I have a Simbiology PK model and the unit of all species (drug) is in microgram/milliliter. However, I would like to include a new reaction considering the drug and receptor binding behavior. The equation for this reaction is reversible as below.
Drug + Receptor <-> Complex: k_on*Drug*Receptor - k_off*Ccomplex
However, the unit of the k_on is 1/Molarity/Second and the unit of the k_off is 1/second and the unit for the Drug, Receptor and Complex should be in molarity. Is there any way I could keep my species unit still in microgram/milliliter but only have their unit become in molarity when they participate in this reaction? or is there any trick I could apply to achieve this thought?
Thank you very much.