Research Journal of Pharmacy and Technology

The use of analytical quality by design (AQbD) process in the optimization of the high-performance liquid chromatography (RP-HPLC) method is a novel tool. The major stages of AQbD such as Risk assessment, Designing of Experiments (DOE) and Development of Method Operable Design Region (MODR) methodology are explained in detail. Factors like flow rate, column length and buffer and responses like retention time, tailing, peak area were selected to create a custom experiment design that was utilised for Epalrestat method analysis and optimisation. The optimized HPLC condition was found as NaH₂PO₄: Methanol (10: 90%v/v), flow rate (1.1ml/min), and UV wave length (240nm). It gives the retention time of 2.877 min with the linearity range of 50–150 μg/ml with a high regression value (r² = 1), and %recovery was found to be 100%. Sensitivity evaluation revealed limit of detection and limit of quantification were found to be 0.082 μg/ml and 0.2μg/ml respectively. The method was found to be precise and accurate with low % RSD of 0.2%, degradation studies were carried as per ICH Q₂R₁. Prediction profiler and contour plots by custom design which also confirms the robustness of the method.