Development and characterization of inhaled nintedanib-loaded PLGA nanoparticles using scalable high-pressure homogenization technique

Presently, non-invasive targeted drug delivery to the lungs represents a routinely investigated approach to treat challenging disorders such as pulmonary fibrosis. Nintedanib (Nint) is an FDA-approved drug for treating idiopathic pulmonary fibrosis and certain interstitial lung diseases. Nint acts as a multiple tyrosine kinase inhibitor, demonstrating anti-neoplastic effects in non-small cell lung cancer. However, limitations of oral administration of Nint include low bioavailability and high dose requirement for adequate therapeutic efficacy, resulting in adverse effects like abdominal pain, sickness, diarrhea, and vomiting. In this project, Nint was reformulated into PLGA nanoparticles (Nint-NPs) for direct-lung administration to address these deficiencies and enhance its potential. In this project, Nint-NPs were designed utilizing a high-pressure homogenization (HPH) approach with excellent reproducibility and scale-up feasibility. Selected Nint-NP formulation revealed 43.3 ± 4.0 % of entrapment efficiency and 179.8 ± 3.1 nm of size. In-vitro release study showed an initial burst release of 36.0 ± 7.5 % within 30 min, followed by sustained release up to 71.0 ± 4.3 % by 96 h. Further, Nint-NPs were found to be stable after 1-month of storage in refrigerated and accelerated conditions. Interestingly, the results of lung deposition demonstrated ideal MMAD values less than 5 μm in all three nebulizer types tested (jet, breath-actuated jet, and vibrating mesh nebulizers), indicating Nint-NPs are appropriate for deep-lung delivery. In-vitro cellular uptake analysis exhibited higher internalization of NPs in alveolar epithelial cells and lung fibroblasts while avoiding macrophage uptake. Toxicity studies on normal lung cells indicated Nint-NPs were safe for use. Taken together, inhalation therapy of Nint-NPs offers a favorable alternative to oral capsules for treating respiratory diseases.