Pharmacokinetic (PK) models are mathematical tools that allow simulating drug concentration levels in the blood prior to real administration. These models can have countless applications in new drug development and clinical activities. Concerning clinical practice, a factor limiting the widespread use of PK models is the difficulty to carry out personalized PK predictions. This article proposes a methodology to individualize a physiologically based pharmacokinetic model for applications in therapeutic drug monitoring. In order to personalize the model, it is necessary to determine patient-specific model parameters. Few drug concentration measures in the blood allow evaluating the parameter values by performing a nonlinear regression between...