Estimation of tegaserod in human plasma by high-performance liquid chromatography-tandem mass spectroscopy and its application to bioequivalence study

A sensitive and novel HPLC-tandem mass spectrometric method has been developed for the estimation of tegaserod in human plasma using atorvastatin as internal standard. The methodology involved solid phase extraction (SPE) of the analyte from human plasma, using the Water's Oasis® HLB 1 cm3 (30 mg) cartridges. The chromatographic separation was achieved within 5 min on XTerra MS C18, 100 mm × 2.1 mm i.d., 3.5 μm analytical column with an isocratic mobile phase containing a mixture of acetonitrile and 0.2% formic acid in water (50:50, v/v) flowing through it at the rate of 0.3 ml/min. Multiple reaction monitoring (MRM) transitions; m/z 302.2, 173.2 and 559.0, 439.7 were measured in positive mode for tegaserod and internal standard, respectively. A detailed validation of the method was performed as per USFDA guidelines. The standard curves were linear in the range 0.2-20.0 ng/ml with the mean correlation coefficient more than 0.99. The absolute recovery for tegaserod was more than 70%. The method was simple, sensitive, precise, accurate and suitable for routine bioequivalence and pharmaco-kinetic studies. The method was successfully applied to the bioequivalence study of tegaserod tablets in healthy, male human subjects.