Spectrophotometric Determination of Loperamide Hydrochloride by Ion-Pair Formation with Rose Bengal Reagent

A simple and accurate spectrophotometric technique has been presented for determining the presence of loperamide hydrochloride. The approach involves forming an ion-pair association complex with rose Bengal (RB), which results in a colored product that is analyzed spectrophotometrically at 568 nm. The validity of Beer’s law was established in the range of 0.5–10 μg/L. The proposed method is specific to the analysis of loperamide and can differentiate it from its pharmaceutical products, which can be detected using HPLC. The conditions for the method were optimized, and the technique was successfully used to analyze the drug in both pure form and dosage forms. The study establishes a low limit of detection of 0.025 and a limit of quantification of 0.082. The method provides a reliable and sensitive approach for the determination of loperamide hydrochloride in pharmaceutical formulations and can be used as an alternative to other analytical methods. The results demonstrate the potential for using this method in routine quality control analysis.