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

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

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.

PhysioCell®; - a Novel, Bio-relevant Dissolution Apparatus: Hydrodynamic Conditions and Factors Influencing the Dissolution Dynamics.

The physiologically relevant dissolution apparatuses simulate various aspects of gastrointestinal physiology and help to understand and predict the in vivo behavior of an oral dosage form. In this paper, we present and characterize for the first time a novel bio-relevant dissolution apparatus - PhysioCell®;. We evaluated the impact of several factors on the hydrodynamic conditions in the key vessel of the apparatus - the StressCell. We observed that the medium flow rate, but not the glass beads' size or amount, significantly influenced the dissolution rate. The relationship was disproportional: the increase in the flow rate from 4.6 to 9.0 mL/min reduced the dissolution time of 85% (T85) of the NaCl tablet by 46%, but from 134 to 300 mL/min decreased the T85 only by 24%. At the same time, the contractions of the StressCell's elastic walls promoted the content mixing and enhanced the dissolution rate of the paracetamol tablets: even very rare mixing contractions (1 per 10 min) decreased the T85 over twofold for the flow rate of 8 mL/min. In conclusion, the hydrodynamic conditions in the StressCell affect the dissolution of solid dosage forms and the understanding of these effects is crucial for modeling physiologically-based test conditions in the novel apparatus. Combinations of the unique PhysioCell®;features - adjustable medium flow, temperature control, controllable pH gradients and predefined mechanical agitation - can create a set of dissolution test scenarios for characterization of oral dosage forms and, in the future, making the in vitro-in vivo predictions. Graphical Abstract.

Influence of Genetic and Epigenetic Factors of P2Y12 Receptor on the Safety and Efficacy of Antiplatelet Drugs.

PURPOSE: P2Y12 receptor inhibitors are drugs that decrease the risk of stent thrombosis and lower the long-term risk of non-stent-related myocardial infarction and stroke. They inhibit the binding of adenosine diphosphate (ADP) to the P2Y12 receptor and effectively reduce platelet reactivity. However, considerable variability in the pharmacodynamics response contributes to a failure of antiplatelet therapy; this phenomenon is especially notorious for older drugs, such as clopidogrel. Some genetic polymorphisms associated with these drugs' metabolic pathway, especially in the CYP2C19 gene, can significantly decrease antiplatelet efficacy. There are few reports on the variability stemming from the target of this drug class that is the P2Y12 receptor itself. RESULTS AND CONCLUSION: This review summarizes the results of research that focus on the influence of P2Y12 genetic polymorphisms on the pharmacodynamics and the efficacy of P2Y12 inhibitors. We found that the conclusions of the studies are unequivocal, and despite several strong candidates, such as G52T (rs6809699) or T744C (rs2046934), they may not be independent predictors of the inadequate response to the drug. Most probably, P2Y12 genetic polymorphisms contribute to the effect exerted by other gene variants (such as CYP2C19*2/*3/*17), drug interactions, or patient habits, such as smoking. Also, epigenetic modifications, such as methylation or miRNA levels, may play a role in the efficacy of antiplatelet treatment.

Impact of genetic variants of selected cytochrome P450 isoenzymes on pharmacokinetics and pharmacodynamics of clopidogrel in patients co-treated with atorvastatin or rosuvastatin.

PURPOSE: Impaired antiplatelet effect of clopidogrel (CLP) can result from drug-drug interactions and genetic polymorphisms of drug-metabolizing enzymes. The aim of the study was to evaluate the effect of genetic polymorphisms of ABCB1 and the selected cytochrome P450 isoenzymes on the pharmacodynamics and pharmacokinetics of CLP and its metabolites in patients co-treated with atorvastatin or rosuvastatin. METHODS: The study involved 50 patients after coronary angiography/angioplasty treated with CLP and atorvastatin (n = 25) or rosuvastatin (n = 25) for at least 6 months. Plasma concentrations of CLP, diastereoisomers of thiol metabolite (inactive H3 and active H4), and inactive CLP carboxylic acid metabolite were measured by UPLC-MS/MS method. Identification of the CYP2C19*2, CYP2C19*17, CYP3A4*1G, CYP1A2*1F, and ABCB1 C3435T genetic polymorphisms was performed by PCR-RFLP, while platelet reactivity units (PRU) were tested using the VerifyNow P2Y12 assay. RESULTS: There were significant differences in the pharmacokinetic parameters of the H4 active metabolite of CLP in the atorvastatin and rosuvastatin group divided according to their CYP2C19 genotype. There were no significant associations between CYP3A4, CYP1A2, and ABCB1 genotypes and pharmacokinetic parameters in either statin groups. In the multivariate analysis, CYP2C19*2 genotype and non-genetic factors including BMI, age, and diabetes significantly affected platelet reactivity in the studied groups of patients (P < 0.01). In the atorvastatin group, CYP2C19*2, CYP3A4*1G, and ABCB1 C3435T TT genotypes were independent determinants of PRU values (P < 0.01). CONCLUSION: The CYP2C19*2 allele is the primary determinant of the exposition to the H4 active metabolite of clopidogrel and platelet reactivity in patients co-treated with atorvastatin or rosuvastatin.

Physiologically Based Dissolution Testing in a Drug Development Process-a Case Study of a Successful Application in a Bioequivalence Study of Trazodone ER Formulations Under Fed Conditions.

Development of generic extended-release (ER) formulations is challenging. Especially under fed conditions, the risk of failure in bioequivalence trials is high because of long gastric residence times and susceptibility to food effects. We describe the development of a generic trazodone ER formulation that was aided with a biorelevant dissolution evaluation. Trazodone hydrochloride 300-mg monolithic matrix tablets were dissolved both in USP and EMA compliant conditions and in the StressTest device that simulated both physicochemical and mechanical conditions of the gastrointestinal passage. The final formulation was tested against the originator, Trittico XR 300 mg, in a randomized cross-over bioequivalence trial with 44 healthy volunteers, in agreement with EMA guidelines. Initially developed formulations dissolved trazodone similarly to the originator under standard conditions (f2 factor above 50), but their dissolution kinetics differed significantly in the biorelevant tests. The formulation was optimized by the addition of low-viscosity hypromellose and mannitol. The final formulation was approved for the bioequivalence trial. Calculated Cmax were 1.92 ± 0.77 and 1.92 ± 0.63 [µg/mL], AUC0-t were 27.46 ± 8.39 and 29.96 ± 9.09 [µg∙h/mL], and AUC0-∞ were 28.22 ± 8.91 and 30.82 ± 9.41 [µg∙h/mL] for the originator and test formulations, respectively. The 90% confidence intervals of all primary pharmacokinetic parameters fell within the 80-125% range. In summary, biorelevant dissolution tests supported successful development of a generic trazodone ER formulation pharmaceutically equivalent with the originator under fed conditions. Employment of biorelevant dissolution tests may decrease the risk of failure in bioequivalence trials of ER formulations.

Population pharmacokinetics of treosulfan and development of a limited sampling strategy in children prior to hematopoietic stem cell transplantation.

PURPOSE: There is an increasing interest in use of treosulfan (TREO), a structural analogue of busulfan, as an agent in conditioning regimens prior to hematopoietic stem cell transplantation (HSCT), both in pediatric and adult populations. The aim of this study was to develop a population pharmacokinetic model and to establish limited sampling strategies (LSSs) enabling accurate estimation of exposure to this drug. METHODS: The study included 15 pediatric patients with malignant and non-malignant diseases, undergoing conditioning regimens prior to HSCT including TREO administered as a 1 h or 2 h infusion at daily doses of 10, 12, or 14 g/m2. A population pharmacokinetic model was developed by means of non-linear mixed-effect modeling approach in Monolix® software. Multivariate regression analysis and Bayesian method were used to develop 2- and 3-point strategies for estimation of exposure to TREO. RESULTS: Pharmacokinetics of TREO was best described with a two-compartmental linear model with proportional residual error. Following sampling schedules allowed accurate estimation of exposure to TREO: 1 h and 6 h or 1 h, 2 h, and 6 h for a TREO dose 12 g/m2 in a 1 h infusion, or at 2 h and 6 h or 2 h, 4 h, and 8 h for a TREO dose of 12 g/m2 and 14 g/m2 in a 2 h infusion. CONCLUSIONS: A two-compartmental population pharmacokinetic model of TREO was developed and successfully used to establish 2- and 3-point LSSs for accurate and precise estimation of TREO AUC0→∞.

Development of a Limited Sampling Strategy for the Estimation of Exposure to High-Dose Etoposide After Intravenous Infusion in Pediatric Patients.

BACKGROUND: Etoposide (VP-16), a podophyllotoxin derivative, is used in conditioning regimens before allogeneic hematopoietic stem cell transplantation in children with acute lymphoblastic leukemia. The aim of this study was to develop a limited sampling strategy (LSS) suitable for the prediction of exposure to VP-16 defined as area under time-concentration curve (AUC). METHODS: The study included 28 pediatric patients with acute lymphoblastic leukemia, who were administered a 4-hour infusion of 60 mg/kg VP-16. VP-16 concentrations were determined in samples collected 4-124 hours after the beginning of infusion. On obtaining the pharmacokinetic (PK) profiles, a population PK model was developed in NONMEM (ICON Development Solutions, Hanover, MD) with first-order conditional estimation with interaction algorithm. LSSs were chosen by means of a multivariate regression analysis and cross-validated with a leave-one-out approach. Predictive performance of LSSs was assessed by calculating relative prediction error (PE), mean PE, mean absolute PE, and root mean squared PE for model-predicted and observed AUC. RESULTS: VP-16 PKs was best described by a 2-compartment first-order model, and a large variability in the PK parameters was observed. A 3-sample strategy allowed the estimation of VP-16 with highest accuracy and precision (mean relative PE = 0.18%, 95% confidence interval, 1.73%-2.09%; mean absolute relative PE = 3.47%, 95% confidence interval, 2.28%-4.66%; root mean squared PE = 4.43%). The final equation was AUC = 6.85 × C6 h + 3.88 × C12 h + 46.11 × C28 h + 282.0 (adjusted R = 0.9540). CONCLUSIONS: In conclusion, developed LSS allows accurate and precise estimation of VP-16 AUC and might be useful for therapeutic drug monitoring.

Influence of genetic co-factors on the population pharmacokinetic model for clopidogrel and its active thiol metabolite.

PURPOSE: A high interindividual variability is observed in the pharmacokinetics of clopidogrel, a widely used antiplatelet drug. In the present study, a joint parent-metabolite population pharmacokinetic model was developed to adequately describe observed concentrations of clopidogrel and its active thiol metabolite (H4). METHODS: The study included 63 patients undergoing elective coronarography or percutaneous coronary intervention. The population pharmacokinetic model was developed in the NONMEM 7.3 software, and first-order conditional estimation method with interaction was applied. Also, the influence of covariates was evaluated (age, weight, body mass index (BMI), obesity defined as BMI ≥ 30 kg/m2, sex, diabetes mellitus, co-administration of PPI or statins, presence of CYP2C19*2, CYP2C19*17, CYP3A4*1G alleles, and ABCB1 3435 TT genotype). RESULTS: It was found that the only significant covariate was the presence of CYP2C19*2 allele, which had an impact on lower conversion of clopidogrel to H4. As a result, predicted area under the time-concentration curve values was lower in carriers of this allele, with median 5.94 ng h/ml (interquartile range 3.92-12.51 [ng∙h/ml]) vs. 12.70 ng h/ml in non-carriers (interquartile range, 7.00-19.39 [ng∙h/ml]), respectively (p = 0.004). CONCLUSIONS: Developed model predicts that the only significant covariate influencing the observed concentrations and therefore the exposure to the active H4 metabolite is the presence of CYP2C19*2 allele.

Determinants of high on-treatment platelet reactivity and agreement between VerifyNow and Multiplate assays.

Dual antiplatelet therapy with clopidogrel is a regimen used before and after drug-eluting stent (DES) implantation. Point-of-care platelet reactivity assays are easy-to-use methods to determine adequate response to the drug. The aim of this study was a comparison of the two platelet reactivity assays: Multiplate® and VerifyNow® and an identification of factors potentially influencing the results of these tests, including common genetic polymorphisms. The study included 39 patients receiving 75 mg clopidogrel daily before angioplasty with DES implantation. Platelet reactivity was measured with Multiplate and P2Y12 VerifyNow assays. Genetic polymorphisms of CYP2C19*2, ABCB1 3435C > T, and CYP3A4*1G were determined with PCR-RFLP method and CYP2C19*17 was determined by means of an allele-specific PCR. Agreement between Multiplate and VerifyNow assays was poor (Cohen's κ = 0.056, p = .273). Hematocrit significantly negatively correlated with VerifyNow assayed platelet reactivity (r = -.487, p = .002). Female sex was significantly associated with higher VerifyNow assay results after adjustment to hematocrit (253.2 ± 47.6 PRU vs. 195.9 ± 56.9 PRU, p = .013) and the prevalence of high-on-treatment platelet reactivity (OR: 8.50; 95% CI 1.13-77.60, p = .024). Reactivity measured with Multiplate was lower in women (82.3 vs. 175.6 AU·min, p = .037) and in patients who received calcium channel blockers (74.7 vs. 191.7 AU·min, p = .002). None of the studied polymorphisms significantly influenced platelet aggregation measurements. In conclusion, different aspects modify between-patient variability of the Multiplate and VerifyNow assays and agreement between those two assays was poor.

Drug dissolution and transit in a heterogenous gastric chyme after fed administration: Semi-mechanistic modeling and simulations for an immediate-release and orodispersible tablets containing a poorly soluble drug.

Mathematical models that treat the fed stomach content as a uniform entity emptied with a constant rate may not suffice to explain pharmacokinetic profiles recorded in clinical trials. In reality, phenomena such as the Magenstrasse or chyme areas of different pH and viscosity, play an important role in the intragastric drug dissolution and its transfer to the intestine. In this study, we investigated the data gathered in the bioequivalence trial between an immediate-release tablet (Reference) and an orally dispersible tablet (Test) with a poorly soluble weak base drug administered with or without water after a high-fat high-calorie breakfast. Maximum concentrations (Cmax) were significantly greater after administering the Reference product than the Test tablets, despite similar in vitro dissolution profiles. To explain this difference, we constructed a novel semi-mechanistic IVIVP model including a heterogeneous gastric chyme. The drug dissolution in vivo was modeled from the in vitro experiments in biorelevant media simulating gastric and intestinal fluids in the fed state (FEDGAS and FeSSIF). The key novelty of the model was separating the stomach contents into two compartments: isolated chyme (the viscous food content) that carries the drug slowly, and aq_chyme open for rapid Magenstrasse-like routes of drug transit. Drug distribution between these two compartments was both formulation- and administration-dependent, and recognized the respective drug fractions from the clinical pharmacokinetic data. The model's assumption about the nonuniform mixing of the API with the chyme, influencing differential drug dissolution and transit kinetics, led to simulating plasma concentration profiles that reflected well the variability observed in the clinical trial. The model indicated that, after administration, the Reference product mixes to a greater extent with aq_chyme, where the released drug dissolves better and transfers faster to the intestine. In conclusion, this novel approach underlines that diverse gastric emptying of different oral dosage forms may significantly impact pharmacokinetics and affect the outcomes of bioequivalence trials.

The influence of P2Y12 gene polymorphisms on clopidogrel therapy in patients after percutaneous coronary intervention.

Aim: We aimed to define the influence of P2Y12 polymorphisms (rs6801273, rs2046934, and rs6809699), diabetes, hypertension, obesity, hypercholesterolemia, statins intake, and smoking habit on clopidogrel therapy in patients undergoing percutaneous coronary intervention. Materials & methods: We used PCR-RFLP and PCR-ASO for P2Y12 genotype analysis. The effectiveness of the therapy was measured with the VerifyNow method and defined in platelet reactivity units. Results: Studied polymorphisms had no statistically significant influence on PRU before (PRU0) and 6 months (PRU6) after the procedure. H1/H1 diabetic carriers had significantly higher PRU6 values than patients without diabetes. Obese H1/H2 subjects had significantly lower PRU6 values than H1/H2 non-obese carriers. Conclusion: We found that obesity and diabetes may influence the long-term outcome of antiplatelet therapy.

Clopidogrel is a medicine that prevents platelets in the blood from clumping and blocking arteries. When the structure of the protein (e.g., P2Y12), responsible for response to clopidogrel is changed, we can observe less efficient therapy. Said changes can be caused for example by genetic polymorphisms, which are two or more variants of the same gene. This is why we wanted to check the impact of P2Y12 polymorphisms. We also wanted to check the impact of diabetes, high blood pressure, being overweight, high cholesterol blood level, cholesterol-reducing drugs, and smoking habits on clopidogrel treatment in patients after a procedure that unblocks blood vessels of the heart to restore its blood supply (percutaneous coronary intervention). We measured the efficacy of the treatment with platelet reactivity units (PRU). Studying polymorphisms had no impact on treatment efficacy before (PRU0) and 6 months (PRU6) after the medical procedure. We found that diabetes can cause higher platelet reactivity after 6 months of therapy. We noticed that being overweight may also be important, as obese patients had lower platelet reactivity values.

An extension of biorelevant fed-state dissolution tests to clinical pharmacokinetics - A study on gastrointestinal factors influencing rivaroxaban exposure and efficacy in atrial fibrillation patients.

A direct oral anticoagulant rivaroxaban fails to prevent stroke and systemic embolism in one-to-several percent of patients with nonvalvular atrial fibrillation (NVAF), but the reasons are unknown. The study used semi-mechanistic in vitro-in vivo prediction (IVIVP) modeling to explore the reasons for ineffective thrombosis prevention in NVAF patients. Steady-state drug concentrations in plasma were measured at 0 h (Ctrough), 3 h (C3h), and 12 h post-dosing in thirty-four patients treated with 20 mg rivaroxaban daily. The clinical data were compared against "virtual twins" generated with a novel IVIVP model that combined drug dissolution modeling, mechanistic description of gastric drug transit, and population pharmacokinetics defining the variability of drug disposition. The nonresponders had significantly lower C3h and Ctrough than the responders (p < 0.001) and the covariates included in the population pharmacokinetic submodel did not fully explain this difference. Simulations involving varied gastrointestinal parameters in the "virtual twins" revealed that lower small intestinal effective permeability (Peff), rather than a slower stomach emptying rate, could explain low rivaroxaban exposure in the nonresponders. IVIVP modeling was effectively used for exploring pharmacotherapy failure. Low Peff, found as a major determinant of ineffective rivaroxaban treatment, encourages further research to find (pato)physiological factors influencing suboptimal absorption.

Conjunction of semi-mechanistic in vitro-in vivo modeling and population pharmacokinetics as a tool for virtual bioequivalence analysis - a case study for a BCS class II drug.

Virtual bioequivalence trial (VBE) simulations based on (semi)mechanistic in vitro-in vivo (IVIV) modeling have gained a huge interest in the pharmaceutical industry. Sophisticated commercially available software allows modeling variable drug fates in the gastrointestinal tract (GIT). Surprisingly, the between-subject and inter-occasion variability (IOV) of the distribution volumes and clearances are ignored or simplified, despite substantially contributing to varied plasma drug concentrations. The paper describes a novel approach for IVIV-based VBE by using population pharmacokinetics (popPK). The data from two bioequivalence trials with a poorly soluble BCS class II drug were analyzed retrospectively. In the first trial, the test drug product (biobatch 1) did not meet the bioequivalence criteria, but after a reformulation, the second trial succeeded (biobatch 2). The popPK model was developed in the Monolix software (Lixoft SAS, Simulation Plus) based on the originator's plasma concentrations. The modified Noyes-Whitney model was fitted to the results of discriminative biorelevant dissolution tests of the two biobatches and seven other reformulations. Then, the IVIV model was constructed by joining the popPK model with fixed drug disposition parameters, the drug dissolution model, and mechanistic approximation of the GIT transit. It was used to simulate the drug concentrations at different IOV levels of the primary pharmacokinetic parameters and perform the VBE. Estimated VBE success rates for both biobatches well reflected the outcomes of the bioequivalence trials. The predicted 90% confidence intervals for the area under the time-concentration curves were comparable with the observed values, and the 10% IOV allowed the closest approximation to the clinical results. Simulations confirmed that a significantly lower maximum drug concentration for biobatch 1 was responsible for the first clinical trial's failure. In conclusion, the proposed workflow might aid formulation screening in generic drug development.

A Rational Approach to Predicting Immediate Release Formulation Behavior in Multiple Gastric Motility Patterns: A Combination of a Biorelevant Apparatus, Design of Experiments, and Machine Learning.

Gastric mechanical stress often impacts drug dissolution from solid oral dosage forms, but in vitro experiments cannot recreate the substantial variability of gastric motility in a reasonable time. This study, for the first time, combines a novel dissolution apparatus with the design of experiments (DoE) and machine learning (ML) to overcome this obstacle. The workflow involves the testing of soft gelatin capsules in a set of fasted-state biorelevant dissolution experiments created with DoE. The dissolution results are used by an ML algorithm to build the classification model of the capsule's opening in response to intragastric stress (IS) within the physiological space of timing and magnitude. Next, a random forest algorithm is used to model the further drug dissolution. The predictive power of the two ML models is verified with independent dissolution tests, and they outperform a polynomial-based DoE model. Moreover, the developed tool reasonably simulates over 50 dissolution profiles under varying IS conditions. Hence, we prove that our method can be utilized for the simulation of dissolution profiles related to the multiplicity of individual gastric motility patterns. In perspective, the developed workflow can improve virtual bioequivalence trials and the patient-centric development of immediate-release oral dosage forms.

Application of a novel PhysioCell apparatus for biopredictive dissolution tests of oral immediate release formulations - A case study workflow for in vitro-in vivo predictions.

Biorelevant dissolution tests of oral solid dosage forms open the gate to valid in vitro-in vivo predictions (IVIVP). A recently developed apparatus, PhysioCell, allows mimicking the fluid flow and pressure waves occurring in the human fasted stomach. In this work, we used the PhysioCell to perform IVIVP for vortioxetine immediate-release (IR) tablets: the originator (Brintellix) and generic product candidates (VORTIO). The dissolved drug was monitored in the gastric (StressCell) and intestinal (Collection Vessel) compartments that contained biorelevant media. Simulated intermittent gastric stress at 15 min and "housekeeping wave" at 30 min increased the dissolution of Brintellix formulations only. A mechanistic model that best described the observations involved the first-order tablet disintegration with a stress-induced enhancement for Brintellix, dissolution of solid particles in the StressCell, and drug transfer to the Collection Vessel. Then, a semi-mechanistic pharmacokinetic model with dissolution parameters as inputs simulated vortioxetine plasma concentrations in healthy volunteers after single and multiple dosing of Brintellix. Despite different dissolution characteristics, VORTIO provided similar concentration profiles to the originator. In conclusion, PhysioCell dissolution tests, combined with semi-mechanistic IVIVP, can be successfully used to develop IR dosage forms exhibiting gastric stress-related effects.

Increasing the efficacy of abiraterone - from pharmacokinetics, through therapeutic drug monitoring to overcoming food effects with innovative pharmaceutical products.

Current guidelines suggest radiotherapy as a first-line treatment for prostate cancer, along with prostatectomy, and androgen deprivation therapy. Abiraterone is a first-in-class medicinal product recommended in the treatment of metastatic castration resistant prostate cancer (mCRPC) that targets androgen receptors and inhibits systemic synthesis. However, successful therapy with this drug may pose some challenges. It has to be administered as an inactive prodrug - abiraterone acetate. It is also dissolved and absorbed poorly with large interindividual variability and exhibits considerable food effects. Additionally, the recommended daily dose of the drug is high (1000 mg abiraterone acetate), and the cost of the therapy is burdensome. The following review focuses on the strategies to optimize therapy with abiraterone acetate. First, it summarizes current findings on abiraterone pharmacokinetics and accentuates the need for utilizing therapeutic monitoring in clinical practice. Next, it extensively describes the options for improving the low bioavailability of the drug. The two major approaches are the utilization of the positive food effect to increase the exposure and development of supergenerics. The review emphasizes how different formulation approaches lead to increased solubility and impact the outcomes of pre-clinical and clinical trials. The review concludes with a discussion on possible future directions that may lead to the increase of the therapeutic efficacy of abiraterone.

Vortioxetine in management of major depressive disorder - a favorable alternative for elderly patients?

Introduction: Depressive disorders are common in older patients, and their prevalence may reach up to 17.1%. Though for older adults, the initial recommended treatment is either life-review treatment or group cognitive-behavioral therapy, a combination of pharmacotherapy with interpersonal psychotherapy is also an option. There are many classes of antidepressants, and some meta-analyses suggest that the efficacy of different antidepressant groups is similar. Therefore, depression treatment in an elderly patient should consider preference, safety, and tolerability. Most reports suggest that SSRIs, such as citalopram, escitalopram, or sertraline, should be proposed as first-time medications.Areas covered: This article discusses the pharmacokinetic and pharmacodynamic properties of vortioxetine, emphasizing the observed differences, benefits, and risks for older patients. Vortioxetine - a multimodal antidepressant drug - was shown to be effective against major depressive disorders in both double-blinded, placebo-controlled trials and open-label studies.Expert opinion: Compared with commonly used antidepressants, vortioxetine appears to have unique properties that may be beneficial for elderly patients. Not only does it enhance cognitive function, but it also has a favorable safety profile.

Development and Bio-Predictive Evaluation of Biopharmaceutical Properties of Sustained-Release Tablets with a Novel GPR40 Agonist for a First-in-Human Clinical Trial.

Sustained-release (SR) formulations may appear advantageous in first-in-human (FIH) study of innovative medicines. The newly developed SR matrix tablets require prolonged maintenance of API concentration in plasma and should be reliably assessed for the risk of uncontrolled release of the drug. In the present study, we describe the development of a robust SR matrix tablet with a novel G-protein-coupled receptor 40 (GPR40) agonist for first-in-human studies and introduce a general workflow for the successful development of SR formulations for innovative APIs. The hydrophilic matrix tablets containing the labeled API dose of 5, 30, or 120 mg were evaluated with several methods: standard USP II dissolution, bio-predictive dissolution tests, and the texture and matrix formation analysis. The standard dissolution tests allowed preselection of the prototypes with the targeted dissolution rate, while the subsequent studies in physiologically relevant conditions revealed unwanted and potentially harmful effects, such as dose dumping under an increased mechanical agitation. The developed formulations were exceptionally robust toward the mechanical and physicochemical conditions of the bio-predictive tests and assured a comparable drug delivery rate regardless of the prandial state and dose labeled. In conclusion, the introduced development strategy, when implemented into the development cycle of SR formulations with innovative APIs, may allow not only to reduce the risk of formulation-related failure of phase I clinical trial but also effectively and timely provide safe and reliable medicines for patients in the trial and their further therapy.