Skincare has invested enormous effort in ingredients, concentration, molecular characteristics, and vehicle design. Those choices matter. They do not determine their own deposition.
The moment a formulation leaves its package, another system begins: quantity released, contact area, electrical conditions, temperature, duration, technique, and the state of the skin barrier.
Surface concentration describes what was applied. Tissue analysis establishes what was deposited.
Formulation variables
Molecular size, charge, hydrophilicity, concentration, viscosity, conductivity, and vehicle composition influence how a payload behaves. A higher surface concentration is still only a surface condition.
Application variables
Dose, contact, field geometry, timing, temperature, and movement can change from one application to another. Without control, two uses of the same formula are not necessarily the same delivery event.
Application is not deposition
What is placed on skin is not equivalent to what is recovered from a specific layer. Deposition is a physical measurement. It requires tissue analysis rather than inference from concentration or telemetry alone.
One protocol
AXIS treats the defined payload and its operating conditions as one protocol so the event can be reproduced, measured, and eventually compared with physical outcomes.