Maceration steeps chopped plant material in a solvent. Each active-compound class has its own partition preference: alkaloids are more lipophilic and leave the tissue faster into alcohol, while flavonoids are more polar/hydrophilic and extract faster into water. Heat speeds diffusion for both, following an Arrhenius-like acceleration.
extracted(t) = 1 − e^(−k·t)
k = k0 · solventFactor(compound) · Q10^((T−20)/10)
The extracted fraction sets how much active compound is actually available in the strained dose. That dose then follows a one-compartment oral pharmacokinetic model:
C(t) = D·ka / (Vd·(ka−ke)) · (e^(−ke·t) − e^(−ka·t))
Because a plant batch's compound content varies naturally (soil, harvest time, drying, incomplete extraction), the herbal curve is drawn as a shaded band (±30%) rather than a single line — unlike a synthetic tablet with a tightly controlled, near-fixed dose (thin reference line). The green band marks the therapeutic range; the red line marks the toxicity threshold.
- Solvent — water favours hydrophilic flavonoids, alcohol favours lipophilic alkaloids.
- Temperature — higher heat accelerates diffusion out of plant tissue for both compound classes.
- Steeping time — how long the material stays in the solvent before straining; caps the extracted fraction fed into the dose.
- Dose taken — nominal mass of strained extract ingested; actual active-compound delivered scales with what was actually extracted.
This is an educational, simplified model — not medical or dosing guidance.