Abstract: To evaluate the bioavailability of cefaclor, we established a reverse phase high performance liquid chromatographic method (HPLC). Ten healthy male volunteers were included in this randomized crossover study of bioavailability. Each was orally administered cefaclor capsule preparation (Keflor, 250 mg) or commercial one (Ceclor as a control, 250 mg), respectively. Venous blood samples were drawn at different times after dosing, and determined by HPLC. The results showed that the mean recovery of cefaclor from serum was 98.0%, and relative standard deviations of within-day and of between-day were observed from 0. 1% to 4.0%. The pharmacokinetic parameters of test preparation (Keflor), Tmax, Cmax, AUC0-∞, t1/2 were 0.55±0.11 h, 5.61±1.27 μg.ml^-1, 11.13±1.64 μg.h.ml^-1, 0.9 h, respectively. The relative bioavailability of Keflor was calculated to be 105.29±19.13%, as compared with control preparation (Ceclor). No statistically significant differences were observed in AUC0-∞, etc, by the two one-sided t-test procedures.

Key words: Cefaclor, HPLC, Capsule, Bioavailability