Meet Honeybun: The most rapid viscometer out there

Significance of the Topic

Viscosity is a key parameter in biologic formulation development, impacting self-interactions, syringeability, filtration, and overall manufacturability.
Accurate and rapid viscosity data at microvolumes can accelerate screening and process development steps while conserving precious samples.

Study Objectives and Overview

This application note presents Honeybun, a rapid microvolume viscometer designed to measure up to 10 samples in under six minutes using only 40 µL per run.
The study evaluates Honeybun’s performance with model proteins bovine serum albumin (BSA) and bovine gamma globulin (IgG) across various concentrations and temperatures.

Methods and Instrumentation

Protein samples (BSA and IgG) were prepared in phosphate buffered saline, centrifuged to remove particulates, and concentration verified by UV/Vis spectroscopy.
Viscosity measurements were performed with Honeybun using the single-use Bun consumable.

• Honeybun rapid microvolume viscometer with temperature control (10–25 °C)
• Bun consumable for sample handling
• UV/Vis spectrophotometer (Stunner) for concentration verification
• Medical grade viscosity standard (2 cP) for calibration

Key Results and Discussion

Throughput and Volume:

• Up to 10 samples measured in parallel within six minutes.
• Only 40 µL sample required per measurement.

Concentration Dependence:

• BSA viscosity rose from ~1.37 to 17.3 cP over 0–300 mg/mL.
• IgG viscosity increased from ~0.91 to 2.0 cP over 0–75 mg/mL.

Shear Rate Independence:

• Both proteins exhibited constant viscosity across shear rates from ~2 000 to ~37 000 s⁻¹, indicating Newtonian behavior.

Temperature Dependence:

• Viscosity decreased with increasing temperature between 10 °C and 25 °C for all tested concentrations.
• BSA ranged from 1.35 to 30.6 cP; IgG ranged from 0.88 to 3.0 cP across the temperature span.

Benefits and Practical Applications

Honeybun’s combination of low sample volume, high throughput, and temperature control makes it well suited for:

• Formulation screening and optimization
• Quality control and batch release testing
• Early-stage antibody and vaccine development
• Process development for fill/finish and filtration steps

Future Trends and Potential Uses

Potential extensions include integration with laboratory information management systems for automated data flow, expansion to other biologic modalities (viral vectors, nucleic acid formulations), and coupling with predictive analytics to guide formulation design.
Further miniaturization and on-line process monitoring could further streamline biomanufacturing workflows.

Conclusion

Honeybun delivers rapid, low-volume viscosity measurements with minimal hands-on time and robust performance across concentrations and temperatures. It represents a valuable tool for accelerating biologic development and ensuring product quality.

References

1. Allmendinger A. et al. High-throughput viscosity measurement using capillary electrophoresis instrumentation and its application to protein formulation. J. Pharm. Biomed. Anal. 99, 51–58 (2014).
2. Shire S.J., Shahrokh Z. & Liu J. Challenges in the development of high protein concentration formulations. J. Pharm. Sci. 93, 1390–1402 (2004).
3. Tomar D.S. et al. Molecular basis of high viscosity in concentrated antibody solutions: Strategies for high concentration drug product development. mAbs 8, 216–228 (2016).