IMPLEMENTATION OF QBD APPROACH TO DEVELOP AND VALIDATE ANALYTICAL METHOD FOR SIMULTANEOUS ESTIMATION OF DULOXETINE HYDROCHLORIDE AND METHYLCOBALAMIN IN PHARMACEUTICAL DOSAGE FORM BY HPTLC METHOD

Objective: To develop and validate High-Performance Thin Layer Chromatography (HPTLC) analytical method for the determination of Duloxetine Hydrochloride (DUL) and Methylcobalamin (MEC) in the standard mixture and pharmaceutical capsule dosage form by implementing Quality by the Design (QbD) approach.Methods: The chromatographic separation was performed on aluminium plates precoated by silica gel 60 F-254 using propanol: water: 25% v/v ammonia solution (9:2:1, v/v/v) as a mobile phase which was optimized with the help of a design expert. Densitometric analysis was carried out in the absorbance mode at 280 nm.Results: Compact spots for Duloxetine HCl and Methylcobalamin were found at retardation factor (Rf) value of 0.77±0.02 and 0.55±0.03, respectively. The linear regression analysis data for the calibration plots showed correlation coefficient 0.9989 and 0.999 with a concentration range of 1200-3600 ng/spot and 60-180 ng/spot for Duloxetine HCl and Methylcobalamin respectively. Limit of detection (LOD) and limit of quantification (LOQ) was found to be 113.39 and 343.62 ng for Duloxetine HCl and 6.68 and 20.24 ng for Methylcobalamin, respectively. The method was validated for precision, accuracy, robustness, LOD and LOQ according to ICH Q2 R1 guidelines.Conclusion: A new, simple, accurate, and precise HPTLC analytical method has been developed and validated for the determination of Duloxetine HCl and Methylcobalamin in pharmaceutical capsule dosage form by QbD concept in favour of fewer trials and error-free experimentation for the optimization process. The method seems to be suitable for the quality control in the pharmaceutical industry because of its sensitivity, simplicity, and selectivity.Keywords: Duloxetine HCl (DUL), Methylcobalamin (MEC), Quality by Design (QbD), HPTLC, Validatio