Objective: To investigate the introcular Pharmacokinetics of gentamicin-chitosan gel. Methods:Pharmacokinetis studies were carried out in 40 albino New Zealand rabbits.They were divided into two groups,gentamicin in a volume of 0.1ml PBS(2 mg/ml)was injected into mid-vitreous cavity of 20 rabbits' eyes as control,0.1ml gentamicin-chitosan gel(2 mg/ml) was injected into the other 20 rabbits' eyes as treated group.2 rabbits of each group were killed at 0.5,1,2,4,8,16,24,48,72 and(96 h) after injection,the vitreous speciemens were obtained. Results: The biological half-life(t_(1/2)) of gentamicin in vitreous is(8.38?0.75)h and the minimal inhibitory conertration(MIC) can be detected in 48 h,while the t_(1/2) of gentamicin-chitosan gel is(24.49?3.44) h and the MIC can be detected after 120 h. Conclusion: Gentamicin-chitosan gel with the same dosage can prolong biological half-life and increase its intraocular biovailability.

Objective:To examine the effect of compound ketotifen eye drops(CKF,containing 0.1% ketotifen and 0.000 5% dexamethasone) on experimental acute allergic conjunctivitis in rats.Methods:27 male Wistar rats were immunized by intraperitoneal injection of egg albumin and were randomized into three groups: CKF,0.1% ketotifen (KF) and 0.000 5% dexamethasone (DM) Rats in each group received the respective eye drops in one eye and vehicle in the other eye 60,45,30,15 min before and 15,30 min after challenge.Immediately before challenge,the rats were injected intravenously with Evans Blue(EB).The challenge was performed by topical instillation of egg albumin,and 60 min later,the animals were killed and the dye was extracted from the eyes.The intensity of EB extravasation was determined by spectrophotometry at 620nm and inhibitory rates were calculated.Results:CKF,KF and DM suppressed EB extravasation significantly.The inhibitory rate was 53.98%±15.57% for CKF,27.91%±28.36% for KF and 11.90%±34.16% for DM.CKF was more effective than both KF and DM on inhibiting dye vascular leakage in the eyes (P＝0.028,0.004,respectively).Conclusion:These data clearly indicate that the compound of ketotifen eye drops has potential as a topical ocular formulation for anti-allergic disease.

Objective　To develop a rapid，sensitive and reliable high-performance gas chromatography to evaluate the fluconazole (FCZ) bioavailability after topically applied FCZ in-situ gelling ophthalmic delivery system to the rabbit eyes.Methods　A megabore capillary column（30m long and inner diameter of 0.530 mm） with a 0.88-μm-thick bonded liquid phase was used.Detector was nitrogen-selective type.Tears adsorbed to the filter paper was directly by methanol with no evaporation stage prior to analysis.Aqueous humors was extracted by ethyl acetate.Results　The duration of each analysis was less 10 min and the minimum detectable concentration was 0.01μg/ml.The assay was linear from 0.1 to 20 μg/ml.The average recoveries from tears and aqueous humors were 99.0% and 94.8%，respectively.Conclusion　This method can be used to determine rabbit tears and aqueous humors levels of fluconazole and was practicable approach for evaluating intraocular pharmacokinetics after topically applied to rabbit eyes.