Objective      To investigate the distribution of a novel immunosuppressant

J2 nano-suspension (NS)

in the peripheral blood and intraocular tissues in rabbits after subconjunctival injection.       Methods      Totally 18 healthy New Zealand white rabbits (36 eyes)

8- to 12-week-old

were given an subconjunctival injection of 0.2 ml 1% J2-NS. Drug concentration in the cornea

aqueous humor

and iris (6 eyes in each time point) and peripheral blood was detected by high-performance liquid chromatography (HPLC) on the days 1 and 3

and the

weeks of 1

2

3 and 4 respectively after injection. The main pharmacokinetic parameters were calculated by pharmacokinetic software

WinNonlin.       Results      J2-NS at different concentrations was found in all detected organs during the observation period after injection. The serum concentration of J2-NS was 11.19±0.33 to 13.23±0.84 ng/mL from the day 1 to week 4 after injection. The cornea had the highest dose in all the eye tissues

but it was at lower dose in the aqueous humor and iris. The concentration was 5.72±1.67 to 11.86±4.35 ng/mg in the cornea from the day 1 to week 4 after injection

with Cmax of 11.861 3 ng/mg

Tmax of 1 d

and area under curve (AUC) of 201.561 5 ng/(mg·d）and T

1/2

of 45 d.       Conclusion      Single subconjunctival injection of J2-NS leads the drug mainly being distributed in the peripheral blood and cornea

and being maintained at the effective drug concentration for a long time.