Erratum to: Impact of Inhalation Flow, Inhalation Volume and Critical Handling Errors on Delivered Budesonide/Formoterol Dose in Different Inhalers: An In Vitro Study

Abstract

Inhaled drugs are essential for treatment of asthma and chronic obstructive pulmonary disease, but drug delivery via the respiratory tract is complex. Correct inhaler use is challenging as inhalers differ and inhaler technique errors are common. This in vitro study examined impact of inhalation flow, volume, and shaking of commonly used budesonide/formoterol (BUD/FORM) dry powder inhalers (DPIs). Two strengths of each included BUD/FORM DPI, Turbuhaler, Easyhaler and Spiromax, were examined. Fine particle dose (FPD) was measured using the Next Generation Impactor, at fixed pressure drops of 2, 4 and 6 kPa. Delivered dose (DD) for inhalation volume and shaking tests was performed at an airflow rate equivalent to a 4-kPa pressure drop, collected on Respirgard II, 303EU filters. FPD flow rate dependence was similar for all inhalers and strengths. BUD/FORM Turbuhaler and Easyhaler were unaffected by inhalation volume, whereas Spiromax showed significant inhalation volume dependence with about 50% decrease for both inhaler strengths. For a BUD/FORM Turbuhaler 160/4.5-µg/dose, there were no differences in the DD between shaking and no shaking, whereas the higher strength showed a 10% decrease after shaking. BUD/FORM Easyhaler DD decreased with about 50% for both strengths when the device was not shaken, while Spiromax decreased with 20% for the lower strength and 80% for the higher strength when shaken. This study revealed significant differences in inhaler performance after testing at different inhalation flow and volume and following exposure to potential pre-inhalation handling errors, which may lead to decreased drug delivery to the lungs. AstraZeneca