Red, Green, and Blue Model-Based Assessment and Principles of White Analytical Chemistry to Robust Stability-Indicating Chromatographic Estimation of Thiocolchicoside and Diclofenac Sodium.

Background: White analytical chemistry (WAC) is a recent approach for evaluating analytical procedures based on their effectiveness in validating results, capacity to be environmentally friendly, and economic effectiveness.

Objective: The detection of diclofenac sodium (DCF) and thiocolchicoside (THC) simultaneously has been established using a WAC-driven stability-indicating chromatographic method (SICM).

Methods: For the concurrent stability study of THC and DCF, the suggested chromatographic technique was developed employing safe and environmentally acceptable organic solvents. To identify critical analytical method parameters (AMPs) and analytical quality attributes (AQAs), a design of experiments (DoE)-based screening design was applied. For the DoE-based response surface modelling (RSM) of critical AMPs and AQAs, the Box-Behnken design (BBD) was employed.

Results: A robust SICM was developed by navigating the analytical design space for simultaneous estimation of THC and DCF. IR, NMR, and mass spectral data were used to characterize the degradation products. Red, green, and blue (RGB) models were used to evaluate the suggested method's validation effectiveness, greenness power, and economic efficiency and compared to published chromatographic techniques. The effectiveness of the chromatographic method's validation concerning the International Council for Harmonization (ICH) Q2 (R1) guideline was evaluated using the red model. The analytical greenness (AGREE) evaluation tool and eco-scale assessment (ESA) approach were used to evaluate the green model's methodology. The blue model-based assessment was carried out for comparison of simplicity of instruments handling, cost, and time during sample analysis. The red, blue, and green scores of the techniques were averaged to arrive at the white score of the suggested and reported methods.

Conclusion: For the concurrent stability study of THC and DCF, the suggested technique was shown to be validated, environmentally friendly, and cost effective. The suggested approach could be a cost-effective and environmentally friendly analytical technique for determining the stability and monitoring the quality of fixed-dose combinations (FDC) of THC and DCF.

Highlights: Stability-indicating HPTLC method was developed for concomitant analysis of THC and DCF using concepts of DoE and WAC.