Implementation of Quality by Design Approach to Develop and Validate Analytical Method for Simultaneous Estimation of Duloxetine Hydrochloride and Methylcobalamin in Pharmaceutical Dosage form by RP-HPLC Method
Quality by Design (QbD) is a philosophy that refines the level of knowledge associate with a product and process to deliver a product with the desired critical quality attributes. The objective of study is to develop and demonstrate multivariate Quality by Design approach and to quantify the constitute concentration of Duloxetine HCl and Methylcobalamin drugs in standard mixture and capsule dosage form by reversed phase high-performance liquid chromatography method. The developed method employed mobile phase 0.05 M Potassium dihydrogen phosphate buffer (pH 3.5±0.05): Methanol (70:30, v/v) and flow rate 1.0 mL/min which was optimized with help of design expert software. Method was developed using column Hypersil BDS C18 and detection wavelength at 215 nm. The retention time was 6.94±0.09 and 4.83±0.16 minutes for Duloxetine HCl and Methylcobalamin respectively. High linearity of the developed method was confirmed over concentration range of 30-90 μg/mL for Duloxetine HCl and 1.5-4.5 μg/mL for Methylcobalamin. Limit of detection (LOD) and limit of quantification (LOQ) were found to be 1.51 and 4.58 μg/mL for Duloxetine HCl as well as 0.09 and 0.28 μg/mL for Methylcobalamin, respectively. The method was validated for precision, accuracy, robustness, limit of detection and limit of quantification according to International Conference on Harmonization guidelines. The results show that the Quality by Design concept can be effectively applied to optimize method with fewer trials and error-free experimentation.