| Oleanolic acid is a kind of active pentacyclic triterpenoids compounds, which widely distributes in Chinese medicinal herbs, Glossy Privet Fruit, Mile Swertia Herb, and so on. It has many pharmacological functions such as eliminating inflammation, enhancing immunifaction, inhibiting degradation of platelet and decreasing concentration of glucose in blood. It is beneficial to liver, and can be clinically used to cure acute aurigo hepatitis and chronic toxic hepatitis. In addition, oleanolic acid can be used as an ancillary anticancer drug.Polybutylcyanoacrylate has advantages of good affinity in vivo, biodegradability, slow-release ability and innocuity. When polybutylcyanoacrylate nanoparticles with particle diameter at 200nm approximately were given by intravenous injection, it can easily be phagocytized by macrophage resulting in its concentration in liver and spleen which include abundant reticuloendothelial system. Then the drug loaded polybutylcyanoacrylate nanoparticles can be anticipated for liver targeting.In this study, butylcyanoacrylate was taken as a carder to prepare oleanolic acid loaded polybutylcyanoacrylate nanocapsules by interfacial polymerization. The nanocapsules were then freeze-dried expecting for its liver targeting.In the first part of the thesis, a single-factor design was taken to research on the effect of solvent used in oil phase, surfactant and concentration temperature of vacuum evaporation during preparation. According to the result, the orthogonal design was used to find the optimum formulation, taking the embedding ratio of OA as index. We took the dosage ratio of OA to BCA, the dosage ratio of acetoacetate to BCA and the volume ratio of oil phase to aqueous phase as main influencing factors, with three levels respectively. The research was arranged according to L9(34) table which was used in orthogonal design. The optimum formation of OA-PBCA-NC was obtained and the ideal conditions were found out as follows: OA: BCA equals to 60mg: 0.1mL, acetoacetate: BCA equals to 2.0mL: 0.1mL and the volume ratio of oil phase to aqueous phase equals to 1:1. The size distribution of OA-PBCA-NC made with optimum formulation was uniform, and the average diameter was 222nm. Its average embedding ratio and drug loading were 76.8% and 26.8%, respectively.In the second part, lyophilization was applied to prepare freeze-dried powder of OA-PBCA-NC. The preparation and formulation to get the powder was studied, and the pharmaceutical properties such as the appearance, size distribution, the redispersion test, pH and the drug loading capacity were considered before and after lyophilization. The results indicated that the OA-PBCA-NC powder we got was quite satisfactory in the appearance,color,drug loading capacity and redispersion. The size distribution and pH before and after lyophilization didn't change evidently. The preliminary stability of the powder we got was investigated at the temperature of 4℃, room temperature and 37℃(RH=75%). Each index didn't have changed evidently, which indicated that the powder we got has good stability and good pharmaceutical quality.In the third part of this paper, the drug-releasing feature of OA-PBCA-NC was studied through dynamic dislysis technique. Different releasing models were examined for the cumulative releasing percentage and we found that the releasing curve of OA-PBCA-NC in vitro was fit for Weibull equation and the half-life time was six hours.In the last part, the same amount of OA, including control group and test group, was given from tail vein to 170 mice. The plasma and the homogenate of heart,liver,spleen,lung and kidney were got at different time. The concentration of OA was calculated by internal standard method and analyzed by 3P87, a pharmacokinetics programme. The pharmacokinetics parameters of both groups were then got. The distribution of OA and OA-PBCA-NC in plasma and different organs were compared by rank sum test. The targeting in vivo of OA-PBCA-NC was estimated by concentration ratio(Ce),targeting efficiency(te),relative uptake rate(re),total targeting efficiency(TEC), relative total targeting efficiency(RTEC). It indicates that the pharmacokinetics in vivo was fit for two-compartment open model, and equations were as follows:OA: C=211.52e-36.97t+2.34e-0.16t;OA-PBCA-NC: C=275.19e-40'06t+1.47e-0.12t;Compared to the OA control group, Ce of OA-PBCA-NC to OA was 3.46, te equals to 7.84, re was 2.88, TEC was 43.74 and RTEC was 59.47, which indicated that the OA-PBCA-NC has good liver targeting feature.
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