Improved risk-benefit ratio for topical triamcinolone acetonide in Transfersome® in comparison with equipotent cream and ointment:: a randomized controlled trial

Background Transfersome(R) is a drug delivery technology based on highly deformable, ultraflexible lipid vesicles which penetrate the skin when applied non-occlusively. Objectives To assess the advantages of this carrier-based formulation in humans, the efficacy and the atrophogenic potential of triamcinolone acetonide (TAC) in Transfersome(R) was compared with commercially available TAC-containing cream and ointment. Methods Healthy volunteers were enrolled in double-blind, placebo-controlled clinical trials with random study medication assignment to the test areas. Results A 10-fold lower dose of TAC in Transfersome(R) (2.5 mug cm(-2)) was bioequivalent to 25 mug cm(-2) TAC in conventional formulations as measured by erythema suppression ( cream: P = 0.01, ointment: P < 0.001). A skin blanching assay revealed different kinetics of the formulations, with a delayed onset of action of the Transfersome(R) and ointment preparations. Ultrasonic measurements revealed a significantly reduced atrophogenic potential. There was a 12.1% reduction in skin thickness given by TAC in Transfersome(R) compared with a 21.1% reduction given by a bioequivalent dose in TAC cream after a 6-week treatment period (P = 0.007). Conclusions Transfersome(R) may significantly improve the risk - benefit ratio of topically applied glucocorticosteroids.