Studies On A Novel Drug Carrier-Water-soluble β-cyclodextrin Polymer

In this paper, a novel water-soluble crosslinked β-cyclodextrin polymer (β-CDP) was studied. The properties of β-CDP on the capability of the solubility and complexation with poorly water soluble drugs were investigated to evaluate the applications of this polymer in pharmaceutical field.The water-soluble β-CDP was prepared by reacting β-cyclodextrin (β-CD) with epichlorohydrin as a crosslinked agent in alkaline media through a one-step condensation polymerization. β-CDP was characterized by Fourier transform infrared spectrophotometry (FT-IR), ¹³C-NMR, X-ray power diffraction method (XRD) and differential scanning calorimetry (DSC). The process parameters including the amount of NaOH and epichlorohydrin, the concentration of NaOH, reaction temperature, and reaction time were examined in single factor test. The physicochemical properties of β-CDP were measured, such as solubility, intrinsic viscosity, content of β-CD and degree of cross linking. To inspect the security, acute toxicity experiment and hemolysis experiment were made.The properties of β-CDP on the solubilization with the poorly water soluble drugs were studied with glipizide, ibuprofen, acyclovir and clarithromycin as model drugs. The stability constants of these drugs for forming complexes with β-CDP were calculated according to phase solubility diagrams in different media at various pH. The 1:1 inclusion complexes of β-CDP with glipizide, ibuprofen and acyclovir were formed, but n: 1(n>1) complex was afforded from β-CDP with clarithromycin owing to the various sites and shapes of different drugs. β-CDP had better properties of increasing the aqueous solubility of poorly water soluble drugs compared to HP-β-CD.In the study of the complexation of glipizide with β-CDP in solution, the host-guest molecular interactions, complexing molar ratio, change of thermodynamic parameters were...