[Pharmacokinetics of Nimodipine after Intraocular Administration in Rats]

Objective To explore the pharmacokinetics of nimodipine in plasma of rats after intraocular administration.Methods Totally 135 SD rats were randomly divided into three groups according to drug administration routes:intraocular(io group),intravenous (iv group),and intragastric (ig group). The doses were 5.0 mg/kg for IO and IV groups and 10.0 mg/kg for IG group. The serum nimodipine level was analyzed by high performance liquid chromatography. The main pharmacokinetic parameters were calculated and compared.Results The pharmacokinetic parameters in io group were as follows:C_max:0.52 mg/ml;t_max:5.0 min;and AUC_0-t:21.10 mg/(ml·min). The main pharmacokinetic parameters in iv group were as follows:C_max:3.62 mg/ml;and AUC_0-t:52.58 mg/(ml·min). The main pharmacokinetic parameters in ig group were as follows:C_max:0.20 mg/ml;t_max:5.0 min;and AUC_0-t:5.98 mg/(ml·min).Conclusions Nimodipine is rapidly absorbed after io administration,and the ophthalmic formulation has a higher bioavailability than the oral solution. Therefore,the io route may help to improve the treatment effectiveness of cardiovascular diseases.