VALIDATION OF AN HPLC METHOD FOR THE DETERMINATION OF DEXAMETHASONE IN JAMU PEGAL LINU

Abstract

Pharmaceutical adulterants are still frequently detected in traditional medicines, including jamu pegal linu. Dexamethasone, a corticosteroid, is often illicitly added to enhance analgesic and anti-inflammatory effects. According to BPOM regulations, traditional medicines are prohibited from containing Active Pharmaceutical Ingredients (APIs). Although dexamethasone identification is commonly performed using Thin Layer Chromatography (TLC) and spectrophotodensitometry, High-Performance Liquid Chromatography (HPLC) offers higher resolution and improved analytical performance. This study aimed to optimize and validate an HPLC method for the determination of dexamethasone in jamu pegal linu. Method validation was performed based on linearity, specificity, accuracy, precision, limit of detection (LOD), and limit of quantification (LOQ). Mobile phase optimization was conducted using four methanol–water ratios (55:45, 60:40, 65:35, and 70:30). The optimal mobile phase was methanol–water (60:40, v/v), producing a retention time of 6.744 minutes, resolution of 2.339, tailing factor of 1.123, and theoretical plate number of 2,262. The validated method demonstrated reasonable specificity, excellent linearity (r = 0.9988), LOD of 1.147 μg/mL, LOQ of 3.823 μg/mL, 101.107% recovery, and precision (%RSD) of 1.918%.