title: Preparation and characterization of puerarin-dendrimer complexes as an ocular drug delivery system.
abstract: OBJECTIVE
  The aim of this study was to prepare and characterize the complex of puerarin and poly(amidoamine) (PAMAM) dendrimers and to evaluate the complex as an ocular drug delivery system.
  
  
  METHODS
  The complexes of puerarin and PAMAM dendrimers were prepared at various puerarin-to-dendrimer ratios. The physicochemical properties of the complexes were characterized by differential scanning calorimetry and Fourier transform infrared spectroscopy. The in vitro release studies were performed by dialysis. Corneal permeation was evaluated by Valia-Chien diffusion cell with excised corneas and ocular residence time in rabbits.
  
  
  RESULTS
  The results showed that puerarin-dendrimer complexes formed primarily by hydrogen-bonding interactions. Typically, 43, 56, 125, and 170 molecules of puerarin could be incorporated into G3.5, G4, G4.5, and G5 PAMAM dendrimer molecule. Puerarin was released more slowly from puerarin-dendrimer complexes than free puerarin in deionized water and phosphate buffer solution (pH 6.8). The in vitro release rate of puerarin complexed with full generation dendrimers was lower than that with half generation dendrimers. Furthermore, puerarin-dendrimer complexes produced longer ocular residence times in rabbits compared with puerarin eye drops. No damages to the epithelium or endothelium were observed after the PAMAM dendrimer administration in this corneal permeation study.
  
  
  CONCLUSIONS
  Puerarin-dendrimer complexes represent a potential ocular drug delivery system to improve the efficacy of drug treatment.
authors.affiliation: School of Pharmacy, Yantai University, Yantai, Shandong, PR China.
authors.forename: Wenjun
authors.initials: W
authors.lastname: Yao
authors.forename: Kaoxiang
authors.initials: K
authors.lastname: Sun
authors.forename: Hongjie
authors.initials: H
authors.lastname: Mu
authors.forename: Na
authors.initials: N
authors.lastname: Liang
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.forename: Chen
authors.initials: C
authors.lastname: Yao
authors.forename: Rongcai
authors.initials: R
authors.lastname: Liang
authors.forename: Aiping
authors.initials: A
authors.lastname: Wang
mesh_terms: D000287:Administration, Topical; D000818:Animals; D003315:Cornea / Q000187:drug effects / Q000378:metabolism*; D050091:Dendrimers / Q000737:chemistry*; D004058:Diffusion; D004337:Drug Carriers; D004339:Drug Compounding; D016503:Drug Delivery Systems; D007529:Isoflavones / Q000008:administration & dosage / Q000737:chemistry* / Q000493:pharmacokinetics; D009883:Ophthalmic Solutions / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D010539:Permeability / Q000187:drug effects; D011817:Rabbits; D012995:Solubility; D014665:Vasodilator Agents / Q000737:chemistry*
chemical_list: D050091:Dendrimers; D004337:Drug Carriers; D007529:Isoflavones; D009883:Ophthalmic Solutions; D014665:Vasodilator Agents; C033607:puerarin