Franz cell

Ex-vivo skin permeation experiment of a loaded drug is an important benchmark for the prediction of percutaneous absorption during the development of transdermal formulations. It gives an idea of the potential steady state concentration following the percutaneous absorption from the tested formulation. It can be a very valuable tool for testing the bioequivalence of developed formulations versus marketed products.

Methodology

Skin permeation experiments are carried out using Franz diffusion cells and rat skin. The receptor compartment to be filled with the chosen receptor medium (depends on the physicochemical properties of the loaded drug) and the tested formulation will be inserted in the donor compartment. Samples will be withdrawn from the receptor compartments at different time intervals up to 24 hours. Drug permeated will be analyzed using HPLC. This allows the establishment of the ex-vivo permeation profile of the loaded drug with the subsequent calculation of the flux rate and the total amount permeated.

Experiment is carried in triplicate and individual results as well as averages are reported