Analysis of hazardous Metallic Impurities in Various Commercial Aspirin Formulations

Abstract

Aspirin is the most extensively used mild analgesic and antipyretic drug. In Libya as well as worldwide, aspirin is purchased without prescription in many forms and is imported into the country without any control. However, conditions for packing, storing and preventing the drug from damage are not properly followed. There are no supervision or quality control procedures on the validity and chemical composition of the drug. In this study, thirteen available aspirin forms imported from different countries and one sample from local factory were collected and analyzed for comparison. The quality of the samples was examined in terms of active ingredient (acetyl salicylic acid- ASA), toxic heavy metal and salicylic acid impurities. ASA contents were analyzed using volumetric titration and HPLC method. The toxic heavy metal impurities were determined using atomic absorption spectrophotometry, and salicylic acid impurity was determined by fluorimetric method. The active ASA contents were found in the range from 87 to 104%. Comparison of the determined ASA contents with the actual contents per tablet indicated that only 14% of the samples were in identical values, whereas; 57.1% were exceeded and 28.6% were less than the actual content per tablet. The salicylic acid impurities were under permissible limit. Although, the results for the toxic heavy metals impurities showed significant variations among the samples, but all were under the limit permitted by the world health organization.