Improvement of the surface hydrophilic properties of naproxen particles with addition of hydroxypropylmethyl cellulose and sodium dodecyl sulphate: In vitro and in vivo studies

Drug Binding to Partially Unfolded Serum Albumin: Insights into Nonsteroidal Anti-Inflammatory Drug Naproxen-BSA Interactions from Spectroscopic and MD Simulation Studies

Understanding the binding details of a small-molecule drug to a protein in its partially unfolded state is important for drug delivery as it provides insight into the overall drug-binding ability of the protein, even when the majority of binding pockets in its unfolded state are impaired. The interaction of partially unfolded proteins with drugs remains poorly understood due to a lack of structural information on proteins in their partially unfolded states. Here, we studied the interaction between serum albumin (bovine serum albumin (BSA) as a model system), an abundant protein in blood serum that is an effective carrier for numerous known drugs, and a nonsteroidal anti-inflammatory drug (NSAID) naproxen (NPS) using various spectroscopic and computational methods. Molecular dynamics simulations starting from the drug-unbound state and performed at physiological and higher temperatures revealed novel hydrophobic sites on the BSA surface. We analyzed the BSA-NPS interaction in the presence and absence of the cationic organized assembly CTAB and two oligosaccharides (β-CD and 2-HP-β-CD) at different excitation wavelengths. The solvation dynamics of BSA under NPS-bound conditions became ∼4.6% faster. Oligosaccharides were found to increase the solubility of NPS by providing a hydrophobic environment for the formation of inclusion complexes through host-guest interactions. These findings provide a comprehensive overview and uncover the binding model and mechanism of interaction of NPS with BSA, revealing hydrophobic and electrostatic interactions and hydrogen bonds required for BSA to bind NPS at these noncanonical sites. The molecular-level understanding of the binding mechanism of commonly used NSAIDs like NPS with partially unfolded BSA will be useful in designing pharmaceutically important molecules with efficient loading and delivery properties.

Drug Nanocrystals in Oral Absorption: Factors That Influence Pharmacokinetics

Despite the safety and convenience of oral administration, poorly water-soluble drugs compromise absorption and bioavailability. These drugs can exhibit low dissolution rates, variability between fed and fasted states, difficulty permeating the mucus layer, and P-glycoprotein efflux. Drug nanocrystals offer a promising strategy to address these challenges. This review focuses on the opportunities to develop orally administered nanocrystals based on pharmacokinetic outcomes. The impacts of the drug particle size, morphology, dissolution rate, crystalline state on oral bioavailability are discussed. The potential of the improved dissolution rate to eliminate food effects during absorption is also addressed. This review also explores whether permeation or dissolution drives nanocrystal absorption. Additionally, it addresses the functional roles of stabilizers. Drug nanocrystals may result in prolonged concentrations in the bloodstream in some cases. Therefore, nanocrystals represent a promising strategy to overcome the challenges of poorly water-soluble drugs, thus encouraging further investigation into unclear mechanisms during oral administration.

Hydroxypropyl Cellulose-Based Orally Dissolving Film Loaded with Insoluble Dexamethasone for Treatment of Oral Ulcers

Oral ulcers present as recurrent and spontaneous lesions, often causing intolerable burning pain that significantly disrupts patients' daily lives and compromises their quality of life. In addressing this clinical challenge, oral dissolving films (ODFs) have emerged as promising pharmaceutical formulations for oral ulcer management due to their rapid onset of action, ease of administration, and portability. In this study, ODFs containing the insoluble drug dexamethasone (Dex) were formulated for the treatment of oral ulcers in rabbits using a solvent casting method with ethanol as the solvent. To optimize the composition of the ODFs, a Box-Behnken Design (BBD) experiment was employed to investigate the effects of varying concentrations of hydroxypropyl cellulose (HPC), low-substituted hydroxypropyl cellulose (L-HPC), and plasticizer (glycerol) on key parameters, such as disintegration time, tensile strength, and peel-off efficiency of the films. Subsequently, the film properties of the Dex-loaded ODFs (ODF@Dex) were thoroughly assessed, revealing favorable attributes, including homogeneity, mechanical strength, and solubility. Notably, the use of ethanol as the solvent in the ODF preparation facilitated the homogeneous distribution of insoluble drugs within the film matrix, thereby enhancing their solubility and dissolution rate. Leveraging the potent pharmacological activity of Dex, ODF@Dex was further evaluated for its efficacy in promoting ulcer healing and mitigating the expression of inflammatory factors both in vitro and in vivo. The findings demonstrated that the ODF@Dex exerted significant antiulcer effects by modulating the PI3K/Akt signaling pathway, thus contributing to ulcer resolution. In conclusion, our study underscores the potential of HPC-based ODFs formulated with ethanol as a solvent as a promising platform for delivering insoluble drugs, offering a viable strategy for the clinical management of oral ulcers.

Enabling modular dosage form concepts for individualized multidrug therapy: Expanding the design window for poorly water-soluble drugs

Multidrug dosage forms (aka combination dosage forms, polypills, etc.) create value for patients through reduced pill burdens and simplified administration to improve adherence to therapy. Enhanced flexibility of multidrug dosage forms would provide further opportunities to better match emerging needs for individualized therapy. Through modular dosage form concepts, one approach to satisfy these needs is to adapt multidrug dosage forms to a wider variety of drugs, each with a variety of doses and release profiles. This study investigates and technically explores design requirements for extending the capability of modular multidrug dosage form concepts towards individualization. This builds on our recent demonstration of independent tailoring of dose and drug release, which is here extended towards poorly water-soluble drugs. The challenging design requirement of carrying higher drug loads in smaller volumes to accommodate multiple drugs at their clinical dose is here met regarding dose and release performance. With a modular concept, we demonstrate high precision (<5% RSD) in dose and release performance of individual modules containing felodipine or naproxen in Kollidon VA64 at both a wide drug loading range (5% w/w and 50% w/w drug) and a small module size (3.6 mg). In a forward-looking design-based discussion, further requirements are addressed, emphasizing that reproducible individual module performance is predictive of dosage form performance, provided the modules are designed to act independently. Therefore, efforts to incorporate progressively higher drug loads within progressively smaller module volumes will be crucial to extend the design window further towards full flexibility of future dosage forms for individualized multidrug therapy.

Multiparticulate Systems of Ezetimibe Micellar System and Atorvastatin Solid Dispersion Efficacy of Low-Dose Ezetimibe/Atorvastatin on High-Fat Diet-Induced Hyperlipidemia and Hepatic Steatosis in Diabetic Rats

The aim of this study was to develop multiparticulate systems with a combination of ezetimibe micellar systems and atorvastatin solid dispersions using croscarmellose as a hydrophilic vehicle and Kolliphor RH40 as a surfactant. The presence of a surfactant with low hydrophilic polymer ratios produces the rapid dissolution of ezetimibe through a drug-polymer interaction that reduces its crystallinity. The solid dispersion of atorvastatin with low proportions of croscarmellose showed drug-polymer interactions sufficient to produce the fast dissolution of atorvastatin. Efficacy studies were performed in diabetic Goto-Kakizaki rats with induced hyperlipidemia. The administration of multiparticulate systems of ezetimibe and atorvastatin at low (2 and 6.7 mg/kg) and high (3 and 10 mg/kg) doses showed similar improvements in levels of cholesterol, triglycerides, lipoproteins, alanine transaminase, and aspartate transaminase compared to the high-fat diet group. Multiparticulate systems at low doses (2 and 6.7 mg/kg of ezetimibe and atorvastatin) had a similar improvement in hepatic steatosis compared to the administration of ezetimibe and atorvastatin raw materials at high doses (3 and 10 mg/kg). These results confirm the effectiveness of solid dispersions with low doses of ezetimibe and atorvastatin to reduce high lipid levels and hepatic steatosis in diabetic rats fed a high-fat diet.

Improvement in the Oral Bioavailability and Efficacy of New Ezetimibe Formulations-Comparative Study of a Solid Dispersion and Different Micellar Systems

Ezetimibe (EZ) is a poorly water-soluble drug with low bioavailability. Strategies such as solid dispersions (SD) and micellar systems (MS) were developed to identify the most effective drug delivery formulations with the highest oral bioavailability, and to improve their lipid-lowering effect. The EZ formulations were prepared with different proportions of Kolliphor^® RH40 as a surfactant (1:0.25, 1:0.5 and 1:0.75) and croscarmellose as a hydrophilic carrier. These excipients, and the addition of microcrystalline cellulose during the production process, led to significant improvements in the dissolution profiles of MS. Powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) revealed an amorphous form of ezetimibe with different semicrystalline states of microcrystalline cellulose for MS-I (1:0.75) and MS-II (1:0.75). Pharmacokinetic analysis after administration of MS-II (1:0.75) demonstrated a 173.86% increase in maximum plasma concentration (C_max) and a 142.99% increase in oral bioavailability compared to EZ raw material (EZ-RM). Efficacy studies with the micellar system MS-II (1:0.75) in rats with hyperlipidemia showed that total cholesterol, triglycerides and high-density lipoprotein were reduced to normal levels and revealed improvements in low-density lipoprotein, aspartate and alanine aminotransferase. The improvement in the dissolution rate with micellar systems increases bioavailability and enhances the anti-hyperlipidemic effect of EZ.

Improvement of the pharmacokinetic/pharmacodynamic relationship in the treatment of invasive aspergillosis with voriconazole. Reduced drug toxicity through novel rapid release formulations

Voriconazole (VCZ) is currently the first-line treatment for invasive aspergillosis, although the doses are limited by its poor solubility and high hepatic toxicity. The aim of this study was to develop a solid self-dispersing micellar system of VCZ to improve the pharmacokinetic/pharmacodynamic (PK/PD) relationship and reduce hepatotoxicity. In this work, solid micellar systems of VCZ are formulated with different polysorbate 80 ratios using mannitol as a hydrophilic carrier. The novel micellar systems were characterized by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC) and dissolution studies. Self-dispersing micellar systems reduced VCZ crystallinity, leading to an improvement in its dissolution rate. The in vitro susceptibility test also revealed that the most common microorganisms in invasive aspergillosis exhibited low minimum inhibitory concentration (MIC) values for micellar systems. Pharmacokinetic studies indicated an improvement in bioavailability for MS-1:3:0.05, and changes in its biodistribution to different organs. MS-1:3:0.05 showed an increased concentration in lungs and a significant decrease in VCZ accumulated in the liver.

Reduction of intraocular pressure using timolol orally dissolving strips in the treatment of induced primary open-angle glaucoma in rabbits

OBJECTIVE

To enhance bioavailability of timolol (TML) and utilize alternatives for traditional eye drops for more patient compliance, this study was aiming to develop biodegradable orally dissolving strips (ODSs) of TML for treatment of primary open-angle glaucoma (POAG).

METHODS

Novel ODSs of TML were formulated and optimized using solvent casting method according to full factorial design (3¹ .2² ). TML ODSs were characterized with respect to many parameters. In-vivo test was carried out using four groups of 24 New Zealand albino rabbits. POAG was induced by subconjunctival treatment of betamethasone. Histopathological examination and oxidative stress markers assay were carried out.

KEY FINDINGS

The optimized formula (F9) exhibited a remarkably 15-s disintegration time and 96% dissolution rate after 10 min. The results revealed a potent significant inhibitory effect of the optimized TML ODS to reduce IOP in induced rabbits in comparison with control rabbits and TML eye drops-treated rabbits. The formula showed also high activity against oxidative stress and absence of histopathological changes in iridocorneal angle and cornea.

CONCLUSION

The ODSs could be a promising alternative delivery system for eye drops with more compliance to enhance delivery and therapeutic activity of TML in treatment of POAG.

Self-Micellizing Technology Improves the Properties of Ezetimibe and Increases Its Effect on Hyperlipidemic Rats

The aim of this work was to develop ezetimibe self-micellizing solid dispersions using Kolliphor^® RH40 (MS-K) as a surfactant incorporating ezetimibe (EZ) into the croscarmellose hydrophilic carrier. Different ezetimibe:Kolliphor^® ratios were studied to select micellar systems that improve the dissolution properties of ezetimibe. The different formulations were characterized by means of solid state analysis by SEM, powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), and dissolution studies. These physicochemical studies showed a decrease from the crystalline structure of ezetimibe (EZ) to its amorphous state in the micellar systems (MS-K). A rapid dissolution profile was observed in these micellar systems compared to the drug raw material and physical mixture. Efficacy studies were conducted using a high-fat diet that induced hyperlipidemic rats. The micellar system selected (MS-K 1:0.75) revealed a significant improvement in serum levels of total cholesterol (TC), low-density lipoproteins (LDL), and triglycerides (TG) compared to ezetimibe raw material. The histopathological examination of liver tissue also showed that this micellar system exhibited more beneficial effects on liver steatosis compared to ezetimibe raw material (EZ-RM) and the high-fat diet group (HFD). This study suggests that EZ micellar systems using Kolliphor^® RH40 could enhance the antihyperlipidemic effect of ezetimibe and reduce liver steatosis.