Effect of gender and device mouthpiece shape on bolus insulin aerosol delivery using the AER x pulmonary delivery system

Abstract

Purpose. A study was designed to compare differences in insulin aerosol deposition profiles in healthy male and female subjects, as well as examine the effect of mouthpiece cross-sectional shape, volume, and taper on deposition profiles using a developmental AER x pulmonary delivery system. Methods. >Six mouthpieces were screened in the laboratory, and three were selected for clinical investigation: a cylindrical mouthpiece with constant-cross-sectional area, an elliptical mouthpiece with constant-cross-sectional area, and a tapered elliptical mouthpiece with an exit cross-sectional area equal to one half the entrance cross-sectional area. Results. There was no significant difference in the lung dose or in the deposition pattern between males and females (p > 0.05, by ANOVA). The cross-sectional shape of the mouthpiece had no significant effect on the clinical lung dose or the deposition pattern (p > 0.05, by ANOVA), although in vitro testing showed lower emitted dose values with the tapered elliptical mouthpiece (by ANOVA and Duncan's multiple range test, α = 0.05). Using the tapered mouthpiece in the clinic resulted in significantly more deposition on the mouthpiece itself when compared to the nontapered mouthpieces. Conclusion. Inhalation of insulin using the AER x system was insensitive to differences in male and female respiratory tract geometry across all mouthpiece designs examined.