This is a PK 1 compartment extravascular model with mixed first order and zero order input, using fractional dosing. Zero order input uses duration as a fitted parameter.
For model translation information, refer to the attached pdf The model is run in both NLME and NONMEM in the attached Phoenix project file.
In NLME, the model engine is Quasi-Random Parametric Expectation Maximization (QRPEM)
For details about QRPEM, refer to Phoenix Help > Contents > Phoenix Model > Phoenix Model Run Modes, Engines, and Output > Phoenix Model Engines > QRPEM.
In NONMEM, the model engine is Importance Sampling (IMP) EM.