title: [Effect of solution viscosity on polymer precorneal residence time evaluated by in vitro method].
abstract: OBJECTIVE
  To evaluate how solution viscosity affects the precorneal residence of five water-soluble polymers with different properties.
  
  
  METHODS
  Captive bubble technique was used, with the consecutive change of contact angle interpreted as an indication of desorption process, to study the residence of those polymers in vitro on freshly enucleated rabbit eyes under physiological conditions.
  
  
  RESULTS
  Carbopol and sodium hyaluronate (HA), which adsorbed to isolated ocular surface more than 15 min, showed the optimum precorneal retentive capabilities. When the solution viscosity increased from 12 mPa.s to 50 mPa.s, the residence time of carbopol and HA were prolonged 10 min and 7 min, respectively, but that of sodium carboxymethylcellulose was not affected.
  
  
  CONCLUSIONS
  The result suggested that higher viscosity is beneficial to improve the ocular residence time of bio-adhesive polymers.
authors.affiliation: School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China. weigangmail@sina.com.cn
authors.forename: Gang
authors.initials: G
authors.lastname: Wei
authors.forename: Ping-tian
authors.initials: PT
authors.lastname: Ding
authors.forename: Yong-yan
authors.initials: YY
authors.lastname: Cui
authors.forename: San-ming
authors.initials: SM
authors.lastname: Li
authors.forename: Jun-min
authors.initials: JM
authors.lastname: Zheng
mesh_terms: D000180:Acrylic Resins; D000268:Adhesiveness; D000818:Animals; D003315:Cornea / Q000187:drug effects / Q000378:metabolism*; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D005260:Female; D006820:Hyaluronic Acid / Q000493:pharmacokinetics* / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D011145:Polyvinyls / Q000493:pharmacokinetics* / Q000494:pharmacology; D011817:Rabbits; D012996:Solutions; D014783:Viscosity
chemical_list: D000180:Acrylic Resins; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D011145:Polyvinyls; D012996:Solutions; C006912:carboxypolymethylene; D006820:Hyaluronic Acid