Executive Summary : | Controlled drug delivery has improved drug tolerability and patient compliance over the past four decades. Oral osmotic drugs are one of the most successful advanced controlled drug delivery systems due to their lower incidence of adverse reactions, better patient compliance, decreased dosing frequency, and independence from gastric pH, agitation, and hydrodynamic conditions. Oral osmotic drug delivery systems (OODDS) consist of a tablet core coated with a semipermeable membrane containing an orifice for drug release. The core consists of the drug, polymer, and osmogen, which provides the driving force for solvent imbibition through a semipermeable membrane. However, OODDS tablets have been commercially successful since the 1990s, but their drug loading has been restricted to around 10% (w/w) with the remaining weight occupied by excipients. Experiments have shown that higher drug loadings lead to incomplete drug release, with most of the drug trapped in the tablet. This limitation is due to a lack of knowledge of the detailed transport mechanisms underlying the drug release process.
To address this issue, researchers propose investigating the drug release mechanism in oral osmotic tablets both experimentally and theoretically. They will design and manufacture OODDS tablets with varying compositions of drug and excipient, measure drug dissolution experiments, and determine the amount of drug extruded using HPLC or MRI imaging. The insights gained from these experiments and modeling will provide a deeper understanding of the complex transport processes, enabling oral osmotic tablets with high drug loading. |