The present invention relates to a methods of preparing active compounds complexed with lipids using aqueous systems that are free of organic solvents, and methods of using the complexes, e.g., in treating a disease in a subject. In some embodiments, the present invention comprises a composition comprising a complex comprising at least one active compound, e.g., a polyene antibiotic, an immunosuppressant agent such as tacrolimus or a taxane or taxane derivative, and one or more lipids. In some embodiments, the present invention provides a method comprising preparing a composition comprising a lipid complex comprising at least one active compound and at least one lipid and administering the composition to a subject. In certain embodiments the subject is a mammal. In certain preferred embodiments, the subject is human.