Innovative TLC-densitometric method with fluorescent detection for simultaneous determination of ternary anti-diabetic mixture in pharmaceutical formulations and human plasma

Abstract Co-administration of Glimepiride (GLIM), Empagliflozin (EMPA) and Linagliptin (LING) promote a preferred glycemic control, besides additional benefits such as reduction of high blood pressure and weight loss. In the present study a feasible TLC method with reflectance/ fluorescence mode for simultaneous determination of GLM, EMPA and LING was established. Separation of the cited drugs was performed on aluminum plates pre-coated with silica gel 60 F254 and developed with (toluene: methanol: ethyl acetate (4: 3: 2 v/v/v)) as a mobile phase. The mentioned drugs were adequately detected after exposing the plate to concentrated (30 - 34%) hydrochloric acid vapor for 15 min. The was scanned in the reflectance/fluorescence mode at 228 nm excitation wavelength using 320 nm emission filter. The three drugs were well separated with Rf values of 0.73 ± 0.02, 0.59 ± 0.02 and 0.10 ± 0.02 for GLIM, EMPA and LING, respectively. The developed method was validated according to ICH guideline with linearity (2.61- 60, 5.53 –120 and 4.68 - 80 ng/band for GLIM, EMPA and LING, respectively) and precision (% RSD was ± 2.98 for GLIM, 2.76 for EMPA, 2.41 for LING). The correlation coefficients were 0.9915, 0.9940 and 0.9921 for GLIM, EMPA and LING, respectively. The developed method was successfully applied for the analysis of the cited drugs in their tablets and real human plasma samples with good accuracy and precision.