Study on the Pharmacokinetics of Naftopidil Sustained-release Capsule in Dogs / 中国药房

ABSTRACT

OBJECTIVE:To study the pharmacokinetics and the bioavailability of naftopidil sustained-release capsules. METHODS:Naftopidil capsule and sustained-release capsules were given to five healthy male dogs respectively in an open randomized cross-over test.Naftopidil concentrations in plasma were determined by HPLC method.The pharmacokinetics parameters and the relative bioavailability were measured and compared between naftopidil capsules and sustained-release capsules.RESULTS:A one-compartment open model with first-order absorption kinetics best fitted the concentration-time data.The T 1/2 ,AUC 0～∞ ,C max and T max of naftopidil capsule were3.2?1.1h,3728.1?573.1ng?h/ml,697.5?94.2ng/ml and1.2?0.59h,these pharmacokinetics parameters of sustained-release capsules were5.9?0.8h,5518.3?391.1ng?h/ml and468.6?61.3ng/ml and4.0?0.7h respectively.The relative bioavailability of naftopidil sustained-release capsules was149.8?14.4%when compared with naftopidil capsules.CONCLUSION:Naftopidil sustained-release capsules have satisfactory property in slow release of drug and much higher bioavailability than naftopidil capsules.