Nonlinear Mixed Effects Models in Population PK/PD, Estimation Routines R package nlmixr2est version 6.0.1 Fit and compare nonlinear mixed-effects models in differential equations with flexible dosing information commonly seen in pharmacokinetics and pharmacodynamics (Almquist, Leander, and Jirstrand 2015 <doi:10.1007/s10928-015-9409-1>). Differential equation solving is by compiled C code provided in the 'rxode2' package (Wang, Hallow, and James 2015 <doi:10.1002/psp4.12052>). Software Depends: nlmixr2data, R (>= 4.1.0) Imports: backports, checkmate, cli, graphics, knitr, lbfgsb3c, lotri, Matrix, methods, minqa, n1qn1 (>= 6.0.1-12), nlme, Rcpp, rex, rxode2 (>= 5.1.2), stats, symengine, utils LinkingTo: BH, n1qn1 (>= 6.0.1-12), lbfgsb3c (>= 2024-3.5), lotri (>= 0.5.0), Rcpp, RcppArmadillo (>= 0.11.2.3.1), RcppEigen, rxode2 (>= 5.1.1) Suggests: broom.mixed, crayon, data.table, devtools, digest, dplyr (>= 1.1.0), generics, nloptr, qs2, sys, testthat, tibble, withr, xgxr, sfsmisc, minpack.lm, remotes, fastGHQuad, rmarkdown, rlang Matthew Fidler <matthew.fidler@gmail.com> Comprehensive R Archive Network (CRAN) Matthew Fidler [aut, cre] (ORCID: <https://orcid.org/0000-0001-8538-6691>), Wenping Wang [aut], Audrey Lavenu [ctb], Ben Goodrich [ctb], David Ardia [cph], Dirk Eddelbuettel [cph], Elizabeth Eskow [ctb], Emmanuelle Comets [ctb], Hadley Wickham [ctb], Hajar Besbassi [ctb], Johannes Pfeifer [ctb], Justin Wilkins [aut] (ORCID: <https://orcid.org/0000-0002-7099-9396>), Katharine Mullen [cph], Mahmoud Abdelwahab [ctb], Marc Lavielle [ctb], Mason McComb [ctb] (ORCID: <https://orcid.org/0000-0001-9871-8616>), Mirjam Trame [ctb], Richard Hooijmaijers [aut], Rik Schoemaker [aut] (ORCID: <https://orcid.org/0000-0002-7538-3005>), Robert B. Schnabel [ctb], Robert Leary [ctb], Teun Post [ctb], Vipul Mann [aut], Yuan Xiong [aut] GPL (>= 3) 2026-06-03 application/tgz https://CRAN.R-project.org/package=nlmixr2est doi:10.32614/CRAN.package.nlmixr2est en-US