An Overview: Methods for Preparation and Characterization of Liposomes as Drug Delivery Systems

Liposomes as artificially prepared vesicles have become important tools for improving delivery of a large number of drugs: antimicrobial agents, drugs against cancer, antifungal drugs, peptide hormones, enzymes, vaccines and genetic materials. Due to the differences in preparation methods and lipid compositions, liposomes can be classified according to their lamellarity, size, charge and application. The flexibility of their behavior can be exploited for the drug delivery through various routes of administration irrespective of their solubility properties. Encapsulation of drugs in liposomes has provided an opportunity to enhance the therapeutic indices of many drugs mainly through alteration in their biodistribution, targeting the drug to particular tissues. The role of liposomes as drug delivery system is to deliver drug in the controlled manner, reducing undesirable side effects improving its in vitro and in vivo activity, as well as reducing the toxicity of the drug and enhancing the efficacy of the encapsulated drug. This article provides an overview of methods for preparation of liposomes, as well as analytical methods for control physical, chemical and biological parameters for different types of drugs.