hemagglutinin and Neuraminidase.

Virosomal Drug Delivery System is the novel drug delivery system available which has been a great revolutionary technology in drug delivery in recent years. Virosomes are the immunogenic compositions that include methods of eliciting an immune response. Virosomes are spherical, unilammellar phospholipid bilayer vesicle with a mean diameter of range 120-180nm. These represent reconstituted empty influenza virus envelopes, which contain 70% phosphatidylcholine and remaining 30% neuraminidase (NA) and haemagglutinin (HA) glycoproteins. A virosome can include at least one viral surface envelope glycoprotein expressed on the surface of the virosome. The virosome can also optionally include at least one adjuvant molecule expressed on the surface of the virosome. A virosome is a drug or vaccine delivery mechanism incorporating virus derived proteins to allow the virosome to fuse with the target cell. Virosomes cannot replicate but are pure fusion active vesicles. Virosomal drug delivery depends on the methods used to prepare the encapsulated bioactive material their incorporation into the virosomes and followed by the characterization and formulation of the finished preparations. All these features allow us to consider influenza virosomes as a promising model for antigen and molecular delivery, which could be helpful for the development of new vaccines or immunotherapeutic protocols that combine safety with immunogenicity and their applicability in different fields of medical research. This technology can potentially be used to deliver peptides, nucleic acids or genes, and drugs like antibiotics, anticancer agents, and steroids. In this paper reviewed about the challenges in drug delivery, advantages of virosomes in successful delivery of immunogens, formulation, Virosomal Technology and its various approaches.