title: Acute Corneal Toxicity of Diquas.
abstract: OBJECTIVE
  This study aimed to investigate acute corneal toxicity of commercially available diquafosol 3% ophthalmic solution (Diquas®), which contains C12 benzalkonium chloride (BAC) as a preservative.
  
  
  METHODS
  Corneal transepithelial electrical resistance (TER) changes after a 60-second exposure to Diquas® (diquafosol 3% preserved with 0.0075% C12 BAC); 0.0075% C12 BAC and 0.0075% C12, C14, C16 BAC mixture were measured in living rabbits. Corneal damage was also examined by scanning electron microscopy (SEM). Hank's balanced salt solution (HBSS) was used as a control.
  
  
  RESULTS
  Diquas® and 0.0075% C12 BAC did not produce any significant decrease in the corneal TER as compared to the HBSS control eyes. There was a significant decrease in the corneal TER after exposure of the cornea to the 0.0075% C12, C14, C16 BAC mixture (p < 0.01). SEM revealed that the superficial cells of the corneas exposed to the 0.0075% BAC mixture were damaged and exhibited degenerated microvilli. Conversely, the superficial cells of corneas exposed to Diquas® or 0.0075% C12 BAC appeared normal and had normal microvilli under SEM examinations.
  
  
  CONCLUSIONS
  The acute corneal toxicity of Diquas® is less than that of the 0.0075% BAC mixture. Diquas® preserved with 0.0075% C12 BAC did not show acute corneal toxicity.
authors.affiliation: Department of Ophthalmology and Visual Sciences, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
authors.forename: Yasser Helmy
authors.initials: YH
authors.lastname: Mohamed
authors.forename: Masafumi
authors.initials: M
authors.lastname: Uematsu
authors.forename: Ryotaro
authors.initials: R
authors.lastname: Ueki
authors.forename: Daisuke
authors.initials: D
authors.lastname: Inoue
authors.forename: Azusa
authors.initials: A
authors.lastname: Fujikawa
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Sasaki
authors.forename: Takashi
authors.initials: T
authors.lastname: Kitaoka
mesh_terms: D000818:Animals; D001548:Benzalkonium Compounds / Q000633:toxicity*; D003316:Corneal Diseases / Q000139:chemically induced* / Q000473:pathology; D019573:Epithelium, Corneal / Q000187:drug effects / Q000473:pathology / Q000648:ultrastructure; D008297:Male; D008855:Microscopy, Electron, Scanning; D009883:Ophthalmic Solutions / Q000633:toxicity*; D011122:Polyphosphates / Q000633:toxicity*; D011310:Preservatives, Pharmaceutical / Q000633:toxicity*; D011817:Rabbits; D014500:Uracil Nucleotides / Q000633:toxicity*
chemical_list: D001548:Benzalkonium Compounds; D009883:Ophthalmic Solutions; D011122:Polyphosphates; D011310:Preservatives, Pharmaceutical; D014500:Uracil Nucleotides; C403315:diquafosol