Drug delivery to the lungs from dry powder inhalers

Abstract

When asthma is being treated, it is essential that sufficient drug is deposited at the site(s) where it is needed. In recent years, many dry powder inhalers have been developed by the pharmaceutical industry. Drug delivery to the lung from dry powder inhalers is dependent upon the patient's peak inhaled flow rate, and so it is very important to be able to assess the amount and location of drug delivered from different devices. Lung deposition has recently been assessed from a new dry powder inhaler, the Novolizer® (ASTA Medica, now VIATRIS GmbH & Co. KG, subsidiary Sofotec GmbH & Co. KG, Frankfurt, Germany), using gamma scintigraphy. It was shown that the Novolizer® deposited significantly more budesonide in the lungs than a Turbuhaler® used either at similar inspiratory flow rates or with similar inspiratory effort. Equivalent clinical efficacy and safety profiles have also been shown in asthmatic patients treated with budesonide from each device.