Linked Life Data

2899338

Source:http://linkedlifedata.com/resource/pubmed/id/2899338

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1988-8-19
pubmed:abstractText
The actual deposition pattern of micronized drugs from metered dose inhalers (MDI) is incompletely known because there are no methods available to label the drugs (beta 2-agonists) with gamma-emitters. Indirect measurements of the distribution of the drug in man differed greatly due to the method used. Our method uses the better solubility of 99mTcO4- in the beta 2-agonist-micronized drug in relation to the propellant with surfactant. The principle is to extract the 99mTcO4- from the original water phase into the liquid phase of the propellant with ethyl methyl ketone. For labeling the micronized drug particles, the original MDI must be cooled to -60 degrees C and some labeled propellant (including surfactant) with high specific activity of 99mTcO4- is added through an aperture in the bottom of the container. The aperture is sealed with a screw. After rewarming the MDI, more than 90% of the added 99mTcO4- is dissolved in the beta 2-agonist-micronized drug in relation to its volume. This is proved by comparing the distribution of the radioactivity component with chemical analysis. The pattern of deposition of both MDIs - placebo and beta 2-agonist-micronized drug - was shown to be similar in healthy volunteers. With a labeled MDI a preliminary study with 2 different inhaling maneuvers was performed in 7 volunteers: inhaling from residual volume after a pause of 2 s the intrabronchial deposition was 18.7%, and inhaling at 50% of vital capacity maneuver the intrabronchial deposition was 33.0%. The data obtained with actual measurement of the inhaled drug from MDI suggest greater intrabronchial deposition than was assumed before in the literature.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0025-7931
pubmed:author
pubmed:issnType
Print
pubmed:volume
53
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
65-73
pubmed:dateRevised
2009-11-11
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
New method for easy labeling of beta-2-agonists in the metered dose inhaler with technetium 99m.
pubmed:affiliation
Department of Internal Medicine, University of Freiburg, FRG.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't