Application of Taguchi OA and Box-Behnken Design for the Implementation of DoE-based AQbD Approach to HPTLC Method for Simultaneous Estimation of Azilsartan and Cilnidipine.

Hypertension is the most prominent disease found in people due to stressful routines and the working environment. The fixed-dose combination (FDC) of azilsartan medoxomil (AZL) and cilnidipine (CLN) is used for the treatment of hypertension. According to the green chemistry approach, organic solvents should be minimized in the development of the analytical method for the safety of the environment. The high-performance thin-layer chromatographic (HPTLC) method required less amount of organic solvent for the analysis of the drug. Hence, it was thought of interest to develop an accurate and robust HPTLC method for the estimation of AZL and CLN in their FDC. The development of the method was carried out by the implementation of the analytical quality by design approach using the Taguchi orthogonal array and BBD for regulatory compliance as per the upcoming ICH Q14 guideline. The analytical design space and control strategy was framed for the lifecycle management of the method. The chromatographic separation was performed using silica gel GF254 and toluene ethylacetate-methanol (6.5 + 1.5 + 2.0, v/v). The method was applied for the assay of FDC and results were found in compliance with the labeled claim. The developed method was also applied for the estimation of spiked human plasma and the recovered amount of drugs was found in the range of 80-85%.