Quantitative Analysis of Flavokawain A by Derivative and Area Under Curve UV-Spectrophotometry

Abstract

This study aims to develop and validate UV-spectrophotometric techniques for the accurate and reproducible quantification of Flavokawain A in both bulk and in house tablet formulations. The methods include zero-order spectrophotometry (Method I), zero-order area under the curve (AUC) spectrophotometry (Method II), first-order derivative spectrophotometry (Method III), and first-order derivative AUC spectrophotometry (Method IV). Validation was performed following the International Council for Harmonisation (ICH) guidelines, evaluating parameters such as linearity, accuracy, precision, sensitivity, and robustness. Flavokawain A shows maximum absorbances at 362.80 nm. All methods exhibited excellent linearity over the concentration range of 1–7 µg/mL, with correlation coefficients (R²) exceeding 0.999. The LOD and LOQ values ranged from 0.07 to 0.08 µg/mL and 0.22 to 0.25 µg/mL, respectively, indicating high sensitivity. Precision studies yielded %RSD values below 2.0 across all methods, confirming reproducibility. Accuracy was validated through recovery studies, with mean recoveries ranging from 98.1 to 101.0%. In-house tablet analysis demonstrated the applicability of all methods for routine quality control, with % amount found between 99.7 and 101.8%. Overall, the developed UV spectrophotometric methods are simple, accurate, and precise, making them suitable for the routine quantification of Flavokawain A in pharmaceutical preparations and plant-based matrices.