How well does the in vitro data match in vivo?
Percutaneous absorption represents the “A” in ADME (Absorption-Distribution-Metabolism-Excretion). Our early work in the 1970s and 1980s, which has since been confirmed by many others, demonstrates that for well-conceived studies conducted under identical conditions (dose, body site, duration, etc.), the in vitro results correlate with and will predict in vivo results. Using basic pharmacokinetic principles, this input-function (the absorption phase) thereafter allows for prediction of systemic blood levels, when the clearance and excretion for the drug of interest has been previously characterized.
