Development and Validation of Stability Indicating RP-HPLC Method for Determination of Daridorexant Drug Using AQbD Approach

The current aim of the research is to design and validate the RP-HPLC method systematically for the bulk analysis of Daridorexant which is simple to use, fast, precise, and economical. This employs analytical quality by design techniques to optimize chromatographic parameters for the routine analysis of Daridorexant. The critical process parameters were optimized using a custom design. A risk assessment matrix was developed to identify the risk associated with the development of the method and the simultaneous linkage of critical analytical attributes and critical method attributes. The RP-HPLC column was programmed in the isocratic elution mode with methanol and KH2PO4 buffer as mobile phase at the flow rate of 1mL per minute with variable ratio for the process development of the RP-HPLC technique. An Intersil C18 column was employed for the chromatographic separation process. The optimized technique from JMP 17 PRO software yielded a desirability function of 73.70%, using a mobile phase ratio of 70:30 (methanol and 0.1N KH2PO4) and a flow rate of 1 ml/min. The results confirmed the LOD and LOQ were found to be 0.232 mcg/mL and 0.773 mcg/mL. It concluded that Daridorexant had a retention time (Rt) of 3.549 minutes. In compliance with ICH Q2 (R1) specifications, this method was developed, approved, and validated. The models were statistically significant with a p-value < 0.0003 for the selected responses. The validation parameters evaluated were within acceptable limits. Stress testing revealed that the drug’s stability deteriorated significantly when subjected to heat and acid stress. Major Findings: A robust and sensitive RP-HPLC method was developed and validated for the stability analysis of Daridorexant using AQbD principles. The method, optimized with an Intersil C18 column and validated per ICH Q2 (R1) guidelines, demonstrated high precision, sensitivity (LOD: 0.232 mcg/mL, LOQ: 0.773 mcg/mL), and stability-indicating capability. It can be applied to pharmaceutical formulations, bioanalytical studies, and routine quality control.