Background: Metformin is the most used antihyperglycemic drug in diabetes, and therefore it is preferred to be
combined with other classes of antihyperglycemic drugs, specially gliptins. Formulating of these two classes of drug in
one pharmaceutical dosage form would be more efficacious to control hyperglycemia than having either drug alone.
Objective: This study was designed and performed to develop a new, simple, and reliable method of analysis for assaying
simultaneously five types of gliptins (Alogliptin, Linagliptin, Saxagliptin, Sitagliptin and Vildagliptin) and Metformin
which has not been documented before.
Methods: The present method was carried out using a C18 column (250x4.6 mm), 5μm particle size, mobile phase
consisting of water to acetonitrile ratio 85:15% (v/v) and the pH was set by orthophosphoric acid at 3, 10 μl injection
volume, 0.5 ml flow rate, 25oC temperature and the eluent was monitored at 232 nm.
Results: The selectivity of the assay showed no interference with inactive ingredients in the formulation, and the
%recovery from each drug dosage forms at three different concentrations were within the acceptable limits of the ICH
guidelines. Although the method showed robustness towards flow rate, it showed significant change at 230 or 234 nm.
Conclusion: The present analytical method is comprehensive and universal for measuring the five drugs and Metformin.
Such an analytical method can be applied to the present available combined drug dosage forms of Metformin and one type
of gliptins and the possible future of triple combinations of two gliptins and Metformin.