Controlled drug delivery systems (CDDS) have been developed as a solution to overcome challenges associated with conventional drug administration routes. These systems consist of a polymeric matrix that contains the therapeutic agent and allows for controlled release of the drug over a prolonged period of time. CDDS offer advantages such as improved drug absorption, reduced side effects, and enhanced therapeutic efficacy. They can be designed for various routes of administration, including oral, transdermal, inhalation, and rectal routes. By utilizing CDDS, drug concentrations in the blood can be maintained at optimal levels for an extended duration, resulting in improved therapeutic outcomes. Researchers continue to explore and refine these systems to optimize drug delivery and enhance patient care.