title: In vitro evaluation of thio-poly acrylic acid for intraoral delivery.
abstract: BACKGROUND
  Intraoral drug delivery as mucosal delivery pathway provides a huge platform in the pharmaceutical field.
  
  
  OBJECTIVE
  Combining mucoadhesiveness and controlled release of thio-poly acrylic acid as advanced excipient for buccal drug delivery.
  
  
  METHODS
  Mediated by carbodiimide, cysteine was covalently attached to poly acrylic acid. This thiomer was assessed with regard to cytotoxicity, stability, mucoadhesion, and rheology as well as release behavior of Lidocaine.
  
  
  RESULTS
  Stability assays of thio-poly acrylic acid were complying with United States Pharmacopeia requirements. Mucoadhesion assay such as tensile (total work of adhesion), bioadhesion, rotating cylinder revealed as this thiomer was superior in comparison to non-thiolated poly acrylic acid with 7.61-fold, 2.8-fold, 5.61-fold improvement, respectively without any toxic effect. The cell viability exhibited over 90% after incubation time of 3 h and 24 h respectively. Lidocaine release showed 1.98-fold more controlled release over 3 h in comparison to unmodified poly acrylic acid.
  
  
  CONCLUSIONS
  Taken the findings in consideration, thio-poly acrylic acid provides excellent stability, controlled release, and superior mucoadhesive features. The prolonged residence time of thio-poly acrylic acid represents a pillar in the buccal drug delivery.
authors.affiliation: a Department of Pharmaceutical Technology , Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of Innsbruck , Innsbruck , Austria.
authors.forename: Flavia
authors.initials: F
authors.lastname: Laffleur
authors.affiliation: a Department of Pharmaceutical Technology , Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of Innsbruck , Innsbruck , Austria.
authors.forename: Nina
authors.initials: N
authors.lastname: Leder
authors.affiliation: a Department of Pharmaceutical Technology , Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of Innsbruck , Innsbruck , Austria.
authors.forename: Jan
authors.initials: J
authors.lastname: Barthelmes
mesh_terms: D000179:Acrylates / Q000737:chemistry* / Q000378:metabolism; D003553:Cystine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D003692:Delayed-Action Preparations / Q000737:chemistry* / Q000378:metabolism / Q000493:pharmacokinetics*; D016503:Drug Delivery Systems; D004355:Drug Stability; D006801:Humans; D008012:Lidocaine / Q000737:chemistry* / Q000378:metabolism / Q000493:pharmacokinetics*; D012212:Rheology
chemical_list: D000179:Acrylates; D003692:Delayed-Action Preparations; C000614853:carbodiimide cystine; C000614852:thio-poly acrylic acid; D003553:Cystine; D008012:Lidocaine
keywords: Intraoral drug delivery; Lidocaine; mucoadhesion; thio-poly acrylic acid; thiomer