Novel High-Throughput Assay for Polysorbate Quantification in Biopharmaceutical Products by Using the Fluorescent Dye DiI

Achieving Acceleration to First-in-Human: MSD's Learnings on Platform Method Validation Strategy

Over the past decades, the number of therapeutic protein pipelines in early-phase clinical studies has increased dramatically. The rapid growth in the pipeline underscores the need to accelerate early-stage development and enable fast first-in-human (FIH) trials to bring novel therapies to patients. Across the industry, various efforts have been developed to achieve this goal. In this communication, a platform analytical method validation approach developed and used by MSD for FIH programs is described. A case study from the release panel, a polysorbate 80 (PS-80) platform method is utilized to illustrate the workflow. In this approach, historical validation data within the same modality are summarized and supplemented with statistical analyses to justify a limited validation for future pipeline projects. The platform method validation strategy has reduced the overall validation timeline from up to 4 months to 1-2 months and has successfully been implemented in FIH filings. This communication provides insights to pharmaceutical companies interested in developing platform analytical method validation approaches for fast FIH studies.

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.

Polysorbates degrading enzymes in biotherapeutics - a current status and future perspectives

Polysorbates, in particular polysorbate (PS) 20 and 80, are the most commonly used surfactants for stabilising biotherapeutics produced by biotechnological processes. PSs are derived from ethoxylated sorbitan (a derivative of sorbitol) esterified with fatty acids of varying chain length and degree of saturation. In the past, these surfactants have been reported to have specific liabilities. Chemical (oxidations and hydrolyses) and enzymatic degradations have been reported to affect the stability of PS in drug products. Specifically, the presence of trace amounts (sub-ppm) of certain host cell proteins (HCPs) can induce enzymatic PS degradation, which can lead to the release of free fatty acids during storage over time. Enzymatic polysorbate degradation may impair the functionality of the surfactant in stabilising therapeutic proteins, leading to the formation of visible and/or sub-visible particles in biopharmaceutical drug products. This review summarises the enzymes currently known to be involved in the degradation of polysorbate in mammalian biotechnological processes for therapeutic proteins. In recent years, advanced analytical methods have been developed to qualify and quantify the PS-degrading enzymes. Most of these assays are based on mass spectrometry with a preceding HCP enrichment approach. Efforts were made to measure the enzyme activity and correlate it with observed PS degradation. The impact on drug product quality attributes, including fatty acid solubility and phase separation, up to the formation of visible particles, and the potential induction of protein and protein/fatty acid mixed particles as well as the sensitivity of specific PS quality towards enzymatic degradation, was considered. Various drug substance (DS) mitigation strategies related to the occurrence of PS degrading enzymes are discussed as amongst them the generation of stable HCP knockout cell lines, which are also carefully analysed. The underlying opinion article reflects the undergoing discussions related to PS degrading enzymes and focusses on (i) impact on drug product, (ii) analytics for identification/quantification (characterisation) of the PS degrading enzymes, (iii) enzyme activity (iv) currently identified enzymes, and (v) potential mitigation strategies to avoid enzymatic PS degradation during DS manufacturing.

High-Throughput Fluorometric Assay For Quantifying Polysorbate In Biopharmaceutical Products Using Micelle Activated Fluorescence Probe N-Phenyl-1-Naphthylamine

PURPOSE

Polysorbates are among the most used surfactants in biopharmaceutical products containing proteins. Our work aims to develop a high-throughput fluorometric assay to further diversify the analytical toolbox for quantification of PSs.

METHOD

The assay leverages the micelle activated fluorescence signal from N-Phenyl-1-Naphthylamine (NPN). The development and optimization of assay parameters were guided by the pre-defined analytical target profile. Furthermore, NMR was used to probe the interaction between protein, PS80 and NPN in the measurement system and understand protein interference.

RESULTS

All assay parameters including excitation and emission wavelengths, standard curve, NPN concentration, and incubation time have been optimized and adapted to a microplate format, making it compatible with automated solutions that will be pursued in the near future to drive consistency and efficiency in our workflows. The specificity, accuracy, and precision of the assay have been demonstrated through a case study. Furthermore, NMR results provided additional insight into the change of the interaction dynamics between PS80 and NPN as the protein concentration increases. The results indicate minimal interaction between the protein and PS80 at lower concentration. However, when the concentration exceeds 75 mg/mL, there is a significant interaction between the protein and PS-80 micelle and monomer.

CONCLUSION

A high-throughput fluorometric assay has been developed for quantification of polysorbates in biopharmaceutical samples including in-process samples, drug substance and drug product. The assay reported herein could serve as a powerful analytical tool for polysorbate quantification and control, complementing the widely used liquid chromatography with charged aerosol detection method.

Discrimination of polysorbate 20 by high-performance liquid chromatography-charged aerosol detection and characterization for components by expanding compound database and library

Analyzing polysorbate 20 (PS20) composition and the impact of each component on stability and safety is crucial due to formulation variations and individual tolerance. The similar structures and polarities of PS20 components make accurate separation, identification, and quantification challenging. In this work, a high-resolution quantitative method was developed using single-dimensional high-performance liquid chromatography (HPLC) with charged aerosol detection (CAD) to separate 18 key components with multiple esters. The separated components were characterized by ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) with an identical gradient as the HPLC-CAD analysis. The polysorbate compound database and library were expanded over 7-time compared to the commercial database. The method investigated differences in PS20 samples from various origins and grades for different dosage forms to evaluate the composition-process relationship. UHPLC-Q-TOF-MS identified 1329 to 1511 compounds in 4 batches of PS20 from different sources. The method observed the impact of 4 degradation conditions on peak components, identifying stable components and their tendencies to change. HPLC-CAD and UHPLC-Q-TOF-MS results provided insights into fingerprint differences, distinguishing quasi products.

How enzymatic hydrolysis of polysorbate 20 influences colloidal protein stability

Polysorbates (PS) are esters of ethoxylated sorbitol anhydrides of different composition and are widely used surfactants in biologics. PSs are applied to increase protein stability and concomitant shelf-life via shielding against e.g., interfacial stresses. Due to the presence of specific lipolytic host cell protein (HCP) contaminations in the drug substance, PSs can be degraded via enzymatic hydrolysis. Surfactant hydrolysis leads to the formation of degradants, such as free fatty acids that might form fatty acid particles. In addition, PS degradation may reduce surfactant functionality and thus reduce the protection of the active pharmaceutical ingredient (API). Although enzymatic degradation was observed and reported in the last years, less is known about the relationship between certain polysorbate degradation patterns and the increase of mechanical and interfacial stress towards the API. In this study, the impact of specifically hydrolyzed polysorbate 20 (PS20) towards the stabilization of two monoclonal antibodies (mAbs) during accelerated shaking stress conditions was investigated. The results show that a specific enzymatic degradation pattern of PS20 can influence the colloidal stability of biopharmaceutical formulations. Furthermore, the kinetics of the appearance of visual phenomena, opalescence, and particle formation depended on the polysorbate degradation fingerprint as induced via the presence of surrogate enzymes. The current case study shows the importance of focusing on specific polysorbate ester fractions to understand the overall colloidal protein stabilizing effect. The performed study gives first insight into the functional properties of PS and helps to evaluate the impact of PS degradation in the formulation development of biopharmaceuticals in general.

Leveraging mass detection to simultaneously quantify surfactant content and degradation mode for highly concentrated biopharmaceuticals

Non-ionic surfactants are commonly used in parenteral protein formulations and include polysorbate 20, polysorbate 80 and poloxamer188. Recently, quantification and characterization of surfactants has generated considerable interest due to their connection to visible particle formation, a critical quality attribute for parenteral formulations. Typically, surfactant quantification is performed by mixed mode chromatography with evaporative light scattering detection (ELSD) or charged aerosol detection (CAD). However, these methods often suffer from loss of specificity in highly concentrated protein formulations. Here we present a mixed mode chromatography method using single quad mass detection, overcoming current limitations for highly concentrated proteins. In addition to content determination of intact surfactants, this method allows to quantify and characterize the predominant degradation patterns of polysorbates within a single measurement. Formulations with up to 200 mg/mL active pharmaceutical product (API) containing surfactant levels between 0.16 and 0.64 mg/mL were tested during method qualification. The obtained results for linearity (r > 0.99), precision (max. 3.8 % RSD) and accuracy (96-116 % recovery) meet current requirements for pharmaceutical products as defined in ICH Q2.

Characterization of Recombinantly-Expressed Hydrolytic Enzymes from Chinese Hamster Ovary Cells: Identification of Host Cell Proteins that Degrade Polysorbate

Enzymatic hydrolysis of polysorbate in drug products is a major challenge for the biopharmaceutical industry. Polysorbate hydrolysis caused by host cell proteins (HCPs) co-purified during bioprocessing can reduce the protective effects of the surfactant for the active pharmaceutical ingredient and cause the accumulation of low-solubility degradation products over the long-term storage. The identities of such HCPs are elusive due to their extremely low concentrations after the efficient purification processes of most biopharmaceuticals. In this work, 20 enzymes-selected for their known or putative hydrolytic activity and potential to degrade polysorbate-were recombinantly expressed, purified, and characterized via orthogonal methods. First, these recombinant HCPs were assessed for hydrolytic activity against a fluorogenic esterase substrate in a recently-developed, high-throughput assay. Second, these HCPs were screened for hydrolytic activity against polysorbate in a representative mAb formulation. Third, HCPs that displayed hydrolytic activities in the first two assays were subjected to more detailed characterization of their enzyme kinetics against polysorbates. Finally, these HCPs were evaluated for substrate specificity towards different sub-species of polysorbates. This work provides critical new insights for targeted LC-MS/MS approaches for identification of relevant polysorbate-degrading enzymes and supports improvements to remove such HCPs, including knockouts or targeted removal during purification.

End-to-End Approach to Surfactant Selection, Risk Mitigation, and Control Strategies for Protein-Based Therapeutics

A survey performed by the AAPS Drug Product Handling community revealed a general, mostly consensus, approach to the strategy for the selection of surfactant type and level for biopharmaceutical products. Discussing and building on the survey results, this article describes the common approach for surfactant selection and control strategy for protein-based therapeutics and focuses on key studies, common issues, mitigations, and rationale. Where relevant, each section is prefaced by survey responses from the 22 anonymized respondents. The article format consists of an overview of surfactant stabilization, followed by a strategy for the selection of surfactant level, and then discussions regarding risk identification, mitigation, and control strategy. Since surfactants that are commonly used in biologic formulations are known to undergo various forms of degradation, an effective control strategy for the chosen surfactant focuses on understanding and controlling the design space of the surfactant material attributes to ensure that the desired material quality is used consistently in DS/DP manufacturing. The material attributes of a surfactant added in the final DP formulation can influence DP performance (e.g., protein stability). Mitigation strategies are described that encompass risks from host cell proteins (HCP), DS/DP manufacturing processes, long-term storage, as well as during in-use conditions.

Fluorescent Nanosystems for Drug Tracking and Theranostics: Recent Applications in the Ocular Field

The greatest challenge associated with topical drug delivery for the treatment of diseases affecting the posterior segment of the eye is to overcome the poor bioavailability of the carried molecules. Nanomedicine offers the possibility to overcome obstacles related to physiological mechanisms and ocular barriers by exploiting different ocular routes. Functionalization of nanosystems by fluorescent probes could be a useful strategy to understand the pathway taken by nanocarriers into the ocular globe and to improve the desired targeting accuracy. The application of fluorescence to decorate nanocarrier surfaces or the encapsulation of fluorophore molecules makes the nanosystems a light probe useful in the landscape of diagnostics and theranostics. In this review, a state of the art on ocular routes of administration is reported, with a focus on pathways undertaken after topical application. Numerous studies are reported in the first section, confirming that the use of fluorescent within nanoparticles is already spread for tracking and biodistribution studies. The first section presents fluorescent molecules used for tracking nanosystems’ cellular internalization and permeation of ocular tissues; discussions on the classification of nanosystems according to their nature (lipid-based, polymer-based, metallic-based and protein-based) follows. The following sections are dedicated to diagnostic and theranostic uses, respectively, which represent an innovation in the ocular field obtained by combining dual goals in a single administration system. For its great potential, this application of fluorescent nanoparticles would experience a great development in the near future. Finally, a brief overview is dedicated to the use of fluorescent markers in clinical trials and the market in the ocular field.

Industry perspective on the use and characterization of polysorbates for biopharmaceutical products Part 1: Survey report on current state and common practices for handling and control of polysorbates

Polysorbates (PS) are widely used as a stabilizer in biopharmaceutical products. Industry practices on various aspects of PS are presented in this part 1 survey report based on a confidential survey and following discussions by 16 globally acting major biotechnology companies. The current practice and use of PS during manufacture across their global manufacturing sites are covered 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. The results of the survey and extensive cross-company discussions are put into relation with currently available scientific literature. Part 2 of the survey report (upcoming) will focus on understanding, monitoring, prediction, and mitigation of PS degradation pathways to develop an effective control strategy.