Quantitative analysis of tiropramide in human plasma by gas chromatography coupled to mass spectrometry for application to a bioequivalence test

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.