Oxytetracycline tablet formulations: the effect of wet mixing time, particle size and batch variation on granule and tablet properties.

The wet mixing time has been shown to influence the properties of an oxytetracycline dihydrate tablet formulation, wet granulated with PVP solution. Increased time of wet mixing produced larger, stronger and more dense granules, which compressed into tablets with longer disintegration and dissolution times. Decreased drug particle size aggravated these trends. A decrease in drug particle size also produced larger, stronger and more dense granules. Above an oxytetracycline mean particle diameter of about 6 mum, the tablet dissolution was satisfactory. As the oxytetracycline particle size was decreased further, however, the distintegration and dissolution of the corresponding tablets was markedly slower.