Agilent AdvanceBio Surfactant Profiling HPLC Columns

Biopharmaceuticals have transformed modern medicine, providing targeted therapies for conditions once considered untreatable. Yet, while biologics are effective, their fragile formulation presents unique challenges. One of the most critical yet often underestimated factors in biologic stability is the role of surfactants. Surfactants are essential in protecting therapeutic proteins against aggregation and adsorption at the air-liquid interface. Without them, many biologics would lose stability during manufacturing, shipping, or storage. However, surfactants themselves are chemically unstable. They degrade over time, producing by-products that can compromise both product quality and patient safety. This is where Agilent’s AdvanceBio Surfactant Profiling HPLC columns deliver exceptional value – by enabling in-depth analysis of surfactant integrity and degradation, they give scientists the insights needed to build safer, more reliable biotherapeutics.

Agilent AdvanceBio Surfactant Profiling HPLC columns are carefully designed to quickly and reproducibly characterise non-ionic surfactants and their degradation products, particularly in biologic formulation buffer. The unique selectivity of this reversed phase column allows for excellent separation and high resolution of various surfactant components.

Each batch of AdvanceBio Surfactant Profiling media is tested with a mix of a polysorbate and its major fatty acid to ensure resolution and reproducibility. With regulatory bodies increasing scrutiny on polysorbate degradation and its adverse effects, it’s prudent to proactively incorporate this analysis in development laboratories now. The AdvanceBio Surfactant Profiling HPLC column is the best-in class column to characterise degradation in polysorbates and other surfactants.

Surfactants: Essential, Yet Vunerable

Polysorbates, such as Polysorbate 20 and 80 (also known as Tween 20 and Tween 80), are widely used in biologic formulations for their protective properties, effectively shielding delicate proteins. However, they are prone to chemical instability. Structurally, polysorbates are composed of three main components: a hydrophilic headgroup (such as sorbitan), four polyoxyethylene chains, and a fatty acid attached to each chain.

One primary degradation pathway of polysorbates is hydrolysis, where ester bonds are broken, releasing free fatty acids. These free fatty acids can form particles that can compromise product clarity and safety. While hydrolysis can occur chemically, it is more frequently driven by enzymatic activity. Figure 1 illustrates this hydrolysis process, showing how polysorbate degradation leads directly to potentially harmful by-products.

Figure 1: Polysorbate hydrolysis cleaves the fatty acid, which can cause formation of proteinaceous or free fatty acid particles

A further mechanism by which polysorbates degrade is oxidation. Oxidative degradation can be triggered by exposure to light, transition metals, or residual peroxides, with the latter two potentially present in formulation buffers. Oxidation can also affect poloaxamers, and unsaturated fatty acids, such as oleic or linoleic acid. This process can lead to the formation of various degradation by-products, which can then de-stabilise the surfactant. In turn, this can lead to damage of the biologic it’s meant to protect, endangering therapeutic potency and stability.

Figure 2 shows polysorbate oxidation can occur at multiple structural sites, generating aldehydes, ketones, and formic acid.

Figure 2: Oxidation can occur at multiple sites on the polysorbate structure, forming numerous by-products. Additionally, oxidation may also affect the biologic itself.

These degradation pathways lead to reduced surfactant concentration, unexpected particle formation, and even reduced shelf life – all of which can hinder regulatory approval, market success, and ultimately, patient outcomes. Due to these risks, monitoring oxidative degradation is no longer optional – it is both a regulatory expectation and a best practice to ensure consistent biologic performance.

Surfactant Quantitation vs. Surfactant Profiling

Historically, laboratories have relied upon established surfactant quantitation methods, typically performed with mixed-mode chromatography. This technique provides a rapid, single-peak readout – typically in under 10 minutes – making it useful for confirming the presence of surfactant. However, this only offers a partial view. The single peak represents total surfactant concentration, but fails to reveal whether the surfactant remains intact and functional.

Critically, mixed-mode columns cannot detect surfactant degradation products such as free fatty acids or polyoxyethylene moieties, which often elute in the void volume and go undetected. As illustrated in Figure 3, a mixed-mode column produces a simplified chromatogram where key degradation signals are absent. Simply confirming the presence of surfactant is no longer sufficient – it's essential to determine whether it is chemically intact and free from harmful by-products. With increasing focus on formulation integrity, a more comprehensive analysis is required.

Surfactant profiling, an emerging method, fully characterises surfactants, including degradation products resulting from hydrolysis or oxidation. This method supports early detection of issues, facilitating timely interventions and reducing the risk of costly quality failures during manufacturing.

Figure 3: The Agilent AdvanceBio Surfactant Profiling column can detect surfactant degradation products even with a short run time. While a mixed-mode column is sufficient for surfactant quantitation, it is unable to detect polysorbate degradation products such as polyoxyethylene moieties or free fatty acids.

Agilent has designed the AdvanceBio Surfactant Profiling HPLC columns specifically to overcome the limitations of quantitation only assays. The unique chemistry of the column enables alternate selectivity, delivering comprehensive resolution of both surfactants and degradation products. The useful benefits of the Surfactant Profiling column results in faster and more reliable results, supporting both early stage formulation development and ongoing quality assurance.

Key Features & Benefits:

Comprehensive Separation: The Surfactant Profiling column cleanly resolves polysorbate mono, di and tri-esters as well as free fatty acids. This is something competitor columns have struggled to achieve, even at enhanced run times.
Shorter Run Times: The column achieves detailed separation in less than 10 minutes, compared with 60+ minutes required using conventional methods (Figure 4).

Figure 4: The Agilent AdvanceBio Surfactant Profiling column easily resolves the free fatty acids from the polysorbate monoester peak in under 10 minutes, outperforming commonly used competitor columns that require up to 60 minutes yet deliver lower resolution.

Time and Cost Efficiency: Estimates show that switching from traditional reversed phase columns can deliver 60 – 83% time savings and 55 – 84% cost savings, freeing labs to process more samples without sacrificing data quality. Shorter run times also provide a greener solution, using less solvents. Try Agilent’s Polysorbate Cost & Time Savings Estimator to find out how much your lab could benefit.
Flexibility: With 50 mm, 100 mm and 150 mm dimensions available, the column is able to be tailored to hydrolysis monitoring, or broader oxidation screening. Figure 5 illustrates even the shortest 50 mm column delivers sufficient resolution for fatty acid separation.

Figure 5: Although longer columns are known to increase resolution, they offer negligible improvement for separating fatty acids/monoesters. A 50 mm column provides sufficient performance for hydrolysis monitoring. Longer columns may be helpful for oxidation studies due to the greater number of degradation by-products involved.

Column Stability & Lifetime

Adopting new technology can raise concerns about ongoing operational costs. Laboratories must also manage operating budgets and ensure long term reliability. Agilent addresses these challenges through design features that enhance the durability of AdvanceBio Surfactant Profiling columns.

Mechanical Stability has been demonstrated across thousands of injections, maintaining resolution between oleic acid and polysorbate monoesters, even under challenging conditions such as high salt conditions (Figure 6). Pressure increases were shown to minimal.
Guard Columns are also available to protect the analytical column from complex formulation matrices, minimising wear and extending column lifetimes.

Figure 6: Lifetime testing was performed with samples in a heavy salt buffer to mimic formulation conditions. Guards were replaced every 150-200 injections. While column pressures eventually increased over 10%, the resolution between oleic acid and polysorbate 80 monoester was maintained. Additionally, column lifetime testing at the column pressure limit was performed with a uracil probe, showing no pressure change over 2000 injections and demonstrating mechanical stability. Red lines indicate a 10% increase in pressure.

Why It Matters

In the competitive world of biotherapeutics, speed and precision are crucial, and for patients, the stakes could not be higher. A stability failure late in development can cost millions and delay critical treatments. Early detection of surfactant degradation helps prevent setbacks, maintain regulatory compliance, and ensure patient safety. By integrating Agilent’s AdvanceBio Surfactant Profiling HPLC columns into their workflows, organisations can gain:

Early insights into vulnerabilities in biologic formulations
Clear evidence that identifies degradation pathways prompting timely corrective actions
Regulatory alignment through comprehensive characterisation rather than basic quantitation

Ultimately, these capabilities help biopharma developers protect both their investment and their patients.

Conclusion

Surfactants may account for only a fraction of a biologic formulation, but their stability plays a pivotal role in therapeutic’s success. Protecting proteins from instability is essential – but only if the surfactants themselves remain intact. Hydrolysis and oxidation pose significant risks that require thorough monitoring.

Agilent’s AdvanceBio Surfactant Profiling HPLC columns provide a breakthrough solution: high-resolution, fast, and comprehensive characterisation of surfactants and their degradation by-products. By combining scientific precision with operational efficiency, they represent a new standard in biopharma formulation analysis. For scientists, manufacturers, and regulators alike, this technology represents a step forward in ensuring biologic integrity from development to market.