| Site of deposition and absorption of an inhaled hydrophilic solute. | |
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MedLine Citation:
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PMID: 17244190 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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AIMS: To characterize the absorption kinetics and bioavailability of an inhaled hydrophilic solute deposited at various sites within the airways. METHODS: Nine healthy nonsmokers received one intravenous, one oropharyngeal and two pulmonary doses of technetium-99 m-labelled diethylene triamine pentaacetic acid ((99m)Tc-DTPA) in an open and crossover fashion. Pulmonary doses were administered as nebulized large and fine droplet-sized aerosols by Pari and UltraVent nebulizers at fairly rapid and slow inhalation flows, respectively. Plasma concentration-time profiles and 24 h urinary excretion of radioactivity were determined. One dose of (99m)Tc-labelled Nanocoll, as a marker of mucociliary clearance (MCC), was also administered by Pari for similar lung deposition as the (99m)Tc-DTPA and followed by repeated chest gamma-imaging. RESULTS: Intrapulmonary deposition patterns of (99m)Tc-DTPA differed significantly (the mean ratio of penetration index (Pari : UltraVent) was 76% with 95% CI 63%, 91%). However, no differences in rate or extent of (99m)Tc-DTPA absorption were detected. Mean absorption time was 1.8 h (mean difference (Pari-UltraVent): -0.1 h with 95% CI -0.6 h, 0.3 h) and the bioavailability was 70% (mean ratio (Pari : UltraVent): 101% with 95% CI 90%, 115%). The pulmonary elimination half-life of (99m)Tc-Nanocoll (8 h and 45 min) was significantly longer than that of (99m)Tc-DTPA (less than 2 h). The oral bioavailability of (99m)Tc-DTPA was estimated to be 3.1%. CONCLUSIONS: The main elimination pathway of the inhaled hydrophilic solute (99m)Tc-DTPA from the lungs is trans-epithelial absorption. Despite different intrapulmonary radioaerosol deposition patterns, as verified by gamma scintigraphy, no differences in (99m)Tc-DTPA absorption kinetics or bioavailability were detected. |
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Authors:
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Eva Bondesson; Thomas Bengtsson; Lars-Erik Nilsson; Per Wollmer |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2007-01-23 |
Journal Detail:
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Title: British journal of clinical pharmacology Volume: 63 ISSN: 0306-5251 ISO Abbreviation: Br J Clin Pharmacol Publication Date: 2007 Jun |
Date Detail:
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Created Date: 2007-05-18 Completed Date: 2007-09-27 Revised Date: 2009-11-18 |
Medline Journal Info:
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Nlm Unique ID: 7503323 Medline TA: Br J Clin Pharmacol Country: England |
Other Details:
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Languages: eng Pagination: 722-31 Citation Subset: IM |
Affiliation:
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AstraZeneca R and D Lund, SE-22187 Lund, Sweden. Eva.Bondesson@astrazeneca.com |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Absorption Administration, Inhalation Adult Aerosols / administration & dosage* Chelating Agents / administration & dosage*, pharmacokinetics Cross-Over Studies Humans Lung / drug effects* Male Middle Aged Mucociliary Clearance Technetium Tc 99m Pentetate / administration & dosage*, pharmacokinetics Tomography, X-Ray Computed / methods |
| Chemical | |
Reg. No./Substance:
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0/Aerosols; 0/Chelating Agents; 65454-61-7/Technetium Tc 99m Pentetate |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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