Microparticles versus Nanoparticles as Drug Carriers: A Comparative Outlook on Applications, Challenges, and Future Directions

Abstract

Microparticles and nanoparticles have become essential platforms for drug delivery, providing distinct benefits in enhancing bioavailability, targeting specific tissues, and regulating drug release. Microparticles, generally within the micrometer size range, are commonly utilized for sustained and localized drug delivery, whereas nanoparticles, measuring less than 200 nm, allow for improved cellular uptake, directed delivery, and the ability to cross biological barriers. Recent developments in fabrication methods, including solvent evaporation, spray drying, Nanoprecipitation, and self-assembly, have increased the adaptability of these carriers. This review examines the physicochemical characteristics, therapeutic uses, benefits, and drawbacks of Microparticles and nanoparticles, concentrating on oral, parenteral, and transdermal delivery systems. Ongoing challenges such as stability, scalability, toxicity, and regulatory issues are highlighted, along with future outlooks on hybrid and stimuli-responsive particulate systems. This detailed review establishes groundwork for the selection of the optimal particulate system tailored to specific clinical uses.