Pharmacokinetic behavior of intravitreal triamcinolone acetonide prepared by a hospital pharmacy.
OBJECTIVE
We developed a new hospital pharmaceutical preparation of triamcinolone acetonide (TA) for intravitreal injections using sodium hyaluronate as the vehicle. The purpose of this study was to compare the pharmacokinetic behavior of this hospital pharmacy preparation of TA (HPP-TA) to that of a commercial preparation of TA (CP-TA) in rats.


METHODS
We injected the two preparations of TA into the vitreous humor of male Wistar rats. The rats were killed between days 1 and 21, and the concentration of TA in the vitreous was measured by high-performance liquid chromatography to determine the pharmacokinetic parameters. We also examined the microscopic appearance of the TA particles in these preparations.


RESULTS
The elimination half-life was 6.08 days for the CP-TA and 5.78 days for the HPP-TA. A two-compartment model was suitable to approximate the pharmacokinetic behavior of HPP-TA in the vitreous body, but this model was not suitable for CP-TA, because its pharmacokinetic behavior was not sufficiently stable. The particle size of CP-TA was largest, followed by TA powder and HPP-TA. Many particles were agglutinated in the CP-TA preparation, whereas the TA particles were fine and dispersed in the HPP-TA medium.


CONCLUSIONS
The TA particle size and the suspension medium are likely important factors in the preparation of a safe and stable suspension of TA. HPP-TA satisfied these requirements and should be suitable for clinical use.
Oishi
Masako
M
Department of Pharmacy, Osaka University Hospital, Osaka, Japan. oishi@hp-drug.med.osaka-u.ac.jp.
Maeda
Shinichiro
S
Department of Pharmacy, Osaka University Hospital, Osaka, Japan.
Hashida
Noriyasu
N
Department of Ophthalmology, Osaka University Medical School, Osaka, Japan.
Ohguro
Nobuyuki
N
Department of Ophthalmology, Osaka University Medical School, Osaka, Japan.
Tano
Yasuo
Y
Department of Ophthalmology, Osaka University Medical School, Osaka, Japan.
Kurokawa
Nobuo
N
Department of Pharmacy, Osaka University Hospital, Osaka, Japan.
D000818:Animals; D003132:Commerce; D005938:Glucocorticoids / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D006207:Half-Life; D007267:Injections; D008297:Male; D008954:Models, Biological; D010316:Particle Size; D004364:Pharmaceutical Preparations; D010594:Pharmacies; D010607:Pharmacy Service, Hospital; D011208:Powders; D051381:Rats; D017208:Rats, Wistar; D013535:Suspensions; D014222:Triamcinolone Acetonide / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D014822:Vitreous Body / Q000378:metabolism*
D005938:Glucocorticoids; D004364:Pharmaceutical Preparations; D011208:Powders; D013535:Suspensions; D014222:Triamcinolone Acetonide