Physical properties of commercially available formulations of triamcinolone acetonide

Triamcinolone acetonide (TA) has been used extensively in the treatment of intraocular inflammation and macular oedema, and for the intraoperative visualisation of vitreous and epiretinal membranes during vitrectomy.1 In the USA, the most commonly used commercially available formulation of TA contains 0.022% benzyl alcohol as a preservative in the vehicle (Kenalog-40; Bristol-Myers-Squibb, Peapack, New Jersey). There is evidence that this preservative may have toxic effects on the retina.2 In an attempt to reduce solvent concentrations and the potential toxicity, methods of resuspending TA have been described.3 4 Recently, triamcinolone acetonide injectable suspension (Triesence, Alcon Laboratories, Fort Worth, Texas) has become commercially available and is approved by the United States Food and Drug Administration specifically for intraocular use. We compared physical properties of TA and TA injectable suspension (TAIS) that may affect the intraocular behaviour of these formulations. TA and PFTA crystals …