A calculation of percutaneous drug absorption--I. Theoretical.

Several theoreticals for simulating percutaneous drug absorption with a computer aid are proposed. By using our theoreticals, the simulation can be made for the process not only during an ointment application but also after its removal. The flow rate of drug from vehicle to skin and that from skin to blood also be estimated. In addition, we defined an apparent length of diffusion, ld and showed how to assess ld. The effect of a change in regional blood flow on drug flux from the skin at the quasi-steady-state is discussed.