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 C_max, AUC_0-t, and AUC_0-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.