Abstract
Simple, accurate and sensitive spectrophotometric and RP-HPLC methods requiring no prior separation have been developed and validated for simultaneous estimation of Epalrestat and Methylcobalamin in tablet dosage form. The absorption correction method (method: A) is based on direct determination of Epalrestat at 389 nm and Methylcobalamin at 264 nm by correcting the absorbance of the Methylcobalamin at 264 nm by deducting standard absorbance of Epalrestat at 264 nm. The RP-HPLC method (method: B) was performed using Hyper chrome ODS, 250mm × 4.6mm, 5μ (particle size) as a stationary phase and Methanol: Water (80:20, v/v) as a mobile phase at 0.8 ml/min Flow rate. The detection was done at 210nm. The beer’s law was followed from 4-20µg/ml and 20-60µg/ml for method A and method B respectively. The proposed methods were validated according to ICH guideline (Q2R1) and the results for validation parameters were within specification limit for both the drugs. The proposed methods were applied for determination of Epalrestat and Methylcobalamin in the marketed formulation in which % assay was found to be 99.33% and 100.44 respectively by method A as well as 99.38 % and 97.77 % for same method B. The proposed methods were found to be accurate, precise, repeatable and robust so, these can be applied for routine analysis of both the drugs in their quality control.
