Due to their unique or superior physical and chemical properties compared to bulk material, nanoparticles have become extremely popular in recent years. The pharmacokinetic and pharmacodynamic properties of many different types of pharmacological compounds have been altered and improved by using particle systems like nanoparticles. They were used in vivo to prevent the drug entity from leaving the systemic circulation, restrict drug access to the targeted areas, and deliver the drug at a steady and controlled rate to the site of action. To maximize therapeutic benefit while reducing adverse effects, a variety of polymers have been utilized in the nanoparticle drug delivery method. Because of its great selectivity towards the target region, nanotechnology use is significantly important in the field of medicine delivery since it can limit the potentially toxic effects of medication on normal cells. Nanoparticles (NP) play a crucial role and can conjugate with various medications using exact methods to deliver the drug to the target place. The nanoparticle surface is constructed with co-polymers to provide protection from immune cells and ligands to gain affinity inside the course of particular cells. The drug that is attached to nanoparticles can eventually recognize the location, join the target, and enter the cell by receptor-mediated endocytosis. Nanoparticles can then release medications under controlled conditions to treat disorders. Here, the review gives various aspects of the nanoparticle characterization, formulation, evaluation and application in delivery of drug molecules.