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 (R) 90 mg (Adium S.A.) and the reference product Arcoxia (R) 90 mg (Merck Sharp & Dohme Farmaceutica 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 (R) 90 mg) has been deemed bioequivalent to the reference product (Arcoxia (R) 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 (R) 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.