Coating technique is used to modify the site, rate and extent of release. It can be applied for single unit dosage forms such as tablets/capsules and multiple unit dosage forms like pellets, granules. Aqueous based and organic based solvents can be used for coating. Coating technique can also be applied to achieve a drug release after a set lag time. Coating on multiparticulate system reduces the dose duping compared to single unit system. Multiparticulate system is more suitable for alterations in release characteristics as they can be coated with different polymers and with altered thickness of coating. The careful selction of coating materials for coating technique allows either first order or zero order release and it can be controlled by diffusion, dissolution, erosion or osmosis. The composition related and equipment related factors affects the efficacy of coated product. Pan coating and fluidized bed coating are commonly employed for coating technique.