Differential Surface Adsorption Phenomena for Conventional and Novel Surfactants Correlates with Changes in Interfacial mAb Stabilization

Abstract

Protein adsorption on surfaces can result in loss of drug product stability and efficacy during the production, storage, and administration of protein-based therapeutics. Surface-active agents (excipients) are typically added in protein formulations to prevent undesired interactions of proteins on surfaces and protein particle formation/aggregation in solution. The objective of this work is to understand the molecular-level competitive adsorption mechanism between the monoclonal antibody (mAb) and a commercially used excipient, polysorbate 80 (PS80), and a novel excipient, N-myristoyl phenylalanine-N-polyetheramine diamide (FM1000). The relative rate of adsorption of PS80 and FM1000 was studied by pendant bubble tensiometry. We find that FM1000 saturates the interface faster than PS80. Additionally, the surface-adsorbed amounts from X-ray reflectivity (XRR) measurements show that FM1000 blocks a larger percentage of interfacial area than PS80, indicating that a lower bulk FM1000 surface concentration is sufficient to prevent protein adsorption onto the air/water interface. XRR models reveal that with an increase in mAb concentration (0.5–2.5 mg/mL: IV based formulations), an increased amount of PS80 concentration (below critical micelle concentration, CMC) is required, whereas a fixed value of FM1000 concentration (above its relatively lower CMC) is sufficient to inhibit mAb adsorption, preventing mAb from co-existing with surfactants on the surface layer. With this observation, we show that the CMC of the surfactant is not the critical factor to indicate its ability to inhibit protein adsorption, especially for chemically different surfactants, PS80 and FM1000. Additionally, interface-induced aggregation studies indicate that at minimum surfactant concentration levels in protein formulations, fewer protein particles form in the presence of FM1000. Our results provide a mechanistic link between the adsorption of mAbs at the air/water interface and the aggregation induced by agitation in the presence of surfactants.

Study of Oncolytic Virus Preservation and Formulation

“…FM1000 blocked a larger percentage of the interfacial area than PS80. Lower volume FM1000 surface concentrations were sufficient to prevent protein adsorption to the air/water interface, whereas PS80 required increasing concentrations (below the critical micelle concentration, CMC), while fixed FM1000 concentrations (above the relatively low CMC) could also inhibit surface adsorption [ 104 ].…”

Defining Structure-Function Relationships of Amphiphilic Excipients Enables Rational Design of Ultra-Stable Biopharmaceuticals

“…Despite this well acknowledged need for new classes of excipients, without a fundamental understanding of how the structural properties of surfactants impact protein stability it remains extremely challenging to design efficacious surfactant excipients a priori. 10,[17][18][19] Specifically, attempts to predict protein stability from structural properties have been thwarted by the highly heterogeneous structure and rapid degradation of current surfactants (pluronics and polysorbates). [11][12][13][14][20][21][22] Recently, we demonstrated that high-throughput combinatorial synthesis of a large library of amphiphilic polyacrylamide copolymers could enable identification and optimization of a novel class of surfactant excipients capable of dramatically improving the stability of biopharmaceuticals.…”

Not the Usual Suspects: Alternative Surfactants for Biopharmaceuticals

“…The balance between these two mechanisms is highly surfactant-, protein- and formulation-dependent . Despite the meticulous investigation of many cases, − a fundamental understanding of the mechanisms underlying surfactant efficacy, which would result in powerful prediction capabilities, has not yet been achieved.…”

“…A subsequent mode of action characterization focused on the structure–activity relationship of the hydrophilic tail length revealed that an ideal length induces better stabilization than either longer or shorter tails, suggesting the possibility of tuning the effect by modifying the structure. Finally, analysis of surface adsorption of FM1000 compared to PS80 demonstrated that FM1000 requires less amount to saturate the air-water interface, while also generating a better API stabilization effect, suggesting a mechanistic link between adsorption dynamics and API protection against agitation-induced aggregation . While these studies thoroughly investigate many aspects of surfactants development, they were only performed on mAbs and thus fail to provide universal functional and mechanistic understandings applicable to other therapeutically relevant protein classes, such as fusion proteins, single chain fragments, or partially disordered proteins (among others).…”

“…Finally, analysis of surface adsorption of FM1000 compared to PS80 demonstrated that FM1000 requires less amount to saturate the air-water interface, while also generating a better API stabilization effect, suggesting a mechanistic link between adsorption dynamics and API protection against agitation-induced aggregation. 11 While these studies thoroughly investigate many aspects of surfactants development, they were only performed on mAbs and thus fail to provide universal functional and mechanistic understandings applicable to other therapeutically relevant protein classes, such as fusion proteins, single chain fragments, or partially disordered proteins (among others). mAbs possess a high level of stability, which often translates to a significant reduction in particle generation compared to non-mAbs, as observed in the recent analysis of 10 years of particles issues at Novartis.…”