Basal pharmacokinetic parameters of topically applied diacerein in pediatric patients with generalized severe epidermolysis bullosa simplex

Michael Ablinger,
Thomas K. Felder,
Monika Wimmer,
Roland Zauner,
Peter Hofbauer,
Thomas Lettner,
Martin Wolkersdorfer,
Florian B. Lagler,
Anja Diem,
Johann W. Bauer and
Verena WallyEmail author View ORCID ID profile

Orphanet Journal of Rare Diseases201813:193

https://doi.org/10.1186/s13023-018-0940-1

Received: 17 September 2018
Accepted: 22 October 2018
Published: 1 November 2018

Abstract

Generalized severe epidermolysis bullosa simplex (EBS-gen sev) is caused by mutations within either the KRT5 or KRT14 gene, phenotypically resulting in blistering and wounding of the skin and mucous membranes after minor mechanical friction. In a clinical phase 2/3 trial, diacerein has recently been shown to significantly reduce blister numbers upon topical application. In this study we addressed basic pharmacokinetic parameters of locally applied diacerein in vitro and in vivo.

Ex vivo experiments using a Franz diffusion cell confirmed the uptake and bio-transformation of diacerein to rhein in a porcine skin model. Rhein, the active metabolite of diacerein, was also detected in both urine and serum samples of two EBS-gen sev patients who topically applied a 1% diacerein ointment over a period of 4 weeks. The accumulated systemic levels of rhein in EBS-gen sev patients were lower than reported levels after oral application.

These preliminary findings point towards the uptake and prolonged persistance of diacerein / rhein within the intended target organ - the skin. Further, they imply an acceptable safety profile at the systemic level.