I think buying bulk rapamycin powder from anyone (China, etc.) other than that manufactured by known brands in europe or western countries, is likely a bad move and very risky.
Having sobered up I have done the research and I went through Indiamart and ordered from two suppliers Varun Medicals email@example.com and Gandhi Medicos firstname.lastname@example.org
both of which supplied a number of boxes which had the same Zydus branding on the outside.
I have not had the boxes chemically tested, however.
Thanks for your help on this John!