IN-VITRO AND IN-VIVO NASAL MUCOADHESION OF SOME WATER-SOLUBLE POLYMERS

In this study the adhesion of water-soluble neutral polymers, i.e. hyd roxypropylcellulose (HPC), xanthan gum (XG), tamarind gum (TG) and pol yvinyl alcohol (PVA), to nasal mucosa was evaluated in vivo and in vit ro. The polymers mixed with a dye were applied to the nasal cavity of rabbits in powder form, and residue of the dye was observed through a thin fiberscope. XG showed the longest residence of the dye in the cav ity, followed by TG, IBC and PVA in this order. These polymers should thus prove useful as bases for mucoadhesive powder formulations. At a ratio of 2:8, a mixture of PVA and XG showed nearly the same residence time as those of HPC and TG, suggesting that it is feasible to contro l the residence time by mixing two or more polymers differing in adhes iveness. The order of adhesion of these polymers to agar plates in two in vitro methods agreed with that of their mucoadhesion in vivo. Thes e in vitro methods may thus be of use for predicting the nasal mucoadh esion of powder formulations of neutral polymers.