title: The Impact of Inspiratory Flow Rate on Drug Delivery to the Lungs with Dry Powder Inhalers.
abstract: Current marketed dry powder inhalers utilize the energy from patient inspiration to fluidize and disperse bulk powder agglomerates into respirable particles. Variations in patient inspiratory flow profiles can lead to marked differences in total lung dose (TLD), and ultimately patient outcomes for an inhaled therapeutic. The present review aims to quantitate the flow rate dependence in TLD observed for a number of drug/device combinations using a new metric termed the Q index. With this data in hand, the review explores key attributes in the design of the formulation and device that impact flow rate dependence. The review also proposes alternative in vitro methods to assess flow rate dependence that more closely align with in vivo observations. Finally, the impact of variations in flow rate on lung function for inhaled bronchodilators is summarized.
authors.affiliation: Novartis Pharmaceuticals Corporation, 150 Industrial Road, San Carlos, California, 94070, USA. jeff.weers@novartis.com.
authors.forename: Jeffry
authors.initials: J
authors.lastname: Weers
authors.affiliation: Aerogen Pharma, San Mateo, California, USA.
authors.forename: Andy
authors.initials: A
authors.lastname: Clark
mesh_terms: D000280:Administration, Inhalation; D001249:Asthma / Q000188:drug therapy*; D001993:Bronchodilator Agents / Q000008:administration & dosage* / Q000494:pharmacology; D002626:Chemistry, Pharmaceutical; D016503:Drug Delivery Systems; D058995:Dry Powder Inhalers / Q000295:instrumentation*; D004867:Equipment Design; D006801:Humans; D008168:Lung; D009330:Nebulizers and Vaporizers; D011208:Powders; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy*; D056152:Respiratory Rate
chemical_list: D001993:Bronchodilator Agents; D011208:Powders
keywords: Bronchodilator; Inertial impaction parameter; Inhalation; Total Lung Dose (TLD)