Development And Validation Of Stability Indicating RP- HPLC Method For Simultaneous Estimation Of Lobeglitazone And Metformin In Tablet Dosage Form

Background: A simple, rapid, sensitive and selective stability-indicating (RP-HPLC) method is suggested for the determination of Lobeglitazone and Metformin in pharmaceutical formulation. Lobeglitazone and Metformin was eluted from a Cosmosphere C18 (250×4.6 mm, 5 µm) column with mobile phase consisting of methanol, Acetonitrile and Potassium Dihydrogen Phosphate Buffer 2.5 pH (70:5:25 %v/v/v) pH adjusted to 2.5 with Orthophosphoric acid. The gradient was optimized with a flow rate of 0.8 mL/min and a wavelength of 250 nm. Result: The complete analytical method validation was successfully carried out as per ICH guidelines. The retrieval study was carried out at 50% to 150% level of working concentration, and results were in the range of 98 to 102%. The linearity was proven in range of 0.5-0.25μg/ml µg/mL of working concentration of Lobeglitazone and 50-250μg/ml µg/mL of working concentration of Metformin with linear regression curve (R2 = 0.999) with limits of detection (LOD) and quantitation (LOQ) being 0.0010 and 0.0031 µg/mL for Lobeglitazone and 0.30 and 0.91 µg/mL for Metformin respectively. The retention time for Lobeglitazone was 8.37 min and for Metformin was 2.83 min. The method shows good recoveries and intra-day and inter-day relative standard deviations were less than 2%. Validation parameters as ruggedness and robustness were also determined as per ICH guidelines and were found to be satisfactory. For stability study, the drug was exposed to various stress conditions such as acid, base, oxidation, Thermal and sunlight as per recommendations of ICH guidelines. Conclusion: The developed HPLC method could be successfully used for the estimation of Lobeglitazone and Metformin in pharmaceutical formulation. The high recovery and low relative standard deviation confirm the suitability of proposed method that can be employed for the routine analysis in bulk and pharmaceutical formulation.