The User Defined Parameters tab allows inclusion of concentrations/Y values at specified times, as well as additional NCA parameters.
Check the Include with Final Parameters box to append the user-defined parameters (both the computed concentrations/Ys and any additional user-defined parameters) to the Final Parameters worksheets, both the pivoted and non-pivoted versions.
Enter time or X values at which to compute the concentration or Y value.
For Plasma models, enter a value(s) in the field to have the NCA object compute the concentration (or the mean concentration, if the Sparse Sampling box in the Options tab is checked) at that time and include the result in the output.
For Drug Effect models, enter a value(s) in the field to have the NCA object compute the Y value at that X value and include the result in the output.
Up to 30 values can be entered as a comma-separated list. Values can also be specified by using multiple ‘seq’ statements with the format seq(first_time,end_time,increment). For example, seq(0,6,1),8,12,seq(18,36,6).
Note: If a concentration/drug effect value does not exist in the data set for the specified time/X value, it is calculated following the same rules as for computing Y-values for partial area endpoints, see the “Partial area calculation” section.
Press Add to define other NCA parameters to include in the output.
Enter a name for the parameter in the Parameter column.
The name is checked for validity as it is entered and a message is displayed in the last column of the table if it is not valid. Since the names become column headers in the output, they must also follow the rules for column headers: start with a letter or underscore; contain only letters, numbers, underscores, and ‘%’; and not contain spaces, periods, or symbols. The name cannot match any of the following:
default names for NCA final parameters
preferred names for NCA final parameters
previously defined additional NCA parameters
names that will be generated by the Compute concentrations at times option
the words “Dose” and “Sort”
names of columns defined as Carry variables
Enter an equation that defines how the parameter is to be computed in the Definition column.
The math function operators +, –, *, /, and ^ can be used in the definition, as well as ln(x), log(x,base), log10(x), exp(x), and sqrt(x). The parameter can be a function of the following:
default parameter names (even if selected to be excluded from the results)
preferred names specified on the Parameter Names setup tab (even if selected to be excluded from the results)
partial areas
if an external dosing worksheet is used, the name of the column mapped to Dose and the name of the column mapped to Tau
if an internal dosing worksheet is used, the “Dose” and “Tau” columns
Carry variables (names of columns mapped as Carry)
previously defined user-defined parameter names (those that are above the current name in the user interface)
Note that:
If more than one dose amount is specified for a profile, the last dose value will be used when computing the parameter.
If a carryalong is a time-dependent variable (that is, if the carryalong takes on different values per profile), any user-defined parameters defined in terms of this carryalong will be undefined.
If any of the values to be used when computing the user-defined parameter are missing (for example, an equation that uses Rsq when the Lambda Z fitting fails or was disabled), the value of the user-defined parameter will be missing (blank) in the results.
Any names used are case-sensitive (they must be correct in terms of uppercase and lowercase).
To assist with entering final parameter names in the equation, a dropdown list provides a list of final parameters that match as the name is typed. Double-click an entry from the list to auto-complete typing that name. The list contains only final parameters, even though other names, such as dosing and carryalong names, can be used. The list contains all possible final parameters in NCA but some may not be applicable to the current selection of model and dosing options.
In the Units Label column enter the unit name that is to appear when the parameter values are reported. No conversion of units is done for user-defined parameters.
Click the red X in the row to remove that parameter.