The liposomes were the first Nano medicine to be accepted for clinical use. They are the spherical vesicles that possess mid empty aqueous space, which is encircled by a phospholipids bilayer. Liposomes have immense capability to prevent the degradation of drugs, reduce side effects and are thus increasingly used for targeted drug delivery. The drugs can either be incorporated inside the aqueous space (hydrophilic drugs) or inside the phospholipids bilayer (hydrophobic drugs) of liposomes for the targeted drug delivery. Considering the importance of liposomes as a drug delivery system, the present review paper tries to look into its details. The entire paper is classified into six parts. The first part is introductory. The second part discusses the classification of liposomes. In the third segment, the structural components of liposomes are detailed. The fourth portion of the paper talks about methods of preparation of liposomes. In the fifth segment, the characterization of liposomes is discussed. The sixth part discusses the application of liposomes and the last part is given to concluding observation. Literature shows distinct types of liposomes, categorized based on size, number of lipid layers, composition and preparation method. They are recently used for various nanoscale drugs formulation and a piece of concrete evidence was seen recently in recommended drug for black fungus i.e., Liposomal Amphotericin B. Although, their development and application are remaining the challenge due to costly and tedious processes involved in their production and development. Therefore, further research and development are required to perform to overcomes these challenges. Keywords: Liposome, characterization, amphiphatic, controlled release, phospholipids

Amid the era of development in all sphere of Biotechnology, Biochemistry and Pharmacology, it would not be an exaggeration to say that we have a myriad of molecules available to us in labs with promising results against many diseases. The limitation lies in the fact that some molecules are toxic when they act on organs other than their targets. Yet others cannot reach their targets in the desired concentration, be it due to easy degradation in the gut or high first-pass metabolism or very short half-life, etc. Thus, to overcome this, we have an alternate drug delivery system, namely Virosomes. The purpose of this review is to understand the drug delivery aspect of the virosomes, its type, structure, method of preparation, mechanism of action, administration routes and the application in the medical field. Virosomes are the regenerated viral envelope having a central empty space that can act as the vehicles for drug delivery. The central empty space can be filled with the desired bioactive molecule. Virosomes are most commonly prepared by using the reconstituted viral envelope of the Influenza virus, but other virus such as Sendai or HVJ, Hepatitis B Virus, HIV, New castle Disease Virus etc., can also be used for the preparation of virosomes. Virosomes has a great potential as the drug delivery system for almost all types of the drugs, and this encourages the researchers and therapeutic industries to enhance their pharmacological profiles, clinical result and stability.