Abstract

PHARMACOKINETIC EVALUATION OF ONCE-DAILY SUSTAINED RELEASE DEXTROMETHORPHAN HYDROBROMIDE (DM) AND IMMEDIATE RELEASE DM IN HEALTHY HUMAN VOLUNTEERS

Dr. Socorrina Colaco*, Ramesh N., Sekar Rajan and Subramania Nainar Meyyanathan

Abstract

The pharmacokinetic study of a newly developed sustained-release dextromethorphan hydrobromide tablet was studied in six healthy human volunteers after single oral administration and compared with an immediate release tablets (IR) in randomized three-period crossover design. A sensitive and rapid HPLC method was developed and validated for the quantitative determination of dextromethorphan hydrobromide in human plasma. The compound and the internal standard (I.S.) (Losartan Hydrochloride) were extracted from the plasma samples by solid phase extraction. The extracts were analyzed by a reversed-phase HPLC with 0.5% triflouro acetic acid: acetonitrile (45:55, v/v) as the mobile phase. The calibration curves were linear in the range between 110.00 to 3000.00 ng/mL. The overall precision (expressed as R.S.D.) of quality controls were within 15%. The method was successfully applied to the pharmacokinetic study of dextromethorphan hydrobromide in the three formulations. The Cmax of sustained-release tablet (SR) was significantly lower than that of the IR and the Tmax was significantly longer than that of the IR.

Keywords: HPLC; Dextromethorphan sustained release tablet; pharmacokinetics; healthy volunteers.