measurement of Percutaneous Absorption Using Fluorescence Polarization Immunoassays in a Diffusion Chamber

Lee, Weon Ju; Kim, Yong Hyun; Kim, Do Won; Jun, Jae Bok; Chung, Sang Lip

Abstract

BACKGROUND: The penetraton in vivo of topically applied substances can be assessed by physiological or pharmacalogical signs or analysed by chemical or histological techniques. In vitro absorption can be commonly quantitated by measuring the passage of a radioisotope-labelled substance across skin that has been mounted in a diffusion chamber.
OBJECTIVE
Fluorescence polarization immunoassay technique has made the possible rapid growth of therapeutic drug nonitoring. We applied this methodology in measuring percutaneous absorption in a diffusion chamber.
METHODS
We utilized sheets of whole epidermis prepared from the circumcised prepuce. Some epidermal sheets were treated with 2 ml of acetone for 2 minutes, and others not. The epidermal sheet was mounted in a diffusion chamber between the donor compartment for the penetrant and the receptor compartment containing saline. Lidocaine HC1(10 microgram/cm2) in vehicle(propylene glycol:ethanol; 7:3, vol/vol) was applied to the donor compartment for the penetrant. With flow rate of about 3 ml/h all of the receptor phase collected during 2 hours interval were quantitated for 10 hours by the fluorescence polarization immunoassay.
RESULTS
Total absorption of lidocaine HC1 in the acetone-untreated group was 2.14+/-0.74% of the applied dose. Total absorption in the acetone-treated group showed no substantial difference (2.09+/-1.25%) compared to those of acetone-untreated group. The amount of lipid extracted from a epiderrnal sheet with acetone was 19+/-2.97%.
CONCLUSION
Fluorescence polarization immunoassay may be a useful method in measuring percutaneous absorption in vitro.