Tramadol/Diclofenac Fixed-Dose Combination for Acute Pain Management: Bioavailability Assessment of a Generic Product.

The multimodal analgesia strategy for acute pain involves using 2 or more analgesic medications with distinct mechanisms of action. This study assessed the bioavailability and tolerability of 2 tramadol hydrochloride (50 mg)/diclofenac sodium (50 mg) fixed-dose combination formulations under fed conditions to attend the Brazilian regulatory requirements for generic product registration. An open-label, randomized, single-dose, 2-period, 2-way crossover trial was conducted, including healthy subjects of both sexes. Subjects received a single dose of either the test or reference formulation of tramadol/diclofenac fixed-dose combination tablets with a 7-day washout period. Blood samples were collected up to 36 hours after dosing for tramadol and 12 hours for diclofenac and quantified using a validated liquid chromatography-tandem mass spectrometry method. Of 56 subjects enrolled, 53 completed the study. The 90% confidence intervals for maximum plasma concentration and area under the concentration-time curve from time 0 to the last quantifiable concentration were within acceptable bioequivalence limits of 80%-125%. Considering the results presented in this study, the test formulation is bioequivalent to the reference formulation and could be interchangeable in medical practice.

Etoricoxib Coated Tablets: Bioequivalence Assessment between Two Formulations Administered under Fasting Conditions.

Etoricoxib is a non-steroidal anti-inflammatory drug with high selectivity for cyclooxygenase 2 (COX-2), exerting a pronounced anti-inflammatory effect with fewer adverse events when compared to COX-1 inhibitors. The present study aimed to evaluate the bioequivalence between two etoricoxib-coated tablet formulations to meet regulatory requirements for a branded generic product registration in Brazil. A crossover study with an open-label, randomized design and a single-dose regimen with two treatments and two periods was conducted on healthy Brazilians of both genders. Subjects randomly received a single dose of a 90 mg etoricoxib coated tablet of test product Xumer® 90 mg (Adium S.A.) and the reference product Arcoxia® 90 mg (Merck Sharp & Dohme Farmacêutica Ltda.) under fasting conditions separated by a 14-day period. Blood samples were collected sequentially for up to 96 h following drug administration, and the concentrations of etoricoxib in plasma were determined using a validated UPLC-MS/MS method. Pharmacokinetic parameters were computed utilizing non-compartmental analysis methods. A total of 32 healthy subjects were enrolled, and 25 subjects completed the study. Geometric mean ratios (90% confidence intervals) for Cmax, AUC0-t, and AUC0-inf were 103.98% (95.63-113.06), 96.82% (91.82-102.09), and 95.79% (90.70-101.16), respectively. In accordance with regulatory standards, the test formulation (Xumer® 90 mg) has been deemed bioequivalent to the reference product (Arcoxia® 90 mg). As a result, these formulations can be considered interchangeable in clinical practice, with both proving to be safe and well-tolerated. The need for in vivo testing for the Xumer® 60 mg strength was waived due to the proportional similarity of the formulations and the similar in vitro dissolution profiles observed across the various strengths.

Methylphenidate Multiphasic Release Tablet: Bioequivalence Assessment between Two Formulations Administered under Fasting and Fed Conditions.

Methylphenidate hydrochloride is used to treat children, adolescents, and adults with attention deficit/hyperactivity disorder (ADHD). Multiphasic release formulation has been used to control drug levels, mainly during children's school period. This study aimed to evaluate the bioequivalence between two methylphenidate hydrochloride extended-release tablets to meet regulatory requirements for registration in Brazil. Two independent studies (under fasting and fed conditions) designed as open-label, randomized, single-dose, two-period, two-way crossover trials were conducted in healthy subjects of both genders. Subjects were enrolled and randomly received a single dose of the test formulation methylphenidate hydrochloride 54 mg extended-release tablet (Consiv®, Adium S.A., São Paulo, Brazil) or the reference formulation (Concerta®, Janssen-Cilag Farmacêutica Ltd., São Paulo, Brazil), in each period, with a 7-day washout interval. Serial blood samples were collected up to 24 h post dose and methylphenidate plasma concentrations were obtained using a validated LC-MS/MS method. A total of 96 healthy subjects were enrolled in the fasting study, of which 80 completed the study. For the fed study, 52 healthy subjects were enrolled, and 46 subjects completed it. In both studies, 90% confidence intervals for Cmax, AUC0-t, AUC0-inf, and partial AUCs were within the acceptable limits of 80.00 to 125.00%. Thus, according to regulatory requirements, the test formulation (Consiv®) was considered to be bioequivalent to the reference formulation (Concerta®) in both conditions (fasting and fed) and, therefore, it can be considered interchangeable in clinical practice. Both formulations were safe and well tolerated in single-dose administration.

Influence of Genetic Polymorphisms on the Pharmacokinetics of Trazodone Hydrochloride: A Scoping Review and Future Perspective.

BACKGROUND: Trazodone hydrochloride is an antidepressant used in clinical practice. As a substrate of cytochrome P450 enzymes that is vulnerable to P-glycoprotein transport, several factors can alter its plasma concentration, and hence, dose adjustment may be required. The aim of this scoping review was to identify genetic polymorphisms that influence the pharmacokinetics of trazodone hydrochloride. METHODS: A literature search was performed using PubMed, PubMed Central, BVS/BIREME, EBSCOhost, Web of Science, Embase, Cochrane Library, and Medline databases for studies published until August 2021. The search strategy was based on the following keywords: Trazodone OR "m-chlorophenyl piperazine" AND "Pharmacogenetics" OR "Genetics" OR "Cytochrome P-450 Enzyme System" OR "Polymorphism, Single Nucleotide" OR "Polymorphism, Genetic." RESULTS: The search retrieved 684 candidate articles; 307 duplicates were eliminated. In total, 377 articles were eligible for the first screen. However, only 4 met the eligibility criteria, and 12 polymorphisms in 5 different genes (CYP2D6, CYP1A2, CYP3A4, CYP3A5, and ABCB1). Notably, only C3435T ABCB1 influenced the pharmacokinetics of trazodone hydrochloride. Individuals with the T/T genotype had lower area under the curve, half-life, and maximum concentration values with a higher clearance rate. CONCLUSIONS: Polymorphisms in CYP450 do not seem to directly influence the pharmacokinetics of trazodone hydrochloride or its metabolites. By contrast, genetic polymorphisms in ABCB1 seem to have an important effect on the pharmacokinetics of trazodone hydrochloride by enhancing drug metabolism and elimination.

In Vitro-In Vivo Correlation for Desvenlafaxine Succinate Monohydrate Extended Release Tablets.

The objective of this study was to develop a dissolution test in order to establish an in vitro-in vivo correlation (IVIVC) model for desvenlafaxine succinate monohydrate (DVSM) extended release (ER) tablets. The in vitro release characteristics of the drug were determined using USP apparatus 1 at 75 rpm, with volume of HCl pH 1.2, acetate buffer solution (ABS) pH 4.5, or phosphate buffer solution (PBS) pH 6.8. In vivo plasma concentrations and pharmacokinetic parameters in healthy volunteers were obtained from a bioequivalence study. The similarity factors f1 and f2 were used to compare the dissolution data. The IVIVC model was developed using fraction dissolved and fraction absorbed of the reference product. For predictability, the results showed that the percentage prediction error (%PE) value of Cmax was 7.63%. The observed low prediction error for Cmax demonstrated that the IVIVC model was valid for this parameter.

In Vivo Predictive Dissolution (IPD) for Carbamazepine Formulations: Additional Evidence Regarding a Biopredictive Dissolution Medium.

The aim of the present study was to bring additional evidence regarding a biopredictive dissolution medium containing 1% sodium lauryl sulphate (SLS) to predict the in vivo behavior of carbamazepine (CBZ) products. Twelve healthy volunteers took one immediate release (IR) dose of either test and reference formulations in a bioequivalence study (BE). Dissolution profiles were carried-out using the medium. Level A in vitro-in vivo correlations (IVIVC) were established using both one-step and two-step approaches as well as exploring the time-scaling approach to account for the differences in dissolution rate in vitro versus in vivo. A detailed step by step calculation was provided to clearly illustrate all the procedures. The results show additional evidence that the medium containing 1% SLS can be classified as a universal biopredictive dissolution tool, and that both of the approaches used to develop the IVIVC (one and two-steps) provide good in vivo predictability. Therefore, this biopredictive medium could be a highly relevant tool in Latin-American countries to ensure and check the quality of their CBZ marketed products for which BE studies were not requested by their regulatory health authorities.

A randomized, single-dose, two-sequence, two-period, crossover study to assess the bioequivalence between two formulations of clonazepam tablet in healthy subjects.

Clonazepam is a benzodiazepine commonly prescribed to treat panic disorder, epilepsy, anxiety, depression and certain types of seizures. This study aimed to evaluate the bioequivalence between two formulations of clonazepam tablets in order to meet regulatory requirements for marketing in Colombia and other countries in Latin America. An open-label, randomized, single-dose, two-period, two-sequence, two-treatment crossover study was conducted in 36 healthy subjects of both genders. Subjects received a single dose of clonazepam 2 mg test tablet (Sanofi-Aventis de Colombia S.A.) and reference product (Rivotril®, Produtos Roche Químicos e Farmacêuticos S.A.) under fasting conditions according to a randomly assigned order with a 21-day washout period. Serial blood samples were collected up to 96 h post-dose. Plasma concentrations of clonazepam were obtained by a validated liquid chromatography-tandem mass spectrometry method. Pharmacokinetic parameters were calculated using non-compartmental methods. A total of 36 healthy subjects were enrolled and 31 of them completed the study. Twenty-nine adverse events were reported (11 events with test product versus 18 events with reference product). There were no serious adverse events during the study. Geometric mean ratios (90% confidence intervals) for Cmax and AUC0-96h were 103.28% (98.10-108.64) and 102.50% (99.87-105.19), respectively. The test formulation of clonazepam 2 mg tablet manufactured by Sanofi-Aventis de Colombia S.A. was considered bioequivalent to reference product Rivotril® (Produtos Roche Químicos e Farmacêuticos S.A.) according to regulatory requirements. Both formulations were safe and well-tolerated during the study.

Sensitive LC-MS/MS method for quantitation of levodopa and carbidopa in plasma: application to a pharmacokinetic study.

AIM: The combination of levodopa with carbidopa has been used for treatment of Parkinson's disease being an important therapy in dopamine level control in the brain. Both are very polar compounds becoming a challenge for analysis by LC-MS/MS. MATERIALS & METHODS: In this work, it was developed and validated a sensitive bioanalytical method by UHPLC-MS/MS for simultaneous levodopa and carbidopa quantification in human plasma using a fast protein precipitation method. Moreover, the bioanalytical method was applied to a pharmacokinetic study in healthy volunteers. RESULTS/CONCLUSION: The results demonstrated a sensitive and adequate method for application to pharmacokinetic/bioequivalence studies.