Author(s): K. Md Ismail, A. Lakshmana Rao* and MV. Basaveswara Rao
Sitagliptin is an oral hypoglycemic agent of the dipeptidyl peptides-4 (DPP-4) enzyme inhibitor used in the treatment of type 2 diabetes mellitus. It acts by stimulating the insulin release by the reduction of glucagon level in pancreas. The main objective of the present study was to develop and validate a simple and rapid liquid chromatography-mass spectrometric method for estimation of Sitagliptin in human plasma using Sitagliptin D4 as internal standard, K2EDTA as anticoagulant and a combination of ethyl acetate and nhexane as extraction solvent. Sitagliptin and Sitagliptin D4 were separated on Shimadzu UHPLC using Phenomenex, Gemini C18, 3µ, 100x4.6mm column and mobile phase composed of acetonitrile and 5mM ammonium formate pH 3.5 in a ratio of 50:50% V/V. UHPLC was operated at a flow rate of 0.8ml/min, run time of about 2.20mins, at column oven temperature of 35±1ºC and with isocratic flow mode. API-4000 (AB SCIEX) mass spectrometer was operated with positive polarity, turbo spray ionization and in multiple reaction monitoring (MRM) scan mode. The linearity was found to be in between 2.002ng/ml797.473ng/ml and the retention times of Sitagliptin and Sitagliptin D4 was found to be at 1.07min and 1.06min respectively. The Q1/Q3 values for Sitagliptin and Sitagliptin D4 was found to be 408.000/174.000 and 412.000/174.000 respectively. Both Sitagliptin and Sitagliptin D4 are stable for about 53hrs 32mins in auto sampler. The developed method was found to be specific, accurate, precise, linear and stable with high recovery and less matrix effect as per standard guidelines.