Development of eco-friendly and sustainable analytical methods for Ritonavir through white analytical chemistry and AQbD approach

The present research study outlines the development and validation of a cost-effective, eco-sustainable, and robust analytical procedure for the quantitative estimation of Ritonavir in bulk and tablet dosage form using UV Spectrophotometry and Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC). The RP-HPLC method was developed and optimized using an Analytical Quality by Design (A-QbD) approach using a Box-Behnken design, considering the critical analytical variables of ethanol concentration, flow rate, and column temperature. The optimized chromatographic procedure using ethanol-water (65:35, v/v) as mobile phase, 1.0 mL/min flow rate, and 30 °C column temperature yielded well-resolved symmetrical peaks with 6.33 ± 0.2 min retention time and 1.24 tailing factor. The optimized UV method at λmax = 239 nm in the ethanol-water mixture provided excellent linearity (20–100 µg/mL; R² = 0.9991), comparable to the HPLC method (5–25 µg/mL; R² = 0.9995). Both methods were validated as per the ICH Q2(R1) guidelines and showed high precision, accuracy, and reproducibility. The assay values were found to be 99.02 ± 0.36% (UV) and 99.16 ± 0.15% (HPLC) of the labeled claim. The sustainability of the environment was measured using the AGREE, Complex GAPI, and White Analytical Chemistry (WAC) scales, which showed high greenness and whiteness values, indicating low toxicity and waste generation compared to the conventional acetonitrile-based methods. The two-green UV-HPLC analytical system provides a sustainable, sensitive, and regulatory-compliant method for the quality control of Ritonavir and can be applied to other antiretroviral drugs.