Development and Validation of Spectrophotometric Method for Determination of Penicillamine (PA) in Pharmaceutical Formulation Using 4-Choro-Nitrobenzo-2-Oxa-1, 3-Diazol (NBD-CL)

Abstract

A sensitive and simple spectrophotometric method has been proposed for the determination of D-Penicillamine (PA) in pharmaceutical formulations. The proposed method is based on the reaction between the PA and 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-CL) at alkaline medium (pH 10.5) to form deep brown-purple adduct, exhibiting maximum absorption (λmax) at 468nm. Under optimized reaction condition, the method was linear in the concentration range 1-15µg mL-1. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.11µg mL-1, 0.38µg mL-1, respectively. The method was applied successfully to the determination of PA in pharmaceutical dosage form. A proposal of the reaction pathway has been postulated. The results were in a good agreement with those obtained with the official USP method. The method is useful for routine analysis of PA in quality control laboratories.