Abstract
Obesity, impaired glucose tolerance, and hypertension are often related and represent a major health burden in modern societies. Telmisartan (TEL) and Metformin HCl (MET) are widely used for the management of these commonly associated diseases. Few attempts have been made for the determination of TEL and MET in human plasma by liquid chromatography tandem mass spectrometry. This study describes the first chromatographic method for the simultaneous quantitation of TEL and MET in human plasma by ultra-performance liquid chromatography coupled to quadruple tandem mass spectrometry (UPLC–MS/MS). Chromatography was performed on aC18 column with isocratic elution using a mobile phase consisting of acetonitrile, water and formic acid (88.2 11.7: 0.1), at a flow rate of 250 μL/min for a total run time of 2 min. Losartan (LOS) was used as the internal standard. Mass spectrometric analysis was carried out by a TSQ Quantum Access MAX triple quadruple system coupled with electro spray ionization (ESI) source in the positive ion mode. The assay was validated over a concentration range of 10–100 ng/ml for both drugs. The precision and accuracy for both intra- and inter-day determination of all analytes were acceptable (<15%). Stability of the compounds was established for short term bench and auto sampler storage as well as freeze/thaw cycles. Moreover, the method was successfully applied to a pharmacokinetic study in six healthy volunteers who had been given a single oral dose of metformin HCl and telmisartan, 500 mg and 40 mg, respectively.
Keywords: Metformin, pharmacokinetics, plasma, tandem MS, telmisartan, UPLC.
Graphical Abstract
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