Four grades of AFFINISOL™ HPMC HME were synthesized to specific target viscosities to first assess the ability to control the dissolution rate of a poorly soluble API using itraconazole (ITZ) as a model drug. These four grades were then used to prepare polymer blends to determine the influence of apparent viscosity on HME processing and ASD dissolution performance.
Dissolution rate was dependent upon polymer viscosity with increasing viscosity resulting in slower drug release. In all cases the solubility of the drug was significantly increased. The dissolution profiles of the blended samples were identical. Thus, a desired dissolution profile can be achieved by blending to the necessary target viscosity.