How to store solutions of steroid hormones

[Martin Offterdinger]

Hi everyone,
I wonder if anyone knows how to store solutions of steroid hormones?
We have stored them in NUNC cryotubes, but I have the impression that
we loose hormones from the solutions through adsorption to the walls
of the vials especially with the less concentrated stocks. Would glass
tubes be a good solution to that problem?? What else can be done to
exclude adsorption to the tube-walls???
Thank you very much-Martin