The Preparation Of 5-Fluorouracil Microemulsion And Its Biological Characteristics

5-Fu was one of the most useful anticancer drugs in clinical application. It was limited because of its high toxicity, short half-life, and low bioavailability. Microemulsion was a novel drug delivery system, which was a clear, isotropic mixture consisting of oil, water, surfactant and co-surfactant. The characteristics of microemulsion were low viscous, stable in thermodynamics and kinetics. Its diameter was less than 100nm, and easy to prepare. Its formation was spontaneous and no energy was required. It can be used either as a carrier of hydrophilic or lipophilic drugs. So microemulsion can be used to enhance the absorption of poor solubility drugs, improve the bioavailability of drug, as well as possess the characteristics of targeting and sustained release. To improve the treatment efficacy, reduce the side effect of 5-Fu, and improve the bioavailability of 5-Fu, microemulsion phase diagram was drawed, the characteristics and preparation craft of 5-Fu microemulsion were also studied. The toxicity of 5-Fu microemulsion against cancer cells was detected by means of MTT method in vitro.1. The preparation and characteristics of microemulsion.The ionic surfactants are generally too toxic to be used for this application. Therefore, non-ionic surfactant is used. Sobean oil is used as the oil phase, Tween80 and Span80 as mixture surfactant, several alcohols with low molecular as co-surfactants and distilled water as the aqueous phase. Ternary phase diagrams are developed using water titration method, the mixtures of oil and surfactant /co-surfactant at certain weigh ratios are diluted by water in a drop-wise manner. Microemulsion is prepared by mixing the above components in proper ratio. The results showed that microemulsion was obtained when Tween80 and Span80 as a mixture surfactant, isopropyl as co-surfactant, the area of existence of microemulsion regions is maximal at the ratio of Tween80:Span80: 1,2-propylene glycol =1:1:2; when Tween80 and Span80 as a mixture surfactant, ethanol absolute as co-surfactant, the area of existence of microemulsion regions is maximal at the ratio Tween80:Span80:ethanol absolute = 4:4:3.Base on the investigation of influence factors, orthogonal design was used to optimize microemulsion formulation and preparation process, and more, the reproducibility of the optimized results were studied. The result showed that the temperature, the agitating rate and the value of pH were the key factors that influence the preparation process of microemulsion. When temperature reached 40 °C, the agitating rate was 300r/min, pH value was 7.0. Microemulsion was monodispersed and spherical in shape. Its diameter was from 10 to 30nm. Conductivity and viscosity of this microemulsion was low. 2. The preparation and characteristics of 5-fluorouracil microemulsionBase on the optimal prescription and preparation process of microemulsion. We prepared 5-fluorouracil microemulsion. The...