Study Of Betulin-MePEG-PLA Polymeric Nano-micelles

Objective:Betulin(betulinol)is the three pentacyclic compounds.Betulin as natural drugs in anti tumor and anti HIV activity of liver fibrosis has shown unique therapeutic effect,side effect and less toxicity.But three pentacyclic drugs have poor water solubility,disadvantages of instability.Amphilphilic block copolymer MePEG-PLA(MePEG-PLA,Block ratio is 5:3),Due to its biodegradability and biocompatibility,It has been widely used in controlled drug release,targeted drug delivery system.The unique advantages of Polymeric nano-micelles and the pharmacological activity of betulin makes the study on MePEG-PLA has important significance.In this article,we prepared paclitaxel-loaded MePEG-PLA polymer nano-micelles,intended to improve the solubility of betulin,thereby improving bioavailability.Methods:The water-soluble polymer poloxamer F68 as surface active agent,MePEG-PLA polymer as the carrier,preparation of betulin-MePEG-PLA polymeric nano-micelles by emulsion solvent evaporation method,with the particle size and entrapment efficiency as the evaluation index of the preparation of polymeric nano-micelnes,Orthogonal L9(34)experiment design was used,with acetone and ethanol,the proportion of drug and MePEG-PLA polymer ratio,poloxamer concentration of F68,the ratio of organic phase to aqueous phase,optimizate preparation of polymeric nano-micelles system,and the optimal distribution,prescription particle size and entrapment efficiency as the evaluation of betulin,MePEG-PLA polymeric nano-micelles release were measured,and the polymer nano-micelles were preliminary pharmacokinetic study.Results:The best preparation for polymer nano-micelles as:acetone and ethanol ratio was 3:1,the ratio of organic phase the aqueous phase was 1:15,drug and polymer ratio was 2:30,the concentration of F68 was 3%.Spherical,polymeric nano-micelles prepared as the rule of uniform size,no adhesion.The average particle diameter is 156.1nm,average entrapment efficiency was 37.10%.The solubility curve can be seen,polymeric nano-micelles increased release in vitro.Pharmacokinetic study revealed that betulin-MePEG-PLA polymeric nano-micelles relative bio availability is increased.Conclusion:Prepared by emulsion solvent evaporation technique of Betulin-MePEG-PLA polymeric nano-micelles has simple preparation technology,quality requirements,compared with the raw material drugs can improve the release in vitro and in vivo bioavailability.