uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Novel Gel Formulations with Catanionic Aggregates Enable Prolonged Drug Release and Reduced Skin Permeation
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
2011 (English)In: Journal of Pharmacy and Pharmacology (JPP), ISSN 0022-3573, Vol. 63, no 10, 1265-1273 p.Article in journal (Refereed) Published
Abstract [en]

Objectives: The aim of this study was to investigate skin permeation rates of a drug substance when applied in novel gel formulations with catanionic aggregates.

Methods: Reference gel without catanionic aggregates was compared with formulations with catanionic aggregates composed of tetracaine and either sodium dodecyl sulphate (SDS) or capric acid. Carbomer and SoftCAT were used to compare the effect of different gel types to elucidate if physically cross-linked, 'self-destructing' systems had benefits compared with classical, covalently cross-linked, gels.

Key findings: The rheological investigation showed that the interactions between the SoftCAT polymer and tetracaine/SDS aggregates were stronger than when the tetracaine/capric acid aggregates were used. The skin permeation was measured ex vivo in horizontal Ussing chambers and the permeation of tetracaine was significantly lower when formulations with tetracaine/SDS aggregates were applied (P < 0.001), but not statistically different from the reference when capric acid was used.

Conclusions: No morphological differences could be distinguished between the skin samples exposed to the different formulations or the reference. Skin permeation was compared with silicone sheet permeation and the results indicated that silicone sheets could be used as a model of skin when using these formulations.

Place, publisher, year, edition, pages
2011. Vol. 63, no 10, 1265-1273 p.
Keyword [en]
catanionic, gel, pig ear skin, silicone membrane, vesicle
National Category
Medical and Health Sciences
URN: urn:nbn:se:uu:diva-147595DOI: 10.1111/j.2042-7158.2011.01339.xISI: 000295093500002OAI: oai:DiVA.org:uu-147595DiVA: diva2:400550
Available from: 2011-02-26 Created: 2011-02-26 Last updated: 2011-10-17Bibliographically approved
In thesis
1. Catanionic Aggregates in Gels: Prolonged Drug Release and Potential Implications for Topical Use
Open this publication in new window or tab >>Catanionic Aggregates in Gels: Prolonged Drug Release and Potential Implications for Topical Use
2011 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Gels are popular dosage forms.  This topical dosage form may be advantageous compared to oral or parenteral dosage forms. Favorable rheological or bioadhesive properties of gels might provide extended contact times at the site of administration compared to aqueous solutions. However, due to the high water content of gels, these are usually quickly emptied of the drug substance. One way of prolonging the drug release from gels is to contain the drug substance in catanionic aggregates in the gel. These aggregates are formed in solutions of oppositely charged surfactants and a drug can be used instead of one of the surfactants.


In this thesis catanionic aggregates composed of drug substances and oppositely charged surfactants were studied and the possibility to use these aggregates for the purpose of prolonged drug release was investigated. The formation of catanionic aggregates when using drugs was found to be a common occurrence in addition to which, the oppositely charged surfactant can be varied and surfactants of natural origin with a low toxicity were used. Most combinations tested rendered either vesicles or elongated micelles. When the catanionic aggregates were contained in gels the drug release was substantially prolonged. The apparent diffusion coefficients were lowered 10-100 times compared to the reference gels. When gels with catanionic vesicles with substantial prolonged drug release were applied to skin the penetration rate was lowered extensively. No morphological differences were observed between skin samples that had been exposed to formulations containing catanionic aggregates and skin samples exposed to saline solution, air or formulations containing only the drug. Both conventional, covalently linked pre-formed gels and physical gels, where the catanionic vesicles form the cross-links upon interaction with the polymer, can be used for these purposes. When the effect of drug release on aggregate structure was studied, it was shown that vesicles are present in both conventional and physical gels throughout the drug release process.


This thesis shows that catanionic aggregates contained in gels can present an advantageous formulation strategy to prolong the drug release, thereby improving the efficiency of gel formulations.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2011. 65 p.
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Pharmacy, ISSN 1651-6192 ; 140
National Category
Pharmaceutical Sciences
Research subject
urn:nbn:se:uu:diva-138447 (URN)978-91-554-8019-6 (ISBN)
Public defence
2011-04-15, B 42, BMC, Husargatan 3, Uppsala, 09:15 (Swedish)
Available from: 2011-03-25 Created: 2010-12-17 Last updated: 2011-05-04Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text
By organisation
Department of Pharmacy
In the same journal
Journal of Pharmacy and Pharmacology (JPP)
Medical and Health Sciences

Search outside of DiVA

GoogleGoogle Scholar
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

Altmetric score

Total: 189 hits
ReferencesLink to record
Permanent link

Direct link