I can fit to individual dose data using pooled fiting or mixed effects no problem. However, for some compounds I have multiple doses and I wish to fit to these simultaneously to obtain a single parameter set. %% PREPARE MODEL gData = groupedData(data); gData.Properties.IndependentVariableName = 'Var1'; gData.Properties.GroupVariableName = 'Var3'; gData.Properties.VariableUnits = {'hour','nanogram/milliliter','',''}; gData.Properties; % One-Compartment Extravascular pkmd = PKModelDesign; pkc1 = addCompartment(pkmd,'Central'); pkc1.DosingType = 'FirstOrder'; pkc1.EliminationType = 'linear-clearance'; pkc1.HasResponseVariable = true; model = construct(pkmd); configset = getconfigset(model); configset.CompileOptions.UnitConversion = true; % Single dose dose = sbiodose('dose'); dose.TargetName = 'Dose_Central'; dose.StartTime = 0; dose.Amount = 75; dose.AmountUnits = 'milligram'; dose.TimeUnits = 'hour'; responseMap = {'Drug_Central = Var2'}; % Use NCA parameter estimates as initial parameter guess NCA.Central = mean(ncaparameters.V_z,'omitnan'); NCA.CL = mean(ncaparameters.CL,'omitnan'); NCA.ka = 1; paramsToEstimate = {'log(Central)','log(Cl_Central)','log(ka_Central)'}; % estimatedParams = estimatedInfo(paramsToEstimate,'InitialValue',[5e-4 1e-6 1],'Bounds',[1 5;0.5 2; 1e-3 10]); estimatedParams = estimatedInfo(paramsToEstimate,'InitialValue',[NCA.Central NCA.CL NCA.ka]); % Fit [Individual, Pooled, Mixed Effects] fitConst = sbiofit(model,gData,responseMap,estimatedParams,dose); pooledFit = sbiofit(model,gData,responseMap,estimatedParams,dose,'Pooled',true); Here is my code for 1 dose. The multiple dose data is in a table similar to the tutorial for phenobarbital, where the next dose and corresponding data follows the previous dose. I wish to do this using PK models and the sbiofit or similar commands that utilise simbiology. Please can someone shed some light on this? Cheers