Abstract

Despite significant progress in oncological pharmacology, conventional chemotherapy remains constrained by poor bioavailability, non-selective biodistribution, dose-limiting systemic toxicity, and the emergence of multidrug resistance, collectively necessitating the development of more sophisticated delivery platforms. Pharmaceutical nanotechnology has addressed these limitations through the rational engineering of nanoscale carriers capable of encapsulating therapeutic agents, overcoming biological barriers, and achieving spatiotemporally controlled drug release within the tumor microenvironment. This review critically examines the current landscape of nanotechnology-based drug delivery systems engineered for targeted cancer therapy, with emphasis on polymeric nanoparticles, liposomal formulations, solid lipid nanocarriers, inorganic nanoparticles, dendrimers, exosomes, and hybrid architectures. The mechanistic foundations of passive targeting via the enhanced permeability and retention effect, active targeting through ligand-receptor interactions, and stimuli-responsive release triggered by endogenous or exogenous stimuli are systematically analyzed. Major therapeutic applications spanning solid tumors, hematologic malignancies, combinatorial regimens, and chemoresistance reversal are evaluated alongside translational status, clinical trial outcomes, and regulatory considerations. Persistent challenges including nanocarrier toxicity, immunogenicity, heterogeneous biodistribution, and scalable manufacturing are critically appraised. Collectively, pharmaceutical nanotechnology constitutes a transformative paradigm in precision oncology, with emerging personalized nanomedicine strategies poised to address intertumoral and intratumoral heterogeneity while improving therapeutic indices and patient survival outcomes.