Sounds like you want a design like this
For the concentrations of the supplements, I left those to vary between 10 and 50%. Note that they sum to 100%
Don't use discrete numeric for continuous variables. Reserve it for when you have something like the number of teeth on a gear so something that can't be easily changed.
The mixture role lets you have correlated X's and you can have more than 3. The modeling type is Scheffe Cubic which causes multiple concentrations to be used, kind of like when you have a quadratic model for a continuous variable. Note, for polynomial terms you don't add the levels yourself, those are calculated from the range you specify.
The attached data table has a representative experiment.
There is a script named, "Run this Model", run that one.
JMP Systems Engineer, Health and Life Sciences (Pharma)