Randomized Trials of Nasal Patency and Dermal Tolerability With External Nasal Dilators in Healthy Volunteers

Background External nasal dilator strips are used as nonpharmacological therapy to reduce snoring and daytime sleepiness. In a product improvement initiative, a marketed strip (BRNS) and 2 prototype nasal strips were evaluated. Objective To compare the nasal patency and multiple-use dermal tolerability of the BRNS and prototype nasal strips using both objective and subject-reported outcome measures. Methods Two studies were conducted separately in healthy volunteers ≥18 years of age. A single-day nasal patency randomized crossover study assessed minimal cross-sectional area (MCA; second restriction) and nasal volume (using acoustic rhinometry); nasal inspiratory flow and resistance (using posterior rhinomanometry); and subject-reported evaluations of the BRNS compared with the butterfly strip and teardrop strip prototypes. A single-center, randomized, controlled, parallel-group, evaluator-blinded study assessed dermal tolerability of the BRNS and the butterfly strip over 7 consecutive nights of use, using the Dermal Response Scale (DRS) and subject-reported comfort and ease of removal. Results In the Patency study (N = 50), all 3 strips demonstrated significant improvement from baseline in MCA, nasal volume, and nasal flow parameters (resistance and peak flow). The prototype strips demonstrated significantly more improvement in nasal volume than the BRNS, and the butterfly strip showed significantly more improvement in MCA than the BRNS; all strips were similar with respect to nasal flow and subject-reported nasal breathing outcomes. In the Dermal Tolerability study (N = 82), all subjects scored 0 (no evidence of irritation) on the DRS at all 7 morning assessments; the BRNS was numerically, but not significantly, superior to the butterfly strip on subject-reported outcomes. Conclusion The Patency study demonstrated significant improvement from baseline in nasal dimensions and flow for all 3 evaluated strips; between-strip differences were confined to nasal dimensions. Both the BRNS and butterfly strip were generally well tolerated, with no evidence of dermal response over 7 consecutive nights of use. ClinicalTrials.gov identifiers: NCT01105949 and NCT01495494

Comparing the effectiveness of nasal dilator strips: does race play a role?

Background:Nasal dilator strips are thought to widen and stiffen the anterior nasal cavity, and thus improve symptoms of nasal obstruction. It is postulated that anthropomorphic differences in external nasal proportions between races may influence the effectiveness of such dilator strips.Methods:Caucasian and Asian subjects were compared. Nasal peak inspiratory flow, nasal airway resistance, minimum cross-sectional area and visual analogue scale measurements of nasal obstruction were recorded at baseline and following the application of two different dilator strips.Results:Nine Caucasian and six Asian subjects were recruited (n = 15). There was a significant difference between races in terms of nasal peak inspiratory flow improvements following nasal strip application (mean of 29.4 litres per minute in Caucasiansvs14.6 litres per minute in Asians;p = 0.04). Only Caucasians experienced a significant decrease in nasal airway resistance (median of 0.12 Pa/cm3/s;p < 0.01).Conclusion:Nasal peak inspiratory flow, minimum cross-sectional area and visual analogue scale values improved from baseline with strip application in both populations. Only Caucasians experienced significant nasal airway resistance improvement with strip application. Both cohorts experienced nasal peak inspiratory flow improvement, with Caucasians experiencing a significantly larger improvement.