title: Cytoprotective properties of carboxymethyl cellulose (CMC) when used prior to wearing contact lenses treated with cationic disinfecting agents.
abstract: OBJECTIVE
  Disinfecting agents found in current multipurpose solutions (MPS) may produce low-grade ocular surface insults. This study investigates the potential for carboxymethylcellulose (CMC) to chemically complex residual disinfectants in situ.
  
  
  METHODS
  The chemical availability of the MPS disinfectant polyhexamethylene biguanide (PHMB) was examined using a spectrophotometric assay. PHMB bioactivity was assessed by survival of bacteria in the presence of MPS with varying amounts of added CMC.
  
  
  RESULTS
  Chemical availability of PHMB in water or MPS was reduced within 10 minutes of adding CMC. With the addition of CMC to MPS, survival rates for bacteria improved substantially, depending on the bacterial species, concentration, and exposure time.
  
  
  CONCLUSIONS
  Carboxymethylcellulose rapidly binds PHMB and reduces its chemical availability and bioactivity. These results suggest a potential cytoprotective effect of CMC on the ocular surface when used before lens insertion.
authors.affiliation: Consumer Eye Care Research and Development, Allergan, Inc., Irvine, CA, USA.
authors.forename: Joseph G
authors.initials: JG
authors.lastname: Vehige
authors.forename: Peter A
authors.initials: PA
authors.lastname: Simmons
authors.forename: Claude
authors.initials: C
authors.lastname: Anger
authors.forename: Richard
authors.initials: R
authors.lastname: Graham
authors.forename: Lam
authors.initials: L
authors.lastname: Tran
authors.forename: Nancy
authors.initials: N
authors.lastname: Brady
mesh_terms: D001645:Biguanides / Q000494:pharmacology*; D001682:Biological Availability; D002266:Carboxymethylcellulose Sodium / Q000494:pharmacology*; D018639:Contact Lens Solutions / Q000494:pharmacology*; D003261:Contact Lenses; D019610:Cytoprotection / Q000187:drug effects; D004347:Drug Interactions; D024881:Drug Resistance, Bacterial; D008826:Microbial Sensitivity Tests; D009883:Ophthalmic Solutions / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D001645:Biguanides; D018639:Contact Lens Solutions; D009883:Ophthalmic Solutions; C031233:polihexanide; D002266:Carboxymethylcellulose Sodium