Tj. Aspden et al., CHITOSAN AS A NASAL DELIVERY SYSTEM - EVALUATION OF INSULIN ABSORPTION ENHANCEMENT AND EFFECT ON NASAL MEMBRANE INTEGRITY USING RAT MODELS, European journal of pharmaceutical sciences, 4(1), 1996, pp. 23-31
The ability of a range of chitosans to act as nasal peptide absorption
promoter systems was investigated using the rat nasal absorption mode
l described by Illum et al. (1989). The systemic absorption of insulin
was monitored indirectly by measuring arterial blood glucose levels.
All five chitosans evaluated produced clinically relevant levels of in
sulin in the blood. The effect on nasal epithelial membranes of circul
ating 0.25% w/v chitosan solutions, was investigated using the rat nas
al perfusion method. Perfusate samples were assayed for total protein
content, the membrane-bound enzyme 5'-nucleotidase (5'ND) and the cyto
solic enzyme lactate dehydrogenase (LDH). All the chitosans tested cau
sed minimal membrane and cellular damage when compared to the membrane
destruction caused by perfusing a 1% w/v Laureth 9 solution. The time
dependent increase in perfusate protein content observed was suggeste
d to be due to the interaction of chitosan with mucin on the membrane
surface.