Development and Validation of a UV Spectrophotometric Method for Evaluating Entrapment Efficiency of Karanjin-Loaded Phytosomes: A Quality by Design Approach

The present study successfully establishes a Quality by Design (QbD)-oriented UV spectrophotometric method for the analysis of karanjin and its application in the characterization of nanoformulations, specifically for assessing entrapment efficiency. Methanol was determined to be the most suitable solvent, with peak absorbance observed at 260 nm. To enhance accuracy and precision, a central composite design (CCD) was utilized to optimize both sonication time and scanning interval. The method underwent statistical validation via ANOVA analysis, which confirmed its robustness with a significant p-value of less than 0.0001. The validation process adhered to the ICH Q2 (R1) guidelines, demonstrating exceptional specificity and selectivity without any interference from solvents. The method displayed linearity within the range of 2–10 µg/mL (r² = 0.9942), with a limit of detection (LOD) established at 3.09 µg/mL and a limit of quantification (LOQ) at 9.38 µg/mL. The method's reliability was further supported by precision (%RSD < 2%) and accuracy (98.35%–100.45%). Assessments of ruggedness and robustness confirmed its reproducibility across various analysts and wavelengths. This method was effectively utilized to characterize a karanjin-loaded phytosome formulation, achieving an entrapment efficiency of 77.90%. This efficient and cost-effective validated UV method demonstrates significant potential for routine analysis of karanjin in pharmaceuticals and for the characterization of nanoformulations.