Controlled release drug systems are an important class of drug de- livery systems that have improved patient compliance while ensuring that drug concentrations in the plasma are maintained at the therapeutic level. The project focuses on the oral osmotic drug delivery system which consists of a tablet core coated with a semipermeable membrane containing an orifice for drug release. The core primarily consists of drug, polymer and osmogen (osmagent). The role of the osmotic agent is to provide the osmotic driving force for solvent imbibition through a semipermeable membrane. When the osmotic tablet is exposed to an aqueous environment, water diffuses into the tablet due to the osmotic pressure difference and hydrates the contents. This is the lag phase during which there is no extrusion of the drug. As more solvent diffuses into the tablet, it increases the hydrostatic pressure until the high pressure extrudes the dispersed drug and polymer through the orifice.
The proposed project has two parts. One involves making tablets in our tablet manufacturing facility and measuring the release rate as a function of the system parameters. The second part involves a detailed mathematical modelling of the drug release process. The latter may involve use of CFD tools to analyse the delivery process.