Abstract: Novel pharmaceutical compositions comprising a chemotherapeutic agent and a polyether block copolymer, and methods of treatment using the compositions.

Abstract: The present invention relates to 1) pharmaceutical compositions and methods for chemotherapeutic agents and 2) pharmaceutical compositions for biological agents, particularly those whose target cells or tissues are resistant to the biological agent. The invention is targeted to overcome the resistance to biological agents that are developed by neoplasms and microbial infections. The formulation contains a biological agent and a polyether block copolymer. The block copolymer comprises an A-type linear polymeric segment joined at one end to a B-type linear polymeric segment; wherein the A type polymeric segment is hydrophilic, has repeating units which contribute an average Hansch-Leo fragmental constant of about 0.4 or less, and has a molecular weight contribution between 30 to about 500. The B-type segment is of relatively hydrophobic character, has repeating units which contribute an average Hansch-Leo fragmental constant of about -0.

Abstract: Compositions of anti-neoplastic agents incorporate the agent in micelles of at least one block copolymer of poly(oxyethylene)-poly(oxypropylene) in which the ratio of (oxypropylene) blocks to the (oxyethylene) blocks is from about 0.25 to about 1.5 and the micelles have an average diameter of from about 10 to about 25 nm.