Abstract
To provide the intended therapeutic effect, the drug delivery system makes it possible for the active pharmaceutical component to be released. Traditional drug delivery methods (tablets, capsules, syrups, ointments, etc.) cannot provide continuous release due to their low bioavailability and variations in plasma drug levels. The entire therapy procedure may be ineffective in the absence of an effective delivery system. To get the highest level of safety and efficacy, the medication must also be administered at a carefully regulated pace and at the intended location. The development of controlled drug delivery systems aims to address the issues with traditional medication delivery. Over the past 20 years, controlled drug delivery systems have advanced significantly, moving from macro- and nano-scale to intelligent targeted delivery. With a focus on the medication's pharmacokinetics, the first section of this paper offers a fundamental grasp of drug delivery methods. The limitations of traditional medication delivery methods are also covered. Furthermore, the design considerations, classifications, and drawings of controlled drug delivery systems are covered in detail. The use of stimuli-responsive and intelligent biomaterials for targeted and intelligent drug delivery, as well as nano-drug delivery, is also covered with recent important discoveries.