Effects of Reference Performance Testing during Aging Using Commercial Lithium-Ion Cells

Abstract

Metered-dose inhalers represent the corner-stone of the drug treatment of asthma. However, their limitations have led to the development of alternative solutions, including powder-based systems. Two designs of multidose powder inhalers are based on opposing principles: inhalers such as the Diskus(registered trademark) inhaler, which uses sealed dose units, packaged in the factory, and those based on a powder reservoir system. In vitro studies show that the Diskus(registered trademark) appears to be a reliable inhaler, delivering regular and homogeneous drug doses, minimally influenced by inspiratory flow rate and the timing of the dose of medicinal product in relation to the life-span of the apparatus. Low-flow inspiration has little influence on the dose released and the fraction of fine inhalable particles. These performances are due to the principle of Diskus(registered trademark): sealed unit doses and low resistance to flow. The Diskus(registered trademark) is also easy to use right from the outset. The feeling of inhalation, due to the presence of lactose, and the precise dose counter are two important points for the majority of patients. Comparison of the two types of inhalers provides a clearer idea about their differences and should facilitate prescription of the most adapted system for each patient.