DINITROANILINE LIPOSOMAL FORMULATIONS AND PROCESSES FOR THEIR PREPARATION

The invention refers to liposomal formulations containing one or several dinitroanilines, varying the liposome size from 50 .mu.m to 0.01 .mu.m with encapsulation efficiencies typically bigger than 30 %. When administered to animals, the liposomal dinitroanilines do not present acute toxicity or significantly diminish the toxicity of the free formula and are effective against infections by protozoarian or other microorganisms. The present invention refers also to a process for the preparation of liposomal formulations that comprises the preparation of multilamellar liposomes containing the dinitroaniline, to submit them to dehydration, rehydration and, optionally, to a sizing step before the dehydration. The dehydration is carried out in the presence of cryoprotectants in order to avoid sublimation and consequent loss of the drug in this step. The present invention refers also to dinitroaniline liposomal formulations containing a mixture of particles that after sizing, present populations superior and inferior to 100 nm in diameter.