**3. Formulation and characterization techniques involved in lipids-based vesicles and nanoparticles**

A general method used in the fabrication of VDDs involves the dissolution of the single or mixture of lipids with surfactants, followed by drying the lipid film, and then dispersion of film in an aqueous medium to obtain a multilamellar vesicular system at required hydration temperature. The hydrating temperature used in the formulation of the VDDs should be always above the phase transition temperature of the lipid used. Later developed multilamellar vesicular systems are further processed to obtained small, stable vesicles [22]. The method of


