The formulation development is important part of pharmaceutical development and essential for therapeutic and commercial success of product by providing quality, safety and efficiency. Conventional drug delivery involves the formulation of the drug into a suitable form, such as a compressed tablet for oral administration or a solution for intravenous administration. Novel drug delivery systems (NDDS) are carriers which maintain the drug concentration in therapeutic range for longer period of time. The amount of drug in a tablet can be a limiting step in formulation design. Oral liquids are formulated as solutions, suspensions and emulsions depending on the nature of the active ingredient particularly solubility and stability. In formulation of any dosage form the various excipients such as coloring agent, flavoring agents, glidandants, binders etc. are added. Gastroretentive dosage forms greatly improved the pharmacotherapy of the Parenteral preparation should be isotonic with blood plasma or other body fluids. The isotonicity of the solution may be adjusted by adding sodium chloride, dextrose and boric acid etc. GIT through local drug release In this article formulation of conventional such as tablets, capsules, semisolids, etc. and in NDDS formulation of Controlled drug delivery system, GRDDS etc. are given. Nose to brain drug delivery system in which drug transport through nasal route to CNS(central nervous system). The main aim of these review is providing a needfull information of excipients and various
apporoaches are used in conventional drug delivery system and novel drug delivery system.