ABSTRACT
When considering the development of potential controlled-release pulmonary drug delivery systems, there is at present no standard method available for the assessment of in vitro drug release profiles necessary to understand how the drug might release following deposition in the lungs. For this purpose, the twin-stage impinger (TSI), apparatus A of the BP, has been redesigned and tested. This modified TSI was found capable of discriminating between drug release rates from conventional and different dry powder formulations consisting of model controlled-release excipients, providing information related to (a) drug diffusion properties of controlled-release dry powder blends with different excipient components and (b) the effect of varying drug concentration within a given formulation.
Subject(s)
Aerosols , Delayed-Action Preparations , Technology, Pharmaceutical/instrumentation , Administration, Inhalation , Albuterol/administration & dosage , Bronchodilator Agents/administration & dosage , Chemistry, Pharmaceutical/methods , Equipment Design , Evaluation Studies as Topic , PowdersABSTRACT
Respirators are currently approved by testing them on a number of subjects without specifying facial sizes. Anthropometrically designed test panels were developed that represent the majority of the working population in terms of relevant facial measurements.
Subject(s)
Cephalometry , Protective Devices/standards , Respiratory Protective Devices/standards , Aerospace Medicine , Cephalometry/instrumentation , Evaluation Studies as Topic , Female , Humans , Male , Occupational Medicine , United StatesABSTRACT
A new sizing program for oral-nasal masks, based on total facial length, has been developed through an analysis of the 1967 USAF anthropometric survey head and face data. A four-size series of three-dimensional face forms has been sculpted based on this sizing program as a design aid for sizing such masks. This report includes a discussion of the theoretical and practical aspects of the sizing analyses and procedures, and establishes design limits and procurement tariffs for the four sizes of masks. The MBU-12/P oxygen mask, an aoral-nasal pressure-demand type of mask, has been fabricated in accordance with this sizing system using the face forms as sizing guides. The results obtained during fit-tests using 66 USAF personnel as subjects are described. The authors concluded that the dimensional sizing of the oral-nasal oxygen mask facepieces is valid for USAF flight crews.
