Bioavailability of betamethasone dipropionate when combined with calcipotriol.

BACKGROUND

Calcipotriol and corticosteroids are commonly used treatments for psoriasis vulgaris, each with different mechanisms of action. The two agents have shown combined action, but current formulations do not permit simultaneous application. Daivobet (LEO Pharma, Denmark) ointment contains calcipotriol and the corticosteroid, betamethasone dipropionate. Such a formulation may provide convenience and enhanced activity compared with separate applications, but it is essential that the biological activity and bioavailability of either active agent is not adversely affected by the other component.

OBJECTIVE

His study was designed to determine whether the bioavailability of the corticosteroid component of Daivobet was equivalent to that in a corticosteroid-only formulation (Diprosone, Schering-Plough Laboratories, France).

METHOD: A vasoconstrictor assay measuring skin blanching was used to determine bioequivalence.

RESULT: Skin blanching measured either by objective chromametric measurement or visual assessment showed Daivobet to be equivalent to Diprosone.

CONCLUSION

The data indicate that the steroid component of Daivobet is not unfavorably affected by the calcipotriol.