[Release of water-soluble active agents from polymer embeddings. 2. The significance of the manufacturing process-dependent macrostructure of the embedded dosage from an active agent release].
When compressed tablets were produced, it was found that, owing to plastic deformation, the polymers flowed round the active agent particles, dependently on their elastic modulus and ball thrust hardness. A log-log plot of active agent liberation against porosity as a function of pressing pressure yielded a linear relationship. The embedding of active agents in liquid phase separation products by coacervation causes that the liberation of the active agents depends on their wettability by the high-colloid phase. The wetting behaviour of the high-colloid phase is controlled by the relative ratio of the dipole moments of the solvent and the non-solvent or, if these dipole moments are equal, by the hydrogen bridge parameter according to Gordy. In cases where the embedding of active agents via the state of the solution of the polymers necessitates the removal of the solvent, the temperature at which the removal is performed may be of importance to the liberation of the active agent. When the solvent is removed at a temperature above its boiling point, the liberation rate is likely to increase, especially with lowboiling solvents.