High-performance liquid chromatographic and pharmacokinetic analyses of an intravenous submicron emulsion of perillyl alcohol in rats

Perillyl alcohol (POH) is currently in phase II clinical trials both as a chemopreventative and chemotherapeutic agent. The present report describes a simple, rapid and sensitive HPLC-UV method to quantify POH in rat plasma. After protein precipitation with acetonitrile, POH was separated using an Agilent Zorbax XDB C18 column (150 mm × 4.6 mm, 5 μm) with a mobile phase consisting of acetonitrile–water (40:60, v/v) at a flow rate of 1.0 ml min−1, and detected at 210 nm. The method has been used successfully to determine trace levels of POH in plasma down to 0.015 μg ml−1. The pharmacokinetics of POH after intravenous administrations in three formulations, i.e. POH solution (POH-SOL), negatively charged submicron emulsions (POH-SE) and positively charged submicron emulsions (POH-CSSE) were investigated. AUC0–∞, MRT, t1/2α and t1/2β of POH-SE and POH-CSSE were significantly higher, while their total body clearance was lower than those of POH-SOL. In addition, AUC0–∞, MRT and t1/2β of POH-CSSE were significantly higher than those of POH-SE. The results indicate that the submicron emulsion formulation significantly increases POH blood concentrations and retention within the systemic circulation.