title: [Preparation of freeze-dried powder of recombinate hirudin-2 nanoparticle for nasal delivery and permeability through nasal membrane in vitro].
abstract: OBJECTIVE
  To optimize the freeze-dried powder preparation technology of recombinate hirudin-2 (rHV2) nanoparticle which has bio-adhesive characteristic for nasal delivery, also to investigate its stability and permeability through nasal membrane in vitro.
  
  
  METHODS
  Taking the appearance, rediffusion of nanoparticle and rHV2 encapsulation efficiency as the evaluation indexes. Cryoprotector, the preparative technique and the effect of illumination and high temperature factors on its stability for rHV2 freeze-dried powder were investigated. Using Fraze diffusion cell technique, the permeability of rHV2 across rabbit nasal mucous membrane in chitosan solution, chitosan nanoparticle, and nanoparticle frozen-dried powder were compared with that in normal saline solution.
  
  
  RESULTS
  The optimized preparation of rHV2 nanoparticle freeze-dried powder was as follows: 5% trehalose and glucose (1:1) was used as cryoprotector, nanoparticle solution was freezed for 24 h in vacuum frozen-dryer after being pre-freezed for 24 h. The content of rHV2 in the freeze-dried powder was 1.1 ug/mg. Illumination had little effect on the appearance, rediffusion and encapsulation efficiency of the rHV2 freeze-dried powder. High temperature could obviously influence the appearance of nanoparticle freeze-dried powder. The permeability coefficient (P) of nanoparticle was 5 times more than that in chictonson solution. It was indicated that chitosan nanoparticle has effect on increasing the permeability of rHV2.
  
  
  CONCLUSIONS
  The freeze-dried powder of chitosan nanoparticle can be a good nasal preparation of rHV2.
authors.affiliation: School of Materia Medica, Beijing University of Chinese Medicine, Beijing 100102, China.
authors.forename: Ming-Xia
authors.initials: MX
authors.lastname: Chen
authors.affiliation: Beijing Medicase Biotechnologies Co. Ltd, Beijing 100012, China.
authors.forename: Jian-Bao
authors.initials: JB
authors.lastname: Zhang
authors.affiliation: School of Materia Medica, Beijing University of Chinese Medicine, Beijing 100102, China.
authors.forename: Ji-Ping
authors.initials: JP
authors.lastname: Yu
authors.affiliation: School of Materia Medica, Beijing University of Chinese Medicine, Beijing 100102, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Ye
authors.affiliation: School of Materia Medica, Beijing University of Chinese Medicine, Beijing 100102, China.
authors.forename: Bao-Hong
authors.initials: BH
authors.lastname: Wei
authors.affiliation: School of Materia Medica, Beijing University of Chinese Medicine, Beijing 100102, China.
authors.forename: Yu-Jie
authors.initials: YJ
authors.lastname: Zhang
mesh_terms: D000042:Absorption; D000281:Administration, Intranasal; D000818:Animals; D048271:Chitosan / Q000008:administration & dosage / Q000737:chemistry; D016503:Drug Delivery Systems; D004355:Drug Stability; D005612:Freeze Drying; D005947:Glucose / Q000008:administration & dosage / Q000737:chemistry; D006629:Hirudins / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D008297:Male; D008353:Mannitol / Q000008:administration & dosage / Q000737:chemistry; D053758:Nanoparticles; D009297:Nasal Mucosa / Q000378:metabolism*; D010539:Permeability; D011208:Powders; D011817:Rabbits; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D013678:Technology, Pharmaceutical / Q000379:methods*
chemical_list: D006629:Hirudins; D011208:Powders; D011994:Recombinant Proteins; D008353:Mannitol; D048271:Chitosan; D005947:Glucose