This proposal relates to the water-insoluble anticancer agent, etoposide, and the use of Microcrystal Technology to produce an improved intravenous formulation, an improved oral formulation with increased bioavailability and a slow-release formulation for intramuscular or subcutaneous administration. The Microcrystal Technology is a unique delivery system in which a fine aqueous suspension of drug is encapsulated in phospholipids by microfluidization. The suspension is stable, does not precipitate readily and can be lyophilized for longer storage, requiring only saline to reconstitute it later. The advantages of the microcrystal formulation are that it avoids toxic solubilizing agents such as tween 80 or polysorbate (which is found in present formulations of etoposide), all components are tissue compatible, slow-release formulations are possible when i.m. or s.c. administration is used and oral bioavailability of compounds can be substantially increased. The Technology has applicability to other poorly soluble anticancer agents, including taxol, taxotere and camptothecin.