Detection of the free acid of bimatoprost in aqueous humor samples from human eyes treated with bimatoprost before cataract surgery.
OBJECTIVE
To determine whether bimatoprost is hydrolyzed to its free acid after topical application in humans in vivo.


METHODS
Prospective, masked, and vehicle controlled.


METHODS
Thirty-one eyes of 31 patients with cataracts.


METHODS
Beginning 7 days before scheduled cataract surgery, one eye of each patient was treated with bimatoprost 0.03% or vehicle once daily, with the last drop administered 2 to 12 hours before anterior chamber paracentesis before cataract surgery. In a masked fashion, aqueous humor specimens were assayed for bimatoprost and its free acid by high-pressure liquid chromatography and mass spectrometry.


METHODS
Detection of the free acid of bimatoprost in aqueous humor.


RESULTS
Aqueous humor concentrations of the free acid of bimatoprost were 22.0+/-7.0 nmol/l (mean +/- standard error of the mean, n = 12) and 7.0+/-4.6 nmol/l (n = 8) at 2 and 12 hours, respectively, and below the limit of detection after vehicle (n = 10). Concentrations of bimatoprost (amide) were 5.7+/-1.4 and 1.1+/-0.4 nmol/l at 2 and 12 hours, respectively, and undetectable after vehicle.


CONCLUSIONS
After topical application of bimatoprost in humans, a sufficient concentration of its free acid, a potent FPprostanoid receptor agonist, is found in the aqueous humor to account for its ability to reduce intraocular pressure.
Camras
Carl B
CB
Department of Ophthalmology, University of Nebraska Medical Center, Omaha, Nebraska 68198-5540, USA. cbcamras@unmc.edu
Toris
Carol B
CB
Sjoquist
Birgitta
B
Milleson
Monica
M
Thorngren
John-Olof
JO
Hejkal
Thomas W
TW
Patel
Nehal
N
Barnett
Edward M
EM
Smolyak
Regina
R
Hasan
S Fareed
SF
Hellman
Courtney
C
Meza
Jane L
JL
Wax
Martin B
MB
Stjernschantz
Johan
J
D000287:Administration, Topical; D000577:Amides; D000959:Antihypertensive Agents / Q000008:administration & dosage*; D001082:Aqueous Humor / Q000737:chemistry*; D000069580:Bimatoprost; D002387:Cataract Extraction; D002851:Chromatography, High Pressure Liquid; D003008:Cloprostenol / Q000031:analogs & derivatives; D015237:Dinoprost / Q000031:analogs & derivatives* / Q000032:analysis*; D006801:Humans; D006868:Hydrolysis; D008055:Lipids / Q000008:administration & dosage*; D011355:Prodrugs / Q000008:administration & dosage*; D011446:Prospective Studies; D021241:Spectrometry, Mass, Electrospray Ionization
D000577:Amides; D000959:Antihypertensive Agents; D008055:Lipids; D011355:Prodrugs; C013646:17-phenyl-18,19,20-trinorprostaglandin F2 alpha; D003008:Cloprostenol; D015237:Dinoprost; D000069580:Bimatoprost