Formulation factors affecting strength and dissolution of uncoated oxytetracycline tablets.

The effect of various formulation and processing factors on the properties of 300-mg oxytetracycline tablets was studied. At a constant moisture level and packing fraction, an increase in gelatin concentration resulted in increased tensile strength, increased disintegration and dissolution times, and reduced capping tendency. The Wagner theory of dissolution applied satisfactorily to tablets containing up to 5% (w/w) gelatin but was less applicable at higher gelatin levels. Dissolution rate constants were calculated, and their values depended on the gelatin content and packing fraction of the tablets.