Chitosan microspheres with hydrocortisone and hydrocortisone-hydroxypropyl-beta-cyclodextrin inclusion complex

In the present study, an inclusion complex composed of hydrocortisone aceta te (HC) and hydroxypropyl-beta-cyclodextrin (HP beta CD) was prepared by th e spray-drying method. HC alone, HC inclusion complex or HC with HP beta CD as a physical mixture were incorporated into chitosan microspheres by spra y-drying. The inclusion complex and microspheres were characterized by X-ra y powder diffractometry and differential scanning calorimetry (DSC). Micros pheres were studied with respect to particle size distribution, drug conten t and in vitro drug release. The results indicate that the HCHP beta CD inc lusion complex is more water soluble than HC alone. The HC release rates fr om chitosan microspheres were influenced by the drug/polymer ratio in the m anner that an increase in the release rate was observed when the drug loadi ng was decreased. However, release data from all samples showed significant improvement of the dissolution rate for HC, with 25-40% of the drug being released in the first hour compared with about 5% for pure HC. The complexa tion method and microsphere preparation method (spray-drying) is simple wit h great potential for industrial production. (C) 2000 Elsevier Science B.V. All rights reserved.