DISTRIBUTION OF BECLOMETHASONE DIPROPIONATE AEROSOL PARTICLES IN THE NASAL CAVITY

Abstract

Distribution of beclomethasone dipropionate (BD) aerosol particles in tnhe masal cavity was studied. A simulated nasal cavity made of acryl resin (Kohken Co. Ltd.) and modified by QSS (Kohken) was used for the experiment. Seven superficial hollows were made at the anterior portion of the lateral wall, the anterior, middle and posterior portions of the middle and inferior turbinates, respectively. These hollows were filled with round shaped filter paper, 5mm in diameter and 0.7mm in thickness, for the measurement of the BD concentration. The filter paper was abstracted in 5ml methanol and the solution was then measured by an automatic spectro-photometer. The concentration of BD was exgressed in absorbance since the concentration of a solution was directly proportional to its absorbance.
BD was delivered by means of gas, liquid and powder. No significant difference was found among these three preparations. The highest concentration was usually found at the anterior portion of the middle turbinate in accordance with the long axis of the aerosol adaptor. In general, continuous stream of the air at 0.5, 1.0, 1.5 and 2.0l/sec from the posterior outlet of the nose little affected the amount of the deposited particles at each portion.
The particles once deposited at the interior part of the nasal cavity might be again conveyed posteriorly by the inhaled air, ciliary movement and diffusion in the mucous layer. This mechanism probably supplements uneven distribution of the particles sprayed into the nasal cavity.