An Exploration of Factors Affecting In Vitro Deposition of Pharmaceutical Aerosols in the Alberta Idealized Throat

摘要

Background: The development of accurate in vitro—in vivo correlations requires the consideration of a number of factors in vitro, including the emulation of upper airway geometry, inhalation maneuver, inhaler orientation, and environmental conditions. In this study, we examine the effects of inhaler insertion angle and humidity on deposition from a number of marketed inhalers.Methods: Three dry-powder inhalers (DPIs; Pulmicort? Turbuhaler?, Budelin? Novolizer?, and Easyhaler? Budesonide) were examined at two insertion angles, one with the inhaler directed toward the back of the oral cavity, the other with the inhaler directed toward the tongue. Three pressurized metered-dose inhalers (pMDIs; QVAR?, Ventolin? Evohaler?, and Flovent? HFA) were examined considering the joint effects of insertion angle (as above) and relative humidity at low (15%–25%) and high (>95%) conditions. Deposited drug masses in an Alberta Idealized Throat and downstream filter were quantified through ultraviolet spectroscopy.Results and Conclusions: Three of six inhalers showed sensitivity to insertion angle. When directed toward the tongue versus the back of the mouth, the filter dose decreased from 21.9% to 15.6% (percent delivered dose) for Easyhaler Budesonide (p?