This paper presents the computer simulation results on the delivery of Etanidazole (radiosensitiser) to the brain tumor and examines several factors affecting the delivery. The simulation consists of a 3D model of tumor with poly (lactide-co-glycolide) (PLGA) wafers of 1% Etanidzole loading implanted in the resected cavity. A zero-order release device will produce a concentration profile in the tumor which increases with time until the drug in the carrier is depleted. This causes toxicity complications during the later stages of drug treatment. However, for wafers of similar loading, such release results in a higher drug penetration depth and therapeutic index as compared to the double drug burst profile. The numerical accuracy of the model was verified by the similar results obtained in the two-dimensional and three-dimensional models. / Singapore-MIT Alliance (SMA)

Drug delivery methods for the treatment of brain tumor cells have been both inefficient and potentially dangerous for cancer patients. Drug delivery must be done in a controlled manner so that the effective amount of medication is delivered to the patient and ensure over-dosage does not cause adverse side reactions in the patient. The focus of this investigation is to design a drug delivery system that would allow for site-specific administration of the drug, protection of the drug from the surrounding environment, and controlled sustained release of the drug. We have proposed a model that incorporates a niosome, which is a non-ionic surfactant vesicle, within a biodegradable polymer hydrogel. The drug is encapsulated in the niosome, and the niosome is embedded within a three-dimensional hydrogel network. It is therefore critical that the release rate of the drug from the niosome be studied. This investigation provides information about the release rate and behavior of the drug within the niosome as it is placed in a semi-permeable membrane. The niosome and dye solution in the cellulose membrane are placed in contact with water or PBS. Intensity measurements are taken using fluorescence spectrometry, and the readings are converted to concentration and moles values. The release rates of the dye from of the niosome and across the membrane are studied as the concentration data is collected over time. The results indicate that most of the niosomes will release their dye within ten hours. The water will create instability in the niosomes, while the PBS solution will maintain the stability of the niosomes. The concentration that diffuses across the cellulose membrane will steadily increase and can be predicted well by a simple diffusion model. We hope to use the information provided in this study to continue to design a drug delivery method that will stabilize the niosomes and allow for the maximum control over the release rate of the drug.