Comparative <i>in vitro</i> Quality Evaluation of Four Brands of Atenolol Tablets Available in Addis Ababa, Ethiopia

Abstract

The circulation of substandard medicines remains a serious problem in resource-limited countries in subSaharan Africa, where most of the drugs available are imported. Antihypertensive drugs are one of the drug categories with numerous brands having significant price  variations. Therefore, it is essential to compare and evaluate the bioequivalence of such drugs. The aim of the present study was to  evaluate the physicochemical quality attributes and in vitro equivalence of four brands of atenolol tablets available in different retail  outlets in Addis Ababa, Ethiopia. Four brands of atenolol 50 mg tablets were purchased from different community pharmacies in Addis  Ababa, and were randomly coded as brand A, B, C, and D. Physicochemical quality control parameters of tablets such as tablet hardness,  friability, weight variation and disintegration time were evaluated. Dissolution profile and active pharmaceutical ingredient (API) content  was also determined by UV absorption spectrophotometry. The study revealed that all the studied brands meet official pharmacopoeial  requirements of weight variation, hardness, thickness, friability, disintegration and dissolution profile. On the other hand, the API content  of all the brands except D (118.30%) complied with the limit of USP. In water medium, disintegration time of the sample tablets ranged from 1.82 ± 0.47 to 16.95 ± 0.88 min and all the brands released >85% of the label claim within 15 min. Hence, all the studied  brands except D can be considered as pharmaceutically equivalent and could be prescribed interchangeably.