An-Najah Staff

In this article we describe the production and characterization of specialized delivery systems for some distamycin derivatives (DD), namely liposomes and micellar dispersions. All the formulations were designed to increase the solubility of DD in an aqueous environment and to reduce the possible toxicity problems related to the administration of these drugs. For instance, liposomes were prepared by reverse phase evaporation technique followed by extrusion through polycarbonate filters, then characterized in terms of dimensions, morphology, and encapsulation efficacy. The analysis of their in vitro antiproliferative activity on cultured human and mouse leukemic cells demonstrated that liposomes and micellar dispersions containing DD exert quite different effects. These effects were compared with those shown by the free drug depending on type of drug and also cell line used.

The present article describes a comparative study of the performances of liposomes and ethosomes as specialized delivery systems for distamycin A (DA) and two of its derivatives. Liposomes and ethosomes were prepared by classical methods, extruded through polycarbonate filters, and characterized in terms of dimensions, morphology, and encapsulation efficiency. It was found that DA was associated with vesicles (either liposomes or ethosomes) by around 16.0%, while both derivatives of DA showed a percentage of association around 80% in the case of liposomes and around 50% in the case of ethosomes. In vitro antiproliferative activity experiments performed on cultured human and mouse leukemic cells demonstrated that vesicles were able to increase the activity of both derivatives of DA. In addition, it was demonstrated that the aging of both liposomes- and ethosomes-associated distamycin suspensions did not heavily influence the vesicle size, while all samples showed a relevant drug leakage with time. Moreover, according to the different physicochemical characteristics of DA and its derivatives (i.e., log P), vesicle-associated DA showed the highest loss of drug with respect to both its derivatives. In conclusion, the enhancement of drug activity expressed by these specialized delivery systems-associated DD could be interesting to obtain an efficient therapeutic effect aimed at reducing or minimizing toxic effects occurring with distamycins administration.