Preparation Of Gambogic Acid Nano-formulation And Its In Vitro Pharmacokinetics And Acute Toxicity

Objective:Gambogic acid has a good anti-tumor effect and has the potential to be developed into an anticancer drug.However,GA has some drawbacks,such as poor water solubility,short half-life,and side effects,which limit its clinical application.In order to address above issues and enhance tumor targeting,in this paper,GA-mPEG₂₀₀₀ micelles and liposomes were prepared,and the pharmacokinetics,tissue distribution and acute toxicity were studied,which provided experimental basis for further utilization of GA.Methods:The macromolecular conjugate GA-mPEG₂₀₀₀ was synthesized by esterification reaction,GA-mPEG₂₀₀₀ micelles were self-assembled by direct dissolution method,and GA-mPEG₂₀₀₀ liposomes were prepared by ethanol injection method.UFLC-MS/MS was developed to study the pharmacokinetics and tissue distribution of each formulation in tumor-bearing mice.The plasma protein binding rate of GA was determined by equilibrium dialysis method,and the concentrations of GA in healthy human plasma,rat plasma and mouse plasma were determined by HPLC.The acute toxicity of each formulation was compared with reference,including general phenomena,median lethal dose and blood physiological as well as biochemical indexes.Result:The prepared GA-mPEG₂₀₀₀ micelles and liposomes exhibited a clear yellow solution,which can significantly increase the water solubility of GA,with small particle size,good dispersion and high encapsulation efficiency.The half-life(T_1/2)and plasma mean residence time(MRT_0-t)of GA-mPEG₂₀₀₀ liposomes were 3.27 and 1.36 times that of GA solution,respectively.The T_1/2 and MRT_0-t of the GA-mPEG₂₀₀₀ micelles were2.88 and 1.35 times that of the GA solution,respectively,indicating that these two formulations not only increased the distribution of GA in vivo,but also prolonged the duration of action of the drug.GA-mPEG₂₀₀₀ micelles and liposomes increased the accumulation of GA in tumors,and significantly reduce the GA concentration in liver and kidney.Therefore,it is expected to reduce liver and kidney toxicity while to enhanceanti-tumor effects.GA had low-intensity binding in healthy human plasma,rat plasma,and mouse plasma.The LD₅₀ of GA-mPEG₂₀₀₀ liposomes was 65.172 mg/kg,which was 1.37times and 1.16 times higher than that of GA solution and GA-mPEG₂₀₀₀ micelles,respectively,and there was no obvious abnormality at the injection sites.The biochemical indicators were also basically normal,indicating that GA-mPEG₂₀₀₀ liposome was the safest one among the three formulations.Conclusion:The prepared GA-mPEG₂₀₀₀ liposomes could significantly improve the solubility of GA,prolong blood circulation time,reduce toxicity,and enhance anti-tumor effect.Thus,it is expected to be developed into a new nanomedicine with better safety and anti-tumor effect.