CHITOSAN AS A NOVEL NASAL DELIVERY SYSTEM FOR PEPTIDE DRUGS

A nasal solution formulation of the cationic material chitosan was sho wn to greatly enhance the absorption of insulin across the nasal mucos a of rat and sheep. The absorption promoting effect was concentration dependent with the optimal efficacy obtained for concentrations higher than 0.2% and 0.5% in rats and sheep, respectively. The absorption pr omoting effect was reversible with time in a ''pulse-chase'' study. Hi stological examination of the nasal mucosa of rats exposed to a chitos an solution for 60 minutes showed little change.