Investigation of the Drug Carrier Properties of Insoluble Cyclodextrin Polymer Microspheres

The investigation of the usability of solid insoluble beta-cyclodextrin polymers (beta CDP) in micro-sized, controlled drug delivery systems has only recently attracted interest. Our aim was to form complexes with poorly soluble active pharmaceutical ingredients (APIs) with two types of beta CDP for drug delivery applications. Solid insoluble cyclodextrin polymer of irregular shape (beta CDPIS) and cyclodextrin microbeads (beta CDPB) were used in the experiments. Morphology, surface area, size distribution and swelling capacity of carriers were investigated. We created complexes with two APIs, curcumin and estradiol, and applied powder X-ray diffraction, FTIR and thermal analysis (TGA/DSC) to prove the complexation. Finally, the dissolution, biocompatibility and permeation of APIs on Caco-2 cells were investigated. The size of the beads was larger than 100 mu m, their shape was spherical and surfaces were smooth; while the beta CDPIS particles were around 4 mu m with irregular shape and surface. None of the polymers showed any cytotoxic effect on Caco-2 cells. Both carriers were able to extract curcumin and estradiol from aqueous solutions, and the dissolution test showed prolonged estradiol release. Caco-2 permeability tests were in accordance with the complexation abilities and dissolution of the complexes. This study offers useful data for further pharmaceutical applications of insoluble cyclodextrin polymers.