Certara offers predictive science and informatics solutions that enable cross-disciplinary and translational approaches to drug development.

PK/PD Modeling and Simulation


Introduction to Phoenix NLME

Exploring Data

Creating Individual Models

Creating Population Models

Adding Covariates to Population Models


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This webinar presented and demonstrated the new features of Phoenix 1.3. (recorded webcast)

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Phoenix® NLME - Nonlinear Mixed Effects Modeling

Powerful Data Processing and Modeling Tools for Population PK/PD Analysis

Phoenix NLME for population PK/PD modeling provides a powerful and easy-to-use, integrated solution for data processing, modeling, and reporting.

Phoenix NLME is an effective population modeling system consisting of optimization engines coupled with pre- and post-processing data management tools and graphics capabilities. 

Users have access to sophisticated tools for creating preliminary plots, determining a base model, doing covariate analysis, developing a final model, and evaluating the final model.  Additionally, using Phoenix NLME, users have capabilities to post-process results for reporting, to run simulations on new datasets, and to communicate the results of the analysis -  all in one easy-to-learn system.

Phoenix NLME includes a wide set of optimization engines for nonlinear mixed effects modeling, including a new EM (expectation maximization) method (QRPEM).  Scientists can construct their models by selecting library models, graphically and/or manually (coding). 

Phoenix NLME shortens the learning curve for drug development scientists to make initial use of population modeling methods, and also provides cutting edge tools required by advanced modelers.

Key Benefits

Comprehensive Analysis Environment

  • Easy to use, robust modeling tools to analyze population PK/PD studies.
  • Powerful data management, modeling and tabulation tools.
  • Manage all analysis steps and documentation within a single file, including plots and tables.

Efficient Workflow Management


  • Create, reuse, and share analyses as stored workflows.
  • Easily process, visualize, and tabulate data.
  • Create reusable templates from desired steps (e.g. pre-processing of data).
  • Rename and organize analysis steps where each input/output relationship can be visualized in a colorful, easy-to-understand diagram.



Easy to Learn and Share

  • Minimize the amount of time spent learning the software and promote collaboration through easily transferable project files, workflows, and templates.
  • Conveniently store input files, models, workflows, tables, charts, analyses, output, email, and Word documents (e.g., the protocol) in a single Phoenix project file.
  • Users can send the project file to another researcher, QA staff, or a regulatory agency for easy re-analysis.

Computationally Powerful

  • Designed to support parallel execution on multiple processors within a single run.
  • Uses the Argonne MPICH2, which allows optimizations to be run on multiple processors simultaneously.
    • Takes advantage of modern dual- or quad-core processors, which results in significant speed gains.

Supports Validated Environments

  • A Validation Suite for Phoenix NLME is available to automate onsite validation.

Enables Compliance

System Requirements

Phoenix NLME is supported for both 32-bit and 64-bit versions of Windows XP SP3, Windows 2003, Windows 7 SP1, Windows 2008 Server R2.

Minimum Hardware Requirements:

  • Processor:  Intel Core 2 Duo 2.0 Ghz, or a CPU of EQUIVALENT processing power

  • RAM:  2 gigabytes RAM

  • Hard drive space:  300 megabytes free

Click here for detailed system requirements, including international language support.