Abstract
Purpose: :
To determine the time course of the concentration of bimatoprost and its acid in the aqeous humor in humans after administration of a single drop.
Methods: :
In a single masked randomized clinical trial 31 subjects scheduled for routine cataract surgery received a single drop of bimatoprost 2 hours (n=15), 4 hours (n=8) and 12 hours (n=8) prior to surgery. None of the patients used any other eye drops or had any ocular abnormality other than cataract. Aqueous humor samples were drawn and deep frozen to –70°C. The samples were examined by an independent lab using HPLC–tandem mass spectrometry. The lower limit of quantification was 0.5ng/ml for bimatoprost and its acid.
Results: :
2 hours after application of a single drop bimatoprost the bimatoprost concentration was (mean±std) 6.8±4.2ng/ml (range 1.9 to 15.2 ng/ml) and concentration of bimatoprost acid was 14.4±8.6 ng/ml (range 2.3 to 27.7 ng/ml). 4 hours after application bimatoprost concentration was (mean±std) 1.0±3.7ng/ml (range 0 to 3.5 ng/ml) and concentration of bimatoprost acid was 3.7±1.8ng/ml (range 0.5 to 6.3 ng/ml). 12 hours after application neither bimatoprost nor its acid was detectable in any of the samples.
Conclusions: :
After a single drop of bimatoprost bimatoprost and its acid were detectable in the aqeous humor. The concentration of bimatoprost acid was higher than the concentration of bimatoprost. The highest concentrations of bimatoprost and its acid were present 2 hours after administration.
Keywords: drug toxicity/drug effects • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials