Although different concentrations of the medicament are used in this study, they do not affect the amount permeated through the membrane (the process is constant).
It is very often regarded as taking part in a fight against the lobbies of the pharmaceutical industry and the conflicts of interest in medicament's policies.
Apart from these, it also has a few additional ingredients such as coloring and opacifying agents, preservatives, acids and medicaments (for desired effects), flavoring agents and sugars.
