The purpose of this project was to evaluate the compatibility of paclitaxel infusions with the IV Expres filter unit, a 0.22-micrometer intravenous solution filter (Millipore Corporation, Bedford, MA). The potential for extraction of diethylhexyl phthalate platicizer from the filter unit by the Cremaophor EL surfactant present in the paclitaxel injection and the potential for loss of paclitaxel to filter unit components due to sorption were evaluated. Plasticizer extraction was tested using the paclitaxel diluent at a concentration equivalent to 1.2 mg/mL over a three-hour simulated infusion. Paclitaxel delivery was evaluated in admixtures containing paclitaxel 0.3 mg/mL. All samples were prepared in triplicate in polyolefin bags of 5% dextrose injections and delivered through IV Express filter units attached to nonpolyvinyl chloride administration sets designed for the adminstration of paclitaxel infusions. The samples were collected in glass collection flasks. Both plasticizer and paclitaxel content were determined using specific high-performance liquid chromatographic methods. None of the admixtures delivered over three hours through the IV Express filter unit exhibited any detectable plasticizer. Further, no loss of paclitaxel due to soption to any filter commponent occurred; the full amount of paclitaxel was deliverd in the simulated ifusions. The IV Express filter unit tested in this study is suitable for the administration of paclitaxel infusions over three hours.