Preparation Of Novel Unsaturated Resin Based Hydrophilic Material For Drug Controlled Release

Polyester has been widely used in biomedical field because of its goodbiocompatibility and biodegradability. Recent years, more and more researchers havefocused on the study on new type of polyester used in drug controlled release field.A new unsaturated polyester prepolymer, which is named as unsaturatedpolyester-urea amide, was prepared by melt polycondensation that is composed of thefollowing mixed monomers: fumaric acid (FA), adipic acid (HA), sebacic acid (SA),ethylene glycol (EG), poly(ethylene glycol)(PEG) and urea (UR). The curing ofunsaturated polyester-urea amide was carried out with normal temperature initiator.The differences on degradability between unsaturated polyester-urea amide andunsaturated polyester were also studied. The previous unsaturated polyester-ureaamide copolymer was terminated at both chain ends with trimethylolpropane diallylether (TMPDE) by melt polycondensation to obtain a hydrophilic prepolymer whichcould be reacted via photopolymerization. The ciprofloxacin hydrochloride-unsaturated polyester-urea amide sustained release tablet was prepared successfullyusing hydrophilic ciprofloxacin hydrochloride as model drug, TMPDE terminatedunsaturated polyester-urea amide as drug carriers. The copolymers were characterizedby FT-IR,1H NMR spectroscopy, thermal analyzer and environmental scanningelectron microscope (ESEM), respectively.The normal temperature curing cross-linked polymer could be prepared in thepresence of a pair of water-soluble redox initiator, potassium persulfate (KPS) andascorbic acid (AA), and a cross-linking agent, methyl methacrylate(MMA). Theresults shows that the degradation rate and drug release rate could be affected by themolar ratio of urea and the amount of cross-linking agent. With the molar ratio of ureaincreased, the hydrophilicity of materials could be improved, the degradation rate andrelease rate was accelerated; with the amount of cross-linking agent increased, thedrug sustained release time was prolonged, the drug release rate was slowed. The drugsustained release time could be controlled in the range of72h-168h as needed.In the UV curing system, the influence of monomers to hydrophilicity wasstudied. The influence of many factors to the degradation and drug controlled releaseproperties was also studied, such as hydrophilic/hydrophobic property, molar ratio ofurea, the amount of end-capping agent, the type of polyether diatomic alcohol, thetype of dicarboxylic acid. The type of polyether diatomic alcohol has a remarkable effect to hydrophilicity, degradation and drug release, especially for PEG400. Thedegradation rate and drug release rate reached a sustained status when the amount ofend-capping agent was20wt%. Also, the degradation rate and drug release rateaccelerated with the increment of hydrophilicity. The drug release results shows thatthe drug release followed first-order kinetics equation.Finally, a new hydrophilic drug controlled release carriers with sustained drugrelease time between15days and70days was obtained by adjusting the type andmolar ratio of monomers. The TMPDE terminated unsaturated polyester-urea amidemay be potentially used as drug carriers and some other biomedical field.