Purchase this article with an account.
Hai Tang, Xin Zhao, Xian Zhang, Qiang Yang; Pharmacokinetics and tissue distribution of gatifloxacin after a single ocular instillation in rabbits. Invest. Ophthalmol. Vis. Sci. 2015;56(7 ):5736.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To investigate the ocular distribution of gatifloxacin after a single topical instillation in New Zealand white rabbit using a simplified liquid chromatograph coupled with tandem mass spectrometry (LC-MS-MS) method.
A 50μl of 0.3% gatifloxacin eye gel was instilled into the left eyes of 30 rabbits and the animals were divided evenly into 6 groups. From each group, tear and blood specimens were collected at 0.5, 1, 3, 5, 7, 10 hrs and the animals were sacrificed immediately to collect aqueous humor from the anterior chamber, and subsequently other eye tissues.<br /> Gatifloxacin and IS(Ciprofloxacin)were extracted from specimens by protein precipitation with methanol. Chromatographic separation was carried out on a Diamonsil C18 column with a mobile phase of methanol-water using isocratic elution. Mass spectrometric detection was achieved by a triple-quadrupole mass spectrometer equipped with an ESI interface operating in positive ionization mode.
The LC-MS-MS method allowed gatifloxacin quantification as low as 5.0ng/ml (R>0.99) with a sample run time of 3.5 minutes, for up to 10 hours after a single administration of 0.3% gatifloxacin to the eye.<br /> After a single topical instillation, gatifloxacin reached a high concentration in aqueous humor and the posterior tissues quickly, due to high permeability through the cornea barrier. All the ocular tissue concentrations were higher than that of the blood (Cmax: 23.5ng/ml). In particular, concentrations detected in the anterior segment are: tears (Cmax: 94880ng/g), cornea (Cmax: 7340ng/g), conjunctiva (Cmax: 3652ng/g), sclera (Cmax: 1745.8ng/g), aqeous humor (Cmax: 1310ng/ml), and iris (Cmax: 1806 ng/g). Except for the virtrous, gatifloxacin was detectable in the following tissues at 10th hour: 244.8 ng/g (retina), 148.2 ng/g (choroid) and 71.3 ng/g (lens), respectively.
Our simplified method achieved the required sensitivity and specificity for a pharmacokinetic study in rabbit specimens after a topical administration of gatifloxacin gel. Due to increase of the viscidity, the elimination rates of gatifloxacin from ocular tissues are slow in general. High distribution to the posterior segment of the eye indicates a potential treatment benefit of gatifloxacin for infections of this region via topical ocular administration.
This PDF is available to Subscribers Only