Preparation of drugs in extrusion pellets with a thermoplastic base. 1. Drug liberation

: In connection with the preparation of solid sustained-release forms extrusion pellets were prepared. The conditions for the processing of the thermoplastics were determined. Lithium sulfate and caffeine served as model drugs. The drug release from the thermoplastics is insufficient. There was no evidence for a possible relation between the properties of the thermoplastics and the drug release. By means of selected examples a correlation between the thermoplastic capacity to water and the drug release could be found.