Comparative bioavailability of two formulations of azithromycin.

ABSTRACT

AIM: To compare the bioequivalence of two brands of azithromycin capsules in healthy male volunteers for regulatory purpose. METHOD: A single oral dose of 500 mg of either test (Panacea Biotec Ltd.) or reference (Pfizer India Ltd.) preparation of azithromycin was administered to 12 volunteers in double blind randomised cross over fashion. Serum levels of azithromycin were analysed using microbiological assay. The pharmacokinetic parameters studied were Cmax, Tmax, AUC, t1/2, Ke, CL and MRT. In vitro dissolution tests were conducted for both the preparations and compared with in vivo absorption. RESULTS: The mean peak serum azithromycin concentration of 0.516 +/- 0.008 microgram/ml was observed at 2.33 +/- 0.22 h with test brand and was similar to that of reference brand with Cmax of 0.494 +/- 0.011 microgram/ml at 2.71 +/- 0.26 h. The statistical difference between all the other paharmacokinetic parameters were insignificant. CONCLUSION: Both the brands of azithromycin can be considered to be bioequivalent on the basis of results obtained.