Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2000-11-21
pubmed:abstractText
Rate constants for transfer of naproxen and lidocaine from different oils and oil mixtures to aqueous buffer, pH 6.00, were determined using the rotating dialysis cell. Significantly different first-order rate constants related to attainment of equilibrium, k(obs), were derived depending on the type of oil/oil mixtures used in the release experiments. For the drugs a linear correlation was found between logk(obs) and the logarithm of the partition coefficient P(app): logk(obs)=-0.68 logP(app)-0.25 (k(obs) in h(-1), n=26). A linear relationship was observed between the calculated and experimentally determined P(app) values for the oil mixtures investigated. The specific rate constants, k(ow) and k(wo), related to the partition process were derived from the determined k(obs) and P(app) values. The rate constant k(ow) representing the rate of transfer of the solute from the oil phase to the aqueous buffer was shown to be strongly dependent on the partition coefficient according to the relationship: logk(ow)=-0.68 logP(app)-log(P(app)+1)-0.25 (k(ow) in h(-1), n=26). In particular, diminished release rates were seen for oil mixtures containing castor oil most likely afforded by hydrogen bonding between the solute and the hydroxy groups of the latter vegetable oil. In this study it has been possible to alter P(app) for a specific compound up to a factor of 10 by variation of the composition of the oil vehicle. Such a span of P(app) values results in in vitro release rates differing a factor of 37. Thus, by proper design of the oil vehicle composition it should be possible to modify the release rate for a specific compound within certain limits.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0928-0987
pubmed:author
pubmed:issnType
Print
pubmed:volume
11
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
231-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Modification of in vitro drug release rate from oily parenteral depots using a formulation approach.
pubmed:affiliation
Department of Analytical and Pharmaceutical Chemistry, The Royal Danish School of Pharmacy, Universitetsparken 2, DK-2100, Copenhagen, Denmark.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't