Determination of apparent drug permeability coefficients through chitosan-sodium cellulose sulfate polyelectrolyte complex films

The permeability coefficient is a fundamental parameter for devices exploiting the controlled drugrelease behavior of films composed of chitosan and sodium cellulose sulfate (NaCS). Here, the transport of two model drugs with different solubilities, i.e., paracetamol and 5-aminosalicylic acid (5-ASA), was studied. The results showed that the permeability of the chitosan/NaCS film was closely related to the swelling properties. In addition, both the permeability and swelling properties of the chitosan/NaCS film were significantly influenced by the mass ratio of chitosan to NaCS, the molecular weights (M_w) of chitosan and NaCS, and the pH value. The permeability of paracetamol across the film was also investigated in simulated gastrointestinal solutions in in vitro tests. The results showed that the films have gastro-, intestine-, and colon-targeting drugrelease properties when they are exposed to simulated gastrointestinal fluids in sequence.