An insight into obtaining of non-spherical particles by mechanical stretching of micro- and nanospheres

Drug encapsulated nanoparticles offer several advantages, including site-specific delivery, improved solubility, stability, bioavailability with reduced toxicity. Besides the particle size, the shape of the particles also plays a significant role in the in vivo performance of nanocarriers. Several nonspherical particles have been prepared and evaluated in cellular uptake and in vivo biodistribution studies in different animal models. Several methods, including advanced manufacturing techniques (PRINT, film lithography) and standard nanoparticle preparation methods (nanoprecipitation and solvent evaporation) have been reported for the preparation of non-spherical particles. Additionally, mechanical stretching of spheres has also produced a wide array of non-spherical particles of defined geometry by mechanical deformation of micro- and nanospheres. The present review describes effect of various process and material related parameters on the final shape of the particles during mechanical stretching of micro- and nanospheres. Benefits and limitations of the method have also been highlighted.