Drug delivery systems (DDS) are a crucial area in pharmacology, ensuring proper delivery of therapeutic agents with enhanced efficacy and decreased side effects. Conventional drug delivery approach, which includes oral, parenteral, transdermal, and topical systems, has been widely employed but often suffers limitations such as poor bioavailability, non-specific targeting of drugs, and frequent dosing needs. The introduction of nanotechnology-based drug delivery systems (NDDS) has revolutionized the field, providing enhanced solubility, target specificity, controlled release, and decreased systemic toxicity. This review provides a comparative analysis of conventional and nanotechnology-based DDS, focusing on their mechanisms, advantages, limitations, and applications. Various nanocarriers like liposomes, dendrimers, polymeric nanoparticles, and metallic nanoparticles are being studied for the purpose of increasing drug solubility, bioavailability, and therapeutic activity. Moreover, the pharmacokinetic and pharmacodynamic properties of NDDS exhibit remarkable improvements in drug absorption, biodegradability, and elimination pathways. Although nanocarriers possess several advantages, they are confronted with challenges such as regulatory issues, toxicity concerns, scalability issues, and increased production costs. New Emerging trends in drug delivery, including AI-based nanocarrier design, personalized medicine, and smart drug delivery systems, have promising avenues to address these challenges. This review is based on the observations on the advancements in drug delivery technology, covering extensively their existing scenario, hurdles, and future scope in clinical practices.
