METHOD DEVELOPMENT AND VALIDATION FOR THE SIMULTANEOUS ESTIMATION OF THYMOL AND EUGENOL BY USING RP-HPLC IN PURE AND IN EMULGEL FORMULATION

Abstract

An attempt was made to develop a simple, selective, rapid and precise high-performance liquid chromatography (HPLC) method for simultaneous estimation of thymol and eugenol. Analysis was performed on a C18 column with the mobile phase consisting of solvent %A (water) and solvent %B (acetonitrile) with the following gradient: 0–1 min, 80 % A, 20 % B; 1–7 min, 40 % A and 60 % B; 7–12 min, 10 % A and 90 % B; and 12–15min, 80 % A and 20 % B at a flow rate of 0.6 mL/min. The compounds were well separated on a Thermo Scientific Hypersil BDS RP C18 column (4.6 mm × 150 mm, dp = 5 µm) and ultraviolet detection at 280 nm. The retention times of eugenol and thymol were 10.5 min and 11.6 min, respectively. Validation of the proposed method was carried out according to the guidelines of the International Council on Harmonization (ICH). The linearity of the method is good for thymol and eugenol over the concentration range of 1–50 ppm, and the r 2 values were 0.9996 for both thymol and eugenol. The calculated limit of detection (LOD) value was 0.5ppm and the limit of quantification (LOQ) value was 1ppm for both the analytes. The intra and interday relative standard deviation (RSD) of the retention time and peak areas was less than 3 %.The established method was appropriate, and the two markers were well resolved, enabling efficient quantitative analysis of thymol and eugenol.