ABSTRACT
Objective: To develop and validate a sensitive liquid chromatography-electrospray ionization-tandem mass spectrometric (LC-ESI-MS/MS) technique for the quantification of dapagliflozin and saxagliptin in plasma by linagliptin as internal standard. Methods: Chromatography was achieved on hypersil C18 (50 mmx4 mm) 5 µ analytical column with 0.1% formic acid and acetonitrile (25:75 V/V) as mobile phase at 0.7 ml/min flow rate. Dapagliflozin, saxagliptin, and linagliptin were detected at m/z 409.14/135.0, m/z 316.2/180.13 and m/z 472.54/456.21 respectively. Drugs and internal standard were extracted by LLE (liquid-liquid extraction). Results: Developed technique was validated over 0.5-1500.0 ng/ml linear concentration range for dapagliflozin and 2.00-2000.0 ng/ml for saxagliptin. This method established with intra-batch and inter-batch precision within 2.44-8.12% and 1.25-7.14 % for dapagliflozin and 1.84-7.5 % and 1.02–6.00 % for saxagliptin. This method established with intra-batch and inter-batch accuracy for dapagliflozin within 98.86-103% and 96.98-102 % respectively and for saxagliptin within 98.05-109.06 % and 97.00-104.00 % respectively. Conclusion: Both dapagliflozin and saxagliptin were stable during three freeze-thaw cycles, long term and bench-top stability studies. The developed method was useful for the routine analysis of dapagliflozin and saxagliptin simultaneously in plasma samples.