Pharmaceutical properties of paclitaxel and their effects on preparation and administration

Paclitaxel is a mainstay in the treatment of ovarian and breast cancers, and its use in other malignancies is being explored. Although it has great clinical utility, the drug and its formulation components pose a number of challenges to pharmacists and nurses. Paclitaxel is insoluble in water and is formulated in an equal parts mixture of ethanol and Cremophor EL, which disperses the drug in an aqueous medium. At concentrations of 0.3-1.2 mg/ml, paclitaxel is stable for at least 2 days. Additional research identified precipitation as the major limitation to long-term stability and supports the use of an inline filter for all infusions. The formulation vehicle also leaches the plasticizer DEHP from polyvinyl (PVC)-containing solution bags and administration sets. This effect is dependent on the concentration of surfactant, the amount of accessible DEHP, and many other factors. Health care practitioners must educate themselves regarding appropriate non-PVC containers and administration sets for safe and convenient delivery of paclitaxel. The compatibility of this and other drugs in solution is under investigation; currently, amphotericin B, chlorpromazine, hydroxyzine, methylprednisolone sodium succinate, and mitoxantrone have been determined to be physically incompatible with paclitaxel infusions.