ASSESSMENT OF PHARMACEUTICAL QUALITY CONTROL AND IN VITRO EQUIVALENCE OF VARIOUS BRANDS OF ATENOLOL (100MG) TABLETS AVAILABLE IN SUDANESE MARKET UNDER BIOWAIVER CONDITIONS.

As Atenolol is one of the first choice medications in the management of hypertension in Sudan, it was very important to carry out post authorization safety studies on some of the brands commercially available on the market. The pharmaceutical equivalence of three Atenolol 100 mg tablets was evaluated using official and non-official standards according to US Pharmacopoeia including weight variation, diameter, hardness, disintegration, and assay. Dissolution profiles were studied using three different buffer solutions: PH 1.2, 4.5, and 6.8 and evaluated using the similarity factor f2 to predict the likely in vivo bioavailability and bioequivalence. The three brands complied with the requirements of the official tests of weight variation, hardness, disintegration, assay and dissolution. The two generics used in this study failed to qualify for biowaivers, as brand (A) did not qualify for the WHO criteria for biowaivers (both the test and reference products are very rapidly dissolving in the three media, ie to release ≥ 85 % in 15 min). The amount released in 15 minutes was less than 85%, while brand (B) released more than 85% in 15 minutes in the three media which means higher rate and extent of absorption than the reference drug. The study shows that the generic drug products assessed do not qualify for biowaivers, therefore in vivo bioequivalence studies are required to ascertain bioequivalence.