Ultrasonic spray coating has emerged as a critical manufacturing technology for the deposition of drug-polymer coatings on implantable medical devices, including drug-eluting stents, coated balloons, and implantable delivery platforms. When compared to traditional coating methods such as dip coating and pneumatic spraying, ultrasonic atomization enables precise control of deposition on intricate, small-scale geometries, low-shear droplet generation, narrow droplet size distributions, and reduced overspray.
This review offers a thorough and practical synthesis of the principles, equipment architectures, process parameters, and quality control techniques related to ultrasonic spray coating for drug-loaded medical devices. The identification of key Critical Process Parameters (CPPs) and Critical Quality Attributes (CQAs) is presented, along with an examination of how these variables are managed using Design of Experiments (DOE), Quality-by-Design (QbD), and Statistical Process Control (SPC) methodologies. Practical manufacturing challenges, including coating defects, batch-to-batch variability, scale-up limitations, and transfer of ultrasonic coating processes from research and development, are discussed in the context of regulatory expectations for combination products.
By integrating academic research with industrial manufacturing experience, this paper aims to provide a comprehensive review and practical reference for engineers, scientists, and regulators involved in the development, scale-up, and commercialization of ultrasonic spray-coated drug-eluting medical devices.
Keywords: Ultrasonic spray coating, Drug-eluting stent, Hypotube-Fed Focused Nozzle, Shroud-Based Focused Nozzle.
How to cite this article: Lathiya HJ, Kolapkar PH. Ultrasonic spray coating for drug-loaded medical devices: a review of focused beam architectures, process control, and future directions. Int J Drug Deliv Technol. 2026;16(3s): 919-941; DOI: 10.25258/ijddt.16.3s.113
Source of support: Nil.
Conflict of interest: None