A Novel Validated Stability Indicating Analytical Method for Simultaneous Quantification of Metformin Hydrochloride and Empagliflozin in Bulk and Marketed Formulation by HPTLC using Box-Wilson Experimental Design Approach

Background: A novel stability indicating analytical method was developed and validated by High Performance Thin Layer Chromatography (HPTLC) using Design of experiment approach. The proposed method is useful for quantification of Metformin hydrochloride and Empagliflozin in bulk and its dosage forms simultaneously. Design of experiment approach was applied for optimization of chromatographic conditions. Materials and Methods: For optimization process independent variables were used as Isopropyl alcohol proportion in mobile phase, saturation time of chamber and distance travelled by mobile phase. Experiments were carried out on silica gel pre-coated plate using mobile phase as 2 % Ammonium acetate: Isopropyl alcohol: Triethylamine (4:6:0.1 v/v/v). Direct evaluation of chromatograms were done by TLC scanner with reflectance/absorbance mode set at 242 nm. Method was validated as per ICH Q2 (R1) requirements. Results: Correlation coefficients for calibration curves were found to be 0.985 and 0.988, the calibration curve is in concentration range of 5000-30000 ng band-1 and 125–750 ng band-1 for Metformin hydrochloride and Empagliflozin respectively. The method showed % recovery between 99.05 to 102.54 % for Metformin hydrochloride and 99.20 to 101.50 % for Empagliflozin. The method has a prospective to determine Metformin hydrochloride and Empagliflozin simultaneously. The Metformin hydrochloride and Empagliflozin were subjected to forced degradation studies like hydrolysis, oxidation, thermolysis and photodegradation. Conclusion: Proposed method has capacity to separate the Metformin hydrochloride and Empagliflozin in its degradation products. Hence one can apply this method effectively for routine analysis and during stability study as per regulatory requirements.