title: Penetration of betaxolol HCL ionic suspension 0.25% and betaxolol HCL solution 0.50% into the aqueous humor.
abstract: OBJECTIVE
  To determine the intraocular penetration of topical drops of betaxolol HCl 0.25% suspension and betaxolol HCl 0.50% solution into the aqueous humor.
  
  
  METHODS
  Fifteen patients were randomly assigned to receive topical betaxolol HCl 0.25% suspension (n=7) or topical betaxolol HCl 0.50% solution (n=8) the day before cataract surgery. Aqueous samples were collected 2 hours after the administration of the morning dose during cataract surgery. Drug concentrations were determined by high-performance liquid chromatography with fluorescence detection.
  
  
  RESULTS
  The mean aqueous humor concentration of topical betaxolol HCl 0.25% suspension was 275.1+/-168.8 micro g/mL (range 570-70 micro g/mL) and the mean aqueous humor concentration of topical betaxolol HCl 0.50% solution was 195.4+/-102.4 micro g/mL (range 334-50 micro g/mL) (p=0.281).
  
  
  CONCLUSIONS
  The mean aqueous humor concentration of betaxolol 0.25% suspension was higher than betaxolol 0.50% solution; however, the difference was not statistically significant. With twofold reduced concentration and similar anterior chamber penetration, betaxolol 0.25% suspension could be first choice for Beta 1 selective blocker therapy when considered for patients with glaucoma.
authors.affiliation: Department of Ophthalmology, Ankara Education and Research Hospital, Ankara, Turkey. iyalvac@hotmail.com
authors.forename: I      Sagdic
authors.initials: I
authors.lastname: Yalvac
authors.forename: N E
authors.initials: NE
authors.lastname: Basci
authors.forename: B
authors.initials: B
authors.lastname: Dulger
authors.forename: S
authors.initials: S
authors.lastname: Duman
mesh_terms: D000293:Adolescent; D000319:Adrenergic beta-Antagonists / Q000493:pharmacokinetics*; D000328:Adult; D000368:Aged; D001082:Aqueous Humor / Q000378:metabolism*; D015784:Betaxolol / Q000493:pharmacokinetics*; D002387:Cataract Extraction; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009883:Ophthalmic Solutions / Q000493:pharmacokinetics; D011446:Prospective Studies; D013535:Suspensions / Q000493:pharmacokinetics
chemical_list: D000319:Adrenergic beta-Antagonists; D009883:Ophthalmic Solutions; D013535:Suspensions; D015784:Betaxolol