In Vitro and In Vivo Correlation Plus Module Equations

This section details the equations that define and support a Level A IVIVC, which is a specific category of IVIVC that you can carry out in the optional Drug-Drug Interaction (DDI) module. See:

Level A IVIVC Deconvolution Equations

For details about the internal standards that were used to define the equations in this section, see Equation Standards.

Level A IVIVC Deconvolution Equations

Equation 5-1: Wagner-Nelson deconvolution method, 1-compartment PK model

where:

Variable	Definition
	The amount (mass) of the drug at time t.
	The volume of distribution of the drug.
	The concentration of the drug in plasma at time t.
	The elimination rate of the drug.
	The concentration of the drug.

Equation 5-2: Loo-Riegelman deconvolution method, 2-compartment PK model (i)

where:

Variable	Definition
	The amount (mass) of the drug at time T.
	The volume of distribution of the drug.
	The concentration of the drug in plasma at time T.
	The elimination rate of the drug.
	The concentration of the drug.
	The rate constant for the transfer of the drug from compartment 1 to compartment 2.
	The rate constant for the transfer of the drug from compartment 2 to compartment 1.

Equation 5-3: Loo-Riegelman deconvolution method, 2-compartment PK model (ii)

where:

Variable	Definition
	The amount (mass) of the drug at time T.
	The volume of distribution of the drug.
	The concentration of the drug in plasma at time T.
	The elimination rate of the drug.
	The concentration of the drug.
	The rate constant for the transfer of the drug from compartment 1 to compartment 2.
	The rate constant for the transfer of the drug from compartment 2 to compartment 1.
	The rate constant for the transfer of the drug from compartment 1 to compartment 3.
	The rate constant for the transfer of the drug from compartment 3 to compartment 1.

Equation 5-4: Shifting and scaling function for the mechanistic deconvolution method

where:

Variable	Definition
	The fraction in vivo dissolution.
	The fraction in vitro dissolution.
	The release scale coefficient.
	The release shift coefficient.
	The time scale coefficient.
	The time shift coefficient.