Nanotechnology, a multidisciplinary scientific undertaking, involves creation and utilization of materials, devices or systems on the nanometer scale. The field has enabled the development of an amazing variety of methods for fabricating nanoparticles in recent years. The technology is expected to create innovations and play a critical role in the field of bio-pharmaceuticals especially in controlled release of drug delivery. Sol-gel technique is one of the most widely used techniques to fabricate porous nanoparticles within the polymer. Such nanoparticles have also applications in vascular drug delivery and release, site-specific targeting (passive as well as active targeting), as well as transfusion medicine. This article concentrates mainly on fabrication of porous nanoparticles, its characterisation and its use for controlled release of drug. It also encompasses the strategies that have been used to translate and fabricate a wide range of particulate carriers e.g., nanospheres, liposomes, micelles, oil-in-water emulsions, with prolonged circulation and/or target specificity. With regard to the targeting issues, attention is particularly focused on the importance of physiological barriers. we have also critically reviewed and assessed the fate and activity of biodegradable/bio-erodable polymeric drug delivery vehicles because the uniformity in degradation of these polymers is questionable
