RP-LC Method in Gradient mode for Combined Quantification of Metformin, Linagliptin, and Empagliflozin in Combination Tablets

It has been developed and validated an accurate, sensitive, precise, quick, and gradient reverse phase HPLC (RP-HPLC) technique for combined quantification of Metformin, Linagliptin, and Empagliflozin in raw materials and pharmaceutical combined tablets. With acetonitrile as the organic solvent, the best separation was achieved on a 250 mm x 4.6 mm i.d., 5µ-particle size Inertsil®-Octadecyl-silyl-3V-Reverse-Phase-C18-column with acetonitrile as the non-polar-modifier and Dipotassium mono-hydrogen phosphate buffers system [0.03M] in water with pH 3.0 adjusted with ortho-phosphoric acid (0.1 %v/v) in the gradient mode of elution as an elution solvent at a speed of 1.0 mL.min−1. UV detection was at 230-nm. Metformin had a retention time of 2.421 minutes, Linagliptin's was 8.187 minutes, and Empagliflozin's was 11.71 minutes. With a correlation coefficient of about 0.9999, the peak-response was obtained as a function of concentration over the range of 80-480 mcg/mL for metformin, 0.4-2.4 mcg/mL for linagliptin, and 0.8-4.8 mcg/mL for empagliflozin. Metformin, Linagliptin, and Empagliflozin were shown to have a percentage assay of 99.92, 99.72, and 99.74, respectively. Metformin, Linagliptin, and Empagliflozin, each have a limit of detection of 0.04 g/mL, 0.004 g/mL, and 0.004 g/mL, respectively. Metformin, Linagliptin, and Empagliflozin, each have a limit of quantification (LOQ) of 0.12 ng/mL, 0.012 g/mL, and 0.012 g/mL, respectively. The presence of excipients in the formulation had no effect on the assay method. The procedure is appropriate for usage in QC- laboratories since it is quick and precise.