Hill equation & free drug concentration

[Christoph27]

Currently the Hill equation is written in PK-Sim in the following way (e.g. a cellular process):
R ~ K_water_cell * C_cell^alpha / (Km^alpha + K_water_cell * C_cell^alpha)
Since K_water_cell * C_cell is the free drug concentration, I would think the equation should read as follows:
R ~ (K_water_cell * C_cell)^alpha / (Km^alpha + (K_water_cell * C_cell)^alpha)
This applies for all metabolization and transport rate equations and analogously to the equations "BrainPgPToPlasma_Hill" and "BrainActiveInfluxFromPlasma_Hill" with fu instead of K_water_cell.