In vitro diffusion equipment
Diffusion cells can be used to measure the transport of a substance, such as a drug, across a membrane, such as skin, over time. The membrane can be either biological (skin, mucosa etc) or a synthetic reference (silicone etc).
Three alternative thermostated in vitro diffusion equipments are available in house, two set ups with flow through cells (15 + 7 cells) [R.L. Bronaugh & R.F. Stewart, J. Pharm. Sci. 74 (1985) 64–67] and 10 static Franz cells [Franz T, J. Invest. Dermatol. 64 (1975) 190-195]. Solute diffusion over skin, oral mucosa , nasal mucosa, nails, plant cuticle, as well as synthetic membranes, has been studied and assayed spectrophotometrically (on-line) or by HPLC-UV. Electrical impedance spectroscopy has been appended to the Franz cells as a tool helping to explain diffusion properties of solutes through these membranes.