A study of intranasal distribution of azelastine hydrochloride aqueous nasal spray with different spray techniques

Topical aqueous nasal sprays are widely used in treating patients with a variety of nasal diseases. Previous studies have suggested that drug delivery to the ciliated mucosa is generally suboptimal. Little is known about the effects of nasal spray delivery technique on intranasal distribution and efficacy of topical nasal drugs. We assessed the intranasal distribution of a nasal spray with two commonly used techniques using azelastine hydrochloride labelled with fluorescein. After spraying, the nasal cavity was photographed endoscopically in two standardized positions, one showing the anterior portion in the region of the nasal valve and one the area of the middle meatus. The photographs were computer analysed to identify the proportion of coverage of fluorescein in each image field. The majority of drug was distributed anteriorly with poor coverage posterior to the nasal valve area. This was the case with both of the positions tested.