Lipo-microdialysis: a new microdialysis method for studying the pharmacokinetics of lipophilic substances

A new microdialysis method (Lipo-MD) using a lipid emulsion as the perfusate instead of Ringer's solution as in conventional microdialysis (MD) was designed. Recovery profiles of the alkylparabens (APBs) dissolved in Ringer' s solution by Lipo-MD were compared with those by MD in vitro. Recovery of APBs in the perfusate in MD decreased with the increasing lipophilicity of APBs, whereas that in Lipo-MD increased. The enhancement of the relative recovery of APBs by Lipo-MD to MD for methyl-, ethyl-, propyl-, and butylparaben were 2.03, 5.24, 77.0, and 390.7, respectively. The utility of Lipo-MD for determination of lipophilic substances to perform pharmacokinetic study was suggested.