[Modification of drug release with application of pharmaceutical technological methods]

Pharmaceutical technological methods, which enable the development of controlled release, prolonged action solid oral dosage forms, are of great importance. The purpose of our study was to apply these methods and evaluate the prepared samples. The first type of the samples were individually coated separated particles, prepared by mixing with lubricant to built up a lubricant film layer on the surface of the drug crystals. The next group of the samples were separately coated particles--wall material was wax--prepared using the following two technologies: fluidisation atomisation process and hot-melt coating. The third group of the samples was the matrix type, where the core material was mixed into the molten mass of the thermosoftening natural coating material or into some synthetic polymer film material. In some cases several surface active agents were added to the molten mixture to achieve a modification in the drug release process and the examined parameters of the samples. For the comparative evaluation of the prepared dosage forms drug release determination and kinetical analysis of the process were maintainly used. The surface morphology was examined on the base of scanning electronmicroscopic and optical microscopic studies. Among the physical and physico-chemical studies particle size analysis was carried out and dynamic contact angles of the solid samples as well as the surface tension decreasing effect was measured to determine the modifying properties of surface active excipients. To sum up, our results demonstrate that the economical and environmentally acceptable melt coating technology was justified as applicable advantageously in a large number of cases for the development of controlled release devices of highly watersoluble drug, even the medical substance is an organic compound having adjustable thermostability.