Relative bioavailability and pharmacokinetics of azithromycin tablet in healthy volunteers

Objective To study the pharmacokinetics and relative bioavailability of azithromycin tablets in healthy volunteers. Methods The serum concentrations of azithromycin of two formulations were determined by microbiological assay in 19 healthy male volunteers after a single oral dose of 500 mg of azithromycin in a randomized, crossover study. The serum samples were collected at various peroids after oral administration.Results Both concentration time curves of test and reference formulations were fitted to the two compartment open modle. The main pharmacokinetic parameters were as followings: t1/2β were (34.61±7.42) h and (31.16±5.28) h;tmax were (2.60±0.21 ) h and( 2.55±0.16) h;Cmax were (557.15±129.57) μg·L-1 and (548.34±137.46) μg·L-1; AUC0-tn(8.45±2.29) h·μg·L-1 and(8.66±2.34) h·mg·L-1.The relative bioavailability of tested to reference tablets was(99.35±19.77)%.Conclusion The two formulations are bioequivalent .