RHEOLOGICAL PROPERTIES OF POLYMER-SOLUTIONS AS CARRIERS FOR NASAL DRUG-DELIVERY SYSTEMS

The bioavailability of nasally applied drugs is reduced by nasal mucoc iliary clearance. To prolong the contact time between drug and mucosa, nasal solutions contain polymers as thickeners. The rheological prope rties of polymer solutions and nasal mucus have an influence on mucus transport rate of nasally administered drugs. To obtain information ab out the behaviour of these solutions on the nasal mucosa, the rheologi cal properties were examined by oscillating measurements. Methylhydrox ypropylcellulose (Viscontran MHPC 3000(R)), often used as thickener fo r eye drops, and gellan gum (Gelrite(R)), a bacterial polysaccharide f rom Pseudomonas elodea, were chosen as thickeners for nasal drug solut ions. The viscosity of Gelrite(R) solutions increases if a physiologic al level of cations is added and therefore, a promising way of lengthe ning the residence time of the drug with gellan gum could be by formin g a gel through the contact with the nasal mucosa.