis spectroscopy method for ketamine HCl analysis. Results: Our solubility screening in various organic co-solvents revealed the following order of effectiveness in enhancing solubility: methanol > water > propylene glycol > ethanol > dimethyl sulfoxide (DMSO) > N-methyl-2-pyrrolidone (NMP). Despite methanol's superior solubility, its potential toxicity, coupled with the relatively lower effectiveness of other solvents compared to water, suggests that a co-solvency approach is not advantageous for ketamine HCl. We found that ketamine HCl solubility increased with medium acidity, with pH 3.5 being the optimal for further formulation studies. The impact of pharmaceutical surfactants on ketamine HCl solubility at an acidic pH was also evaluated. Surfactants tested included SDS, PEG 400, PVP, Tween 20, poloxamer 188, and lecithin. Notably, PEG 400 and PVP reduced solubility due to a salting-out effect, whereas Tween 80, lecithin, and poloxamer 188 slightly improved solubility through micelle formation. Among the surfactants tested, 1% SDS emerged as the most effective in enhancing ketamine HCl solubility. Conclusions: These outcomes highlight the potential of these solubilization strategies to address the solubility limitations of ketamine HCl, enabling the preparation of highly concentrated ketamine HCl formulations for intranasal delivery.

Pharmacokinetic and Pharmacodynamic Interaction of Finerenone with Diltiazem, Fluconazole, and Ritonavir in Rats

BACKGROUND AND OBJECTIVES

Finerenone, a novel selective non-steroidal mineralocorticoid receptor antagonist, has been indicated in chronic kidney disease associated with type 2 diabetes mellitus. Considering the potential complications of diabetes, finerenone can be co-administered with various drugs, including fluconazole, diltiazem, and ritonavir. Given that finerenone is a substrate of cytochrome P450 (CYP) 3A4, the concurrent administration of finerenone with CYP3A4 inhibitors (diltiazem or fluconazole or ritonavir) could potentially lead to drug interactions, which may cause adverse events such as hyperkalemia. No studies have investigated interactions between finerenone and diltiazem or fluconazole or ritonavir. Therefore, this study aims to investigate the pharmacokinetic interaction of finerenone with diltiazem or fluconazole or ritonavir and to evaluate the impact of fluconazole on the pharmacodynamics of finerenone.

METHODS

The pharmacokinetic study included four rat groups (n = 8 rats/group), including a control group (finerenone alone) and test groups (finerenone pretreated with diltiazem or fluconazole or ritonavir) using both non-compartment analysis (NCA) and population pharmacokinetic (pop-PK) modeling. The pop-PK model was developed using non-linear mixed-effects modeling in NONMEM® (version 7.5.0). In the pharmacodynamic study, serum potassium (K+) levels were measured to assess the effects of fluconazole on finerenone-induced hyperkalemia.

RESULTS

The NCA results indicated that the area under the plasma concentration-time curve (AUC) of finerenone increased by 1.86- and 1.95-fold when coadministered with fluconazole and ritonavir, respectively. In contrast, diltiazem did not affect the pharmacokinetics of finerenone. The pharmacokinetic profiles of finerenone were best described by a one-compartment disposition with first-order elimination and dual first-order absorption kinetics. The pop-PK modeling results demonstrated that the apparent clearance of finerenone decreased by 50.3% and 49.2% owing to the effects of fluconazole and ritonavir, respectively. Additionally, the slow absorption rate, which represents the absorption in the distal intestinal tract of finerenone, increased by 55.7% due to the effect of ritonavir. Simultaneously, a pharmacodynamic study revealed that finerenone in the presence of fluconazole caused a significant increase in K+ levels compared with finerenone alone.

CONCLUSIONS

Coadministration of finerenone with fluconazole or ritonavir increased finerenone exposure in rats. Additionally, the administration of finerenone in the presence of fluconazole resulted in elevated K+ levels in rats. Further clinical studies are required to validate these findings.

In Vitro Susceptibility and Synergistic Effect of Bismuth Against Helicobacter pylori

Background/objectives: Bismuth is commonly used in Helicobacter pylori (H. pylori) eradication therapy. However, few studies have examined the in vitro susceptibility of H. pylori to bismuth. Moreover, the exact mechanism of action of bismuth on H. pylori remains unclear. The aim of this study was to identify the anti-bacterial effect of bismuth as well as to evaluate potential synergistic effects between bismuth and various antibiotics. Methods: The minimum inhibitory concentrations (MICs) of three bismuth preparations, bismuth subsalicylate, bismuth potassium citrate, and colloidal bismuth subcitrate (CBS, De-Nol) were determined for H. pylori strains using the agar dilution technique. Agar plates of varying pH values from 5.0 to 8.0 were used to investigate whether acidity influences the anti-bacterial effect of bismuth. A checkerboard assay was performed to assess the synergism between CBS and antibiotics (amoxicillin, clarithromycin, and metronidazole). Results: Twelve H. pylori strains, including three reference strains (H. pylori 26695, J99, and ATCC 43504), and nine clinically isolated strains were tested. The MICs for bismuth subsalicylate, bismuth potassium citrate, and CBS ranged from 4 to 32 μg/mL, 2 to 16 μg/mL, and 1 to 8 μg/mL, respectively. The bismuth MICs for the reference strains were similar at pH 5-8. In the checkerboard assay, no interactions between CBS and any of the antibiotics were observed in the reference H. pylori strains. Conclusions: Bismuth showed in vitro susceptibility against H. pylori. The enhanced eradication efficacy of bismuth-containing regimens appears to be due to mechanisms other than direct synergy with antibiotics.

Key Factors for Improving Predictive Accuracy and Avoiding Overparameterization of the PBPK Absorption Model in Food Effect Studies of Weakly Basic Water-Insoluble Compounds in Immediate Release Formulations

Background/Objectives: Physiologically based pharmacokinetic (PBPK) absorption models are instrumental for assessing drug absorption prior to clinical food effect studies, though discrepancies in predictive and actual outcomes are observed. This study focused on immediate release formulations of weakly basic water-insoluble compounds, namely rivaroxaban, ticagrelor, and PB-201, to investigate factors that could improve the predictive accuracy of PBPK models regarding food effects. Methods: Comprehensive in vitro experimental results provided the basis for the development of mechanistic absorption models, which were then combined with mechanistic disposition models to predict the systemic exposure of the model drugs in both fasted and fed states. Results: The developed PBPK models showed moderate to high predictive accuracy for food effects in Caucasian populations. For the Chinese population, the ticagrelor model's initial overestimation of fed-state absorption was addressed by updating the permeability parameters from Caco-2 cell assays to those derived from parallel artificial membrane permeability assays in FaSSIF and FeSSIF media. This refinement was also applied to the rivaroxaban and ticagrelor models, leading to a more accurate representation of absorption in Caucasians. Conclusions: This study highlights the importance of apparent permeability in enhancing the predictive accuracy of PBPK absorption models for weakly basic water-insoluble compounds. Furthermore, the precipitation of PB-201 in the two-stage transfer experiments suggests that precipitation may not be a universal phenomenon for such compounds in vivo. Consequently, the precipitation rate constant, a theoretically essential parameter, should be determined based on experimental evidence to avoid overparameterization and ensure robust predictive accuracy of PBPK models.

Unlocking the Potential of Probiotics: A Comprehensive Review on Research, Production, and Regulation of Probiotics

This review provides a comprehensive overview of the current state of probiotic research, covering a wide range of topics, including strain identification, functional characterization, preclinical and clinical evaluations, mechanisms of action, therapeutic applications, manufacturing considerations, and future directions. The screening process for potential probiotics involves phenotypic and genomic analysis to identify strains with health-promoting properties while excluding those with any factor that could be harmful to the host. In vitro assays for evaluating probiotic traits such as acid tolerance, bile metabolism, adhesion properties, and antimicrobial effects are described. The review highlights promising findings from in vivo studies on probiotic mitigation of inflammatory bowel diseases, chemotherapy-induced mucositis, dysbiosis, obesity, diabetes, and bone health, primarily through immunomodulation and modulation of the local microbiota in human and animal models. Clinical studies demonstrating beneficial modulation of metabolic diseases and human central nervous system function are also presented. Manufacturing processes significantly impact the growth, viability, and properties of probiotics, and the composition of the product matrix and supplementation with prebiotics or other strains can modify their effects. The lack of regulatory oversight raises concerns about the quality, safety, and labeling accuracy of commercial probiotics, particularly for vulnerable populations. Advancements in multi-omics approaches, especially probiogenomics, will provide a deeper understanding of the mechanisms behind probiotic functionality, allowing for personalized and targeted probiotic therapies. However, it is crucial to simultaneously focus on improving manufacturing practices, implementing quality control standards, and establishing regulatory oversight to ensure the safety and efficacy of probiotic products in the face of increasing therapeutic applications.

Updated aspects of alpha-Solanine as a potential anticancer agent: Mechanistic insights and future directions

Cancer remains a critical global health challenge, with limited progress in reducing mortality despite advancements in diagnosis and treatment. The growing resistance of tumors to existing chemotherapy exacerbates this burden. In response, the search for new anticancer compounds from plants has intensified, given their historical success in yielding effective treatments. This review focuses on α-solanine, a glycoalkaloid primarily derived from potato tubers and nightshade family plants, recognized for its diverse biological activities, including anti-allergic, antipyretic, anti-inflammatory, anti-diabetic, and antibiotic properties. Recently, α-solanine has gained attention as a potential anticancer agent. Utilizing resources like PubMed/MedLine, ScienceDirect, Web of Science, Scopus, the American Chemical Society, Google Scholar, Springer Link, Wiley, and various commercial websites, this review consolidates two decades of research on α-solanine's anticancer effects and mechanisms against nine different cancers, highlighting its role in modulating various signaling pathways. It also discusses α-solanine's potential as a lead compound in cancer therapy. The abundant availability of potato peel, often discarded as waste or sold cheaply, is suggested as a sustainable source for large-scale α-solanine extraction. The study concludes that α-solanine holds promise as a standalone or adjunctive cancer treatment. However, further research is necessary to optimize this lead compound and mitigate its toxicity through various strategies.

Enteral Route Nanomedicine for Cancer Therapy

With the in-depth knowledge of the pathological and physiological characteristics of the intestinal barrier-portal vein/intestinal lymphatic vessels-systemic circulation axis, oral targeted drug delivery is frequently being renewed. With many advantages, such as high safety, convenient administration, and good patient compliance, many researchers have begun to explore targeted drug delivery from intravenous injections to oral administration. Over the past few decades, the fields of materials science and nanomedicine have produced various drug delivery platforms that hold great potential in overcoming the multiple barriers associated with oral drug delivery. However, the oral transport of particles into the systemic circulation is extremely difficult due to immune rejection and biochemical invasion in the intestine, which limits absorption and entry into the bloodstream. The feasibility of the oral delivery of targeted drugs to sites outside the gastrointestinal tract (GIT) is unknown. This article reviews the biological barriers to drug absorption, the in vivo fate and transport mechanisms of drug carriers, the theoretical basis for oral administration, and the impact of carrier structural evolution on oral administration to achieve this goal. Finally, this article reviews the characteristics of different nano-delivery systems that can enhance the bioavailability of oral therapeutics and highlights their applications in the efficient creation of oral anticancer nanomedicines.

Neither an Individualised Nor a Standardised Sodium Bicarbonate Strategy Improved Performance in High-Intensity Repeated Swimming, or a Subsequent 200 m Swimming Time Trial in Highly Trained Female Swimmers

Inconsistent swimming performances are often observed following sodium bicarbonate (NaHCO3) ingestion, possibly because the time taken to reach peak blood buffering capacity is highly variable between individuals. Personalising NaHCO3 ingestion based on time-to-peak blood bicarbonate (HCO3-) could be a solution; however, this strategy is yet to be explored in swimming, or adequately compared to standardised NaHCO3 approaches. Therefore, six highly trained female swimmers ingested 0.3 g·kg BM-1 NaHCO3 in capsules to pre-determine their individual time-to-peak blood HCO3-. They then participated in three experimental trials, consisting of a 6 × 75 m repeated sprint swimming test, followed by a 200 m maximal time trial effort after 30 min active recovery. These experiments were conducted consuming a supplement at three different timings: individualised NaHCO3 (IND: 105-195 min pre-exercise); standardised NaHCO3 (STND: 150 min pre-exercise); and placebo (PLA: 90 min pre-exercise). Both NaHCO3 strategies produced similar increases in blood HCO3- prior to exercise (IND: +6.8 vs. STND: +6.1 mmol·L-1, p < 0.05 vs. PLA) and fully recovered blood HCO3- during active recovery (IND: +6.0 vs. STND: +6.3 mmol·L-1 vs. PLA, p < 0.05). However, there were no improvements in the mean 75 m swimming time (IND: 48.2 ± 4.8 vs. STND: 48.9 ± 5.8 vs. PLA: 49.1 ± 5.1 s, p = 0.302) nor 200 m maximal swimming (IND: 133.6 ± 5.0 vs. STND: 133.6 ± 4.7 vs. PLA: 133.3 ± 4.4 s, p = 0.746). Regardless of the ingestion strategy, NaHCO3 does not appear to improve exercise performance in highly trained female swimmers.

Radioactive ADME Demonstrates ARV-110's High Druggability Despite Low Oral Bioavailability

Proteolysis-targeting chimeras (PROTACs) have emerged as potentially effective therapeutic medicines, but their high molecular weight and poor solubility directly impact their oral bioavailability. This work synthesized 14C-labeled bavdegalutamide (ARV-110) as a model compound of PROTACs to evaluate its ADME features. Compared with targeted antitumor drugs, the use of food increased oral bioavailability of ARV-110 in rats from 10.75% to 20.97%, which is still undesirable. However, the therapeutic effect of ARV-110 at a low dose was much better than that of enzalutamide, demonstrating the specific catalytic medicinal properties of PROTACs. Moreover, the specific distribution of ARV-110 in subcutaneous prostate tumors was determined by quantitative whole-body autoradiography (QWBA). Notably, the specificity and activity of PROTACs take precedence over their oral absorption, and high oral bioavailability is not necessary to produce excellent therapeutic effects. This work presents a roadmap for developing future PROTAC medications from a radioactive drug metabolism and pharmacokinetics (DMPK) perspective.

Mathematical Modeling of the Gastrointestinal System for Preliminary Drug Absorption Assessment

The objective of this study is to demonstrate the potential of a multicompartmental mathematical model to simulate the activity of the gastrointestinal system after the intake of drugs, with a limited number of parameters. The gastrointestinal system is divided into five compartments, modeled as both continuous systems with discrete events (stomach and duodenum) and systems with delay (jejunum, ileum, and colon). The dissolution of the drug tablet occurs in the stomach and is described through the Noyes-Whitney equation, with pH dependence expressed through the Henderson-Hasselbach relationship. The boluses resulting from duodenal activity enter the jejunum, ileum, and colon compartments, where drug absorption takes place as blood flows countercurrent. The model includes only three parameters with assigned physiological meanings. It was tested and validated using data from in vivo experiments. Specifically, the model was tested with the concentration profiles of nine different drugs and validated using data from two drugs with varying initial concentrations. Overall, the outputs of the model are in good agreement with experimental data, particularly with regard to the time of peak concentration. The primary sources of discrepancy were identified in the concentration decay. The model's main strength is its relatively low computational cost, making it a potentially excellent tool for in silico assessment and prediction of drug adsorption in the intestine.

Duodenal microbiota dysbiosis in functional dyspepsia and its potential role of the duodenal microbiota in gut-brain axis interaction: a systematic review

Background and aims

Functional dyspepsia (FD) is a common gastrointestinal disorder associated with brain-gut interaction disturbances. In recent years, accumulating evidence points to the duodenum as a key integrator in dyspepsia symptom generation. Investigations into the pathological changes in the duodenum of FD patients have begun to focus on the role of duodenal microbiota dysbiosis. This review summarizes duodenal microbiota changes in FD patients and explores their relationship with gut-brain interaction dysregulation.

Methods

Ten databases, including PubMed, MEDLINE, and the Cochrane Library, were searched from inception to 10th October 2023 for clinical interventional and observational studies comparing the duodenal microbiota of FD patients with controls. We extracted and qualitatively summarized the alpha diversity, beta diversity, microbiota composition, and dysbiosis-related factors.

Results

A total of nine studies, consisting of 391 FD patients and 132 non-FD controls, were included. The findings reveal that the alpha diversity of the duodenal microbiota in FD patients does not exhibit a significant difference compared to non-FD controls, although an upward trend is observed. Furthermore, alterations in the duodenal microbiota of FD patients are associated with the symptom burden, which, in turn, impacts their quality of life. In FD patients, a considerable number of duodenal microbiota demonstrate a marked ascending trend in relative abundance, including taxa such as the phylum Fusobacteria, the genera Alloprevotella, Corynebacterium, Peptostreptococcus, Staphylococcus, Clostridium, and Streptococcus. A more pronounced declining trend is observed in the populations of the genera Actinomyces, Gemella, Haemophilus, Megasphaera, Mogibacterium, and Selenomonas within FD patients. A negative correlation in the relative abundance changes between Streptococcus and Prevotella is identified, which correlates with the severity of symptom burden in FD patients. Moreover, the alterations in specific microbial communities in FD patients and their potential interactions with the gut-brain axis merit significant attention.

Conclusion

Microbial dysbiosis in FD patients is linked to the onset and exacerbation of symptoms and is related to the disorder of gut-brain interaction. Larger-scale, higher-quality studies, along with comprehensive meta-omics research, are essential to further elucidate the characteristics of the duodenal microbiota in FD patients and its role in FD pathogenesis.Systematic review registration: CRD42023470279, URL: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023470279.

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.

Mechanisms of intestinal pharmacokinetic natural product-drug interactions

The growing co-consumption of botanical natural products with conventional medications has intensified the need to understand potential effects on drug safety and efficacy. This review delves into the intricacies of intestinal pharmacokinetic interactions between botanical natural products and drugs, such as alterations in drug solubility, permeability, transporter activity, and enzyme-mediated metabolism. It emphasizes the importance of understanding how drug solubility, dissolution, and osmolality interplay with botanical constituents in the gastrointestinal tract, potentially altering drug absorption and systemic exposure. Unlike reviews that focus primarily on enzyme and transporter mechanisms, this article highlights the lesser known but equally important mechanisms of interaction. Applying the Biopharmaceutics Drug Disposition Classification System (BDDCS) can serve as a framework for predicting and understanding these interactions. Through a comprehensive examination of specific botanical natural products such as byakkokaninjinto, green tea catechins, goldenseal, spinach extract, and quercetin, we illustrate the diversity of these interactions and their dependence on the physicochemical properties of the drug and the botanical constituents involved. This understanding is vital for healthcare professionals to effectively anticipate and manage potential natural product-drug interactions, ensuring optimal patient therapeutic outcomes. By exploring these emerging mechanisms, we aim to broaden the scope of natural product-drug interaction research and encourage comprehensive studies to better elucidate complex mechanisms.

Ocular Surface Fluid: More than a Matrix

Although the eye can be subjected to therapeutic manipulation, some of its structures are highly inaccessible. Thus, conventional therapeutic administration pathways, such as topical or systemic routes, usually show significant limitations in the form of low ocular penetration or the appearance of side effects linked to physiology, among others. The critical feature of many xenobiotics is the drug gradient from the concentrated tear reservoir to the relatively barren corneal and conjunctival epithelia, which forces a passive route of absorption. The same is true in the opposite direction, towards the ocular surface (OS). With the premise that tears can be regarded as equivalent to or a substitute for plasma, researchers may determine drug concentrations in the OS fluid. Within this framework, a survey of scholarly sources on the topic was conducted. It provided an overview of current knowledge, allowing the identification of relevant theories, methods, and gaps in the existing research that can be employed in subsequent research. OS fluid (tears particularly) has enormous potential as a source of biological material for external drug screening and as a biomarker of various systemic diseases. Given the numerous alternate matrices, knowledge of their properties is very important in selecting the most appropriate specimens in toxicological analyses.

Ceftazidime and Usnic Acid Encapsulated in Chitosan-Coated Liposomes for Oral Administration against Colorectal Cancer-Inducing Escherichia coli

Escherichia coli has been associated with the induction of colorectal cancer (CRC). Thus, combined therapy incorporating usnic acid (UA) and antibiotics such as ceftazidime (CAZ), co-encapsulated in liposomes, could be an alternative. Coating the liposomes with chitosan (Chi) could facilitate the oral administration of this nanocarrier. Liposomes were prepared using the lipid film hydration method, followed by sonication and chitosan coating via the drip technique. Characterization included particle size, polydispersity index, zeta potential, pH, encapsulation efficiency, and physicochemical analyses. The minimum inhibitory concentration and minimum bactericidal concentration were determined against E. coli ATCC 25922, NCTC 13846, and H10407 using the microdilution method. Antibiofilm assays were conducted using the crystal violet method. The liposomes exhibited sizes ranging from 116.5 ± 5.3 to 240.3 ± 3.5 nm and zeta potentials between +16.4 ± 0.6 and +28 ± 0.8 mV. The encapsulation efficiencies were 51.5 ± 0.2% for CAZ and 99.94 ± 0.1% for UA. Lipo-CAZ-Chi and Lipo-UA-Chi exhibited antibacterial activity, inhibited biofilm formation, and preformed biofilms of E. coli. The Lipo-CAZ-UA-Chi and Lipo-CAZ-Chi + Lipo-UA-Chi formulations showed enhanced activities, potentially due to co-encapsulation or combination effects. These findings suggest potential for in vivo oral administration in future antibacterial and antibiofilm therapies against CRC-inducing bacteria.

Enhancement of hepatoprotective activity of limonin from citrus seeds against acetaminophen-induced liver injury by HSCCC purification and liposomal encapsulation

Limonin is a natural tetracyclic triterpenoid compound in citrus seeds that presents hepatoprotective effects but is often discarded as agricultural waste because of its low content and low solubility. Herein, limonin with high purity (98.11%) from citrus seeds was obtained via purification by high-speed counter-current chromatography (HSCCC) and recrystallization. Limonin-loaded liposomes (Lip-LM) prepared by thin film hydration and high pressure homogenization method to enhance its solubility and hepatoprotective effect on APAP-induced liver injury (AILI). Lip-LM appeared as lipid nanoparticles under a transmission electron microscope, and showed well dispersed nano-scale size (69.04 ± 0.42 nm), high encapsulation efficiency (93.67% ± 2.51%), sustained release, fine stability. Lip-LM also exhibited significantly better hepatoprotective activity on AILI than free limonin in vivo. In summary, Lip-LM might be used as a potential hepatoprotective agent in the form of dietary supplement and provide an effective strategy to improve the potential value of citrus seeds.

Is there a fast track ("Darmstrasse") for fluids in the small intestine? Evidence from magnetic resonance imaging

BACKGROUND

The transit and distribution pattern of fluids in the small intestine is a key parameter for the dissolution and absorption of drugs. Although some information is known about the small intestinal water content after administration of fluid volumes and meals, the intestinal transit of orally ingested fluids and solutions has been barely investigated. The aim of this three-arm, cross-over, 9-subject human study was to investigate the transit of orally ingested water in the small intestine under fasting and postprandial conditions using MRI. To identify the ingested water, manganese gluconate, which can be identified with T1-weighted MRI sequences, was added as a marker. Using Horos (DICOM software), quantification of the distribution of Mn2+ ions in the gastrointestinal tract in fasted versus fed state (standard meal by FDA guidance and a light meal) was possible. The distribution and approximate wetted intestinal length was very similar in the fasting and postprandial states, suggesting rapid transport of water ingested after a meal through the chyme-filled small intestine in continuation of the "Magenstrasse" (stomach road). In some subjects, manganese gluconate reached deeper parts of the small intestine even more quickly in the postprandial state than in the fasting arm of the study. A deeper understanding of the behaviour of solutes in the gastrointestinal tract is fundamental to a mechanistic explanation for the kinetic interaction between food and drug intake (food effects).

Advances in Stimuli-Responsive Chitosan Hydrogels for Drug Delivery Systems

Sustainable and controllable drug transport is one of the most efficient ways of disease treatment. Due to high biocompatibility, good biodegradability, and low costs, chitosan and its derivatives are widely used in biomedical fields. Specifically, chitosan hydrogel enables drugs to pass through biological barriers because of their abundant amino and hydroxyl groups that can interact with human tissues. Moreover, the multi-responsive nature (pH, temperature, ions strength, and magnetic field, etc.) of chitosan hydrogels makes precise drug release a possibility. Here, the synthesis methods, modification strategies, stimuli-responsive mechanisms of chitosan-based hydrogels, and their recent progress in drug delivery are summarized. Chitosan hydrogels that carry and release drugs through subcutaneous (dealing with wound dressing), oral (dealing with gastrointestinal tract), and facial (dealing with ophthalmic, ear, and brain) are reviewed. Finally, challenges toward clinic application and the future prospects of stimuli-responsive chitosan-based hydrogels are indicated.

SerotoninAI: Serotonergic System Focused, Artificial Intelligence-Based Application for Drug Discovery

SerotoninAI is an innovative web application for scientific purposes focused on the serotonergic system. By leveraging SerotoninAI, researchers can assess the affinity (pKi value) of a molecule to all main serotonin receptors and serotonin transporters based on molecule structure introduced as SMILES. Additionally, the application provides essential insights into critical attributes of potential drugs such as blood-brain barrier penetration and human intestinal absorption. The complexity of the serotonergic system demands advanced tools for accurate predictions, which is a fundamental requirement in drug development. SerotoninAI addresses this need by providing an intuitive user interface that generates predictions of pKi values for the main serotonergic targets. The application is freely available on the Internet at https://serotoninai.streamlit.app/, implemented in Streamlit with all major web browsers supported. Currently, to the best of our knowledge, there is no tool that allows users to access affinity predictions for serotonergic targets without registration or financial obligations. SerotoninAI significantly increases the scope of drug development activities worldwide. The source code of the application is available at https://github.com/nczub/SerotoninAI_streamlit.

Selective Aza-Michael Addition to Dehydrated Amino Acids in Natural Antimicrobial Peptides

We report the efficient and site selective modification of non-canonical dehydroamino acids in ribosomally synthesized and post-transationally modified peptides (RiPPs) by β-amination. The singly modified thiopeptide Thiostrepton showed an up to 35-fold increase in water solubility, and minimum inhibitory concentration (MIC) assays showed that antimicrobial activity remained good, albeit lower than the unmodified peptide. Also the lanthipeptide nisin could be modified using this method.

Roles of breast cancer resistance protein and organic anion transporting polypeptide 2B1 in gastrointestinal toxicity induced by SN-38 under inflammatory conditions

Drug transporters are among the factors that determine the pharmacokinetic profiles after drug administration. In this study, we investigated the roles of drug transporters involved in transport of SN-38, which is an active metabolite of irinotecan, in the intestine under inflammatory conditions in vitro and determined their functional consequences. The expression alterations of breast cancer resistance protein (BCRP) and organic anion transporting polypeptide (OATP) 2B1 were determined at the mRNA and protein levels, and the subsequent functional alterations were evaluated via an accumulation study with the representative transporter substrates [prazosin and dibromofluorescein (DBF)] and SN-38. We also determined the cytotoxicity of SN-38 under inflammatory conditions. Decreased BCRP expression and increased OATP2B1 expression were observed under inflammatory conditions in vitro, which led to altered accumulation profiles of prazosin, DBF, and SN-38, and the subsequent cytotoxic profiles of SN-38. Treatment with rifampin or novobiocin supported the significant roles of BCRP and OATP2B1 in the transport and cytotoxic profile of SN-38. Collectively, these results suggest that BCRP and OATP2B1 are involved in the increased cytotoxicity of SN-38 under inflammatory conditions in vitro. Further comprehensive research is warranted to completely understand SN-38-induced gastrointestinal cytotoxicity and aid in the successful treatment of cancer with irinotecan.

In vitro release and bioaccessibility of oral solid preparations in a dynamic gastrointestinal system simulating fasted and fed states: A case study of metformin hydrochloride tablets

Food and formulation characteristics are crucial factors affecting the gastrointestinal release and absorption kinetics of oral solid preparations. In the present study, the dynamic continuous release and bioaccessibility of metformin hydrochloride immediate-release (IR) and sustained-release (SR) tablets were investigated in the dynamic human stomach-intestine (DHSI-IV) system simulating fasted and fed states in healthy adults. Both tablet formulations (particularly IR tablet) exhibited a postponed release in the fed state compared to the fasted state. Correspondingly, the bioaccessible fraction of metformin from IR tablets in the presence of high-fat meal was significantly reduced to 76.2 % of the fasted state. However, the in vitro bioaccessibility was less impaired by food for SR tablets with a fed/fasted ratio of 95.5 %. A convolution-based approach was used to convert in vitro bioaccessibility results to plasma concentration data. The predicted plasma concentration curve showed good agreement with human data in terms of pharmacokinetic (PK) parameters. In the fasted state, the predicted Cmax, Tmax and AUC0-24h of IR tablets were 943.9 ± 25.7 ng/mL, 2.0 ± 0.4 h and 7090.7 ± 112.0 ng.h/mL, respectively, mirroring values observed in healthy subjects. Overall, the DHSI-IV system has demonstrated potential to assess and predict the impact of meal intake on the in vivo release and absorption behaviors of oral solid preparations.

Clofazimine pharmacokinetics in HIV-infected adults with diarrhea: Implications of diarrheal disease on absorption of orally administered therapeutics

Oral drug absorption kinetics are usually established in populations with a properly functioning gastrointestinal tract. However, many diseases and therapeutics can alter gastrointestinal physiology and cause diarrhea. The extent of diarrhea-associated impact on drug pharmacokinetics has not been quantitatively described. To address this knowledge gap, we used a population pharmacokinetic modeling approach with data collected in a phase IIa study of matched human immunodeficiency virus (HIV)-infected adults with/without cryptosporidiosis and diarrhea to examine diarrhea-associated impact on oral clofazimine pharmacokinetics. A population pharmacokinetic model was developed with 428 plasma samples from 23 HIV-infected adults with/without Cryptosporidium infection using nonlinear mixed-effects modeling. Covariates describing cryptosporidiosis-associated diarrhea severity (e.g., number of diarrhea episodes, diarrhea grade) or HIV infection (e.g., viral load, CD4+ T cell count) were evaluated. A two-compartment model with lag time and first-order absorption and elimination best fit the data. Maximum diarrhea grade over the study duration was found to be associated with a more than sixfold reduction in clofazimine bioavailability. Apparent clofazimine clearance, intercompartmental clearance, central volume of distribution, and peripheral volume of distribution were 3.71 L/h, 18.2 L/h (interindividual variability [IIV] 45.0%), 473 L (IIV 3.46%), and 3434 L, respectively. The absorption rate constant was 0.625 h-1 (IIV 149%) and absorption lag time was 1.83 h. In conclusion, the maximum diarrhea grade observed for the duration of oral clofazimine administration was associated with a significant reduction in clofazimine bioavailability. Our results highlight the importance of studying disease impacts on oral therapeutic pharmacokinetics to inform dose optimization and maximize the chance of treatment success.

A comprehensive review on potential drug-drug interactions of proton pump inhibitors with antidiabetic drugs metformin and DPP-4 inhibitors

A drug interaction is a condition in which two or more drugs are taken at the same time. Type 2 diabetes mellitus is a significant contributor to polypharmacy. Proton pump inhibitors (PPIs) are often prescribed in combination with metformin or DPP-4 inhibitors (sitagliptin, saxagliptin, linagliptin, and alogliptin) or a combined dose of metformin and DPP-4 inhibitor to treat gastritis in diabetic patients. This review article mainly focused on evaluating the potential drug-drug interactions (DDIs) between PPIs (i.e. esomeprazole, lansoprazole, omeprazole, pantoprazole, and rabeprazole) with metformin and PPIs with DPP-4 inhibitors. The findings demonstrated the existence of pharmacokinetic and pharmacodynamic DDIs between the aforementioned PPIs with metformin and DPP-4 inhibitors, which could impact the biological activities (i.e., hypoglycemia) of these drugs. Moreover, this review suggested that esomeprazole could be the best drug in the PPI group to be prescribed simultaneously with metformin and DPP-4 inhibitors, as most of the antidiabetic drugs of this study did not show any interaction with esomeprazole. The findings of this study also revealed that both antidiabetic drugs and PPIs could have positive interactions as PPIs have the potential to lessen the gastrointestinal side effects of metformin and DPP-4 inhibitors. To achieve the greatest therapeutic impact with the fewest side effects, careful dose control of these drugs is required. So, more extensive research on both human and animal subjects are needed to ascertain the veracity of this hypothesis.

Pectin-coated whey protein isolate/zein self-aggregated nanoparticles as curcumin delivery vehicles: Effects of heating, pH, and adding sequence

In this work, pectin was employed as a coating material to fabricate zein/whey protein isolate (WPI)/pectin complex nanoparticles via a pH-adjusted and heat-induced electrostatic adsorption process for potential oral administration applications of curcumin. Factors such as the order of raw material addition, heating temperature and pH, and zein concentration were comprehensively examined. In addition to electrostatic interactions, Fourier transform infrared and fluorescence spectroscopy indicated that hydrophobic interactions and hydrogen bonds were also involved in the development of complex nanoparticles. The complex nanoparticles obtained not only improved the antioxidant activity of curcumin in aqueous phase, but also contributed to its controlled release under gastrointestinal conditions. Our findings revealed that the heating pH and adding sequence of raw materials had a notable impact on the properties of complex nanoparticles, and that pectin coating had an exceptional stabilizing effect on complex nanoparticles under gastrointestinal circumstances. This study provides novel insights and perspectives for the preparation of polysaccharide-protein complex nanoparticles, signifying the potential use of zein/WPI/pectin complex nanoparticles as delivery vehicles in the functional food and pharmaceutical industries.

Orally Administered Drugs and Their Complicated Relationship with Our Gastrointestinal Tract

Orally administered compounds represent the great majority of all pharmaceutical compounds produced for human use and are the most popular among patients since they are practical and easy to self-administer. Following ingestion, orally administered drugs begin a "perilous" journey down the gastrointestinal tract and their bioavailability is modulated by numerous factors. The gastrointestinal (GI) tract anatomy can modulate drug bioavailability and accounts for interpatient drug response heterogeneity. Furthermore, host genetics is a contributor to drug bioavailability modulation. Importantly, a component of the GI tract that has been gaining notoriety with regard to drug treatment interactions is the gut microbiota, which shares a two-way interaction with pharmaceutical compounds in that they can be influenced by and are able to influence administered drugs. Overall, orally administered drugs are a patient-friendly treatment option. However, during their journey down the GI tract, there are numerous host factors that can modulate drug bioavailability in a patient-specific manner.

Potentials of ionic liquids to overcome physical and biological barriers

Over the last decades, ionic liquids (IL) have shown great potential in non-invasive delivery starting from synthetic small molecules to biological large molecules. ILs are emerging as a particular class of drug delivery systems due to their unique physiochemical properties, simple surface modification, and functionalization. These features of IL help achieve specific design principles that are essential for a non-invasive drug delivery system. In this review, we have discussed IL and their applications in non-invasive drug delivery systems. We evaluated state-of-the-art development and advances of IL aiming to mitigate the biological and physical barriers to improve transdermal and oral delivery, summarized in this review. We also provided an overview of the various factors determining the systemic transportation of IL-based formulation. Additionally, we have emphasized how the ILs facilitate the transportation of therapeutic molecules by overcoming biological barriers.