Calcium channel blocker （nifedipine）: pharmacokinetics in cochlear perilymph of guinea pig

Objective:To investigate the determination of nifedipine in perilymph of guinea pig. Methods:The guinea pigs were injected with nifedipine for one week, and then perilymphatic fluids of guinea pig were aspirated at 30min, 150min and 270min after injection. The nifedipine in perilymph was determined by using reversed phase high-performance liquid chromatography （RP-HPLC）.Results:The sensitivity introduced in our article is 5ng/ml. The average recovery is 98% at the concentration of 50ng/ml. The relative precision is 8.56%. The concentrations of nifedipine in perilymph of guinea pig range from 50.2 ng/ml to 124.2ng/ml. Conclusions:The study indicates that nifedipine has excellent penetration into perilymph. RP-HPLC can be used effectively in pharmacology determination of nifedipine in perilymph of guinea pig.