title: Permeation-enhancing effects of chitosan formulations on recombinant hirudin-2 by nasal delivery in vitro and in vivo.
abstract: OBJECTIVE
  To investigate the enhancing effects of chitosan with or without enhancers on nasal recombinant hirudin-2 (rHV2) delivery in vitro and in vivo, and to evaluate the ciliotoxicity of these formulations.
  
  
  METHODS
  The permeation-enhancing effect of various chitosan formulations was estimated by using the permeation coefficient of fluorescein isothiocyanate recombinant hirudin-2 (FITC-rHV2) across the excited rabbit nasal epithelium in vitro. The effect was further evaluated by measuring the blood concentration level after nasal absorption of FITC-rHV2 in rats. The mucosal ciliotoxicity of different formulations was evaluated with an in situ toad palate model.
  
  
  RESULTS
  Chitosan at a concentration of 0.5% with or without various enhancers significantly increased the permeability coefficient (P) and relative bioavailability (Fr) of FITC-rHV2 compared with the blank control. The addition of 1% sodium dodecylsulfate, 5% Brij35, 5% Tween 80, 1.5% menthol, 1% glycyrrhizic acid monoammonium salt (GAM) or 4% Azone into the 0.5% chitosan solution resulted in a further increase in absorption (P<0.05) compared with 0.5% chitosan alone. But co-administration of chitosan with 5% hydroxyl-propyl-beta-cyclodextrin (HP-beta-CD), 5% lecithin or 0.1% ethylenediamine tetraacetic acid (EDTA) was not more effective than using the 0.5% chitosan solution alone. Chitosan alone and with 5% HP-beta-CD, 0.1% EDTA, 1% GAM or 5% Tween 80 was relatively less ciliotoxic.
  
  
  CONCLUSIONS
  Chitosan with or without some enhancers was able to effectively promote the nasal absorption of recombinant hirudin, while not resulting in severe mucosal ciliotoxicity. A chitosan formulation system would be a useful approach for the nasal delivery of recombinant hirudin.
authors.affiliation: School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100083, China.
authors.forename: Yu-jie
authors.initials: YJ
authors.lastname: Zhang
authors.forename: Chang-hua
authors.initials: CH
authors.lastname: Ma
authors.forename: Wan-liang
authors.initials: WL
authors.lastname: Lu
authors.forename: Xuan
authors.initials: X
authors.lastname: Zhang
authors.forename: Xiao-liang
authors.initials: XL
authors.lastname: Wang
authors.forename: Jian-ning
authors.initials: JN
authors.lastname: Sun
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
mesh_terms: D000042:Absorption / Q000187:drug effects; D000281:Administration, Intranasal; D000818:Animals; D019540:Area Under Curve; D001682:Biological Availability; D002023:Bufo bufo; D048271:Chitosan / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D016650:Fluorescein-5-isothiocyanate / Q000493:pharmacokinetics*; D006629:Hirudins / Q000493:pharmacokinetics*; D008297:Male; D009297:Nasal Mucosa / Q000187:drug effects*; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000493:pharmacokinetics
chemical_list: D006629:Hirudins; D011994:Recombinant Proteins; C072299:hirudin HV2; D048271:Chitosan; D016650:Fluorescein-5-isothiocyanate