Enhancing Osteoblast Differentiation from Adipose-Derived Stem Cells Using Hydrogels and Photobiomodulation: Overcoming In Vitro Limitations for Osteoporosis Treatment.

Osteoporosis represents a widespread and debilitating chronic bone condition that is increasingly prevalent globally. Its hallmark features include reduced bone density and heightened fragility, which significantly elevate the risk of fractures due to the decreased presence of mature osteoblasts. The limitations of current pharmaceutical therapies, often accompanied by severe side effects, have spurred researchers to seek alternative strategies. Adipose-derived stem cells (ADSCs) hold considerable promise for tissue repair, albeit they encounter obstacles such as replicative senescence in laboratory conditions. In comparison, employing ADSCs within three-dimensional (3D) environments provides an innovative solution, replicating the natural extracellular matrix environment while offering a controlled and cost-effective in vitro platform. Moreover, the utilization of photobiomodulation (PBM) has emerged as a method to enhance ADSC differentiation and proliferation potential by instigating cellular stimulation and facilitating beneficial performance modifications. This literature review critically examines the shortcomings of current osteoporosis treatments and investigates the potential synergies between 3D cell culture and PBM in augmenting ADSC differentiation towards osteogenic lineages. The primary objective of this study is to assess the efficacy of combined 3D environments and PBM in enhancing ADSC performance for osteoporosis management. This research is notably distinguished by its thorough scrutiny of the existing literature, synthesis of recent advancements, identification of future research trajectories, and utilization of databases such as PubMed, Scopus, Web of Science, and Google Scholar for this literature review. Furthermore, the exploration of biomechanical and biophysical stimuli holds promise for refining treatment strategies. The future outlook suggests that integrating PBM with ADSCs housed within 3D environments holds considerable potential for advancing bone regeneration efforts. Importantly, this review aspires to catalyse further advancements in combined therapeutic strategies for osteoporosis regeneration.

Utilization of a Human Liver Tissue Chip for Drug-Metabolizing Enzyme Induction Studies of Perpetrator and Victim Drugs.

Polypharmacy-related drug-drug interactions (DDIs) are a significant and growing healthcare concern. An increasing number of therapeutic drugs on the market underscores the necessity to accurately assess new drug combinations during pre-clinical evaluation for DDIs. In vitro primary human hepatocytes (PHH) models are only applicable for short term induction studies due to their rapid loss of metabolic function. Though co-culturing non-human stromal cells with PHH has been shown to stabilize metabolic activity long-term, there are concerns about human specificity for accurate clinical assessment. In this study, we demonstrate a PHH-only liver microphysiological system (MPS) in the Liver Tissue Chip (LTC) is capable of maintaining long-term functional and metabolic activity of PHH from three individual donors, and thus a suitable platform for long-term DDI induction studies. The responses to rifampicin induction of three PHH donors were assessed using CYP activity and mRNA changes. Additionally, victim PK studies were conducted with midazolam (high clearance) and alprazolam (low clearance) following perpetrator drug treatment, rifampicin-mediated induction, which resulted in a 2-fold and a 2.6-fold increase in midazolam and alprazolam intrinsic clearance values respectively compared to the untreated liver MPS. We also investigated the induction effects of different dosing regimens of the perpetrator drug (rifampicin) on CYP activity levels, showing minimal variation in the intrinsic clearance of the victim drug (midazolam). This study illustrates the utility of the LTC for in vitro liver-specific DDI induction studies, providing a translational experimental system to predict clinical clearance values of both perpetrator and victim drugs. Significance Statement This study demonstrates the utility of the Liver Tissue Chip (LTC) with primary human hepatocyte (PHH)-only liver microphysiological system (MPS) for drug-drug interaction (DDI) induction studies. This unique in vitro system with continuous recirculation maintains long-term functionality and metabolic activity for up to 4 weeks, enabling the study of perpetrator and victim drug pharmacokinetics, quantification of drug-induced CYP mRNA and activity levels, investigation of patient variability, and ultimately clinical predictions.

Candesartan Has No Clinically Meaningful Effect on the Plasma Concentrations of CYP2C8 Substrate Repaglinide in Humans.

In vitro evidence show that the acyl-ß-D-glucuronide metabolite of candesartan inhibits cytochrome P450 (CYP) 2C8 with an inhibition constant of 7.12 µM. We investigated the effect of candesartan on the plasma concentrations and glucose-lowering effect of repaglinide, a sensitive clinical CYP2C8 index substrate. In a randomized crossover study, ten healthy volunteers ingested 8 mg of candesartan or placebo daily for three days, and on day 3, they also ingested 0.25 mg of repaglinide one hour after candesartan or placebo. We measured the plasma concentrations of repaglinide, candesartan, and candesartan acyl-ß-D-glucuronide, and blood glucose concentrations for up to nine hours after repaglinide intake. Candesartan had no effect on the area under the plasma concentration-time curve and peak plasma concentration of repaglinide compared to placebo, with ratios of geometric means of 1.02 [P = 0.809; 90% confidence interval (CI) 0.90-1.15] and 1.13 (P = 0.346; 90% CI 0.90-1.43), respectively. Other pharmacokinetic variables and blood glucose concentrations were neither affected. Candesartan acyl-ß-D-glucuronide was detectable in seven subjects, in whom the peak concentration of repaglinide was 1.32-fold higher in the candesartan phase than in the placebo phase (P = 0.041; 90% CI 1.07-1.62). Systemic concentrations of candesartan acyl-ß-D-glucuronide were very low compared to its CYP2C8 inhibition constant (ratio << 0.1). Furthermore, in a cohort of 93 cancer patients, no indication of decreased paclitaxel clearance was found in four patients using candesartan concomitantly. In conclusion, candesartan therapy is unlikely to inhibit CYP2C8-mediated metabolism of other drugs to any clinically significant extent. Significance Statement The findings of this study suggest that candesartan is unlikely to cause drug-drug interactions via inhibition of CYP2C8. Even though candesartan acyl-ß-D-glucuronide has been shown to inhibit CYP2C8 in vitro, it shows no clinically relevant CYP2C8 inhibition in humans due to low systemic concentrations.

More Than a Gut Feeling─A Combination of Physiologically Driven Dissolution and Pharmacokinetic Modeling as a Tool for Understanding Human Gastric Motility.

In vivo studies of formulation performance with in vitro and/or in silico simulations are often limited by significant gaps in our knowledge of the interaction between administered dosage forms and the human gastrointestinal tract. This work presents a novel approach for the investigation of gastric motility influence on dosage form performance, by combining biopredictive dissolution tests in an innovative PhysioCell apparatus with mechanistic physiology-based pharmacokinetic modeling. The methodology was based on the pharmacokinetic data from a large (n = 118) cohort of healthy volunteers who ingested a capsule containing a highly soluble and rapidly absorbed drug under fasted conditions. The developed dissolution tests included biorelevant media, varied fluid flows, and mechanical stress events of physiological timing and intensity. The dissolution results were used as inputs for pharmacokinetic modeling that led to the deduction of five patterns of gastric motility and their prevalence in the studied population. As these patterns significantly influenced the observed pharmacokinetic profiles, the proposed methodology is potentially useful to other in vitro-in vivo predictions involving immediate-release oral dosage forms.

Impact of Formulation and Microneedle Length on Transdermal Metronidazole Permeation through Microneedle-Treated Skin.

OBJECTIVE: This study aimed to determine the impact of formulation (gel vs cream) and microneedle characteristics (length, number) on permeation of metronidazole through excised microneedle-treated skin. The long-term goal is to apply these results towards a pharmacokinetic study in human subjects with diverse skin types, using in vitro flux data to determine dosing conditions and ultimately establish in vitro-in vivo correlations. METHODS: Metronidazole release from 0.75% gel and cream was quantified with flow-through diffusion cells, using a cellulose membrane. Excised porcine skin was treated with stainless steel microneedles (500 or 800 µm length), to create 50 or 100 micropores. Metronidazole gel or cream was applied to microneedle-treated skin and replaced every 48 h for up to 7 days. Metronidazole permeation was quantified using HPLC. Intact skin (no microneedle treatment) served as controls. RESULTS: Metronidazole release was faster from the gel vs cream. At 7 days there was no difference between gel vs cream in total metronidazole permeated through intact skin. For both formulations, metronidazole permeation was significantly higher (vs intact skin) following microneedle application, regardless of microneedle length or micropore number. Increasing microneedle length and micropore number enhanced MTZ permeation multiple fold for both gel and cream. The greatest enhancement in total permeation for both formulations was achieved with the 800 µm MN, 100 micropore condition. CONCLUSIONS: Formulation and microneedle conditions both impacted metronidazole permeation. These data will be used to estimate in vivo serum concentrations after applying metronidazole to microneedle-treated skin in humans.

Fish Physiologically Based Toxicokinetic Modeling Approach for In Vitro-In Vivo and Cross-Species Extrapolation of Endocrine-Disrupting Chemicals in Risk Assessment.

High-throughput in vitro assays combined with in vitro-in vivo extrapolation (IVIVE) leverage in vitro responses to predict the corresponding in vivo exposures and thresholds of concern. The integrated approach is also expected to offer the potential for efficient tools to provide estimates of chemical toxicity to various wildlife species instead of animal testing. However, developing fish physiologically based toxicokinetic (PBTK) models for IVIVE in ecological applications is challenging, especially for plausible estimation of an internal effective dose, such as fish equivalent concentration (FEC). Here, a fish PBTK model linked with the IVIVE approach was established, with parameter optimization of chemical unbound fraction, pH-dependent ionization and hepatic clearance, and integration of temperature effect and growth dilution. The fish PBTK-IVIVE approach provides not only a more precise estimation of tissue-specific concentrations but also a reasonable approximation of FEC targeting the estrogenic potency of endocrine-disrupting chemicals. Both predictions were compared with in vivo data and were accurate for most indissociable/dissociable chemicals. Furthermore, the model can help determine cross-species variability and sensitivity among the five fish species. Using the available IVIVE-derived FEC with target pathways is helpful to develop predicted no-effect concentration for chemicals with similar mode of action and support screening-level ecological risk assessment.

Assessment of in Vivo Performance of Lipid-Based Formulations: Correlation between in Vitro Drug Release Profiles and in Vivo Absorption Rate Profiles.

The purpose of this study was to assess the in vivo absorption enhancement effects of lipid-based formulations (LBFs) through in vitro release studies. The type IIIA-MC (medium-chain) and type IIIA-LC (long-chain) formulations containing a Biopharmaceutics Classification System (BCS) Class II drug (dipyridamole or ketoconazole) were used as model LBFs. The type IIIA-MC formulation, but not the type IIIA-LC formulation, showed a higher initial absorption rate than the control suspension for both model drugs in rats. An in vitro side-by-side chamber system coupled with a lipid digestion model was used to measure free drugs, available for intestinal absorption, that are released from a model LBF. The profiles of free drug concentration on the donor side were determined by calculating the ratio of permeation rate (LBF/suspension) at every sampling interval. The in vitro free drug concentration was immediately supersaturated when the digestion of type IIIA-MC formulation was initiated for both drugs, which would cause the initially high absorption rate in rats. In contrast, the free concentration of the type IIIA-LC formulation became lower than the equilibrium solubility over time for both drugs. Overall, the profiles of in vitro free concentrations were consistent with those of in vivo absorption rates for both drugs and all LBFs. These findings would help predict the in vivo performance and establish an in vitro-in vivo correlation (IVIVC) of LBFs.

Exploring the frontiers of therapeutic breadth of antifungal peptides: A new avenue in antifungal drugs.

The growing prevalence of fungal infections alongside rising resistance to antifungal drugs poses a significant challenge to public health safety. At the close of the 2000s, major pharmaceutical firms began to scale back on antimicrobial research due to repeated setbacks and diminished economic gains, leaving only smaller companies and research labs to pursue new antifungal solutions. Among various natural sources explored for novel antifungal compounds, antifungal peptides (AFPs) emerge as particularly promising. Despite their potential, AFPs receive less focus than their antibacterial counterparts. These peptides have been sourced extensively from nature, including plants, animals, insects, and especially bacteria and fungi. Furthermore, with advancements in recombinant biotechnology and computational biology, AFPs can also be synthesized in lab settings, facilitating peptide production. AFPs are noted for their wide-ranging efficacy, in vitro and in vivo safety, and ability to combat biofilms. They are distinguished by their high specificity, minimal toxicity to cells, and reduced likelihood of resistance development. This review aims to comprehensively cover AFPs, including their sources-both natural and synthetic-their antifungal and biofilm-fighting capabilities in laboratory and real-world settings, their action mechanisms, and the current status of AFP research. ONE-SENTENCE SUMMARY: This comprehensive review of AFPs will be helpful for further research in antifungal research.

Histological evaluation of different concentrations of hyaluronic-acid-added zinc oxide eugenol on rat molar pulp.

Hyaluronic acid (HA), known for diverse properties, was investigated for its potential in dental pulp therapy. This study investigated the potential of HA in dental pulp therapy by examining the physical properties and effects of zinc oxide eugenol (ZOE) pulpotomy materials containing varying HA concentrations on rat molar teeth. In vitro tests assessed compressive strength and hardness of ZOE materials blended with HA (0.5%, 1%, 3%) and HA gels (0.54%, 0.8%). 120 samples, encompassing the control group, underwent compressive strength testing, while 60 samples were designated for hardness assessment. In vivo experiments on rat molars studied histological effects of HA-containing ZOE on dental pulp over 1 week and 1 month. Gels with HA concentrations of 0.5%, 1%, and 0.54% were used in pulpotomy on 22 rats. Each rat underwent the procedure on four teeth, with one tooth serving as a control, totaling 88 teeth subjected to the intervention. In the analyses, SPSS 22.0 was used and the significance level was set at P = 0.05. Findings showed that HA at 0.5% maintained compressive strength, but higher concentrations decreased mechanical properties significantly (P = 0.001). Histological assessments indicated better outcomes with lower HA concentrations in terms of odontoblast layer continuity (P = 0.005 at 1 month) and pulp vitality (P = 0.001 at 1 week and P = 0.018 at 1 month). The study suggests HA holds promise for pulpotomy and regenerative endodontic treatments, but further research is needed to understand long-term clinical implications.

Quercetin nanocrystals for bioavailability enhancement: impact of different functional stabilizers on in vitro/in vivo drug performances.

The purpose of this study was to investigate the impact of different functional stabilizers on in vitro/in vivo drug performances after oral administration of drug nanocrystals. Quercetin nanocrystals (QT-NCs) respectively stabilized by five types of functional stabilizers, including hydroxypropyl methyl cellulose E15 (HPMC E15), poloxamer 407 (P407), poloxamer 188 (P188), D-α-tocopherol polyethylene glycol succinate (TPGS), and glycyrrhizin acid (GL), were fabricated by wet media milling technique. The particle size, morphology, physical state, drug solubility, drug dissolution in vitro, and orally pharmacokinetic behaviors of all QT-NCs were investigated. All QT-NCs with similar particle size about 200 nm were obtained by controlling milling speed and milling time. No significant differences in particles shape and crystalline nature were found for QT-NCs stabilized by different functional stabilizers. But the solubility and dissolution of QT-NCs were significantly influenced by the different functional stabilizers. The AUC0∼t of all QT-NCs after oral administration was in the following order: QT-NCs/P188 ≈ QT-NCs/HPMC E15 > QT-NCs/GL > QT-NCs/P407 ≈ QT-NCs/TPGS, and the Cmax showed an order of QT-NCs/P407 > QT-NCs/P188 ≈ QT-NCs/GL > QT-NCs/HPMC E15 > QT-NCs/TPGS. Both of QT-NCs/P407 and QT-NCs/TPGS exhibited faster oral absorption with Tmax at 0.5 h and 0.83 h, respectively, while the other three QT-NCs (QT-NCs/P188, QT-NCs/GL and QT-NCs/HPMC E15) showed a relatively slow absorption with same Tmax at 5.33 h. The longest MRT0∼t (11.72 h) and t1/2z (32.22 h) were observed for QT-NCs/HPMC E15. These results suggested that the different functional stabilizers could significantly influence on drug solubility, drug dissolution in vitro and orally pharmacokinetic behavior of QT-NCs, and it is possible to alter the drug dissolution in vitro, oral absorption and drug retention in vivo by changing the type of functional stabilizers in NCs preparation.

Lipid-Gelucire based rectal delivery of ramipril prodrug exhibits significant lowering of intra-ocular pressure in normotensive rabbit: sustained structural relaxation release kinetics and IVIVC.

Carboxylesterase enzymes convert a prodrug ramipril into the biologically active metabolite ramiprilat. It is prescribed for controlling ocular hypertension after oral administration. High concentrations of carboxylesterase enzymes in rectal and colon tissue can transform ramipril significantly to ramiprilat. Sustained rectal delivery of ramipril has been developed for intra-ocular pressure lowering effect using a normotensive rabbit model. Rectal suppositories have been formulated using a matrix base of HPMC K100-PEG 400-PEG 6000, incorporating varying amounts of Gelucire by the fusion moulding method. The presence of Gelucire in the suppository exhibited sustained structural relaxation-based release kinetics of RM compared to its absence. Intravenous and oral administration of ramipril has decreased IOP in the treated rabbit up to 90 and 360 min, respectively. Treated rabbits with suppositories have revealed decreased IOP for an extended period compared to the above. Formulation containing GEL 3% reduced intra-ocular pressure to 540 min, with the highest area under the decreased IOP curve. Compared to oral, the pharmacodynamic bioavailability of ramipril has been improved significantly using a sustained-release rectal suppository. A rectal suppository for sustained delivery of ramipril could be used to lower IOP significantly.

Discriminative Power of the Flow through Cell Dissolution Tester in Predicting the In Vivo Performance of Pentoxifylline SR Product under Fed and Fasting Conditions.

This study explored, for the first time the role of different designs of the Flow-Through-Cell (FTC, USP IV) dissolution Tester in predicting the in-vivo performance of Pentoxifylline (PTX) sustained-release (SR) market product, under fed & fasting conditions. Release studies of Trental® SR 400 mg (Sanofi, Egypt), were carried-out in the FTC under different conditions, including: different volumes / compositions of release media, variable FTC flow patterns as well as applying open / closed loop configuration setups. Pharmacokinetic (PK) data, obtained from literature, were converted to in-vivo fraction-absorbed [FA] using Wagner-Nelson (WN) method. A 1:1 IVIVC was investigated by comparing PTX fraction-dissolved [FD] under different FTC release designs versus calculated [FA]. Predicted PK parameters were evaluated, and compared with actual data, with estimation of prediction-error (PE%). The suggested FTC design; a closed-loop setup, with turbulent-flow pattern of the dissolution medium; provided the most acceptable PTX release according to USP labeled limits (USP 27). Also, results showed that PTX release was pronouncedly increased in a finite-volume of gradient-buffer system rather than water, which guarantee complete resemblance to GIT environment. This release design presented the most predictive IVIVC model with PTX in-vivo performance under fasting / fed states, with acceptable PE% values in terms of Cmax and AUCs. A suggested FTC design is proposed as an alternative dissolution model in the official USP-monograph for PTX SR products.

Development and in vitro-in vivo evaluation of ocular insert containing ketorolac tromethamine and moxifloxacin hydrochloride.

PURPOSE: Conjunctivitis is a common eye disorder that causes swelling and inflammation of the conjunctiva. Topical dosage form containing antibiotics and non-steroidal anti-inflammatory drugs are prescribed for the treatment and in order to overcome problems of conventional dosage forms the present study aims to develop an ocular insert containing moxifloxacin HCl and ketorolac tromethamine. METHODS: Insert was prepared by a solvent casting method by taking different polymers PVA, PVP K-30, and a combination of both as film-forming polymer, and glycerol as a plasticizer and characterized by various parameters like thickness, folding endurance, pH, swelling index, drug content, mechanical properties, in vitro and in vivo release study. RESULTS: The formulation prepared by a combination of both polymers demonstrated significantly improved properties including % elongation, tensile strength, swelling index, drug content and drug release compared to the formulation made with single polymer. The in vitro release data indicated that the batch R8 exhibited sustain release of drug (85% release in 10 hr) and following the Higuchi model for release kinetics. In vivo, study in rabbit eyes revealed the sustained release of the drug up to 16 hr with a good correlation between in vitro and in vivo release data. CONCLUSION: From the study, it can be concluded that the developed ocular insert can be a promising formulation for rational therapy of conjunctivitis.

Evaluating drug-drug interaction risk associated with peptide analogues using advanced in vitro systems.

Drug-drug interaction (DDI) assessment of therapeutic peptides is an evolving area. The industry generally follows DDI guidelines for small molecules, but the translation of data generated with commonly used in vitro systems to in vivo is sparse. In the current study, we investigated the ability of advanced human hepatocyte in vitro systems namely HepatoPac, spheroids, and Liver-on-a-chip to assess potential changes in regulation of CYP1A2, CYP2B6, CYP3A4, SLCO1B1 and ABCC2 in the presence of selected therapeutic peptides, proteins, and small molecules. The peptide NN1177, a glucagon and GLP-1 receptor co-agonist, did not suppress mRNA expression or activity of CYP1A2, CYP2B6, and CYP3A4 in HepatoPac, spheroids, or Liver-on-a-chip; these findings were in contrast to the data obtained in sandwich cultured hepatocytes. No effect of NN1177 on SLCO1B1 and ABCC2 mRNA was observed in any of the complex systems. The induction magnitude differed across the systems (e.g., rifampicin induction of CYP3A4 mRNA ranged from 2.8-fold in spheroids to 81.2-fold in Liver-on-a-chip). Small molecules, obeticholic acid and abemaciclib, showed varying responses in HepatoPac, spheroids and Liver-on-a-chip, indicating a need for EC50 determinations to fully assess translatability data. HepatoPac, the most extensively investigated in this study (3 donors), showed high potential to investigate DDIs associated with CYP regulation by therapeutic peptides. Spheroids and Liver-on-a-chip were only assessed in one hepatocyte donor and further evaluations are required to confirm their potential. This study establishes an excellent foundation towards the establishment of more clinically-relevant in vitro tools for evaluation of potential DDIs with therapeutic peptides. Significance Statement At present, there are no guidelines for drug-drug interaction (DDI) assessment of therapeutic peptides. Existing in vitro methods recommended for assessing small molecule DDIs do not appear to translate well for peptide drugs, complicating drug development for these moieties. Here, we establish evidence that complex cellular systems have potential to be used as more clinically-relevant tools for the in vitro DDI evaluation of therapeutic peptides.

Real-world application of PBPK in drug discovery.

The utility of PBPK models in support of drug development has been well documented. During the discovery stage, PBPK has increasingly been applied for early risk assessment, prediction of human dose, toxicokinetic dose projection and early formulation assessment. Previous review articles have proposed model building and application strategies for PBPK-based first in human predictions with comprehensive descriptions of the individual components of PBPK models. This includes the generation of decision trees, based on comprehensive literature reviews, to guide the application of PBPK in the discovery setting. The goal of this mini review is to provide additional guidance on the real-world application of PBPK, in support of the discovery stage of drug development. In this mini review, our goal is to provide guidance on the typical steps involved in the development and application of a PBPK model during drug discovery to assist in decision making. We have illustrated our recommended approach through description of case examples, where PBPK has been successfully applied to aid in human PK projection, candidate selection and prediction of drug interaction liability for parent and metabolite. Through these case studies, we have highlighted fundamental issues, including pre-verification in preclinical species, the application of empirical scalars in the prediction of in vivo clearance from in vitro systems, in silico prediction of permeability and the exploration of aqueous and biorelevant solubility data to predict dissolution. In addition, current knowledge gaps have been highlighted and future directions proposed. Significance Statement Through description of three case studies, we have highlighted the fundamental principles of PBPK application during drug discovery. These include pre-verification of the model in preclinical species, application of empirical scalars where necessary in the prediction of clearance, in silico prediction of permeability, and the exploration of aqueous and biorelevant solubility data to predict dissolution. In addition, current knowledge gaps have been highlighted and future directions proposed.

Inhibition of human UDP-glucuronosyltransferase enzyme by ripretinib: Implications for drug-drug interactions.

Ripretinib, a tyrosine kinase inhibitor (TKI), is the first FDA approved fourth-line therapy for adults with advanced gastrointestinal stromal tumor (GIST). Studies have shown that several TKIs for treating GIST were potent inhibitors of human UDP-glucosyltransferase (UGTs) enzymes. However, whether ripretinib affects the activity of UGTs remains unclear. The aim of this study was to investigate the effects of ripretinib on major UGT isoforms, as well as to evaluate its potential drug-drug interactions (DDIs) risk caused by the inhibition of UGTs activities. The inhibitory effects and inhibition modes of ripretinib on UGTs were systematically evaluated using high-performance liquid chromatography (HPLC) and enzyme kinetic studies, respectively. Our data showed that ripretinib exhibited potent inhibition against UGT1A1, UGT1A3, UGT1A4, UGT1A7 and UGT1A8. Enzyme kinetic studies indicated that ripretinib was not only a competitive inhibitor of UGT1A1, UGT1A4 and UGT1A7, but also a noncompetitive inhibitor of UGT1A3, as well as a mixed inhibitor of UGT1A8. The prediction results of in vitro-in vivo extrapolation (IVIVE) demonstrated that ripretinib might bring the potential risk of DDIs when combined with substrates of UGT1A1, UGT1A3, UGT1A4, UGT1A7 or UGT1A8. Therefore, special attention should be paid when ripretinib is used in conjunction with other drugs metabolized by UGTs to avoid risk of DDIs in clinic.

Accelerated Wound Healing with a Diminutive Scar through Cocrystal Engineered Curcumin.

Pharmaceutical cocrystals ( Regulatory Classification of Pharmaceutical Co-Crystals Guidance for Industry; Food and Drug Administration, 2018) are crystalline solids produced through supramolecular chemistry to modulate the physicochemical properties of active pharmaceutical ingredients (APIs). Despite their extensive development in interdisciplinary sciences, this is a pioneering study on the efficacy of pharmaceutical cocrystals in wound healing and scar reducing. Curcumin-pyrogallol cocrystal (CUR-PYR) was accordingly cherry-picked since its superior physicochemical properties adequately compensate for limitative drawbacks of curcumin (CUR). CUR-PYR has been synthesized by a liquid-assisted grinding (LAG) method and characterized via FT-IR, DSC, and PXRD analyses. In vitro antibacterial study indicated that CUR-PYR cocrystal, CUR+PYR physical mixture (PM), and PYR are more effective against both Gram-negative (Pseudomonas aeruginosa and Escherichia coli) and Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacteria in comparison with CUR. In vitro results also demonstrated that the viability of HDF and NIH-3T3 cells treated with CUR-PYR were improved more than those received CUR which is attributed to the effect of PYR in the form of cocrystal. The wound healing process has been monitored through a 15 day in vivo experiment on 75 male rats stratified into six groups: five groups treated by CUR-PYR+Vaseline (CUR-PYR.ung), CUR+PYR+Vaseline (CUR+PYR.ung), CUR+Vaseline (CUR.ung), PYR+Vaseline (PYR.ung), and Vaseline (VAS) ointments and a negative control group of 0.9% sodium chloride solution (NS). It was revealed that the wounds under CUR-PYR.ung treatment closed by day 12 postsurgery, while the wounds in other groups failed to reach the complete closure end point until the end of the experiment. Surprisingly, a diminutive scar (3.89 ± 0.97% of initial wound size) was observed in the CUR-PYR.ung treated wounds by day 15 after injury, followed by corresponding values for PYR.ung (12.08 ± 2.75%), CUR+PYR.ung (13.89 ± 5.02%), CUR.ung (16.24 ± 6.39%), VAS (18.97 ± 6.89%), and NS (20.33 ± 5.77%). Besides, investigating histopathological parameters including inflammation, granulation tissue, re-epithelialization, and collagen deposition signified outstandingly higher ability of CUR-PYR cocrystal in wound healing than either of its two constituents separately or their simple PM. It was concluded that desired solubility of the prepared cocrystal was essentially responsible for accelerating wound closure and promoting tissue regeneration which yielded minimal scarring. This prototype research suggests a promising application of pharmaceutical cocrystals for the purpose of wound healing.

Mechanistic Static Model based Prediction of Transporter Substrate Drug-Drug Interactions Utilizing Atorvastatin and Rifampicin.

OBJECTIVE: An in vitro relative activity factor (RAF) technique combined with mechanistic static modeling was examined to predict drug-drug interaction (DDI) magnitude and analyze contributions of different clearance pathways in complex DDIs involving transporter substrates. Atorvastatin and rifampicin were used as a model substrate and inhibitor pair. METHODS: In vitro studies were conducted with transfected HEK293 cells, hepatocytes and human liver microsomes. Prediction success was defined as predictions being within twofold of observations. RESULTS: The RAF method successfully translated atorvastatin uptake from transfected cells to hepatocytes, demonstrating its ability to quantify transporter contributions to uptake. Successful translation of atorvastatin's in vivo intrinsic hepatic clearance (CLint,h,in vivo) from hepatocytes to liver was only achieved through consideration of albumin facilitated uptake or through application of empirical scaling factors to transporter-mediated clearances. Transporter protein expression differences between hepatocytes and liver did not affect CLint,h,in vivo predictions. By integrating cis and trans inhibition of OATP1B1/OATP1B3, atorvastatin-rifampicin (single dose) DDI magnitude could be accurately predicted (predictions within 0.77-1.0 fold of observations). Simulations indicated that concurrent inhibition of both OATP1B1 and OATP1B3 caused approximately 80% of atorvastatin exposure increases (AUCR) in the presence of rifampicin. Inhibiting biliary elimination, hepatic metabolism, OATP2B1, NTCP, and basolateral efflux are predicted to have minimal to no effect on AUCR. CONCLUSIONS: This study demonstrates the effective application of a RAF-based translation method combined with mechanistic static modeling for transporter substrate DDI predictions and subsequent mechanistic interpretation.

Hydrazinecarbonyl-thiazol-2-acetamides with pronounced apoptotic behavior: synthesis, in vitro/in vivo anti-proliferative activity and molecular modeling simulations.

A new series of N-[4-(2-substituted hydrazine-1-carbonyl)thiazole-2-yl]acetamides was synthesized and evaluated in vitro against six human cell lines as antitumor agents. Compounds 20, 21 and 22 showed remarkable inhibition to HeLa (IC50 values of 1.67, 3.81, 7.92 µM) and MCF-7 (IC50 values of 4.87, 5.81, 8.36 µM, respectively) cell growth with high selectivity indices and safety profiles. Compound 20 showed significant decreases in both tumor volume and body weight gain compared to vehicle control, in the solid tumor animal model of Ehrlich ascites carcinoma (EAC) with recovered caspase-3 immuno-expression. Flow cytometry cell analysis showed that 20 exerts anti-proliferative activity in mutant Hela and MCF-7 cell lines through arresting the cell growth at the G1/S phase producing cell death via apoptosis rather than necrosis. To explain the antitumor mode of action of the most active compounds, EGFR-TK and DHFR inhibition assays were carried out. Compound 21 conveyed dual EGFR/DHFR inhibition with IC50 0.143 (EGFR) and 0.159 (DHFR) µM. Compound 20 showed DHFR inhibition with IC50 0.262 µM. Compound 22 exhibited the best EGFR inhibitory efficacy with IC50 0.131 µM. Molecular modelling study revealed that 21 and 22 have binding interactions with EGFR amino acid residues Lys745 and Asp855. Compounds 20 and 21 showed affinity toward DHFR amino acid residues Asn64, Ser59 and Phe31. The ADMET profile and Lipinski's rule of five calculated for these compounds were acceptable. Compounds 20, 21 and 22 could be regarded as promising prototype antitumor agents for further optimization.

Florfenicol sustained-release granules: an in vitro-in vivo correlation study in pigs.

The objective of this study was to synthesize and characterize pharmaceutical characteristics of florfenicol sustained-release granules (FSRGs) in vitro and in vivo. FSRGs were synthesized using monostearate, polyethylene glycol 4000 and starch. In vitro dissolution profiles were studied using the rotating basket method in pH 1.2 HCl solution and pH 4.3 acetate buffer. Twenty-four male healthy Landrace×Yorkshire pigs were equally divided into three groups and administered a 20 mg/kg i.v bolus of florfenicol solution and dosed orally with FSRGs in the fasting and fed states. The Higuchi model was the best fit for the drug release profile in pH 1.2 and pH 4.3 media, and the mechanism of drug dissolution was governed by both diffusion and dissolution. We established a level A in vitro - in vivo correlation for FSRGs and the in vivo profile of the FSRGs can be estimated by the in vitro drug release.