I am trying to model a drug that is an alkylating agent and binds irreversibly to plasma proteins. I defined the drug in PKSim (including its metabolic degradation using endogenous enzyme expression data and defining albumin as its binding partner). I then created a simulation using the above + real patient's individual data, administration protocol and the observed TDM data. It ran smoothly and then I saved the simulation in pkml format. After loading to MoBi I encountered a problem attempting to define the drug's irreversible reaction with albumin as indicated in the enclosed file. Given that MoBi insists on a kinetic equation to describe the reaction, the parameter - "k_on" should have units of 1/(time *concentration). Such unit does not seem to be available in MoBi. As far as I understand using a wrong unit definition for this parameter created the parsing problem that prevents the completion of the defintion of the Drug - albumin reaction.
I would be grateful for your assistance in resolving this to facilitate the setting up of the model I am seeking.
I am trying to model a drug that is an alkylating agent and binds irreversibly to plasma proteins. I defined the drug in PKSim (including its metabolic degradation using endogenous enzyme expression data and defining albumin as its binding partner). I then created a simulation using the above + real patient's individual data, administration protocol and the observed TDM data. It ran smoothly and then I saved the simulation in pkml format. After loading to MoBi I encountered a problem attempting to define the drug's irreversible reaction with albumin as indicated in the enclosed file. Given that MoBi insists on a kinetic equation to describe the reaction, the parameter - "k_on" should have units of 1/(time *concentration). Such unit does not seem to be available in MoBi. As far as I understand using a wrong unit definition for this parameter created the parsing problem that prevents the completion of the defintion of the Drug - albumin reaction. I would be grateful for your assistance in resolving this to facilitate the setting up of the model I am seeking.
Kinetic equation.docx