Utility of an oxidation reaction for the spectrophotometric determination of acarbose in controlled release tablets at various simulated gastrointestinal media.

A sensitive kinetic method for spectrophotometric determination of acarbose is developed and validated for the determination of the drug in bulk and pharmaceutical formulations. The drug was estimated in simulated gastrointestinal media i.e., 0.1 M HCl (pH 1.2) and phosphate buffer (pH 6.8). The method involves the oxidation of acarbose by treating it with a strong oxidizing agent (potassium permanganate (1 x 10(-2) M)) in alkaline media. The reaction kinetics was determined for 20 min at room temperature. The reaction followed first order kinetics and the absorbance of the corresponding manganate ions produced was determined at 610 nm. The absorbance-concentration plot was found to be rectilinear over the concentration range of 2-20 microg/mL. The proposed method was used for estimation of the drug in a novel controlled release dosage form. Thus, the method developed was simple, reproducible and can be successfully applied for the determination of the drug in simulated gastrointestinal fluid.