Do you know anything about the degradation of Corticostero ï den by zinc oxide?

I find only 1 reference that is in line with the question posed. Barnes et al. (Journal Clinical Pharm. Ther. 1991, 16:103-109) have investigated the stability of corticosteroids containing diluted 1:10 with Compound Zinc Paste British Pharmacoepeia, which contains 25% zinc oxide, 25% starch and 50% vaseline and Temperature of 25 ° C. The results were the following:

Stero ï the Betamethasondipropion
0.05% betamethasonvalerate
0.1% Fluocinolonacetonide
0.025% Fluocinonide
0.05% 7 days at 25 ° C 93.5% 60% 34% 65.5% 14 days at 25 ° C 87.5% - - 55%

These are quite important outbreaks for a Vetexcipiens. A clear explanation is not given in the article. Other authors found an analogue behaviour for hydrocortisone butyrate.