Determinação de gatifloxacino, moxifloxacino e besifloxacino por LC-MS/MS na córnea e humor aquoso de cães

Abstract

The fourth-generation of fluoroquinolones, represented by gatifloxacin (GA), moxifloxacin (MO) and besifloxacin (BE) are one of the most widely used ophthalmic drug classes. Thus, this study aimed to validate a new analytical technique for simultaneous quantification of GA, MO and BE with the use of liquid chromatography tandem/mass spectrometry (LC-MS/MS) in the cornea and aqueous humor (AH) and identify and quantitate these drugs in 10 minutes time and one hour after instillation of ophthalmic suspension. Twenty two male dogs are used, with an approximate age between one to seven years-old, these dogs were destined to euthanasia to be carriers of canine visceral leishmaniasis without lesions observed at the ophthalmic examination. Initially, it was made avaluation by histology to certify if the eyeball of used dogs had microscopic lesions. Among the 22 selected dogs, it was found that only 15,9% of the eyeball had inflammatory lesions and two animals had retinal degeneration, changes related to the advanced age of, because of that, these animals was withdrawn from the study. The validation of the analytical technique was determined by means of steps that determine the selectivity, sensitivity and reprocibility of the method, its effective for simultaneous quantification of these drugs. Regarding the concentration of the cornea within 10 minutes of time was obtained, on average, the followings results: MO (18,6 g/g) followed BE (6,01 g/g) and GA (4,35 g/g). At the time of one hour the order of drugs remained, as follow: MO (11,7 g/g), BE (5,51 g/g) and GA (2,36 g/g). In the AH time of 10 minutes, the following results were obtained: BE (1,70 g/mL), followed MO (1,62 g/mL) and GA (0,06 g/mL). At the time of one hour the order of drugs remained, and BE (1,71 g/mL), MO (1,68 g/mL) and GA (0,10 g/mL). Thus, it was found that in both measurement time analyzed, the MO was the drug which obtained the highest concentration in the cornea, while the AH is the BE.