Continuous Electrospraying of Inhalable Biological Drug Products: Novel Formulation and Manufacturing Technology

Traditional pharmaceutical manufacturing largely depends on batch processes that contribute to equipment downtime, higher carbon footprint, contamination risks, and elevated operational costs. Additionally, the oral delivery of biologics remains challenging due to degradation and poor gastrointestinal absorption. This study aims to develop and evaluate a continuous manufacturing platform based on electrospraying to produce a dry powder inhalation formulation of biologics.

A continuous electrospraying system was designed to generate core-shell structured microparticles composed of biodegradable PLGA encapsulating bovine serum albumin (BSA) and insulin. The microparticles were subsequently adhered to lactose carriers using a custom-built conveyor-belt-assisted collection setup. Particle morphology was examined via scanning electron microscopy, while protein distribution was assessed using fluorescence microscopy. Protein secondary structure and conformational stability were analyzed using FTIR and circular dichroism (CD), respectively. Encapsulation efficiency and in vitro release were quantified using UV-Vis spectroscopy.

The electrospraying process successfully produced PLGA core-shell microparticles approximately 4-20 µm in diameter, uniformly attached to lactose carrier particles. Fluorescence analysis confirmed relatively uniform protein distribution within the particles. FTIR and CD measurements indicated that the protein structure remained nearly identical to the native form, demonstrating minimal structural alteration during processing. The formulation achieved an encapsulation efficiency of 78.16%, with nearly 72% cumulative protein release within 12 h.

The developed electrospraying-based continuous manufacturing platform demonstrates strong potential as a scalable and versatile approach for producing stable, biologic-loaded DPI formulations. Its ability to encapsulate sensitive proteins while preserving structural stability highlights its promise for future inhalable biologic delivery applications.