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Volume 6, Issue 4 (Suppl)
Clin Pharmacol Biopharm, an open access journal
ISSN: 2167-065X
Page 31
Euro Biopharma & Ethnopharmacology 2017
November 09-11, 2017
&
6
th
International Conference and Exhibition on
November 09-11, 2017 Vienna, Austria
4
th
EUROPEAN BIOPHARMA CONGRESS
PHARMACOLOGY AND ETHNOPHARMACOLOGY
Joint Event
2,2’Dithiodinicotinyl ligands: Key to more reactive thiomers
Claudia Menzel
University of Innsbruck, Austria
T
he goal of this study was to establish a new type of preactivated thiomers showing comparatively higher reactivity with mucus
and improved mucoadhesive properties. The dimeric form of 2-mercaptonicotinic acid (MNA-MNA) was directly attached
to the polymeric backbone of chitosan (CHI) to achieve a higher reactivity. Amide bond formation mediated by 1-ethyl-3-(3-
dimethylaminopropyl) carbodiimide (EDAC) was used as a coupling reagent. The remaining free amino groups were reacted with
succinic anhydride (Succ) to gain a homogeneously anionically charged polymer (CHI-Succ-MNA-MNA). Within our study, various
coupling rates of up to 170 µmol MNA-MNA per gram polymer were obtained. The coupling of the dimeric ligand resulted in
a preactivated thiomer with a more reactive disulfide substructure due to the additional nitrogen atom in conjugation over the
aromatic moieties. Furthermore, the obtained polymer is completely preactivated and therefore protected against unwanted oxidation
reactions. Our kinetic studies of disulfide exchange reactions showed a 3.8-fold higher reactivity of CHI-Succ-MNA-MNA compared
to a state-of-the-art preactivated thiomer. Rheological measurements showed that CHI-Succ-MNA-MNA with a coupling rate of 170
µmol (CHI-Succ-MNA-MNA 170) lead to a 5.7-fold higher mucus viscosity than the non-thiolated control polymer (CHI-Succ).
This indicates a rheological synergism due to mucoadhesive properties. These results were confirmed by an additional mucoadhesion
experiment, which showed a significantly prolonged retention time of CHI-Succ-MNA-MNA on the small intestinal mucosa
compared to CHI-Succ (P<0.02). According to the presented results, the double preactivation seems to be a promising strategy to
obtain entirely preactivated polymers with improved mucoadhesive properties.
Biography
Claudia Menzel is a PhD student from the Institute of Pharmacy at University of Innsbruck. Her work focuses on the improvement of drug bioavailability and the
development of drug delivery systems for the non-invasive administration of poorly absorbed drugs. She has published three papers and one review article in
reputed journals.
claudia.menzel@uibk.ac.atClaudia Menzel, Clin Pharmacol Biopharm 2017, 6:4(Suppl)
DOI: 10.4172/2167-065X-C1-025