Development and validation of rapid ultra high performance liquid chromatography with tandem mass spectroscopic method for the quantification of N-nitrosodimethyl amine and N-nitrosodiethyl amine in sitagliptin and metformin hydrochloride immediate and extended-release formulations.

ABSTRACT

A simple, effective LC-MS based method is developed and validated to determine N-nitrosodimethylamine and N-nitrosodiethylamine in pharmaceutical formulations of Sitagliptin and Metformin hydrochloride combination dosage forms. Atlantis T3 (100 × 3 mm, 3 µm) column, eluent-A (0.1% formic acid in water), and eluent-B (0.1% formic acid in methanol) were used to achieve chromatographic separation. A gradient program time (min)/%B 0.01/3, 2/3, 4/55, 5/55, 5.5/90, 6.0/90, 6.5/3, and 7/3, and column flow rate 0.75 mL/min was employed. The column oven and auto sample cooler temperatures were 40°C and 10°C, respectively. Atmospheric Pressure Ionisation positive mode with corona discharge potential as 4.0 V, drying gas (N2 ) flow as 110 mL/min, and nebulizer gas (N2 ) flow as 350 mL/min. Employing PerkinElmer triple quadrupole mass spectrometer, QSight 200 series, the source temperature was 450°C, and hot surface-induced desolvation temperature was 250°C. Under optimized conditions, diluent-1 and diluent-2 offered better recovery and improved peak shapes. The required method sensitivity of nitrosodimethylamine (LOQ 0.74 ng/mL) and nitrosodiethylamine (LOQ 0.37 ng/mL) for the nitrosamine impurities were achieved using an optimized test concentration of Metformin hydrochloride at 45.7 mg/mL.