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In vivo measurements of the deposition of an inhaled radiolabeled pharmaceutic have provided useful information related to the inhaler efficiency for depositing drug in the lung. A number of labeling techniques have been developed and applied to pharmaceutical aerosols delivered by pressurized metered-dose inhalers (pMDIs), dry powder inhalers (DPIs) and nebulizers; the choice of radiotracer depends on the type of imaging study being performed and the equipment used to image the lung. Preparation, validation and calibration of the radiolabeled pharmaceutical product is key to successful interpretation of the imaging study. When imaging a subject after inhalation of a radiolabeled formulation, it is the radioactivity that is detected and measured by the scanner; absolute amounts of deposited drug are inferred from the counts of radioactivity in the lung and other regions, based on the assumption that there is a 1:1 relationship between the two components—drug and radioactivity. This relationship holds true for direct-labeled PET products or for those formulations where a firm bond can be demonstrated between the drug and radiotracer for the time taken to acquire all the images. This chapter will discuss radiolabeling methods applied to therapeutic aerosols for the purpose of determining the deposition efficiency of these aerosols in the lung. The techniques apply to both in vivo studies in man and in animal models, and to some extent to in vitro models. [ABSTRACT FROM AUTHOR]

Background: The proliferation of inhaler devices has resulted in a confusing number of choices for clinicians who are selecting a delivery device for aerosol therapy. There are advantages and disadvantages associated with each device category. Evidence-based guidelines for the selection of the appropriate aerosol delivery device in specific clinical settings are needed. Aim: (1) To compare the efficacy and adverse effects of treatment using nebulizers vs pressurized metered-dose inhalers (MDIs) with or without a spacer/holding chamber vs dry powder inhalers (DPIs) as delivery systems for β-agonists, anticholinergic agents, and corticosteroids for several commonly encountered clinical settings and patient populations, and (2) to provide recommendations to clinicians to aid them in selecting a particular aerosol delivery device for their patients. Methods: A systematic review of pertinent randomized, controlled clinical trials (RCTs) was undertaken using MEDLINE, EmBase, and the Cochrane Library databases. A broad search strategy was chosen, combining terms related to aerosol devices or drugs with the diseases of interest in various patient groups and clinical settings. Only RCTs in which the same drug was administered with different devices were included. RCTs (394 trials) assessing inhaled corticosteroid, β2-agonist, and anticholinergic agents delivered by an MDI, an MDI with a spacer/ holding chamber, a nebulizer, or a DPI were identified for the years 1982 to 2001. A total of 254 outcomes were tabulated. Of the 131 studies that met the eligibility criteria, only 59 (primarily those that tested β2-agonists) proved to have useable data. Results: None of the pooled metaanalyses showed a significant difference between devices in any efficacy outcome in any patient group for each of the clinical settings that was investigated. The adverse effects that were reported were minimal and were related to the increased drug dose that was delivered. Each of the delivery devices provided similar outcomes in patients using the correct technique for inhalation. Conclusions: Devices used for the delivery of bronchodilators and steroids can be equally efficacious. When selecting an aerosol delivery device for patients with asthma and COPD, the following should be considered: device/drug availability; clinical setting; patient age and the ability to use the selected device correctly; device use with multiple medications; cost and reimbursement; drug administration time; convenience in both outpatient and inpatient settings; and physician and patient preference. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Problems Patients Have Using Pressurized Aerosol Inhalers," by G. K. Crompton in the 1982 issue.

This article reports on discussions at the 2015 workshop cosponsored by the International Pharmaceutical Aerosol Consortium on Regulation and Science (IPAC-RS) and the International Society for Aerosols in Medicine (ISAM), entitled 'Regulatory and Patient Considerations for Inhalation Device Design, Development and Use.' Key topics addressed at the workshop and presented here include patient-focused device design for orally inhaled products (OIPs), instructions for use (IFU), human factors, regulatory considerations in the United States and Europe, development of generic inhalers, quality-by-design, and change management of OIP devices. Workshop participants also identified several areas for further consideration and emphasized the need for increased focus on the patient to create therapeutic products (inclusive of device design, IFU, education, training) that support adherence with an individual patient's treatment regimen. Advances in patient-centric product development will require engagement and collaboration by industry, regulators, patients, physicians, and other stakeholders. The article includes summaries of presented talks as well as of panel and audience discussions. [ABSTRACT FROM AUTHOR]