Biodegradation of polyelectrolyte complex films composed of chitosan and sodium cellulose sulfate as the controllable release carrier

For the applications of polyelectrolyte complex (PEC) of chitosan and sodium cellulose sulfate (NaCS) as the controlled release drug carrier, the biodegradation characteristics of chitosan, NaCS and chitosan/NaCS PEC films were investigated with pepsin, trypsin, lipase, α-amylase, and cellulase. The results showed that pepsin, amylase, trypsin and lipase have the appreciable hydrolytic activity to chitosan, but cannot degrade NaCS. However, cellulase showed high cellulosic activity and low chitosanolytic activity. For the hydrolysis of chitosan/NaCS films, the degradation rates were greatly influenced by the molecular weights of chitosan and NaCS. In vitro tests showed that different formulations caused diverse disintegration time of the films through the gastrointestinal tract. The results indicated the PEC based on chitosan and NaCS showed good potential for the gastrointestinal delivery systems.