Allopurinol is the drug of choice in the treatment of gout It reduces the concentration of urates and uric acid in tissues, plasma and urine, while increasing the concentration of xanthine and hypoxanthine. The purpose of this study was to examine the possibility of Biowaiver study for approval of generic brands of allopurinol tablets without additional in vivo bioequivalence and, to collect information on the safety and efficacy of the different allopurinol tablet brands using simple and cost effective in vitro methods. Physicochemical characteristics comprising drug content, hardness, friability, weight variation, disintegration and dissolution were evaluated for the six brands in comparison with the innovator. Dissolution test was carried under Biowaiver condition and the data analyzed by simple statistics and similarity and difference factors. The assay results showed that all the brands had active pharmaceutical ingredient within the specified official limits except Allo-4- , The crushing strength of three brands (Allo-1-, Allo-5- and Allo-7-) was out of the specified official limits, all the brands were complied with the specified limits For disintegration test, all the brands met the specified limits that stated by USP 32 for dissolution test , and according to f1 and f2 values, all the brands were similar to the innovator except Allo-4 and allo-6. From these results we can conclude that all the brands were met the specified limits for the physical tests, there is a failure of 9 % for content percent, and the brands were not accepted for Biowaiver under WHO criteria