Linked Life Data

16414222

Source:http://linkedlifedata.com/resource/pubmed/id/16414222

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2006-2-28
pubmed:abstractText
The issue of incomplete release of poorly soluble drugs from sustained-release oral formulations is addressed using prednisolone (PDS) as the model drug and a novel highly swelling hydrogel as the rate-controlling material. The hydrogel was formed by heating N-carboxymethylchitosan (CMC) to 80 degrees C for 24 h. Swelling, alkalimetry, FTIR, DSC, and solid-state NMR studies showed that the treatment produced physical crosslinking, i.e., polymer chain entanglement. A controlled-release system was prepared by coating an inert compacted support of ethylcellulose (50 mg; diameter, 6 mm) with a CMC layer containing dispersed PDS powder (10-50 microm). The system was heated to crosslink the CMC coating, then drug release to simulated GI fluids was studied in vitro. The drug release pattern and term were modulated via the layer mass (LM) (10 or 14 mg cm(-2)) and/or the drug-polymer wt ratio (D/P) (1:5 or 2:5). The rate parameter, K, and the time exponent, n, of the Peppas equation were: K=26.6+/-0.3 h(-n), n = 0.78+/-0.02 (LM, 10 mg cm(-2); D/P, 1:5); K = 24.7+/-0.7 h(-n), n = 0.56+/-0.02 (LM, 14 mg cm(-2); D/P, 1:5); K = 20.7+/-0.3 h(-n), n = 0.76+/-0.01 (LM, 10 mg cm(-2); D/P, 2:5). Hydrogel swelling was faster than drug release. This was controlled, in a first stage, by drug dissolution-diffusion in the swollen gel, and subsequently, by diffusion. The drug release rate was unaffected by the GI pH variations, and slightly affected by the environmental hydrodynamics. The system promises an extended and complete release of poorly soluble drugs in the GI tract.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0378-5173
pubmed:author
pubmed:issnType
Print
pubmed:day
9
pubmed:volume
310
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
154-61
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
A new hydrogel for the extended and complete prednisolone release in the GI tract.
pubmed:affiliation
Department of Bioorganic Chemistry and Biopharmaceutics, University of Pisa, Via Bonanno 33, 56126 Pisa, Italy.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't