NMR Study of the Association of Propofol with Nonionic Surfactants

Momot, Konstantin I., Kuchel, Philip W., Chapman, Bogdan E., Deo, Peter, & Whittaker, Darryl (2003) NMR Study of the Association of Propofol with Nonionic Surfactants. Langmuir, 19(6), pp. 2088-2095.

View at publisher

Abstract

The general anesthetic 2,6-diisopropylphenol (propofol) is very poorly soluble in water and is normally administered in the form of an emulsion. We demonstrated that several commercially available nonionic surfactants (Tween 80, Cremophor EL, Poloxamer 188, Poloxamer 407, Solutol HS15, and Vitamin E TPGS)render propofol soluble with a specific solubilization capacity of at least 0.1 g/g. The room-temperature stability of the solutions appeared to be limited only by the chemical stability of the compounds involved. Theassociation between propofolandthe surfactantswasinvestigated by various NMR approaches, including measurements of diffusion coefficients, 1H longitudinal relaxation times, and the magnitude of intermolecular nuclear Overhauser effects. The results were consistent with the micellar solubilization mechanism of propofol by the surfactants (unimer solubilization in the case of Poloxamer 188). The 1H longitudinal relaxation and diffusion behavior of propofol were monoexponential in each case. Solubilization caused a considerable shortening of propofol’s proton T1’s. The values of the diffusion coefficient of propofol were several percent higher than those of surfactants. This was explained by the partitioning of propofol between swollen micelles and the aqueous solution. Diffusion measurements also revealed the presence of a rapidly diffusing ethylene oxide population in surfactant solutions, which is consistent with free poly(ethylene oxide) (PEO) known to be present in commercially produced surfactants. The free PEO blocks exhibited molecular association with the extramicellar propofol.

Impact and interest:

61 citations in Scopus
Search Google Scholar™
59 citations in Web of Science®

Citation counts are sourced monthly from Scopus and Web of Science® citation databases.

These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.

Citations counts from the Google Scholar™ indexing service can be viewed at the linked Google Scholar™ search.

Full-text downloads:

1,957 since deposited on 15 Sep 2006
48 in the past twelve months

Full-text downloads displays the total number of times this work’s files (e.g., a PDF) have been downloaded from QUT ePrints as well as the number of downloads in the previous 365 days. The count includes downloads for all files if a work has more than one.

ID Code: 2674
Item Type: Journal Article
Refereed: Yes
Additional Information: This article is freely available from the American Chemical Society website 12 months after the publication date. See links to publisher website in this record.
Additional URLs:
Keywords: nuclear magnetic resonance, PGSE NMR diffusion measurements, micellar nonionic surfactants, propofol, drug delivery
DOI: 10.1021/la026722g
ISSN: 0743-7463
Divisions: Past > QUT Faculties & Divisions > Faculty of Science and Technology
Copyright Owner: Copyright 2003 American Chemical Society
Copyright Statement: The contents of this journal can be freely accessed online via the ACS web page 12 months after publication. See hypertext link.
Deposited On: 15 Sep 2006 00:00
Last Modified: 29 Feb 2012 13:20

Export: EndNote | Dublin Core | BibTeX

Repository Staff Only: item control page