A selection of short essays from our blog, written to empower our customers with modeling and simulation (M&S) and regulatory writing solutions in order to help them solve the toughest drug development problems. Certara staff contributions range in topic from pharmacometrics to systems biology to the growing importance of regulatory writing and sharing clinical trial results.
Read MoreAuthors: Nathan Teuscher
How Can You Get the Most out of Phoenix 8.0?
In this webinar, Dr. Nathan Teuscher demonstrated how to get the most out of Phoenix 8.0’s new features, including how to automatically calculate new NCA parameters, set up parallelization of Phoenix NLME runs, and leverage the new validation suite to get up and running in no time.
Read MoreA Distributed Delay Approach for Modeling Delayed Outcomes in Pharmacokinetics and Pharmacodynamics Studies
Implementation of Distributed Delays for Absorption Delays and Delayed Drug Response
Feedback from the Phoenix Community: Our Visits with the FDA
We recently completed a week-long set of meetings with the FDA, where we met with over 300 FDA reviewers from 7 of the 11 FDA centers that use Phoenix. Here are a few topics that took center-stage during our visits: Q: How can we create Phoenix workflow templates that are reusable across different studies with […]
Read MorePopulation Pharmacokinetic of L-DOPA and Its Main Metabolites: Use of the Phoenix-based QRPEM Algorithm
Modeling & Simulation for Drug Development & Formulation
A look at how to leverage modeling and simulation technology to enhance all phases of the drug development process.
Read MoreAccomplish More with Phoenix—New Phoenix 8.1 Release in June 2018!
June 6, 2018 – As the gold standard for PK/PD software, our upcoming Phoenix 8.1 release delivers new capabilities to automate processes, reduce errors, and save you time. Dr. Nathan Teuscher, VP of Pharmacometric Consulting, and Kevin Trimm, Director of Phoenix Technology Services, will share our latest innovations in WinNonlin and NLME and conduct a live demo.
Read MoreA First Look at Phoenix 7.0, the World’s Most Advanced PK/PD Software
Watch this webinar with Certara’s Dr. Nathan Teuscher to learn more about the amazing features and enhancements now available in Phoenix 7.0.
Read MoreEvery Ending has a New Beginning
I created the Learn PK/PD site in May 2010 in response to a communication issue that I was facing in my daily work in the world of clinical pharmacology and pharmacokinetics. In my first post, I stated the reason for creating my blog and the website: My blog is dedicated to providing clear, concise, accurate, and […]
Read More9 Frequently Misunderstood Concepts in PK/PD Modeling
In teaching pharmacometrics, I’ve noticed that scientists have difficulty with certain PK/PD modeling concepts. Maybe you’ve read about some of these terms in journal articles, but didn’t know what they meant? Or you’ve heard these terms bandied about by colleagues, but felt too shy to ask them what they meant? I’ll clarify some important concepts […]
Read More9 Things Your Boss Wishes You Knew About PK/PD Modeling
Over the course of my career, I have taught the theory and practical applications of PK/PD modeling to hundreds of scientists. In this blog post, I’ll share some of my most popular tips for solving common difficulties encountered by pharmacometricians. The tools of the trade While I have worked with a number of pharmacometrics tools, I […]
Read MoreDerivation for Logarithmic Trapezoidal AUC Calculation
Calculating area under the curve requires the use of two separate equations: one is follows the “linear trapezoidal rule” and the other follows the “logarithmic trapezoidal rule.” These equations are normally presented in textbooks without derivations so all you have to do is insert the concentrations and times and you can calculate the area under […]
Read MoreConnecting Phoenix to your PK/PD Data Analysis and Reporting Workflow
The pharmaceutical industry is rapidly integrating systems, software, and knowledge across many disciplines. What were once stand-alone systems are now part of a larger workflow that moves research from the bench to the clinic. Pharmacokinetic (PK) and pharmacodynamic (PD) analysis is an essential part of that workflow. Certara’s Phoenix platform enables users to seamlessly integrate […]
Read MoreCalculating the Elimination Rate Constant
The elimination rate constant is the rate at which drug is cleared from the body assuming first-order elimination. Various abbreviations are used to represent the elimination rate constant including ke, kel, λ, and λz. The calculation of the elimination rate constant can be done using pharmacokinetic parameters or it can be done directly from a […]
Read MoreAdding a Placebo Component to Your PK/PD Model in Phoenix
PK/PD modeling is an exciting are of research in clinical pharmacology. Most often we try to model the effect of a drug by drawing relationships between the concentration and effect. This usually entails subsetting the data to exclude information from subject that received placebo during the trial. But statistical comparisons in clinical studies are most […]
Read MoreBioanalytical Calibration Curves
At the request of a reader, I have decided to extend my series on bioanalysis to include another topic: calibration curves. The calibration curve is they keystone of bioanalysis. It is what links the instrument response to a specific concentration of drug. It is like the magic decoder ring that helps you decipher the hidden […]
Read MoreBioanalytical Method Validation
In this final post regarding bioanalysis, I will review a few of the main ideas related to bioanalytical method validation. The purpose of a method validation is to demonstrate that a specific bioanalytical method can reliably determine the concentration of drug in a study sample with a high degree of confidence. Validation does not mean […]
Read MoreRadiometric Analysis
One of the oldest methods used for the quantitation of drug molecules is radiometric analysis. This generally involves quantitation of radiation from beta-emitting radioactive isotopes such as 14C, 3H or 32P. Radiometric analysis is one of the most precise, sensitive, and efficient detection methods; however, there are many technical and social challenges with using this […]
Read MoreLigand Binding Assays
Our discussions of various bioanalytical methodologies over the past few weeks has focused on chromatography and small molecule analysis. Today we are going to discuss a collection of methods that is commonly used for large molecules, such as peptides, peptides and macro-molecules. These molecules are often called “biologics” because they are generally derived from endogenous […]
Read More