Bubble masking: reducing false rejects

Nov 6, 2026 | 2 min read

Automated visual inspection systems can mistake harmless air bubbles for particles. Our specially developed bubble masking software reduces false rejects and improves pharmaceutical inspection efficiency.

Key Takeaways
              Bubble masking distinguishes bubbles from particles
Fewer false rejects improve yield and reduce reinspection
No additional equipment is required
The patented tool is suited for ampoules, cartridges, syringes and vials as well as different liquid formulations

            

Air bubbles are common, especially in biopharmaceuticals such as monoclonal antibodies, vaccines, and anti-body drug conjugates (ADCs), while they can also occur in less complex products. They may result from high viscosity, protein concentration, temperature changes, mechanical agitation, filling, or transport.

Automated visual inspection of pharmaceutical containers

Why bubbles challenge inspection systems

Although bubbles generally do not affect product quality or patient safety, they can interfere with automated visual inspection software. Camera systems may interpret shadows or dark contours as particles or cosmetic defects, leading to false rejects and additional inspection efforts.

Intelligent bubble masking

Syntegon’s patented Bubble Masking tool identifies bubbles by their characteristic shape and excludes them from being rejected. Containers containing only bubbles will consequently be accepted, while containers with genuine particles are rejected as intended. The software-based solution requires no additional hardware, special illumination, or complex setups. It supports ampoules, cartridges, syringes, and vials, as well as several different liquid formulations.

Technicians operating a Syntegon control panel for automated visual inspection.

Small reduction, huge impact

Even a small reduction in false rejects can have a significant impact. On a line that, for example, processes 280,000 containers per day, an improvement of one percent may prevent up to 3,000 unnecessary reinspection procedures. Bubble masking therefore helps pharmaceutical manufacturers reduce reinspection efforts, improve the efficiency of new and existing machines, and bring products to market faster.

Benefits at a glance
              Less false rejects from misinterpretation of bubbles and particles
Reduced reinspection efforts
Wide applicability across containers and liquid solutions
Quick and easy implementation
No special equipment required
Retrofits for existing Syntegon machines

            