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

Direct link
Rheological studies of the gelation of deacetylated gellan gum (Gelrite®) in physiological conditions
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
1999 (English)In: European Journal of Pharmaceutical Sciences, ISSN 0928-0987, E-ISSN 1879-0720, Vol. 9, no 1, 99-105 p.Article in journal (Refereed) Published
Abstract [en]

Gels have been successfully used to increase the mucosal contact time and hence the bioavailability of nasal and ophthalmic formulations. The use of in situ gelling polymers requires a rapid sol-gel transition that produces a strong gel for an optimal contact time. In this study, the rheological behaviour of deacetylated gellan gum (Gelrite) was analysed in order to better understand the reasons for the good performance in humans. Thermal scans were used to study gel formation and other changes in the structure of the samples when the macromolecular and ionic contents were altered. The effect the different ions in tear fluid (Na+, K+, Ca2+) had on the gel strength and the consequences of dilution due to the ocular protective mechanisms were examined. Na+ was found to be the most important gel-promoting ion in vivo. It was also found that gels are formed in tear fluid even when the concentration of Gelrite) is only 0.1%. Samples with concentrations of Gelrite of 0.5-1% do not require more ions than 10-25% of those in tear fluid to form gels. These two findings can partly explain the good performance of Gelrite in vivo. Gels with a high elastic modulus can thus be formed even though dilution of instilled drops takes place.

Place, publisher, year, edition, pages
1999. Vol. 9, no 1, 99-105 p.
National Category
Pharmaceutical Sciences
Research subject
URN: urn:nbn:se:uu:diva-241847DOI: 10.1016/S0928-0987(99)00051-2OAI: oai:DiVA.org:uu-241847DiVA: diva2:781786
Available from: 2015-01-19 Created: 2015-01-19 Last updated: 2015-01-19

Open Access in DiVA

No full text

Other links

Publisher's full text
By organisation
Department of Pharmacy
In the same journal
European Journal of Pharmaceutical Sciences
Pharmaceutical 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: 165 hits
ReferencesLink to record
Permanent link

Direct link