Pharmacokinetics and Bioequivalence Evaluation of 2 Loxoprofen Tablets in Healthy Egyptian Male Volunteers

The objective of this study was to assess the in vitro dissolution and to evaluate the bioavailability of two brands of Loxoprofen sodium dihydrate tablets. Loxoprofen tablets (68.1 mg loxoprofen sodium dihydrate equivalent to 60 mg loxoprofen; test) relative to Roxonin tablets (68.1 mg loxoprofen sodium dihydrate equivalent to 60 mg loxoprofen; reference). In vitro study was adopted to determine and compare the dissolution behavior of both products. In vivo study was conducted according to a single-center, randomized, single-dose, and laboratory-blinded, 2-period, 2-sequence, crossover design with a washout period of 1 week. Under fasting conditions, 24 healthy Egyptian adult male volunteers were randomly allocated to receive a single dose of either test or reference product. Blood samples were collected at specified time intervals, and plasma was analyzed for loxoprofen concentrations using a validated high-performance liquid chromatography assay method. The pharmacokinetic parameters Cmax , AUC0-t , AUC0-∞ , tmax , and t1/2 were determined from plasma concentration-time profiles. The 90% confidence intervals for the ratio Cmax , AUC0-t , and AUCt-∞ of the test product over those of reference were within the acceptable range (0.8-1.25) for bioequivalence. On the basis of these results, the two-loxoprofen formulations are considered bioequivalent.