The safety of calcitriol 3 microg/g ointment. Evaluation of cutaneous contact sensitization, cumulative irritancy, photoallergic contact sensitization and phototoxicity

Abstract

Vitamin D analogues are widely used for the treatment of psoriasis. A new topical formulation of calcitriol (3 microg/g ointment) has been shown to be effective in the treatment of stable plaque-type psoriasis. This paper reports the results of four separate studies designed to evaluate specific local-safety parameters: cumulative irritancy, cutaneous contact sensitization, potential photoallergic contact sensitization and phototoxicity. Calcitriol 3 microg/g ointment was classified as non-irritant when compared to calcipotriol, tacalcitol and white petrolatum. Petrolatum and tacalcitol were slightly irritant and calcipotriol moderately irritant. No sensitization was observed with calcitriol 3 microg/g ointment. With regard to phototoxic potential, sites treated with calcitriol 3 microg/g ointment or vehicle ointment were less irritated than those treated with white petrolatum or those that were untreated. Using standard photoallergenicity testing methodology, there were no skin reactions of a photoallergic nature to the study material. These studies showed that calcitriol 3 microg/g ointment is a well-tolerated treatment for stable plaque-type psoriasis.