Selected polysaccharides at comparison for their mucoadhesiveness and effect on precorneal residence of different drugs in the rabbit model

Abstract

Mucoadhesive polysaccharides may prolong the residence of ophthalmic drugs in precorneal area. In this article, the mucoadhesiveness of arabinogalactan, tamarind seed polysaccharide, hyaluronan, hydroxyethylcellulose is compared in vivo, by the polymer residence time in rabbit tear fluid, and in vitro, by the polymer-induced increase of viscosity of a mucin dispersion. Polymer residence is prolonged by increased viscosity but shortened by reflex tearing caused by excessive viscosity. Tamarind seed polysaccharide is the most effective in prolonging the residence of ketotifen and diclofenac in precorneal area; hence, it is the optimal eyedrop additive as it is mucoadhesive while not increasing viscosity excessively.