Bioequivalence Study of Two Ibuprofen Arginine Formulations in Healthy Chinese Subjects Under Fed Conditions

To evaluate the bioequivalence and safety of a generic ibuprofen arginine formulation (T) compared to Sibide (R) in healthy Chinese subjects under fed conditions, a randomized, open-label, single-dose, two-period, two-sequence crossover study was conducted. Twenty-eight eligible healthy subjects received a single 400 mg dose of either the T or R formulation following a standardized high-fat meal, with a 3-day washout period between doses. Plasma ibuprofen concentrations were quantified using a validated LC-MS/MS method. Pharmacokinetic parameters, including C_max, AUC_0-t, and AUC_0-∞, were calculated using non-compartmental analysis. Bioequivalence was assessed based on the geometric mean ratios (GMRs) and 90% confidence intervals (CIs) derived from ANOVA. All 28 enrolled subjects completed the study. The GMRs (90% CIs) for C_max, AUC_0-t, and AUC_0-∞ were 107.03% (100.02%-114.52%), 100.99% (98.46%-103.58%), and 100.95% (98.24%-103.74%), respectively. All 90% CIs fell entirely within the regulatory bioequivalence acceptance range of 0.80-1.25. Both formulations were well tolerated; adverse events were mild to moderate, and no serious adverse events were reported. Thus, the T formulation of ibuprofen arginine demonstrated bioequivalence to the R formulation in healthy Chinese subjects under fed conditions.