A quantitative analysis of the intranasal delivery of topical nasal drugs to the middle meatus: spray versus drop administration

The delivery of nasal drugs specifically to the middle meatus is of critical importance in the medical treatment of rhinosinusitis. In this respect, topical nasal drug administration by drops has generally been perceived to be superior to nasal sprays, although there is a lack of evidence to support this notion. This study aims to compare the intranasal delivery of nasal sprays and drops to the middle meatus in vivo, using a novel quantitative method. A surgical patty was placed in the middle meatus. Radio-labelled topical nasal drops and aqueous sprays were administered in a standardized fashion in normal volunteers (10 nasal cavities). The subsequent absorption of administered radio-labelled saline on the patty was measured using a gamma counter. A randomized prospective crossover design was used for the study. The mean percentage (range) of absorbed administered saline on the swab was 8.7 (0.3–39.5) and 9.7 (0.03–20.4) for the spray and drop administration techniques respectively (p = 0.8). Thus, there is wide variation in the delivery of topical nasal drugs and the perceived superiority of nasal drop administration, in terms of delivery to the middle meatus, may be incorrect.