Document Detail

1H-NMR microscopy of tablets.
MedLine Citation:
PMID:  7616364     Owner:  NLM     Status:  MEDLINE    
A 1H-nuclear magnetic resonance (NMR) microscopy method was utilized for the first time to determine the porosity distribution of physically intact tablets. The main advantage of this newly developed method was that porosity cross sections through whole tablets or specific locations could be obtained without mechanically destroying the tested tablet. This was achieved by filling tablet cavities with silicone oil under vacuum. The amount of silicone oil locally within the tablet was then determined by 1H-NMR microscopy, revealing the inverse inner structure. To reduce the measuring time, a paramagnetic gadolinium complex was added to the silicone oil. The cross sectional signals produced by 1H-NMR microscopy through the tablet were transformed into a color image by a specially designed computer graphic program. To improve the signal-noise ratio an algorithm of 3D-filtering was introduced. The maximal spatial resolution achieved with this method was about 95 microns for a cube's edge length corresponding to some 380,000 positions in a 9-mm-diameter compression-coated tablet. Uneven porosity distributions within tablets, cracks, or cavities could be visualized with this newly developed method. Different compaction mechanisms were observed with plastic- or brittle-type tablets. The different states of densification during compaction of powders could be detected. The integrity of compression coatings was determined to be dependent on the pressure load and the location of the core within the coat.
G Nebgen; D Gross; V Lehmann; F Müller
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Journal of pharmaceutical sciences     Volume:  84     ISSN:  0022-3549     ISO Abbreviation:  J Pharm Sci     Publication Date:  1995 Mar 
Date Detail:
Created Date:  1995-08-23     Completed Date:  1995-08-23     Revised Date:  2000-12-18    
Medline Journal Info:
Nlm Unique ID:  2985195R     Medline TA:  J Pharm Sci     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  283-91     Citation Subset:  IM    
Pharma Operations Manufacturing, POMF-DL, F. Hoffmann-La Roche LTD, Basel, Switzerland.
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MeSH Terms
Magnetic Resonance Imaging / methods*
Microscopy, Electron
Reg. No./Substance:
0/Tablets; 10028-17-8/Tritium

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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