Relative bioavailability and pharmacokinetics of azithromycin in healthy volunteers

Aim: To study the pharmacokinetics and relative bioavailability of azithromycin in healthy volunteers. Methods: The serum concentraions of azithromycin of two formulations were determined in 8 healthy male volunteers after an oral dose of 1000 mg azithromycin granules or capsules in crossways. The serum and urine samples were collected at various periods after oral administration. The serum and urine concentrations of azithromycin were determined by microbiological method. Results: The concentration time curves of azithromycin granules and capsules were fitted to the two compartment open model. The C max values were (1.77±0.42)mg/L and (1.78±0.63) mg/L,the T\- max values were (1.88±0.64) h and (1.88±0.35) h and the AUC were (16.69±3.20) mg·h·L -1 and (16.95±3.09) mg·h·L -1 , respectively. The relative bioavailability of granules to capsules were (101.97±10.46)%. Conclusion: It is suggested that the 2 formulations are bioequivalent.