Development and validation of a UV spectrophotometric method for baicalin quantification in QbD-assisted Symplocos racemosa extract and nano-transferosomal gel: greenness and whiteness assessment

This study reports the development and validation of a simple, cost-effective and environmentally sustainable UV spectrophotometric method for the quantification of baicalin in Symplocos racemosa bark extract and its nano-transferosomal gel, using phosphate buffer as the diluent. Soxhlet extraction parameters were optimized using the Box–Behnken design through Design-Expert® software to improve extraction efficiency. The UV spectrum of reference standard baicalin revealed a characteristic maximum absorbance (λmax) at 274 nm, enabling selective spectrophotometric quantification. The developed method was validated according to ICH guidelines and demonstrated excellent linearity (R2 ≈ 0.999), accuracy, precision, sensitivity, specificity and robustness. The baicalin content was quantified as 8.663 ± 0.08 mg of baicalin per 10 mg extract, (86.63 ± 0.80% w/w) and baicalin content in the S. racemosa extract-loaded nano-transferosomal gel was found to be 0.796 ± 0.06 mg per 100 mg of gel, (0.796 ± 0.60% w/w). Forced degradation and short-term stability studies confirmed method suitability and analyte stability under experimental conditions. The environmental sustainability and analytical performance of the developed method were assessed using Analytical Eco-Scale, AGREE, GAPI, BAGI, RAPI, and Whiteness Evaluation for Chemical Analysis (WECA) assessment tools. The results demonstrated favorable greenness and whiteness characteristics, with scores of (AGREE = 0.72, Eco-Scale = 76 and BAGI =80, RAPI = 67.5, WECA = 88) indicated favorable greenness, whiteness, and analytical performance. Overall, the developed UV spectrophotometric method offers a sustainable, reproducible, and regulatory-compliant analytical platform for cost-effective routine quality control and phytopharmaceutical standardization.