Triamcinolone acetonide preparations: impact of crystal size on in vitro behavior.
OBJECTIVE
To characterize the in vitro behavior of three preparations of triamcinolone acetonide (TA).


METHODS
Three preparations of TA were mixed with Balanced Salt Solution Plus: commercially available TA (Kenalog 40, Bristol-Myers Squibb, Princeton, NJ), compounded preservative-free triamcinolone acetonide (PFTA, New England Compounding Center, Framingham, MA), and triamcinolone acetonide injectable suspension (TAIS, TRIESENCE, Alcon, Inc., Fort Worth, TX). We determined the mean number of crystalline aggregates per high-power deconvolution microscopy field, largest aggregate area, and spectroscopic photometric absorption.


RESULTS
Preservative-free triamcinolone acetonide had larger mean number of aggregates compared with TA (time 0 P = 0.002, 10 minutes P < 0.001) and TAIS (time 0 P < 0.001, 10 minutes P = 0.003). Aggregate size varied at both 0 and 10 minutes: TAIS > TA > PFTA. Spectroscopic photometric absorption decreased in direct correlation to aggregate size over time for all three preparations.


CONCLUSIONS
In vitro, PFTA in Balanced Salt Solution Plus had more aggregates of smaller size than either TA or TAIS. By contrast, TAIS had much larger aggregate size than both PFTA and TA, and this increased over time. These findings correlate with the clinical observations that PFTA and TA tend to disperse throughout the vitreous, whereas TAIS tends to conglomerate and gravitate toward the most dependent portion of the eye in a globular fashion.
Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Palm Beach Gardens, Florida, USA.
Andrew A
AA
Moshfeghi
Alex K
AK
Nugent
Hiroyuki
H
Nomoto
Steven R
SR
Sanislo
John W
JW
Kitchens
Darius M
DM
Moshfeghi
D003460:Crystallization; D005938:Glucocorticoids / Q000737:chemistry*; D007091:Image Processing, Computer-Assisted; D066298:In Vitro Techniques; D008853:Microscopy; D009883:Ophthalmic Solutions / Q000737:chemistry; D011310:Preservatives, Pharmaceutical; D013053:Spectrophotometry; D014222:Triamcinolone Acetonide / Q000737:chemistry*
D005938:Glucocorticoids; D009883:Ophthalmic Solutions; D011310:Preservatives, Pharmaceutical; D014222:Triamcinolone Acetonide