Spectrophotometric Determination of Loperamide Hydrochloride in Pure and Pharmaceutical Dosage Forms Using Oxidative Coupling Reaction

Abstract

Loperamide hydrochloride (LopH) has been determined by oxidative - coupling reaction using phenothiazine reagent in the presence of potassium dichromate as an oxidant to create a greenish-blue soluble complex measured at 625 nm., linearity range is from0.8 to 40 μg.ml-1 of LopH. The molar absorptivity is 0.3799×104 l.mol-1.cm-1, Sandell's sensitivity is 0.1351μg cm-2, limit of detection and limit of quantitation are 0.33918, and 1.1306 μg.ml-1 respectively. The method is new ,simple, sensitive and it has been applied successfully for determination of LopH in pharmaceutical preparation of three dosage forms of LopH; Loperamide 2 mg/tablets Medochemie Ltd, Limassol-Cyprus (Europe), Loperamide 2 mg/tablets Safa Co. - Diala (Iraq) and Loperamide 2 mg/capsules Janssen pharmaceuticals (Belgium).