Abstract: Nanocarrier-based drug delivery systems represent a transformative advancement in precision medicine, offering the potential to enhance therapeutic efficacy while minimizing off-target effects. This review explores the molecular pharmacology underlying nanocarrier technologies, focusing on the mechanisms of drug loading, release, and cellular uptake, as well as the pharmacokinetic and pharmacodynamic profiles shaped by nanoscale delivery platforms. We discuss the molecular interactions between nanocarriers and biological systems, including receptor-mediated targeting, endocytic pathways, intracellular trafficking, and drug release kinetics. Special emphasis is placed on how surface modifications—such as PEGylation, ligand conjugation, and pH-/enzyme-responsive coatings—enable selective delivery to diseased tissues, particularly in oncology, neurodegenerative diseases, and inflammatory disorders. Furthermore, we examine emerging trends in nanocarrier design, such as biomimetic systems and stimuli-responsive nanoparticles, and their implications for overcoming biological barriers and drug resistance. By integrating insights from molecular pharmacology with nanotechnology, this review provides a comprehensive understanding of how rationally engineered nanocarriers can optimize therapeutic outcomes and pave the way for next-generation precision therapeutics.
