An in-vitro in-vivo correlation (IVIVC) has been defined by the U.S. Food and Drug Administration (FDA) as 'a predictive mathematical model describing the relationship between an in-vitro property of a dosage form and an in-vivo response'. An in-vitro in-vivo correlation (IVIVC) has been defined by the U.S. Food and Drug Administration (FDA) as 'a predictive mathematical model describing the relationship between an in-vitro property of a dosage form and an in-vivo response'.