Quantitative Analysis of Acetylsalicylic Acid in Commercial Pharmaceutical Formulations and Human Control Serum Using Kinetic Spectrophotometry

Snežana S. Mitić*, Gordana Ž. Miletić, Aleksandra N. Pavlović, Snežana B. Tošić and Slavica M. Sunarića

Faculty of Sciences and Mathematics, Department of Chemistry, University of Niš, Višegradska 33,
P.O. Box 224, 18000 Niš, Serbia
aFaculty of Medical Sciences, Bulevar Zorana Ðin|ica 81, 18000 Niš, Serbia
* Corresponding author: E-mail: mitich_s@yahoo.com

The aim of this work is to develop a new kinetic spectrophotometric method for the determination of acetylsalicylic acid (ASA) in pharmaceutical formulations. In general, ASA analysis is not realised directly, and a previous quantitative hydrolysis in a basic medium is necessary, converting ASA to salicylate ions for its determination. The hydrolysis is carried out by sodium hydroxide solution. The method is based on a ligand-exchange reaction. The reaction was followed spectrophotometrically by monitoring the rate of disappearance of the cobalt(II)-1-nitroso-2-naphthol complex in alkaline medium at 410 nm. The optimum operating conditions regarding reagent concentrations and temperature were established. The initial-rate method is adopted for constructing the calibration curve, which was found to be linear over the concentration range 0.72–9.00 µg mL–1. The optimized conditions yielded a theoretical detection limit of 0.35 µg mL–1 based on the 3.3S0 criterion. The interference effects of certain ingredients of powdery drugs, foreign ions and amino acids upon the reaction rate were studied in order to assess the selectivity of the method. The results are validated statistically and through recovery studies. The point hypothesis test have been performed which indicate that there is no significant difference between the proposed method and the reference method. The developed procedure was successfully applied to the rapid determination of acetylsalicylic acid in commercial pharmaceutical preparations and human control serum. The unique features of this procedure are that determination can be carried out at room temperature and analysis time is short. The newly developed method is simple, inexpensive and efficient for use in the analysis of a large number of samples.

Keywords: Acetylsalicylic acid; kinetic spectrophotometry; validation; pharmaceutical analysis