Plant-Derived Nanostructured Drug Delivery Systems for Attenuating Chronic Obstructive Pulmonary Diseases: Raising Concerns, Recent Trends, and Comparative Advancements.

Chronic Obstructive Pulmonary Disease (COPD) remains a major global health burden. Although conventional therapies are effective, they are often associated with systemic side effects, poor target specificity, and corticosteroid resistance. This study emphasizes the therapeutic potential of plant-derived bioactive compounds, when integrated into Nanostructured Drug Delivery Systems (NDDS), for improved COPD management. This is a narrative review based on a comprehensive literature search across major electronic databases (PubMed, Scopus, Web of Science, and Google Scholar) up to July 2025. The analysis focused on phytochemicals with proven anti-inflammatory and antioxidant properties, as well as on nanocarriers such as polymeric nanoparticles, liposomes, and solid lipid nanoparticles, designed to enhance pulmonary targeting and delivery efficiency. Phytochemicals, including curcumin, baicalein, quercetin, berberine, and andrographolide, have shown remarkable efficacy in reducing oxidative stress and inflammation in preclinical COPD models. However, their therapeutic utility is hindered by poor solubility and rapid metabolism. Integration into nanostructured carriers enhanced pulmonary accumulation by 3-6-fold, prolonged drug release up to 24-48 hours, and reduced dosing frequency by approximately 50%, while minimizing systemic toxicity.