CHARACTERIZATION OF RHEOLOGICAL AND MUCOADHESIVE PROPERTIES OF 3 GRADES OF CHITOSAN HYDROCHLORIDE

In the present study the rheological and mucoadhesive properties of th ree viscosity grades of a cationic polymer, chitosan, were investigate d to assess the suitability of this polymer for gastroadhesive formula tions. The influence of the pH, ionic strength and temperature of the hydration medium on the rheological properties was studied. The mucoad hesive performance was assessed in vitro by means of rheological syner gism and tensile stress testing. A correlation was found between rheol ogical synergism and tensile parameters (force of detachment and work of adhesion), which proves that both methods can correctly predict the mucoadhesive performance of the polymers examined. It was found that the interaction of chitosan with mucin decreases on increasing molecul ar weight.