Study Of Preparation And Preliminary Evaluation Of Pharmacodynamics About GC-51 Lyophilized Submicron Emulsion

The purpose of this study is to solve the pharmaceutical problems of parenteral administration of Cheliensisin A(GC-51),and to value the physical and chemical characteristics,stability,safety,in vitro and in vivo antitumor effects.The fusing point,dissolubility,stability,oil/water partition coefficient was firstly measured.Several different kinds of parenteral preparation of GC-51 were examined taking into account of its character of instability and poor dissolubility in water,and Lyophilized submicron emulsion was proved to be the optimal preparation.One factor influence study and central composite design-response surface methodology were combined to optimize the formulation and preparation methods.The content measuring methods was established.Influential test and long term stability test were performed.Hemolysis,stimulation,acute toxicity test were taken,whose results were considered as safety parameters.MTT assay was performed to measure and compare the antitumor character,and its concentration and time dependence were also determined.Mice lung metastasis tumor model was established for the in vivo antitumor effects study. The mice living status,antitumor rate,surviving period,tissue slices were investigated after administrated the GC-51 Lyophilized submicron emulsion in order to determine the therapeutic effects.The prepared GC-51 Lyophilized submicron emulsion had smooth and tight appearance.Dispersed with water,the size,PDI,viscosity,and pH of the Lyophilized submicron emulsion were 168±5nm,0.133±0.070,2.80 fold of water and 7.04 respectively.The formulation and preparation method were both stable.Under the storage condition,which is below 30℃and avoiding air,the GC-51 Lyophilized submicron emulsion had stable physical and chemical property,and the prospected shelf life could be longer than normal emulsion.The GC-51 Lyophilized submicron emulsion would not cause hemolysis and stimulation to rabbit.Injected this submicron emulsion through the tail vein of mice,no serious side effects was observed,and the max forbearing amount can reach 120 mL/kg-day.The prepared submicron emulsion could reach the safety requirements, therefore could be used for i.v. injection.Compared with common antitumor drugs,such as Doxorubicin,cisplatin,and 5-fluorouracil,GC-51 Lyophilized submicron emulsion was proved to have higher inhibiting effects on HepG2,Hela,A549,CT26 cell lines with in vitro study,with some time and concentration dependence.The in vivo distribution and pharmacokinetics study results indicated that GC-51 was eliminated so quickly that it could hardly be measured in vivo, and the T_1/2 was extremely short.But the mechanism for that phenomenon was still uncertain.The antitumor effect of GC-51 Lyophilized submicron emulsion was lower than cisplatin,but the side effects of GC-51 Lyophilized submicron emulsion was lower than cisplatin judging from the animal living status,fur appearance,eating,and spleen parameters.The results that the in vivo antitumor effects were much lower than that in vivo indicated the influence of biological environment,which was consistent with the results of former study and the prediction of in vivo study.