Pharmacokinetics of nifedipine matrix sustained-release pellets in rats and the relationship with CYP3A4 / 中国药科大学学报

ABSTRACT

@#To conduct the characterization of its pharmacokinetics in rats of nifedipine sustained-release pellets and to study the relationship between the pellets and CYP3A4 activity. A gradient HPLC method was developed to simultaneously determine 6β-hydroxycortisol and hydrocortisone. CYP3A4 activity of rats was quantified by urinary ratio of 6β-hydroxycortisol/hydrocortisone after intravenous injection of hydrocortisone as a biomarker. HPLC method was also developed to quantify the drug concentration in plasma of rats, and the studies of pharmacokinetics were performed after oral administration of single dose of two formulations Nifedipine matrix sustained-release pellets and nifedipine tablet(using as control). The results showed that the ratio of ten rats was 0. 271±0. 129. cmax of nifedipine sustained-release pellets decreases by nearly 70%, tmax significantly increased by 400% and t1/2 and MRT significantly increased by 230% compared to control. Nifedipine sustained-release pellets had a significant sustained-release property compared to the control and CYP3A4 activity affected its pharmacokinetics behavior.