A Mini Review on Pulmonary Drug Delivery System

Abstract

Respiratory drug delivery has emerged as an attractive, non-invasive route for drug administration due to its large surface area, rich vasculature, and rapid onset of action. In addition to drugs intended for local therapeutic effects within the lungs, this route is increasingly explored for the systemic delivery of molecules, offering advantages such as avoidance of first-pass metabolism and improved bioavailability. However, successful pulmonary drug delivery depends on several critical factors. Beyond the physicochemical properties of the drug, formulation into a stable and effective inhalable dosage form is essential to ensure consistent performance and shelf life. The formulation must be compatible with an appropriate inhaler device capable of generating an aerosol with an optimal particle or droplet size to achieve deposition in the targeted region of the respiratory tract, whether the upper airways, bronchi, or deep alveolar regions. Furthermore, patient-related factors play a significant role in therapeutic outcomes. Variations in lung anatomy, respiratory diseases, breathing patterns, and inspiratory flow rates can markedly influence aerosol deposition and drug absorption. Therefore, an integrated approach considering drug characteristics, formulation design, inhaler technology, and patient (patho-)physiology is crucial for the effective development and clinical success of respiratory drug delivery systems.