I think CMC will only serve as a vehicle...so 0.25% - 5% CMC is reasonable

See: http://www.iiste.org/Journals/index.php/JNSR/article/viewFile/15861/16667

you can follow the acute toxicity protocol and you can prepare a suspension of your extract in 0.25 to 0.5 % CMC for giving orally.

see protocol of acute

https://ntp.niehs.nih.gov/iccvam/suppdocs/feddocs/oecd/oecd_gl425-508.pdf

Hi Eswar. I suggest to consult and follow up specific guidelines as the OECD for toxicology studies. Than will facilitate your work and the acceptance of the publication when you are at that stage. The guideline suggested above is also good. Use as much as you need in time to plan. Here is also a reference textbook that may help

HASCHEK AND ROUSSEAUX’S HANDBOOK OF TOXICOLOGIC PATHOLOGY THIRD EDITION, 2013 ISBN : 978-0-12-415763-7 (volume 1)

Thank you all