Design and evaluation of buccal-adhesive system made of modified xanthan
Flavia Laffleur1, Martina Michalek1, Wongsakorn Suchaoin1
1Department of Pharmaceutical Technology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria.
Background:
Introducing the concept of mucoadhesion in the 1980s, application of mucoadhesive polymers for buccal drug delivery has been the subject of pharmaceutical interest.
Aim:
The purpose of this study was to modify well-known xanthan in order to remarkably boost its suitability for buccal adhesiveness.
Method:
Xanthan (X) was chemically modified by covalent binding of L-cysteine (SH) exhibiting sulfhydryl groups on the polymeric backbone via amide bond formation. Cytotoxicity, stability properties and mucoadhesiveness, respectively, of sulfhydryl-modified xanthan (H-SH) was investigated compared with unmodified xanthan (X).
Results:
According to cell viability studies X-SH was safe to use. X-SH revealed 1.61-fold higher stability in comparison to unmodified xanthan. Thereafter, mucoadhesion of X-SH augmented 8.35-fold in case of rotating cylinder assay. Tensile study showed 2.65-fold higher total work of adhesion when comparing X-SH with X.
Conclusion:
In completion, novel sulfhydryl-modified xanthan proved itself being a useful and promising excipient for buccal-adhesive delivery systems.
