Due to their incapacity to confine and localize the system at specific parts of the gastrointestinal tract, formulation scientists have faced difficulties in developing oral controlled release systems. A well-characterized dosage form that regulates medication intake into the body within the parameters of the intended release profile has been created using a variety of physical and chemical techniques. The most dependable method for delivering drugs under control is thought to be osmotic pumps. Drug release from ODDS is regulated and not influenced by the dissolution medium's pH or thermodynamics. Drug release from ODDS occurs according to zero order kinetics. Numerous formulation criteria, including solubility, the osmotic pressure of the core components, the size of the delivery orifice, and the type of rate-controlling membrane, affect how quickly a medication releases from an osmotic system. The medicine, osmogens, and excipients are contained in the core of the controlled porosity osmotic pump (CPOP), which is coated with a semipermeable membrane containing water soluble additives. Water soluble additives in CPOP dissolve when they come into contact with water, causing an in situ microporous membrane to develop. This paper provides an overview of osmosis, CPOP, its constituent parts, and its assessment.