Controlled Loading And Releasing Of Benzophenone By β-Cyclodextrin And Derivatives Polymeric Network

β-cyclodextrin（β-CD）with a hydrophobic central cavity and a hydrophilic outer surface could encapsulate hydrophobic drug molecules and improve solubility of drugs.The introduction of β-CD into hydrogels as a binding site could solve the problems that hydrogels were difficult to load hydrophobic drug molecules.Therefore,cyclodextrin hydrogels have gained more and more attention from scholars.In this article,β-cyclodextrin polymer(（3-CDP）and hydroxypropyl-β-cyclodextrin polymer（HP-β-CDP）were synthesized by crosslinking cyclodextrin with epichlorohydrin（EPI）under alkaline conditions.Octadecylamine(C₁₈NH2)was grafted onto polyacrylic acid（PAA）by amidation to form modified polymer C₁₈ 8PAA.The products were characterized by 1HNMR,FI-IR methods and colorimetric method.We studied the inclusion association between β-CD monomer,HP-β-CD monomer,β-CDP,HP-β-CDP with benzophenone（BZ）and results showed inclusion ratios of above four cyclodextrins with BZ were 1:1.Binding constants of four cyclodextrins with BZ were measured by UV-Vis spectrophotometry.And results indicated binding constants of cyclodextrin polymers with drug were larger than that of monomers with drug,which proved increase of viscosity hindered dissociation of drug.Binding constants of β-CDP and HP-β-CDP with different cyclodextrin contents with BZ were also studied,indicating binding constants were independent of cyclodextrin content in cyclodextrin polymers.β-CDP/C₁₈PAA(or HP-P-CDP/C₁₈PAA)hydrogels were constructed based on inclusion associations between cyclodextrin and hydrophobic side chain C₁₈.Rheological method was used to study factors which could affect the viscosity of cyclodextrin hydrogels,such as polymer concentration.Besides,we studied the influence of mass concentration,binding constants,hydrophobic association,inclusion association,cyclodextrin content and introduction of hydroxypropyl on drug release.The results indicated cyclodextrin hydrogels could be used as an ideal carrier for drug delivery.