title: Development of mucoadhesive thio-carboxymethyl cellulose for application in buccal delivery of drugs.
abstract: OBJECTIVE
  L-cysteine (CYS) was covalently attached to carboxymethyl cellulose (CMC) to obtain the thiolated conjugate CMCCYS. Methodology & results: CMCCYS and controls were investigated in terms of safety, disintegration, erosion and mucoadhesiveness. Furthermore, mechanical, physicochemical properties, mucoadhesive strength, swelling behavior and residence time were evaluated. Exhibiting 99.61 ± 2.51% cell viability, CMCCYS was considered as non toxic at all. Furthermore, CMCCYS displayed 2.8-fold higher polymer stability as well as 5.8-fold less erosion than unmodified CMC. Mucoadhesive strength assay displayed 1.6-fold improved adhesion on buccal mucosa as well as 2.7-fold improved mucoadhesiveness on the rotating cylinder.
  
  
  CONCLUSIONS
  Chemical modification of well-known CMC encourage further evaluation and application of the mucoadhesive potential for the buccal delivery.
authors.affiliation: 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: Department of Pharmaceutical Technology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria.
authors.forename: Alexie
authors.initials: A
authors.lastname: Messirek
mesh_terms: D018938:Caco-2 Cells; D002266:Carboxymethylcellulose Sodium / Q000737:chemistry* / Q000633:toxicity; D002470:Cell Survival / Q000187:drug effects; D003545:Cysteine / Q000737:chemistry; D004337:Drug Carriers / Q000737:chemistry* / Q000633:toxicity; D006801:Humans; D006820:Hyaluronic Acid / Q000737:chemistry; D009061:Mouth Mucosa / Q000166:cytology / Q000378:metabolism*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D004337:Drug Carriers; D006820:Hyaluronic Acid; D002266:Carboxymethylcellulose Sodium; D003545:Cysteine
keywords: buccal delivery; carboxymethyl cellulose; mucoadhesion; polymer; thiomer