title: In situ evaluation of drug-loaded microspheres on a mucosal surface under dynamic test conditions.
abstract: The ability of polymeric microspheres fabricated from Carbopol, polycarbophil, chitosan or Gantrez to retain a model hydrophilic drug (sodium fluorescein) was evaluated in situ, using a dynamic test system and image analysis. This technique used oesophageal tissues and simulated the physiological conditions within the oral cavity in terms of temperature, humidity and saliva flow. The point of sample application was observed over a 2h period by means of a digital camera. No significant differences in fluorescein colour intensity was obtained for the Gantrez and chitosan particles over 100min, indicate that these two polymers provide the possibility of prolonged action. Carbopol and polycarbophil particles became rapidly swollen and released the sodium fluorescein completely within 20min. It was concluded that the test system allowed the evaluation of the in situ behaviour of test particles, in terms of their ability to retain a water-soluble, coloured marker in 'dynamic' test conditions, and that chitosan and Gantrez were promising candidates for the production of mucoadhesive, sustained-release microspheres for water-soluble materials.
authors.affiliation: Biomaterials and Drug Delivery Group, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth PO1 2DT, UK.
authors.forename: Sandra
authors.initials: S
authors.lastname: Kockisch
authors.forename: Gareth D
authors.initials: GD
authors.lastname: Rees
authors.forename: Simon A
authors.initials: SA
authors.lastname: Young
authors.forename: John
authors.initials: J
authors.lastname: Tsibouklis
authors.forename: John D
authors.initials: JD
authors.lastname: Smart
mesh_terms: D000180:Acrylic Resins; D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D002686:Chitin / Q000031:analogs & derivatives* / Q000494:pharmacology; D048271:Chitosan; D003287:Contrast Media / Q000008:administration & dosage / Q000493:pharmacokinetics; D003692:Delayed-Action Preparations; D016503:Drug Delivery Systems; D004947:Esophagus / Q000187:drug effects / Q000378:metabolism*; D019793:Fluorescein / Q000008:administration & dosage / Q000493:pharmacokinetics*; D008298:Maleates / Q000494:pharmacology; D008863:Microspheres; D009061:Mouth Mucosa / Q000187:drug effects / Q000378:metabolism; D011145:Polyvinyls / Q000494:pharmacology; D011480:Protease Inhibitors / Q000494:pharmacology; D013552:Swine; D014014:Tissue Adhesives / Q000494:pharmacology
chemical_list: D000180:Acrylic Resins; D001672:Biocompatible Materials; D003287:Contrast Media; D003692:Delayed-Action Preparations; D008298:Maleates; D011145:Polyvinyls; D011480:Protease Inhibitors; D014014:Tissue Adhesives; C058026:polyvinylmethoxyethylene-maleic anhydride copolymer; C006912:carboxypolymethylene; D002686:Chitin; D048271:Chitosan; D019793:Fluorescein