Pharmacokinetcs and bioequivalence of azithromycin dispersible tablets in healthy volunteers

Objective To improve the determination of azithromycin in human plasma,and study the relative bioavailability of azithromycin dispersible tablets.Methods A single oral dose of 500 mg test and reference formulations was given to 20 healthy volunteers in a randomized cross-over study.Sample(0.1 mL) was determined by HPLC-MS/MS after proteinum precipitation by acetonitrile.DAS 2.0 was used to assess pharmacokinetcs bioavailability and bioequivalence of azithromycin dispersible tablets.Results The linear range of the calibration curves was 1~1000 ng·mL-1 for azithromycin with a lower limit of quantitation(1ng·mL-1).Within-and between-run precision was less than 10%.Accuracy ranged 97%~110%.The recovery was above 91%.The main pharmacokinetic parameters t1/2,tmax,Cmax,AUC0~t,AUC0~∞were(40.3±6.5)h,(2.1±0.7)h,(541.7±179.4)ng·mL-1,(4 772.4±913.9) ng·h ·mL-1,(5 346.9±1 300.0) ng·h ·mL-1 and(35.6±5.1)h,(1.8±0.5)h,(584.9±147.3) ng·mL-1,(5 059.5±1 347.4) ng·h ·mL-1,(5 480.5±1 484.3) ng·h ·mL-1,respectively.The relative bioavailability of azithromycin test reference was(99.4%±28.3%).Conclusion The present method is sensitive,effiective,and reliable.The method described has been successfully used for bioequivalence study of an azithromycin formulation product.The test and reference azithromycin dispersible tablets are bioequivalent.