Degradation of polysorbate investigated by a high-performance liquid chromatography multi-detector system with charged aerosol and mass detection

Physicochemical stability of a polysorbate-80-containing solvent compounded in the hospital pharmacy and used to reconstitute a biologic for nebulisation

OBJECTIVES

To assess the long-term physicochemical stability of a solvent (10 mM phosphate buffer pH 6.5 containing sodium chloride (145 mM) and polysorbate 80 (PS80) 0.02%) used to reconstitute a biologic for nebulisation. The solvent was compounded in the hospital pharmacy and stored in amber glass vials at -20°C for 1 year.

METHODS

Samples were analysed immediately on compounding and then 1, 3, 6, 9 and 12 months after storage at -20°C (immediately after thawing, and also 1 month later keeping the vials at 2-8°C). The assays included a visual examination, measurement of the pH, osmolality, sub-visible particulate contamination, the concentration of PS80, and the concentration of oleic acid and peroxides (both major markers of PS80 degradation). Quantification of PS80 was challenging due to the substance's molecular heterogeneity and the lack of a good chromophore. The strategy adopted consisted of hydrolysis in a strong base and then liquid-liquid extraction of the oleic acid (PS80's hydrolysis product). The oleic acid content was determined using reversed phase high performance liquid chromatography with ultraviolet detection. The peroxide content was determined spectrophotometrically using a ferrous oxidation with xylenol orange assay.

RESULTS

Over 12 months, there was no significant change in the samples' visual appearance, pH and osmolality. The PS80 concentration remained above 90% of the initial value. The subvisible particle counts remained far below the European Pharmacopoeia thresholds. The oleic acid content of the non-hydrolysed samples remained constant, and no peroxide was detected.

CONCLUSIONS

A PS80-containing solvent is stable for 1 year when stored at -20°C (±5°C) in amber glass vials. Moreover, the solvent is stable for up to 1 month after thawing if stored at 2-8°C.

A review of polysorbate quantification and its degradation analysis by liquid chromatography coupled with charged aerosol detection

Polysorbates (PS), as non-ionic surfactants, contribute significantly to the stability of proteins in formulations. However, their lack of chromophore groups makes them difficult to detect with high sensitivity and simplicity. The charged aerosol detector (CAD) is an emerging and universal detector that can provide highly sensitive response signals to non-volatile or semi-volatile substances, such as esters, acids, oxidized aldehydes, and contaminant ions in PS. This article provides a comprehensive review of the qualitative and quantitative analysis of PS, profiling its composition, investigating the reasons for its degradation, and discussing its reaction mechanisms. This review aims to promote the quality control of PS production for the development of stable and safe protein formulations.

Detailed profiling of polysorbate 80 oxidative degradation products and hydrolysates using liquid chromatography-tandem mass spectrometry analysis

RATIONALE

Polysorbate 80 (PS80) is an amphipathic, nonionic surfactant that is commonly used to stabilize proteins in biopharmaceutical formulations. PS80 undergoes oxidative and/or enzymatic degradation. However, because PS80 is a complex mixture consisting of many constituents, comprehensive evaluations of its oxidative degradation products are difficult and insufficient.

METHODS

Our previously reported comprehensive liquid chromatography-tandem mass spectrometry (LC/MS/MS)-based method for PS80 effectively provides an overall profile of PS80 components under simple LC conditions. In this study, we attempted to shorten the analysis time. Furthermore, PS80 was oxidatively degraded in a solution containing histidine and iron, and the oxidative degradation products were evaluated using a modified LC/MS/MS method. In addition, enzymatically hydrolyzed PS80 samples were analyzed.

RESULTS

We succeeded in shortening the analysis time from 70 to 20 min while maintaining the resolution of the PS80 components of the same selected reaction monitoring transition. Both the previously reported oxidative degradation products and the newly discovered products were successfully detected, and their composition ratios and changes over time were observed. Changes in the hydrolysates over time are shown in the analysis of the hydrolyzed PS80 samples.

CONCLUSIONS

This study clearly showed the presence of changes in PS80 oxidative and/or enzymatic degradation products, including those previously unreported. These results demonstrate that a detailed profiling of PS80 degradation products can be performed using LC/MS/MS, which is less expensive and more generally adopted than high-resolution MS.

High throughput multidimensional liquid chromatography approach for online protein removal and characterization of polysorbates and poloxamer in monoclonal antibody formulations

The majority of commercially available monoclonal antibody (mAb) formulations are stabilized with one of three non-ionic surfactants: polysorbate 20 (PS20), polysorbate 80 (PS80), or poloxamer 188 (P188). All three surfactants are susceptible to degradation, which can result in functionality loss and subsequent protein aggregation or free fatty acid particle formation. Consequently, quantitative, and qualitative analysis of surfactants is an integral part of formulation development, stability, and batch release testing. Due to the heterogeneous nature of both polysorbates and poloxamer, online isolation of all the compounds from the protein and other excipients that may disturb the subsequent liquid chromatography with charged aerosol detection (LC-CAD) analysis poses a challenge. Herein, we present an analytical method employing LC-CAD, utilizing a combination of anion and cation exchange columns to completely remove proteins online before infusing the isolated surfactant onto a reversed-phase column. The method allows high throughput analysis of polysorbates within 8 minutes and poloxamer 188 within 12 minutes, providing a separation of the surfactant species of polysorbates (unesterified species, lower esters, and higher esters) and poloxamer 188 (early eluters and main species). Accuracy and precision assessed according to the International Council for harmonisation (ICH) guideline were 96 - 109 % and ≤1 % relative standard deviation respectively for all three surfactants in samples containing up to 110 mg/mL mAb. Subsequently, the method was effectively applied to quantify polysorbate 20 and polysorbate 80 in nine commercial drug products with mAb concentration of up to 180 mg/mL.