Author(s): Johnbull Aiwaguore Obarisiagbon, Oladejo Peter Ogunlowo

Erythromycin drug products have been mostly imported into Nigeria from different countries of the world; with relatively no Nigeria based pharmaceutical company manufacturing same. Cases of therapeut ic failures have been reported in some of our hospitals. Hence, the need arises to study some of the physicochemical parameters of some of the available drug products in the Nigerian Pharmaceutical Market with a view to detecting drug products that meet the specified pharmacopeia standards and those that fall short of such standards. The parameters measured were the uniformity of weight, friability, tensile strength, disintegration time and dissolution rate of 12 selected erythromycin stearate 500mg film-coated tablets. The tensile strength of the tablets was determined using the static loading method and Mosanto hardness tester to find the crushing strength and their results compared. The 12 samples disintegrated within 30mins with four of them disintegrating within 3mins, suggestive of possible inclusion of superdisintegrants in their formulations. All products, except two had a percentage release of the drug within 90mins of 70% and above. The friability of three of the products exceeded 1%. However, their tensile strengths did not prolong the disintegration time beyond the official limits. The results obtained from the physicochemical testing of the drug products revealed the failure of two products having release rates of less than 70% within 90mins. Further tests need to be done on these two products (namely Rycin® and Erythromycin 500mg) in order to draw a more definite conclusion.