Smart Packaging: A Novel Technique For Localized Drug Delivery

In this project, we have developed a model drug delivery system consisting of non-ionic surfactant vesicles (niosomes) packaged within a biodegradable, temperature and pH sensitive hydrogel network. We have characterized the behavior of individual niosomes when exposed to environments that mimic body fluids. Diffusion and mass transfer characteristics of 5,6-Carboxyfluorescein, a dye with similar physical properties as therapeutic drugs for cancer, is used to determine release rate from the niosomes. The release rate can be controlled to last from 24 hours to more than 144 hours depending on the conditions to which individual niosomes are exposed. We used a cross-linked hydrogel (chitosan) network into which the niosomes were embedded. The hydrogel provides another layer of control, gives a stable environment for the niosomes, and enhances the release rate. The niosome-hydrogel system, which is a liquid at room temperature, starts gelling once inside the body since it undergoes a phase transition at 37°C. Surface characteristics, such as the interaction between the niosomes and chitosan, Van der Waals forces and chemical bonding are being measured by the Surface Force Apparatus (SFA) technique. One of the systems that we are targeting with this study is intraperitonial cavities after ovarian cancer is discovered and removed to increase the life span of patients. Single administration rates have been tested and compared to local delivery via an external catheter. We found that our system lasted longer than catheter administration leading to less frequent administration and also resulted in reduced toxicity. Our results will help in the development of a low cost and improved method for drug delivery with application to intracavitary ovarian cancer treatment and other cancer types.