Analele UniversităŃii din Bucureti – Chimie, Anul XIV (serie nouă), vol. III, pg. 401406 Copyright © 2005 Analele UniversităŃii din Bucureti SIMULTANEOUS DETERMINATION OF PROCAINE AND BENZOIC ACID BY DERIVATIVE SPECTROMETRY Irinel Adriana Badea * , LuminiŃa Vlădescu abstract: A derivative spectrometric method has been developed for the determination of benzoic acid in presence of procaine. The method is precise and accurate and ensures the assay of both compounds benzoic acid and procaine in finished drugs. Introduction Procaine, (2diethylaminoethyl4aminobenzoate hydrochloride), belongs to local anesthetics and is the active substance of Romanian drugs Aslavital and Gerovital H3 used in treatment of several disease related to aging, asthma and arthritis [1]. Finished products with procaine contain up to 6% benzoic acid as major excipients. In the present study a rapid, precise and accurate derivative spectrometric method for direct and simultaneous determination of both compounds procaine and benzoic acid has been developed. Such a method is required in quality control of finished drugs as the official monographs are based on a classical volumetric method for benzoic acid [2] and on a potentiometric titration for procaine [2]. These official methods can not be used for direct determination of both compounds. The research of the literature reveals that electrochemical [35], ultraviolet visible spectrometry [6], fluorimetry [7], highperformance liquid chromatography [8,9] and gas chromatography [10] methods were developed for the determination of procaine both in pharmaceuticals and biological fluids. Only one method has been reported for the determination of procaine in presence of benzoic acid [11]. * Department of Analytical Chemistry, Faculty of Chemistry, University of Bucharest, 412 Bv. Regina Elisabeta, 030018 Bucharest, Romania