An important updated of BIOKMOD is available: http://oed.usal.es/webMathematica/Biokmod/

What things you can do with BIOKMOD? (i) It is especially useful for modeling the distribution of isotopes in the human organism (F-18, In-111, Ga-67, I-131, Tc-99m, etc.) ii) The user can build and solve its own compartmental model (constant and variable coefficients can be used). (iii) Most of the ICRP (ICRP 130/134/137/141/151) biokinetic models are included and they can be applied in internal dosimetry, bioassay evaluations and Nuclear Medicine (The Intake Retention Fractions or IRF, their analytical expressions, compartmental content, accumultaded disintegrations, TIAC and the graphic representations can be obtained).

User manual: http://oed.usal.es/webMathematica/Biokmod/Docs/BIOKMOD_MANUAL.pdf