Citation
Zhou Tianyang, Yang Jingjing, Li Xiang, et al. Effect of brinzolamide-timolol maleate eye drops on the metabolism of vancomycin hydrochloride in rabbit eyes[J]. Chin J Exp Ophthalmol, 2025, 43(1):27-31. DOI: 10.3760/cma.j.cn115989-20240410-00102.
ABSTRACT [Download PDF] [Read Full Text]
Objective To investigate the effect of brinzolamide-timolol maleate eye drops on the metabolism of intravitreally injected vancomycin hydrochloride (VH) in rabbit eyes.
Methods Nine healthy male New Zealand white rabbits were selected.Among them, three were used to extract blank aqueous humor and the right eyes of the remaining six were set as experimental eyes.The experimental eye was topically administered 30 μl of brinzolamide-timolol maleate eye drops twice a day.The fellow eyes were set as control eyes.The intraocular pressure of both eyes was measured before the initial application of the eye drops and 1 hour after application of the eye drops next day.Both eyes of each rabbit were intravitreally injected with 0.5 mg of VH (10 mg/ml) solution.The aqueous humor was drawn at 2 hours and 1, 2, 4, 6, 8, 10 and 12 days after intravitreal injection.VH concentrations in aqueous humor were measured by high performance liquid chromatography.The time of peak concentrations ( t max), peak concentration ( C max), elimination half-life ( t 1/2) and the area under the concentration-time curve ( AUC) of VH in rabbit eyes were calculated by the average concentrations.This study was approved by the Ethics Committee of Henan Eye Hospital (No.HNEECA-2023-01).
Results The intraocular pressure after eye drop was significantly lower than that before eye drop in experimental eyes ( P<0.01).The t max of VH in experimental eyes and control eyes were both 1 day.The C max of VH in experimental eyes and control eyes were (61.40±13.48) and (51.56±5.07)μg/ml, respectively.The VH aqueous concentrations in the experimental eyes on days 4, 6 and 8 after injection were all significantly higher than those in the control eye ( t=2.378, 3.150, 2.694; all P<0.05).The t 1/2 of VH in the aqueous humor of the experimental eyes was 2.69 days, which was 31% longer than 2.05 days of the control eyes.The AUC 0-10 d of experimental eyes increased by 24.3% relative to the control eyes.
Conclusions Brinzolamide-timolol maleate eye drops can significantly extend the ocular residence time of intravitreally injected VH.