Automation of mAbs stress testing with visual inspection on Junior

Significance of the Topic

Visual inspection is a cornerstone of biologics quality assessment. Changes in color, particulate load or turbidity signal formulation instability, which may impact safety and efficacy. Traditional manual inspection is subjective, labor-intensive and destructive when particle counting or turbidity assays require sample dilution. An automated, non-destructive platform that quantifies color, particles and turbidity while archiving images enhances reproducibility, throughput and data integrity.

Objectives and Study Overview

This application note demonstrates the integration of a Visual Inspection Station (VIS) on the Junior automation platform to stress-test monoclonal antibody (mAb) formulations. Key goals were to:

• Automate color matching against Pharm Eur calibration standards
• Quantify visible particle counts via motion-based imaging
• Measure turbidity non-destructively using a 180° optical configuration
• Evaluate the effect of surfactant (PS80) and compare two mAbs under vortex stress

Methodology and Instrumentation

Samples: mAb A was prepared at 1–150 mg/mL in 10 mM histidine pH 6.0, with and without 0.1% polysorbate 80. mAb B in a proprietary buffer served as a stable control.

Instrumentation: VIS installed on Unchained Labs Junior (or Big Kahuna) automated platform. LEA software with Library Studio and Automation Studio handled experimental design and execution. Data analysis used the LEA Analysis Excel add-in.

Procedures:

1. Color Calibration: Pharm Eur BY1–BY6 standards plus water blank.
2. Particle Counting: Motion profile spins and stops vials; 30 successive images are subtracted to isolate moving particles.
3. Turbidity Measurement: 180° illumination and imaging compared to AMCO Clear standards (0–800 NTU).

Key Results and Discussion

Color Matching: VIS matched each mAb A sample to the correct standard with relevance scores of 99.7–100% and Euclidean match distances of 0.7–2.2. Yellow discoloration increased predictably from the water blank at 1 mg/mL to BY4 at 150 mg/mL.

Particle Count: Higher protein concentration yielded fewer visible particles (32 ± 5 at 1 mg/mL down to 8 ± 0.9 at 150 mg/mL). The non-destructive approach preserved samples and archived images for defect verification.

Turbidity Analysis: mAb B remained stable under 180 min vortex stress. mAb A without surfactant exceeded 800 NTU after prolonged mixing. Addition of 0.1% PS80 maintained turbidity within the calibration range and matched the stability profile of mAb B.

Benefits and Practical Applications

The VIS workflow delivers rapid, reproducible and quantitative results in minutes per sample set, reducing hands-on time and human bias. Non-destructive analysis preserves precious biologic samples for downstream assays. Automated archiving of images supports data traceability and regulatory compliance. This approach suits formulation screening, stability studies, and routine QC in biopharmaceutical development.

Future Trends and Opportunities

Integration of advanced image analytics and machine learning could enhance defect classification and predictive stability modeling. Miniaturized vial handling and multiplexed imaging could further boost throughput. Coupling VIS data with electronic lab notebooks and LIMS will streamline workflows. Expansion to other dosage forms (pre-filled syringes, cartridges) and real-time in-process monitoring are promising directions.

Conclusion

Automated VIS on the Junior platform enables comprehensive, non-destructive assessment of biologic formulations—quantifying color, particles and turbidity with high precision and throughput. The system supports robust stress testing, formulation optimization and QC, preserving sample integrity and providing traceable image records.

References

• Unchained Labs. Automation of mAbs Stress Testing with Visual Inspection on Junior. Application Note, 2018.
• Pharmacopeia Europaea. Color Reference Solutions BY1–BY6, Sigma-Aldrich.
• GFS Chemicals. AMCO Clear Turbidity Standards (0–800 NTU).