title: Effects of ophthalmic vehicles on the stability of the precorneal film.
abstract: The break up time (B.U.T.) of the precorneal film has been studied before and after application of 34 different vehicles. The material examined comprised 646 eyes. Maximum increase of the B.U.T. was obtained with 2% methyl cellulose (four times) and 10% polyvinyl alchohol (seven times). These vehicles in the usually employed concentrations, fat-free ointment (polyethylene glycol), acetyl cysteine and polysaccharide (dextran) affected a less pronounced prolongation. The B.U.T. was reduced four or five times by fatty, anhydrous ointments and by silicone oil, about two or three times by emulsions and oils, and twice by 0.01% benzalkonium chloride. The clinical significance of the B.U.T. alterations is discussed.
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000934:Antifoaming Agents / Q000494:pharmacology; D001548:Benzalkonium Compounds / Q000494:pharmacology; D003042:Cocaine / Q000494:pharmacology; D003315:Cornea / Q000187:drug effects* / Q000378:metabolism; D003911:Dextrans / Q000494:pharmacology; D005260:Female; D006801:Humans; D008297:Male; D008747:Methylcellulose / Q000494:pharmacology; D008875:Middle Aged; D009821:Oils / Q000494:pharmacology; D009824:Ointments; D009883:Ophthalmic Solutions / Q000494:pharmacology*; D010578:Petroleum; D014677:Pharmaceutical Vehicles / Q000494:pharmacology*; D011092:Polyethylene Glycols / Q000494:pharmacology; D011142:Polyvinyl Alcohol / Q000494:pharmacology; D012828:Silicones / Q000494:pharmacology; D013194:Staining and Labeling; D013229:Stearic Acids / Q000494:pharmacology
chemical_list: D000934:Antifoaming Agents; D001548:Benzalkonium Compounds; D003911:Dextrans; D009821:Oils; D009824:Ointments; D009883:Ophthalmic Solutions; D010578:Petroleum; D014677:Pharmaceutical Vehicles; D012828:Silicones; D013229:Stearic Acids; D011092:Polyethylene Glycols; D011142:Polyvinyl Alcohol; D008747:Methylcellulose; D003042:Cocaine; D000111:Acetylcysteine