Effects of Impurities from Sugar Excipient on Filtrate Flux during Ultrafiltration and Diafiltration Process.

Jieun Lee,Jiwon Na,Youngbin Baek

doi:10.3390/membranes11100775

Abstract

Sugar excipients such as sucrose and maltose are widely used for biopharmaceutical formulation to improve protein stability and to ensure isotonicity for administration. However, according to recent literature, pharmaceutical-grade sucrose contained nanoparticulate impurities (NPIs) that result in protein aggregation and degradation. The objective of this study was to evaluate the filtrate flux behavior of sugar solution during ultrafiltration (UF) and diafiltration (DF). Filtrate flux data were obtained using either a tangential flow filtration (TFF) system for DF experiments or a normal flow filtration system for UF experiments. In diafiltration experiments, which were performed using 7 g/L of human immunoglobulin G in a 20 mM histidine buffer with the 100 mM sucrose or maltose, the filtrate flux with sucrose solution decreased significantly. In contrast, the one with maltose solution was in good correspondence with the calculated filtrate flux accounting for the effects of solution viscosity. This large decline in the flux was also observed during UF experiments, in which the presence of NPIs was identified by dynamic light scattering analysis and by capturing an SEM image of the membrane surface after filtration. In addition, highly purified sucrose resulted in a much lower flux decline in TFF in the absence of NPIs. These results provide important insights into the factors governing the optimization of the UF/DF process using appropriate excipients for biopharmaceutical formulation.

Highlights

Antibody-based therapeutics have recently become the predominant class of drugs, with more than 80 approved and commercialized monoclonal antibodies, since muromonab-CD3 (i.e., Orthoclone OKT3 as the first therapeutic mAb) was approved in 1986 [1,2]
During a set of diafiltration experiments using 7 g/L of immunoglobulin G (IgG) in 20 mM histidine buffer as a feed solution and the histidine buffer with 100 mM sucrose (99.5% purified from Daejung) solution as a diafiltration buffer
This study evaluated the filtrate flux behavior of sucrose in solution, which is often used as an excipient for the formulation of biotherapeutics

Summary

Introduction

Antibody-based therapeutics have recently become the predominant class of drugs, with more than 80 approved and commercialized monoclonal antibodies (mAbs), since muromonab-CD3 (i.e., Orthoclone OKT3 as the first therapeutic mAb) was approved in 1986 [1,2]. Bioprocessing to manufacture antibody-based therapeutics is composed of an upstream process for growing cells capable of producing the desired pharmaceutical compounds and a downstream process for protein separation/purification [6]. The downstream process, which is important to determine the efficacy and stability of biotherapeutics, accounts for 30–50% of the total production costs (for particular therapeutics, this could be as much as 70%) [7]. This process comprises the following steps: clarification, primary capture, polishing, virus filtration, and formulation [8]. Highly concentrated protein solution has high viscosity, with a tendency to form aggregates in solution [11]. Excipients which either induce changes in the conformational or colloidal stability of proteins in solution are used to preserve the colloidal stability and guarantee reliable processing and safe formulations [12]

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