Lipid vesicular drug delivery systems in treatment of intracellular infections: capabilities and challenges

Lipid vesicles composed of amphiphilic compounds and cholesterol are classified as new drug delivery systems for transfer of vast range of chemical and biological ingredients through biological membranes. Liposomes, niosomes, ufasomes and many other somes are used nowadays for treatment of intracellular infections such as tuberculosis, leishmaniasis, malaria and AIDS. For example, in order to better penetration of paromomycin, a cationic aminoglycoside compound through biological membranes including macrophage cytoplasmic membrane, stratum corneum of skin and amastigote/promastigote cell membranes, we designed niosomal formulation and assessed its in vitro and in vivo antileishmanial effect. Furthermore, niosomal zinc sulfate, amphotericin B, glucantime and dapsone were also formulated, pharmaceutically characterized and practically evaluated and utilized, in some cases, in clinical trials to treat Leishmania major or L. tropica cutaneous infections. Hereby, some commercialized antimicrobials formulated as lipid vesicles will be presented and their clinical application(s) will be shown. Then, some new aspects of these micro/nano-particulate dosage forms, including new formulations prepared in Kerman University of Medical Sciences (KMU), will be introduced. Some challenges such as sterile formulation and packaging, active pharmaceutical ingredients (APIs) stability and probable cytotoxicity or side effects will also be discussed.