A Release Rate Study for Controlled Drug Delivery Using Niosomes

The emerging technology of drug-encapsulated nanoparticles plays a critical role in the development of treatment for various life-threatening diseases due to the versatility, control, and future potential of the design of these systems. A current treatment technique for the treatment of brain tumor cells, after major surgery, utilizes a drug adhered to a biodegradable polymer wafer that provides the release of medication over about 120 hours. The setback to a design such as this is the levels of toxicity that can be delivered to other organs in the body due to over-medication of the drug, causing adverse reactions in the patients. This project proposes to design a drug-delivery vehicle that utilizes a double controlled mechanism that is based on a package within a package system, or a smart-packaging system. The drug will be encapsulated in non-ionic surfactant vesicles, or niosomes, and then embedded in a biodegradable temperatureand pH-sensitive chitosan polymer hydrogel. This double packaging system will allow for the controlled release of the drug based on the diffusion properties and physical characteristics of the niosomes and chitosan hydrogel. The goal of this investigation was to study the release rate of the drug from the niosome in an in vitro environment. The niosomes were prepared by thin film hydration and sonication, and 5(6)carboxyfluorescein dye was encapsulated in the vesicles to mimic the behavior of the drug. The concentration of the dye varied from 4mM to 5mM to 14mM. The niosome solution was placed in a semi-permeable cellulose membrane and submerged in a bulk solution of either Milli-Q water or PBS. The system was placed on a stirring plate and allowed to run for 72 hours. Samples were taken from the contents in the membrane and contents in the bulk solution at different time intervals. Fluorescence spectroscopy was used to measure the intensity and concentration of the samples. It was found that the dye was released from the niosomes submerged in the water solution within the first 10 hours of the experiment, indicating their instability in that environment. It was also found that the niosomes submerged in the PBS solution maintained their stability, with their release rates being relatively lower than in the water solution. It was shown that the release rate behavior of the niosomes was similar regardless of initial concentration of dye encapsulated in the vesicles. It can be concluded that the niosomes are unstable in Milli-Q water and require a hydrogel that will stabilize the vesicles, similar to PBS. The hydrogel will prevent the premature release of the drug from the vesicles. This technique allows for control over the release rates of the drugs, which can decrease toxicity to other parts of the body, increase direct utilization of the drug, and increase the survival time of brain cancer patients. It is the goal of this research to design a novel drugdelivery technique that will be safe and effective for the treatment for brain tumor cells, while improving the quality of life and duration of survival for these patients.