A Novel, Potential Microflora-Activated Carrier for a Colon-Specific Drug Delivery System and Its Characteristics

A novel polyelectrolyte complex (PEC) formed by sodium cellulose sulfate (NaCS) and chitosan was prepared as a potential material for a colon-specific drug delivery system. The characteristics of NaCS-chitosan film were measured by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), in vitro degradation, and in vitro drug release experiments. SEM data indicated that the NaCS-chitosan film had relatively homogeneous and smooth morphology at the initial state and deformed after being immersed in simulated colonic fluid (SCF). FTIR data indicated that the NH3+ of the chitosan had reacted with the SO4- of the NaCS. In vitro degradation behavior revealed that NaCS-chitosan could be degraded by colon microflora and be hydrolyzed in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). It is found in the experiment of in vitro drug release that the capsules formed by the NaCS-chitosan complex could release about 80% of the drug loaded in the SCF during 4 h. All these results indicated that the NaCS-chitosan complex shows excellent behavior for colon specificity and could be a potential material for a colon-specific drug, delivery system.