The Evolution of Drug Delivery Systems: Historical Advances and Future Directions

Abstract

Drug delivery methods have evolved to improve therapeutic outcomes, patient compliance, and therapy outcomes. This review examines the historical progression of drug delivery strategies, current innovations, and emerging trends shaping the future of therapeutic approaches. Traditional methods of giving medications, like oral and injection routes, had many problems, such as low bioavailability and systemic side effects. This review looks at how drug delivery systems have changed throughout several drug development eras. It focuses on new developments such as nanotechnology-based delivery, biologics, and the creation of smart drug delivery systems. This review highlights breakthroughs in controlled-release systems, nanocarriers, transdermal patches, and implantable drug-delivery devices, comparing both conventional and modern strategies. Further, advances in microencapsulation technology, gene therapy delivery strategies, and AI-assisted drug formulation are examined in the context of precision and efficacy. These innovations reflect a paradigm shift toward precision medicine with personalized drug delivery strategies minimizing side effects while maximizing therapeutic outcomes. Importantly, nanomedicine and biological therapies have successfully addressed critical challenges of drug stability, bioavailability, and drug delivery mechanisms for controlled release devices.