Green metrics-based HPLC method for quantification of three antidiabetic drugs in tablet dosage form using Box–Behnken design

Abstract

This paper describes the systematic development of green and sustainable HPLC method for quantification of antidiabetic drugs teneligliptin hydrobromide hydrate, metformin hydrochloride and pioglitazone HCl in tablet formulation using Box–Behnken design. Box–Behnken design was used to know the influence of identified critical method parameters, volume of acetonitrile, flow rate and column temperature on the retention time of all three drugs and resolution between two drugs. Statistical analysis by Analysis of variance was computed to understand the potential interactions among critical method parameters. Further mathematical model was validated by using statistical and graphical optimization to define the design space. From the three parameters under investigation the study revealed that the response was more influenced by slight change in volume of acetonitrile, demanding its strict control. A mixture of KH₂PO₄ phosphate buffer (20 mM): acetonitrile: methanol (40:30:30%v/v) was employed as the mobile phase for chromatographic separation using octadecyl silyl column (250 × 4.6 mm, 5 µm). Detection was performed at 236 nm and 0.86 ml/min was set as the flow rate of mobile phase. The linearity was observed in the range of 12–28 µg/ml for Teneligliptin hydrobromide hydrate, 300–700 µg/ml for Metformin hydrochloride and 9–21 µg/ml for Pioglitazone hydrochloride as shown by r² ≥ 0.99 for all three drugs. Retention time of Teneligliptin hydrobromide hydrate, Metformin hydrochloride and Pioglitazone hydrochloride was 4.09, 3.01 and 11.44 min, respectively. The % relative standard deviation for accuracy, precision and robustness were all within the specification, less than 2, which indicates that method was validated properly as per guideline. The studies successfully demonstrate the application of Box–Behnken design in the development of accurate and sensitive liquid chromatographic technique with enhanced method performance. Furthermore, greenness of the analytical method was assessed using 12 principles of green analytical chemistry by AGREE, complex GAPI and Analytical eco-scale tool, indicating that the developed method was ecofriendly.