Preparation Technique Of Gambogic Acid Nanoparticals

Gambogic acid(GA),the main active ingredient in gamboge,has been reported to have good anti-tumor activity with good selectivity.However,the poor water solubility,poor stability and adverse reaction limited its further in vivo research and application in clinic.Preparation of nanoformulations is undoubtedly a good solution,which can not matched by other formulations.Medicine in nanometer size will achieve a great of improved medicine utility:small particle size,high stability,display tumor targetability due to the EPR effect after i.v.administration,so it is expected to be able to crack the bottleneck preventing GA from the further antitumor application.As a result,we chose different method to prepare GA nanopartaticals,in order to increase the solubility and stability,cut down side effect and increase the effect of anti-tumor.We made GA nanopartaticals in this study.Suitable stabilizer and method was screened according to the size and PDI.Dynamic light scattering method was used to measure the particle size and transmission electron microscopy was used to observe the morphology.The drug release was evaluated using dialysis method.MTT assay was used to assess their in vitro cytotoxicity against cancer cell lines.Anti-tumor effect in vivo was investigated on tumor-bearing mice with reasonable mode of adminstration.Preparation one was to prepare gambogic acid nanosuspensions(GA-NSps)by microprecipitation method based on pH adjustment,and the in vitro and in vivo evaluation was carried out.GA-NSps prepared by the best preperation were(135.9±5.1)nm in diameter,with the polydispersity index(PDI)value being(0.26±0.01)and the Zeta potential being(-35.1±1.36)mV.GA-NSps were nearly spherical measured by TEM.The drug-loading rate was(83.73±1.03)%.0.5%PVP can be used as a good freeze-dried protective effect of gambogic acid nanosuspensions.GA-NSps showed a sustained drug release pattern,with the cumulative release reaching 90.26%within 312 h.MTT assay showed that GA-NSps had stronger cytotoxicity against HepG2 cells and 4T1 than free drug(IC50,HepG2 0.8518?g·mL-1 vs 2.1040 ?g·mL-1;4T1 1.1185 ?g·mL-1 vs 2.2500 ?g·mL-1).The pharmacodynamics study showed that antitumor effect of GA-NSps was dose dependent.The anti-tumor effect of the high dose is better than that the PTX control(72.35%vs 66.80%).Prepartion two chose the different preparation to make GA-NPs in order to reduce the hemolytic of gambogic,which has the size of(127.1±0.5)nm,Zeta of(-38.9±2.0)mV,GA-NPs were nearly spherical with stratification.They were quite stable in various physiological media and anmolytic below 0.4 g·mL-1 and met the demand of intravenous injection(iv).The nanosuspensions which changed the preparation of Gambogic acid,0.4 mg·mL-1 and the following concentrations are not hemolytic,which can be achieved intravenous safe administration.GA-NPs showed a sustained drug release pattern,with the cumulative release reaching 85.0%within 244 h.MTT assay displayed that GA-NPs had stronger cytotoxicity against 4T1 cells than free drug(ICso,1.711 ?g·mL-1 vs 4.395 ?g·mL-1).The pharmacodynamics study showed that antitumor effect of GA-NPs was dose dependent.The anti-tumor effect of the high dose is better than that of paclitaxel control(72.35%vs 66.80%).Pharmacodynamics experiment chose intravenous injection,and the resuli showed that GA-NPs can achieve the better tumor suppression with a third dose of positive medicine(66.55%VS 69.76%),and the nanoparticals with FA got better result than that without FA.To sum up:First,GA-NSPs prepared by microprecipitation method based on pH adjustment with high drug loading capacity,small particle size and good stability was successfully prepared,avoided the use of organic solvent,simplfyed the preparation process,improved the anti-tumor effect of gambogic acid and be expected to realized industrial production.Prescription two prepared GA-NPs with low hemolytic and met the demand of intravenous injection(iv.),achieved the goal of lose dose and high tumor inhibition rate,provided a reliable dosage form for gambogic acid in its tumor treatment in clinic and had practical significance.