Ocular pharmacokinetics of fluocinolone acetonide after Retisert intravitreal implantation in rabbits over a 1-year period.
OBJECTIVE
The present study was designed to examine the pharmacokinetics of a fluocinolone acetonide (FA) intravitreal implant in pigmented rabbits.


METHODS
Pigmented rabbits were randomly assigned to receive either a 0.5 mg or 2.0 mg FA intravitreal implant (Retisert). Four animals were sacrificed per time point (2 hours; 2 weeks; and 3, 6, 9, and 12 months after implantation) for FA intraocular levels determination.


RESULTS
In the vitreous, concentration of FA was relatively constant from the first time point, 2 hours, through 1 year, and dose-related, approximately seven- to eight-fold greater in the 2-mg implant. Concentrations of FA were generally higher in the vitreous (11-18 and 75-146 ng/g) and retina (42-87 and 224-489 ng/g) than in the aqueous humor (0.21-1.1 and 2.6-13.0 ng/g) for the 0.5- and 2-mg implants, respectively. Urine and plasma values were below the lower limit of quantitation (200 pg/mL) for all observations, indicating no evidence of systemic absorption.


CONCLUSIONS
In this rabbit study, the Retisert provides relatively constant levels of FA in the posterior pole, which is consistent with previous reports of its clinical utility.
Driot
Jean-Yves
JY
Bausch & Lomb, Montpellier, France. jean-yves.driot@bausch.com
Novack
Gary D
GD
Rittenhouse
Kay D
KD
Milazzo
Chris
C
Pearson
P Andrew
PA
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D001682:Biological Availability; D016503:Drug Delivery Systems / Q000379:methods*; D004343:Drug Implants; D005123:Eye / Q000378:metabolism*; D005446:Fluocinolone Acetonide / Q000008:administration & dosage / Q000493:pharmacokinetics*; D011817:Rabbits; D013997:Time Factors; D014822:Vitreous Body
D000893:Anti-Inflammatory Agents; D004343:Drug Implants; D005446:Fluocinolone Acetonide