4-Hydroxynonenal is An Oxidative Degradation Product of Polysorbate 80

Development of Relatively Simple Sample Pretreatment Strategies to Selectively Remove Chromatographic Interfering Peaks of Polysorbate 80 from Liquid Oral Finished Drug Product

Polysorbate 80 (PS 80) is a nonionic surfactant, used in myriad of pharmaceutical, food and cosmetic formulations. PS 80 components have strong UV absorbance and retain under reversed-phase chromatographic conditions, significantly masking sections of the chromatogram. PS 80-related peaks interferences in a sample are common and can be difficult to separate from the analyte peaks. A liquid oral finished product (LOFP) containing PS 80 and Ivermectin as the active pharmaceutical ingredient (API) was selected for this study. Herein, we report two sample pretreatment strategies focusing on the selective removal of PS 80 from the LOFP. Both methods significantly reduce and/or practically eliminate excipients and PS 80-related peaks interferences from the LOFP without a negative impact on the API and its key-related substances recovery. The solid-phase extraction (SPE) strategy uses a C18 SPE followed by a silica gel SPE, whereas the liquid-liquid extraction strategy uses in situ-generated sodium caprylate for the removal of formulation excipients and PS 80. These methods can significantly increase the reliability of high-performance liquid chromatography methods and decrease false positive out-of-specifications events because of coelution of PS 80-related peaks with peaks of interest.

All-in-one stability indicating polysorbate 20 degradation root-cause analytics via UPLC-QDa

Polysorbates (PS) are the most frequently used surfactants to stabilize biologicals. Ironically, these excellent stabilizing non-ionic surfactants have inherent structural properties, which lead to instabilities of their own. Such PS degradation can be triggered by multiple root-causes, like chemical and enzymatic hydrolysis or oxidative degradation. This can on the one hand reduce the concentration of surface-active PS and on the other hand lead to the formation of unfavorable degradants, like poorly soluble free fatty acids (FFA), which may phase separate and form visible FFA particles. Due to the potential criticality of PS degradation in biopharmaceutical formulations, various analytics have been established in recent years not only to monitor the PS content but also to evaluate specific PS markers and crucial degradants. However, in most cases sample preparations and several analytical assays have to be conducted to obtain a comprehensive picture of potential PS degradation root-causes. Here we show a novel approach for PS degradation UPLC-QDa based root-cause analytics, which utilizes previously established analytics for (i) most relevant polysorbate 20 (PS20) esters, (ii) PS20 free fatty acids and (iii) a newly developed method for the evaluation of PS20 specific oxidation markers. Thereby, this triad of analytical methods uses the same sample preparation and detector, which reduces the overall necessary effort, time investment and sample volume. Furthermore, the innovative PS20 oxidation marker method allows to quantify specific concentrations of the determined markers by external calibration and possible perception of oxidative degradation processes prior to relevant losses of PS20 esters, which could serve as an early indication during formulation development. The applicability of this method set was verified using several PS20 containing stress samples, which cover the most relevant root-causes, including acidic and alkaline hydrolysis, enzyme mediated hydrolysis, oxidative AAPH stress and Fe2+/H2O2 mediated degradation as well as autoxidation via long-term storage at elevated temperatures. Overall, this analytical setup has shown to deliver in-depth data about PS20 degradation, which can be used to narrow down the causative stress without the necessity of fundamentally different methods. Therefore, it can be seen as all-in-one solution during sometimes troublesome development of biopharmaceutical formulations, that supports the elucidation of the PS degradation mechanism(s) and thus establish mitigation strategies.

Oxidation of polysorbates - An underestimated degradation pathway?

To ensure the stability of biologicals over their entire shelf-life, non-ionic surface-active compounds (surfactants) are added to protect biologics from denaturation and particle formation. In this context, polysorbate 20 and 80 are the most used detergents. Despite their benefits of low toxicity and high biocompatibility, specific factors are influencing the intrinsic stability of polysorbates, leading to degradation, loss in efficacy, or even particle formation. Polysorbate degradation can be categorized into chemical or enzymatic hydrolysis and oxidation. Under pharmaceutical relevant conditions, hydrolysis is commonly originated from host cell proteins, whereas oxidative degradation may be caused by multiple factors such as light, presence of residual metal traces, peroxides, or temperature, which can be introduced upon manufacturing or could be already present in the raw materials. In this review, we provide an overview of the current knowledge on polysorbates with a focus on oxidative degradation. Subsequently, degradation products and key characteristics of oxidative-mediated polysorbate degradation in respect of different types and grades are summarized, followed by an extensive comparison between polysorbate 20 and 80. A better understanding of the radical-induced oxidative PS degradation pathway could support specific mitigation strategies. Finally, buffer conditions, various stressors, as well as appropriate mitigation strategies, reagents, and alternative stabilizers are discussed. Prior manufacturing, careful consideration and a meticulous risk-benefit analysis are highly recommended in terms of polysorbate qualities, buffers, storage conditions, as well as mitigation strategies.

Investigation of excipients impact on polysorbate 80 degradation in biopharmaceutical formulation buffers

A study on the polysorbate 80 stability in various formulation buffers commonly used in biopharmaceuticals was performed, to investigate the excipients influence on polysorbate 80 degradation. Polysorbate 80 is a common excipient in biopharmaceutical products. However, its degradation will potentially impact the drug product quality, and may trigger protein aggregation and particles formation. Due to the heterogeneity of the polysorbates and the mutual effects with other formulation compositions, the study of polysorbate degradation is challenging. Herein, a real-time stability study was designed and performed. The polysorbate 80 degradation trend was monitored by fluorescence micelle-based assay (FMA), reversed-phase-ultra-performance liquid chromatography-evaporative light scattering detector (RP-UPLC-ELSD) assay, and LC-MS assay. These assays provide orthogonal results to reveal both the micelle-forming capability and the compositional changes of polysorbate 80 in different buffer systems. The degradation occurred after a period of storage under 25 °C in different trend, which indicates the excipients could impact the degradation kinetics. Upon comparison, the degradation is prone to happen in histidine buffer than in acetate, phosphate or citrate buffers. LC-MS confirms oxidation as an independent degradation pathway with detection of the oxidative aldehyde. Thus, it is necessary to pay more attention to the excipients selection and their potential impact on polysorbate 80 stability to achieve longer shelf life for the biopharmaceuticals. Besides, the protective roles of several additives were figured out, which could be applied as potential industrial solutions to the polysorbate 80 degradation issues.

Profiling polysorbate 80 components using comprehensive liquid chromatography-tandem mass spectrometry analysis

RATIONALE

Polysorbate 80 (PS80) is an amphipathic, nonionic surfactant commonly used in pharmaceutical protein formulations and is composed of fatty acid (FA) esters of polyethoxylated sorbitan. However, commercial PS80 products contain substantial amounts of by-products. The development of simple and reliable methods for PS80 component analysis is challenging given the inherent heterogeneity.

METHOD

We developed a comprehensive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to profile the components of PS80. Semi-comprehensive LC-MS/MS analyses of 11 subspecies in three commercial PS80 products were performed to estimate the average degree of polymerization of the ethylene oxide units (Avg-n) in the molecules. Furthermore, three subspecies (polyoxyethylene sorbitan monoester, polyoxyethylene isosorbide monoester, and polyoxyethylene monoester) were analyzed to estimate the composition ratios of the seven ester-bonded FAs present in PS80.

RESULTS

The Avg-n values of five polyoxyethylene sorbitan esters (none, mono, di, tri, and tetra), three polyoxyethylene isosorbide esters (none, mono, and di), and three polyoxyethylene esters (none, mono, and di) were 26.5-30.6, 12.1-14.6, and 11.4-15.8, respectively. These values were comparable regardless of the number of ester-bonded FAs. Each product had a similar FA composition ratio regardless of the differences in the subspecies. However, the obtained C18:2 values were higher than those reported in the product certificates.

CONCLUSION

The proposed LC-MS/MS method evaluated the overall PS80 components, revealing the possibility of underestimation of ester-bonded linoleic acid using the conventional gas chromatography-mass spectrometry method. The similarity of Avg-n values and FA compositions among subspecies suggested the high reliability of these results, indicating that the presented approach may help in the quality control of PS80 formulations.

Industry Perspective on the Use and Characterization of Polysorbates for Biopharmaceutical Products Part 2: Survey Report on Control Strategy Preparing for the Future

Polysorbate (PS) 20 and 80 are the main surfactants used to stabilize biopharmaceutical products. Industry practices on various aspects of PS based on a confidential survey and following discussions by 16 globally acting major biotechnology companies is presented in two publications. Part 1 summarizes the current practice and use of PS during manufacture in addition to aspects like current understanding of the (in)stability of PS, the routine QC testing and control of PS, and selected regulatory aspects of PS.¹ The current part 2 of the survey focusses on understanding, monitoring, prediction, and mitigation of PS degradation pathways in order to propose an effective control strategy. The results of the survey and extensive cross-company discussions are put into relation with currently available scientific literature.

Effect of Fatty Acid Composition in Polysorbate 80 on the Stability of Therapeutic Protein Formulations

Purpose

Polysorbate excipients are commonly used as surfactants to stabilize therapeutic proteins in formulations. Degradation of polysorbates could lead to particle formation and instability of the drug formulation. We investigated how the fatty acid composition of polysorbate 80 impacts the degradation profile, particle formation, and product stability under stress conditions.

Methods

Two polysorbate 80-containing therapeutic protein formulations were reformulated with either Polysorbate 80 NF synthesized from a fatty acid mixture that contains mainly oleic acid (≥58%) or a version of polysorbate 80 synthesized with high oleic acid (>98%). Stress conditions, including high temperature and esterase spiking, were applied and changes to both the polysorbate and the therapeutic protein product were investigated for stability, purity, innate immune response and biological activity.

Results

The addition of esterase and storage at 37°C led to significant hydrolysis of the polysorbate and increases in sub-visible particle formation for both polysorbates tested. The fatty acid composition of polysorbate 80 did not directly alter the stability profile of either therapeutic protein as measured by size exclusion chromatography, or significantly impact innate immune response or biological activity. However, formulations with Polysorbate 80 NF showed greater propensity for sub-visible particle formation under stress conditions.

Conclusions

These results suggest that composition of fatty acids in polysorbate 80 may be a promoter for sub-visible particulate formation under the stress conditions tested but may not impact protein aggregation or biological activity.

4-Hydroxynonenal - A Toxic Leachable from Clinically Used Administration Materials

INTRODUCTION

The migration of chemicals from processing materials into biopharmaceuticals can lead to various problems. Leachables from administration materials, with no possibility of further clearance, are of particular concern. Released chemicals can be toxic or react with formulation components, thereby impacting product safety. Therapeutic proteins, which are susceptible to chemical modifications, have highest risk to be affected.

AIM

The aim of this study was to identify a previously unknown leachable compound from clinical administration sets, which was present above the applied generic safety threshold.

METHODS

Extracts of commonly used clinical administration sets were analyzed using a recently established specific assay allowing the identification and quantification of the α,β-unsaturated aldehyde 4-hydroxynonenal (HNE) in a drug product surrogate solution. HNE was quantified after derivatization with 2,4-dinitrophenylhydrazine (DNPH) and liquid extraction of the formed hydrazone by LC-MRM analysis.

RESULTS

Potentially genotoxic HNE was a leachable compound from all tested administration sets, in parts exceeding safety thresholds for genotoxicants. The HNE-releasing polymer was identified as PVC.

CONCLUSION

Clinical administration sets should be, like manufacturing materials and container closure systems, in the focus of routine leachables studies. Manufacturers of clinical administration sets should show responsibility to avoid the presence of safety concerning chemicals, like HNE.

Identification of an Oxidizing Leachable from a Clinical Syringe Rubber Stopper

Leaching of toxic or reactive chemicals from polymeric materials can adversely affect the quality and safety of biopharmaceuticals. It was therefore the aim of the present study to analyze leachables from a disposable clinical administration syringe using a polysorbate-containing surrogate solution and to assess their chemical reactivity. Analytical methods did include (headspace) GC-MS, Fourier-transform-infrared spectroscopy, a ferrous oxidation-xylenol orange assay, and nuclear magnetic resonance analysis. In the syringe leachables solution, the carcinogenic 1,1,2,2-tetrachloroethane (TCE) was detected in concentrations above the ICH M7-derived analytical evaluation threshold. TCE was shown to be an oxidation product of dichloromethane used during sample preparation. Since TCE was only isolated from incubations with the contained rubber stopper, we hypothesized that a stopper-derived leachable acted as a reactive oxidant promoting this chemical reaction. Subsequently, the leachable was identified to be the polymerization initiator Luperox® 101. Combining different analytical approaches led to the structural elucidation of a chemical reactive oxidant, which has the potential to interact and alter drug products. We conclude that chemically reactive compounds, such as the newly identified rubber stopper leachable Luperox® 101, may be of concern and therefore should be routinely considered if a prolonged exposure of polymers with drug products can be anticipated.