The therapeutic effect is brought about by the drug delivery system dispensing the active medicinal ingredient. Due to fluctuations in plasma drug levels, traditional drug delivery devices have poor bioavailability and cannot generate a continuous release. The drug must also be supplied at a tightly regulated rate and to the correct location for it to be most effective and safe. To solve the problems inherent in the current methods of administering medication, scientists are working on perfecting controlled drug delivery systems. Controlled pharmaceutical delivery systems have come a long way in the last twenty years, from bulk distribution to nanoscale precision to smart, patient-specific dosing. The paper's initial portion provides background knowledge on drug delivery methods, emphasizing pharmacokinetics. The article also discusses the pros and cons of more conventional drug delivery methods. Controlled drug delivery systems' design factors, categorizations, and schematics are also discussed in length. In addition, recent advances in nano-drug delivery, targeted, and innovative drug delivery utilizing stimuli-responsive, intelligent biomaterials are discussed. The limitations of regulated medicine distribution and some possible solutions are discussed at the end of the study.