Abstract
A simple, precise and stability-indicating HPLC method was developed and validated
for the simultaneous determination of metformin hydrochloride (MET) and vildagliptin
(VLG) in pharmaceutical dosage forms. The method involves use of easily available
inexpensive laboratory reagents. The separation was achieved on Grace Cyano column
(250 mm×4.6 mm) 5 µm with isocratic flow. The mobile phase was pumped at a flow rate
of 1.0 mL/min, consisted of 25 mM ammonium bicarbonate buffer and acetonitrile (65:35,
v/v). The UV detection was carried out at 207 nm. A linear response was observed over
the concentration range of 25–125 µg/mL for MET and 50–250 µg/mL for VLG respectively.
Limit of detection and limit of quantification for MET were 0.36 µg/mL and 1.22 µg/mL,
and for VLG were 0.75 µg/mL and 2.51 µg/mL respectively. The method was successfully
validated in accordance to ICH guidelines acceptance criteria for specificity, linearity,
accuracy, precision, robustness, and system suitability. Individual drugs (MET and
VLG) were exposed to thermal, photolytic, hydrolytic and oxidative stress conditions.
The resultant stressed samples were analyzed by the proposed method. The method gave
high resolution among the degradation products and the analytes. The peak purity of
analyte peak in the stressed samples was confirmed by photo diode array detector.
The proposed method was successfully applied for the quantitative analysis of MET
and VLG in tablet dosage form, which will help to improve quality control and contribute
to stability studies of pharmaceutical tablets containing these drugs.
Key words
antidiabetic drugs - LC-MS compatible - RP-HPLC - forced degradation - validation
