Organ perfusion chambers were custom made and used for in vitro percutaneous absorption, penetration, cutaneous metabolism, transdermal delivery (active and passive) studies using the isolated perfused porcine skin flap (IPPSF). This is a perfused model that allows for skin pharmacology and toxicology studies as well as drug distribution experiments using compartmental and physiological-based pharmacokinetic models, to be conducted in a viable skin preparation having a normal anatomical structure and a functional microcirculation. The skin flap is first created in weanling Yorkshire/ Landrace pigs, harvested after two days and then placed in the computer-controlled and temperature-regulated perfusion chamber for up to 24 hrs. These chambers are housed under a fume hood so that volatile chemicals (e.g. jet fuels and other caustic agents) can be safely conducted. The correlation of IPPSF data to in vivo studies can be studied along with biochemical, physiological and histological responses to the skin when topically applied toxicants (e.g. vesicants, irritants) are exposed. Currently, the IPPSF is an ideal in vitro model to investigate the local biodistribution of nanoparticles after controlled arterial infusions.
|Diffusion Flow-Through Cells
The flow-through diffusion cell system (Bronaugh type flow-through cells) allows for in vitro assessment of dermal absorption or transdermal flux of topically applied drugs or chemicals. This is a dermatomed skin preparation where over 28 pieces of skin can be maintained and viable and transdermal flux assessed, either by use of radioisotopes or classic analytical determinations (GC-MS/ LC-MS/MS, HPLC, etc). Because of the ability to conduct large number of replicates, formulations and vehicle mixture effects on an individual drug or chemical absorption can be assessed.