QbD and green metric based HPLC method development and validation of bromocriptine mesylate in bulk product and biological samples.

Bromocriptine mesylate (BM) is a well-established antiparkinsonian drug, yet its analytical methodologies remain limited in terms of efficiency, cost-effectiveness, and reproducibility from commercial product and biological samples. We aimed at systematic analytical quality by design-assisted method development for routine quantitative assessment. Initially, various plausible variables (peak area, retention time, tailing factor, and plates) were screened using Ishikawa fishbone method. Following risk estimation studies, factor screening exercise was conducted employing a Taguchi design (TgD) for selecting various significant variables. Furthermore, a central composite-design (CCD) was conducted to delineate operable conditions and design space verification using Monte Carlo simulations. In the optimization, flow rate (X as A) and the injection volume (X as B) were two significant factors against four responses (Y: peak area, Y: retention time, Y: Tailing factor and Y: Theoretical plate count). The method was validated by estimating validation parameters as per ICH guidelines under environmentally sustainable conditions (using AGREE tools). Finally, optimized mobile phase composition (Acetonitrile (ACN): Trifluoroacetic acid (TFA) 70:30) and the flow rate (0.9 mL.min) were set as the optimal chromatographic conditions. The method was found to be highly robust, precise, and sensitive, with a wide linearity range of 0.2-100 μg/mL. Conclusively, AQbD paradigms coupled with simulations enabled in selecting environmentally sustainable and influential method variables, and arriving at the "best possible" chromatographic conditions for effective quantification of BM.