Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Characterisation of Aqueous Solutions, Liquid Crystals and Solid State of Non-ionic Polymers in Association with Amphiphiles and Drugs
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
2003 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Cellulose ethers and polyethylene glycols are used in drug formulations as water swelling or water soluble matrices. Polar lipids, for example monoglycerides, and surfactants can be used to solubilise hydrophobic or amphiphilic drugs and to formulate potential drug delivery vehicles such as emulsions, liposomes and cubic phases. In this thesis mixtures of these excipients are characterised in various environments, from dilute aqueous solutions to solid dispersions. Special focus has been on the understanding of the associating processes involved.

Detailed understanding of the association of cellulose ethers, of varying hydrophobicity, and amphiphilic substances is presented. The hydrophobicity of the polymer was found to have an impact on the interaction scheme. The amphiphiles were found to bind at lower amphiphile concentrations to a more hydrophobic polymer thus influencing both micro- and macroscopic structure of the aggregates.

The choice of counterion to the amphiphile has a small but significant effect on the interaction and the structure of the aggregates. Also amphiphilic drug molecules can interact with nonionic polymers in a similar way as surfactants in aqueous solution. Due to the higher cmc of the drug ibuprofen the interaction is largely influenced by the ionic strength of the solution. The type of amphiphile also influences the cooperativity of the amphiphile-polymer binding.

In more concentrated systems liquid crystals are formed into which the polymer interact with the amphiphiles. Both cubic and sponge phases were found with relatively large polymers interacting with polar lipids. These phases were found to swell and shrink mainly controlled by the amount of polymer inside them. Also membrane interacting substances added to the sponge phase could influence the size of the water channels in the phase.

In water free systems polymers and polar lipids were found to interact as well as forming solid dispersions. The behaviour of the phase separation between polymer and lipid depended on the concentration of the dispersed phase. The polar lipid was found to be distributed in the lamellar part of the semicrystalline polymer influencing the polymer folding.

Place, publisher, year, edition, pages
Uppsala: Universitetsbiblioteket , 2003. , p. 66
Series
Comprehensive Summaries of Uppsala Dissertations from the Faculty of Pharmacy, ISSN 0282-7484 ; 298
Keywords [en]
Physical chemistry, polymer, surfactant, phase diagram, x-ray diffraction, fluorescence spectroscopy, calorimetry, PEG, cellulose ether, viscometry, cubic phase, liquid crystals, drugs, solid dispersion
Keywords [sv]
Fysikalisk kemi
National Category
Physical Chemistry
Research subject
Physical and Inorganic Pharmaceutical Chemistry
Identifiers
URN: urn:nbn:se:uu:diva-3607ISBN: 91-554-5757-6 (print)OAI: oai:DiVA.org:uu-3607DiVA, id: diva2:163437
Public defence
2003-10-31, B42, BMC, Uppsala, 10:15
Opponent
Supervisors
Available from: 2003-10-07 Created: 2003-10-07 Last updated: 2015-09-09Bibliographically approved
List of papers
1. Influence of counterion on the interaction of dodecyl sulfates and cellulose ethers
Open this publication in new window or tab >>Influence of counterion on the interaction of dodecyl sulfates and cellulose ethers
2002 In: Journal of Colloid and Interface Science, ISSN 0021-9797, Vol. 247, no 2, p. 381-388Article in journal (Refereed) Published
Identifiers
urn:nbn:se:uu:diva-90913 (URN)
Available from: 2003-10-07 Created: 2003-10-07Bibliographically approved
2. Amphiphilic association of ibuprofen and two nonionic cellulose derivates in aqueous solution
Open this publication in new window or tab >>Amphiphilic association of ibuprofen and two nonionic cellulose derivates in aqueous solution
1999 In: Journal of Pharmaceutical Sciences, Vol. 88, no 11, p. 1175-1181Article in journal (Refereed) Published
Identifiers
urn:nbn:se:uu:diva-90914 (URN)
Available from: 2003-10-07 Created: 2003-10-07Bibliographically approved
3. Shrinking and swelling the cubic phase of the polyethylene glycol/monoolein/water-system
Open this publication in new window or tab >>Shrinking and swelling the cubic phase of the polyethylene glycol/monoolein/water-system
Article in journal (Refereed) Submitted
Identifiers
urn:nbn:se:uu:diva-90915 (URN)
Available from: 2003-10-07 Created: 2003-10-07Bibliographically approved
4. On the water content of the solvent/monoolein/water sponge (L3) phase
Open this publication in new window or tab >>On the water content of the solvent/monoolein/water sponge (L3) phase
2003 (English)In: Colloids and Surfaces A: Physicochemical and Engineering Aspects, ISSN 0927-7757, E-ISSN 1873-4359, Vol. 228, no 1-3, p. 17-24Article in journal (Refereed) Published
Abstract [en]

The water content of the solvent/monoolein/water sponge phase depends on the lipophilicity of the solvent used. The relatively lipophilic solvent 2-methyl-2,4-pentanediol (MPD) gives a sponge phase at about 60 wt.% water compared with 30 wt.% for the sponge phase formed with polyethylene glycol (Mw≈400, PEG 400). A reasonably good correlation is found between the water content of the sponge phase and the octanol/water partition coefficient for the solvent. The water content of the PEG 400 sponge phase increases considerably (to about 50 wt.%) by adding up to 3 wt.% of ionic compounds such as SDS, CTAB and salts of amphiphilic drugs. Nonionic detergents show less effect on increasing the water content, whereas membrane lipids such as lecithins and cholesterol show unchanged or even decreasing effect on the water content of the sponge phase.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-90916 (URN)10.1016/S0927-7757(03)00299-1 (DOI)
Available from: 2003-10-07 Created: 2003-10-07 Last updated: 2017-12-14Bibliographically approved
5. Solid-state characterisation of PEG 4000/monoolein mixtures
Open this publication in new window or tab >>Solid-state characterisation of PEG 4000/monoolein mixtures
2004 (English)In: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 37, no 7, p. 2665-2667Article in journal (Refereed) Published
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-92198 (URN)10.1021/ma0354344 (DOI)
Available from: 2004-10-07 Created: 2004-10-07 Last updated: 2017-12-14Bibliographically approved

Open Access in DiVA

fulltext(668 kB)6678 downloads
File information
File name FULLTEXT01.pdfFile size 668 kBChecksum SHA-1
bfc8de7e3d6a746f58408c2b30b0afd9e6ffddcb15137d45929bbaf5911fd496e0e51d4b
Type fulltextMimetype application/pdf
Buy this publication >>

By organisation
Department of Pharmacy
Physical Chemistry

Search outside of DiVA

GoogleGoogle Scholar
Total: 6678 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 1827 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf