AIM: To evaluate the effect of different routes of dexamethasone administration on aqueous humor concentration and blood glucose in type 2 diabetic(T2DM)rats.

METHODS: The T2DM rats successfully modeled were randomly divided into the experimental group(dexamethasone sodium phosphate injection)and the control group(normal saline injection). Each group was randomly divided into three subgroups: peribulbar injection group, post-bulbar injection group and subconjunctival injection group according to different drug delivery routes. Rat tail venous blood was collected 0-24h after injection and blood glucose concentration was determined by dipstick method. After injection, dexamethasone concentration in aqueous aqueous solution of both eyes was determined by HPLC at 0.5-24h.

RESULTS: Dexamethasone sodium phosphate or normal saline injection had no significant effect on blood glucose concentration in T2DM rats(P>0.05). After dexamethasone sodium phosphate was injected in different ways for 0.5-24h, rats in the experimental group received dexamethasone concentration peak under bulbar conjunctiva injection group(957.34±3.60ng/mL)>post-bulbar injection group(859.60±3.56ng/mL)>perbulbar injection group(732.38±4.56ng/mL).

CONCLUSION: Injection of dexamethasone sodium phosphate into bulbous injection, post-bulbar injection and subconjunctival injection had no significant effect on blood glucose of T2DM rats, while subconjunctival injection was simple and could reach higher drug concentration in a short time than that injected into bulbous injection and sub-bulbous injection.