Controlled formation of the anhydrous polymorph of ciprofloxacin crystals embedded within chitosan scaffolds: study of the kinetic release dependence on crystal size

This work describes a simple procedure for preparation of chitosan (CHI) scaffolds containing ciprofloxacin (CFX) anhydrous crystals. The capability of CHI scaffolds to control the CFX crystal size and to preserve the anhydrous crystal habit even after long term storage was useful for the development of drug delivery systems (e.g., CFX/CHI scaffolds) exhibiting a novel way to control the kinetic release, that is, by the solubility/hydration ratio of CFX anhydrous crystals depending on their crystal size rather than by typical mechanisms based on swelling, hydration and/or erosion of the polymer acting as carrier.