Ten Steps to Percutaneous Absorption16

1. Vehicle release
2. Absorption kinetics a. Skin site of application b. Individual variation c. Skin condition d. Occlusion e. Drug concentration and surface area f. Multiple dose application
3. Excretion kinetics
4. Effective cellular and tissue distribution
5. Substantivity
6. Wash-and-rub resistance
7. Volatility 8. Binding
9. Anatomic pathways
10. Cutaneous metabolism