Abstract
Three types of chitosan films containing prednisolone (PD) were prepared and drug release fromt the films was studied in vitro. The films prepared include 1) a monolayer type (ML) film prepared by evaporating the solvent from a chitosan/drug mixture, 2) a double layer type (DL) film prepared by sticking together two ML films, one of which contained a drug, and 3) N-Ac film which is a DL film with one of the ML films N-acetylated and stuck onto the other ML film, which contained a drug. Release of PD from ML films was retarded as the films became thicker. Release of the drug from N-Ac films was more depresed than from the corresponding DL film and was found to follow zero-order kinetics. Pores were observed in chitosan films by scanning electron microscopy. These result suggested that chitosan and N-acetyl chitosan (chitin) films could be applicable for controlled-release preparations of drugs.
