NASAL DELIVERY SYSTEMS AND THEIR EFFECT ON DEPOSITION AND ABSORPTION

Due to nasal anatomy and physiology, with a non-ciliated area in the a nterior part of the nasal cavity and a ciliated region in the more pos terior part of the nose, the site of deposition is of importance for t he nasal mucociliary clearance and retainment of a formulation in the nose. Many drug delivery devices for nasal application of liquid, semi solid and solid formulations were investigated in respect to their dep osition in the nasal cavity. The site of deposition and the deposition area depend on several parameters which are related to the delivery d evice, such as mode of administration, particle size of the formulatio n and velocity of the delivered particles. Several in vitro and in viv o methods have been used to study distribution and clearance of intran asally delivered therapeutics. The relationship between deposition, ab sorption and related bioavailability of the nasally applied formulatio n has been shown. (C) 1998 Elsevier Science B.V.