Oxytetracyline tablet formulations: effect of variations in binder concentration and volume on granule and tablet properties.

Formulation studies have been conducted on an oxytetracycline dihydrate tablet formulation containing microcrystalline cellulose and alginic acid, wet granulated with polyvinylpyrrolidone (PVP) solution. A range of granule properties including size, strength packing and porosity, and tablet properties including breaking load, porosity, disintegration and dissolution have been measured. Increased compaction pressure decreased tablet porosity. The reproducibility of the above properties was determined by tests on nine standard batches of granules and tablets. An increased concentration of PVP in the binder solution decreased the rate of tablet dissolution. Although the volume of granulating solution apparently controlled the granule size, it did not significantly alter the tablet dissolution, when the amount of PVP was constant.