A new assay for lipiodol in a tumor using a combination of m-chloroperbenzoic acid-mediated oxidation and the iodo-starch reaction

Lipiodol, an iodine adduct lipid, has been used as a targeting carrier of a nticancer drugs in experimental animals and humans. In most studies, the co ncentrations of the anticancer drugs in tissues and organs have been monito red, but not of the carrier because a simple method for measuring lipiodol in biological organs did not exist. Here we present an analytical method fo r the quantitative determination of lipiodol in tissue. This method is base d on the measurement of iodine released from lipiodol by an oxidative react ion. The released iodine was measured spectrophotometrically by monitoring the iodo-starch reaction. Using this method, we were able to demonstrate th e tumor specificity of lipiodol using rabbits bearing VX2 tumors in the liv er. The present method is also expected to be applicable to human cancers, such as hepatic and colon cancer. (C) 2000 Elsevier Science Ireland Ltd, Al l rights reserved.