title: Design and evaluation of buccal-adhesive system made of modified xanthan.
abstract: Introducing the concept of mucoadhesion in the 1980s, application of mucoadhesive polymers for buccal drug delivery has been the subject of pharmaceutical interest.
  
  
  
  The purpose of this study was to modify well-known xanthan in order to remarkably boost its suitability for buccal adhesiveness.
  
  
  
  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).
  
  
  
  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.
  
  
  
  In completion, novel sulfhydryl-modified xanthan proved itself being a useful and promising excipient for buccal-adhesive delivery systems.
authors.affiliation: Department of Pharmaceutical Technology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria.
authors.forename: Flavia
authors.initials: F
authors.lastname: Laffleur
authors.affiliation: Department of Pharmaceutical Technology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria.
authors.forename: Martina
authors.initials: M
authors.lastname: Michalek
authors.affiliation: Department of Pharmaceutical Technology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria.
authors.forename: Wongsakorn
authors.initials: W
authors.lastname: Suchaoin
authors.affiliation: Department of Pharmaceutical Technology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Ijaz
mesh_terms: D000268:Adhesiveness; D000269:Adhesives; D000278:Administration, Buccal; D003545:Cysteine; D016503:Drug Delivery Systems; D005079:Excipients; D009061:Mouth Mucosa; D011108:Polymers; D011135:Polysaccharides, Bacterial
chemical_list: D000269:Adhesives; D005079:Excipients; D011108:Polymers; D011135:Polysaccharides, Bacterial; D003545:Cysteine; C002563:xanthan gum
keywords: biomaterial Â; buccal; mucoadhesion; tissue; xanthan