I am doing NCA on a sparse plasma concentration vs time data where the drug is administered as IV bolus. The AUCs and the linked parameters like CL are almost two times different when analyzed in sparse mode vs using the mean concentration data at each time point. I also did compartment modeling, AUC and CL obtained by model fitting are similar to the NCA parameters obtained by mean conc. vs time data. I am not sure why sparse NCA analysis is not giving me the similar results.
Can you please provide the Phoenix project file so that we can have a detailed look. Otherwise it is difficult to find out the root cause. If this is confidential data, please send them to support@certara.com.
Bernd