Paclitaxel in cancer treatment: perspectives and prospects of its delivery challenges

Crit Rev Ther Drug Carrier Syst. 2009;26(4):333-72. doi: 10.1615/critrevtherdrugcarriersyst.v26.i4.10.

Abstract

Paclitaxel (PTX) is a potent anticancer agent whose clinical usefulness is marred by a delivery problem that is caused by its unfavorable pharmacokinetic and physical properties. Paclitaxel is currently formulated in a mixture of Cremophor EL and ethanol, which is diluted 5-20 times with normal saline or 5% dextrose prior to administration via slow infusion to avoid precipitation in plasma. Many adverse reactions to the PTX formulation have been reported because of the presence of Cremophor EL, including hypersensitivity reactions, nephrotoxicity, and neurotoxicity. Cremophor EL also causes vasodilation, labored breathing, lethargy, hypotension, and leaching of plasticizers, such as diethylhexylpthalate, from the polyvinylchloride infusion bags/sets. Significant research efforts have been conducted to develop an alternative formulation approach to increase the aqueous solubility of PTX without using Cremophor, thereby decreasing its toxicity. This article reviews the various investigated formulation approaches including pastes; liposomes; conjugates with antibodies, peptides, and fatty acids; nanospheres and microspheres; cyclodextrin complexes; emulsions; mucoadhesive gel; prodrugs; and nanoparticulate systems. The pros and cons of each approach are also discussed. Finally, this review concludes with a discussion of nanoparticulate delivery, which is the most promising PTX delivery system of the future because it incorporates the benefits of other approaches such as conjugation, complexation, and prodrugs.

MeSH terms

  • Animals
  • Antineoplastic Agents, Phytogenic / chemistry
  • Antineoplastic Agents, Phytogenic / pharmacokinetics
  • Antineoplastic Agents, Phytogenic / therapeutic use*
  • Chemistry, Pharmaceutical / methods
  • Chemistry, Pharmaceutical / trends
  • Drug Delivery Systems / methods
  • Drug Delivery Systems / trends
  • Humans
  • Neoplasms / drug therapy*
  • Paclitaxel / chemistry
  • Paclitaxel / pharmacokinetics
  • Paclitaxel / therapeutic use*
  • Pharmaceutic Aids / adverse effects
  • Pharmaceutic Aids / chemistry

Substances

  • Antineoplastic Agents, Phytogenic
  • Pharmaceutic Aids
  • Paclitaxel