CHITOSAN AS A NASAL DELIVERY SYSTEM - EVALUATION OF THE EFFECT OF CHITOSAN ON MUCOCILIARY CLEARANCE RATE IN THE FROG PALATE MODEL

The effect on mucociliary transport velocity (MTV) of 0.25% solutions of five different types of chitosan, with varying molecular weights and degrees of deacetylation, was evaluated using the frog palate model. The MTV was determined by monitoring the speed of movement of graphite particles placed on the palate before and after 10 min exposure times to chitosan solutions, using a video camera and a novel image analysis system. This system can be used for manual or automatic tracking of all or selected particles on the palate. The five types of chitosan tested were shown to have no toxic effect on the frog palate clearance mechanism. The transient decrease in MTV seen was considered to be the result of an ionic interaction between the positively charged chitosan and the negatively charged mucus. The use of image analysis for the determination of MTV is an improvement in comparison with established manual techniques. A large number of particles can be tracked simultaneously and accurately and changes in transport velocity of the particle speed and direction during the recording period can be identified. Operator fatigue due to laborious manual tracking procedures is also avoided.