Pulmonary Drug Delivery Technologies and Formulations

Pulmonary administration exploits the large surface area and thin epithelial barrier of the lung to achieve both local and systemic therapy with rapid onset. Delivery platforms include nebulisers, metered-dose inhalers and dry powder inhalers, each presenting unique formulation and engineering demands. Key challenges involve generating particles with an aerodynamic diameter of 1–5 µm, ensuring adequate dispersibility, minimising aggregation and avoiding phagocytic clearance. Formulation strategies have evolved from simple carrier-based blends—where drug crystals adhere to lactose or other excipient carriers—to advanced carrier-free systems in which active molecules are engineered into corrugated or porous microparticles. Techniques such as spray-drying, spray-freeze-drying and supercritical fluid processing are employed to modulate particle morphology, surface chemistry and density. Computational fluid dynamics is increasingly applied to device design, optimising airflow and patient-device interactions. Emerging nano-embedded microparticles and agglomerates aim to combine the targeting precision of nanoparticles with the aerodynamic requirements of inhalable dry powders. Such advances are driving novel therapies for asthma, chronic obstructive pulmonary disease, cystic fibrosis, infectious diseases and systemic conditions such as diabetes or pulmonary hypertension.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Pulmonary Drug Delivery Technologies and Formulations publication trend

The graph below shows the total number of articles in pulmonary drug delivery technologies and formulations across all publications each year (not limited to Nature Index journals).

Technical terms

Aerodynamic diameter: The diameter of a hypothetical sphere with unit density that settles at the same velocity as the particle of interest; critical for lung deposition.

Carrier-free particles: Dry powder formulations in which active molecules form self-standing microparticles without inert excipient carriers, often produced by spray-drying.

Spray-drying: A technique to convert liquid formulations into dry powders by rapid evaporation, controlling particle size, morphology and density.

Fine particle fraction (FPF): The proportion of aerosolised particles below a specified aerodynamic diameter threshold (commonly 5 µm), indicative of deep-lung delivery efficiency.

Computational fluid dynamics (CFD): The use of numerical methods to simulate airflow and particle trajectories within inhaler devices, guiding engineering optimisation.

References

1. Nano-enabled agglomerates and compact: Design aspects of challenges. Asian Journal of Pharmaceutical Sciences (2023).
2. Design, development, and technical considerations for dry powder inhaler devices. Drug Discovery Today (2024).
3. Preparation and Characterization of Ibuprofen Containing Nano-Embedded-Microparticles for Pulmonary Delivery. Pharmaceutics (2023).
4. Influence of Composition and Spray-Drying Process Parameters on Carrier-Free DPI Properties and Behaviors in the Lung: A review. Pharmaceutics (2020).
5. New Mechanisms to Explain the Effects of Added Lactose Fines on the Dispersion Performance of Adhesive Mixtures for Inhalation. PLOS ONE (2014).
6. Recent advances in capsule-based dry powder inhaler technology. Multidisciplinary Respiratory Medicine (2017).
7. Particle engineering in dry powders for inhalation. European Journal of Pharmaceutical Sciences (2022).