[rothko]

Hi there, I was hoping someone could help me. 

In aqueous solution dissolved hydrocortisone-21-butyrate rearranges to form hydrocortisone-17-butyrate (degradation product).  I think the process is intramolecular transesterification, but I am not sure.  I have heard that addition of an omega-6-fatty acid stops this degradation occuring.  Does anyone know how this could be.

Thanks

Rothko