The present invention provides liposome compositions containing sparingly soluble drugs that are used to treat life-threatening diseases. A preferred method of encapsulating a drug inside a liposome is by remote or active loading. However, this process as described in the literature has been limited to drugs that are freely soluble in aqueous solution or solubilized as a water-soluble complex. This invention describes compositions and methods for remote loading drugs with low water solubility (<2 mg/mL). In the preferred embodiment the drug in the solubilizing agent is mixed with the liposomes in aqueous suspension so that the concentration of solubilizing agent is lowered to below its capacity to completely solubilize the drug. This results in the drug precipitating but remote loading is capability retained. The process is scalable and the resulting drug-loaded liposomes are characterized by a high drug-to-lipid ratios and predictable drug retention when the liposome encapsulated drug is administered in patients.
