title: Improved nasal bioavailability of FITC-dextran (Mw 4300) from mucoadhesive microspheres in rabbits.
abstract: The nasal bioavailability of fluorescein isothiocyanate-dextran (FITC-dextran) (Mw = 4300) encapsulated in non-mucoadhesive and mucoadhesive microspheres in New Zealand White rabbits was investigated. FITC-dextran was administered nasally encapsulated in carbopol 934P, chitosan and lactose microspheres and the bioavailability compared to intravenous administration of FITC-dextran solution. Administration of FITC-dextran as carbopol microspheres produced a significantly greater bioavailability (33%) than after administration as chitosan (13%) and non-mucoadhesive rapidly dissolving control lactose microspheres (9%). The FITC-dextran terminal plasma half-lives after carbopol 934P and chitosan microsphere administration were significantly longer than after intravenous administration of FITC-dextran. The FITC-dextran terminal plasma half-life after carbopol 934P microspheres administration was significantly longer than after lactose microsphere administration. This data suggested that the increase in FITC-dextran bioavailability after carbopol 934P microspheres administration was due to increased residence at the absorptive site via mucoadhesion and reduced mucociliary clearance. A change in mucosal permeability could not however be discounted especially for the chitosan microspheres.
authors.affiliation: The Welsh School of Pharmacy, Cardiff University, UK.
authors.forename: M A
authors.initials: MA
authors.lastname: El-Shafy
authors.forename: I W
authors.initials: IW
authors.lastname: Kellaway
authors.forename: G
authors.initials: G
authors.lastname: Taylor
authors.forename: P A
authors.initials: PA
authors.lastname: Dickinson
mesh_terms: D000818:Animals; D001682:Biological Availability; D002686:Chitin / Q000008:administration & dosage / Q000031:analogs & derivatives; D048271:Chitosan; D003911:Dextrans / Q000008:administration & dosage* / Q000493:pharmacokinetics; D016503:Drug Delivery Systems; D016650:Fluorescein-5-isothiocyanate / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D008297:Male; D008863:Microspheres; D009297:Nasal Mucosa / Q000378:metabolism*; D011817:Rabbits
chemical_list: D003911:Dextrans; C015219:fluorescein isothiocyanate dextran; D002686:Chitin; D048271:Chitosan; D016650:Fluorescein-5-isothiocyanate