WinNonlin

WinNonlin is a pharmacokinetic and pharmacodynamic analysis software package used to analyze drug concentration data, estimate PK parameters, and simulate dosing regimens. It supports noncompartmental analysis, compartmental PK/PD modeling, population analyses, bioequivalence testing, and various statistical assessments, making it a common tool in drug development and regulatory submissions.

Originally developed by Pharsight Corporation, WinNonlin became part of Certara’s product portfolio after an acquisition and is marketed today as Phoenix WinNonlin within the Phoenix platform. The software is widely used by pharmacometricians, toxicologists, and clinical pharmacologists in pharmaceutical and biotech settings for analyzing clinical trial data and supporting decision-making throughout development.

Key features include data import and management from multiple formats, noncompartmental analysis for standard PK parameter estimation, and a range of compartmental models for PK/PD analysis. Users can perform nonlinear least-squares parameter estimation, fit user-defined models via a model editor, and conduct population PK/PD analyses. The software supports simulations, bootstrap analyses, and various diagnostic tools to evaluate model fit and predictive performance, such as goodness-of-fit plots and visual predictive checks. It also offers reporting capabilities and can generate outputs suitable for regulatory documentation.

WinNonlin is designed to operate on Windows platforms and integrates into broader pharmacometric workflows, often alongside other tools and databases. It remains a widely cited standard in pharmacokinetic analysis and is frequently used to support dose selection, exposure-response evaluations, and bioequivalence assessments in drug development programs.