The THC Model Borrowed Terminal Parameters Rather Than Measuring the Full Elimination Phase
The inhaled-THC model fixed two terminal-disposition parameters using earlier research. The short sampling session did not independently estimate every part of the drug’s long-term elimination.
Early distribution supplied most of the new data
The study collected closely timed blood samples after witnessed inhalation. Its three-compartment analysis fixed elimination clearance and the slowly equilibrating distribution volume to prior estimates because the session did not include terminal-phase observations. Other parameters were estimated from the current dataset.
A fixed value has a different evidentiary basis
Using an external value can make a short-duration model estimable, but that value is an input assumption rather than a newly observed finding. A successful fit to early concentrations does not demonstrate that the borrowed terminal values are exact for each person.
Long-interval reconstruction requires additional support
The model was useful for exploring early exposure and inhaled-dose variability under its conditions. It did not directly measure a terminal half-life in every participant or validate back-calculation over an arbitrary interval after unknown consumption. A scientific report should distinguish fixed parameters, estimated parameters and measured concentrations. That distinction prevents the model’s complete-looking diagram from implying complete observation of every physiological phase.
Related analysis: the study’s broader findings and limitations.
