[Preparations of preoral sustained-release preparations with a biological polymer base. 5 (correct title supplied from Table of Contents)].

Triethylamine and chloroacetic acid were used for the preparation of polyglycolic acid. The polyester was characterized by elementary analysis, IR-spectroscopy, X-ray-test and the determination of the molecular mass. With regard to the pharmaceutical and technological characterization the determination of the grain size, moisture content, flowability and the parameters for the direct compression were carried out. Polyglycolic acid was compressed together with caffeine as model drug. These tablets distinguished by a great strength, but in water a rapid decay took place. A greater stability in artificial gastrointestinal fluids was obtained, if the tablets were plastified. Release investigations showed then the desired retard effect.