Background: Tiropramide is used as an antispasmodic agent. A sensitive, selective and simple gas chromatography coupled to mass spectrometry (GC/MS) was developed for quantification of tiropramide in human plasma using internal standard (ISD, (+/-) alpha-benzoylamino-4-[2-(dimethylamino) ethoxy]-N,N-dipropylbenzenepropanamide).
Methods: Tiropramide and ISD were extracted from plasma by solid-liquid extraction and analyzed on a HP-5MS column with mass selective detector.
Results: The retention times of tiropramide and ISD were approximately 9.8 and 10.2 min, respectively. The calibration curve showed good linearity in the concentration range 5-500 ng/ml (r2=0.998) for tiropramide in human plasma and showed good precision with CVs between 0.24% and 7.69%, respectively. The method was showed good accuracy with all intra-day (n=5) and inter-day (n=5) mean concentrations within 87.9-114.1% from nominal. The recovery of tiropramide and ISD were about 75.1% and 71.0% on the average, respectively. This method was successfully applied for the bioequivalence test of 2 formulations of tiropramide in 18 healthy male volunteers who received a single 100 mg dose of each formulation.