Aspirin from Various Analgesic Formulations Using Titrimetry, UV Spectroscopic and HPLC Techniques: A Comparative Analysis

Abstract

Aspirin, acetyl salicylic acid or 2-acetoxybenzoic acid, has the carboxylic acid functional group hence easier to quantify using a strong alkali like NaOH. Overdoes of aspirin can have serious consequences, resulting in significant morbidity and death. In most analgesic drug formulations in tablets form, aspirin is generally bind or compounded with other excipients or substituents which are acidic in nature and has acidic groups thus reacts easily with NaOH, hence making sodium hydroxide not a suitable reagent for quantifying aspirin in multicomponent aspirin tablet formulation. Six different tablets from reputable drug manufacturing company containing aspirin as an active substance were taken. Methods using sodium hydroxide as the main reagent in quantification involves a lot of stoichiometric mathematical manipulations as in case of titrimetric method while UV-VIS spectroscopy via multivariate calibration gave values at lower limit or outside the lower limits of US & BP pharmacopeia with respect to label claims, while the HPLC gave very good resolution and precise results within the pharmacopeia limits.