Measuring Bioadhesive Binding Strength

The bioadhesive binding strength between mucin and chitosan was measured using a viscometric technique. The assessment was carried out according to Hassan and Gallo’s procedure [50 (link)].
The viscosity coefficient of a hydrophilic dispersion including mucin and bioadhesive polymers HPMC and Carbopol^® was computed using the equation below: $${\eta }_t={\eta }_m+{\eta }_p+{\eta }_b$$
where η_t is the viscosity coefficient of the system, and η_m and η_p are the individual viscosity coefficients of mucin and bioadhesive polymer, respectively, and η_b is the viscosity of component due to bioadhesion and can be obtained by rear-ranging above equation: $${\eta }_b={\eta }_t-{\eta }_m-{\eta }_p$$
The force of bioadhesion, F, represents the additional intermolecular frictional force per unit area and was determined by: $$F={\eta }_b\times \sigma$$
where σ is the rate of shear per second.