Nanoparticulate Impurities in Pharmaceutical-Grade Sugars and their Interference with Light Scattering-Based Analysis of Protein Formulations.

Daniel Weinbuch,Wim Jiskoot,Andrea Hawe,Jurgen Ketelaars,John Den Engelsman,Vasco Filipe,Jason K Cheung

doi:10.1007/s11095-015-1634-1

Abstract

PurposeIn the present study we investigated the root-cause of an interference signal (100–200 nm) of sugar-containing solutions in dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA) and its consequences for the analysis of particles in biopharmaceutical drug products.MethodsDifferent sugars as well as sucrose of various purity grades, suppliers and lots were analyzed by DLS and NTA before and (only for sucrose) after treatment by ultrafiltration and diafiltration. Furthermore, Fourier transform infrared (FTIR) microscopy, scanning electron microscopy coupled energy-dispersive X-ray spectroscopy (SEM-EDX), and fluorescence spectroscopy were employed.ResultsThe intensity of the interference signal differed between sugar types, sucrose of various purity grades, suppliers, and batches of the same supplier. The interference signal could be successfully eliminated from a sucrose solution by ultrafiltration (0.02 μm pore size). Nanoparticles, apparently composed of dextrans, ash components and aromatic colorants that were not completely removed during the sugar refinement process, were found responsible for the interference and were successfully purified from sucrose solutions.ConclusionsThe interference signal of sugar-containing solutions in DLS and NTA is due to the presence of nanoparticulate impurities. The nanoparticles present in sucrose were identified as agglomerates of various impurities originating from raw materials.Electronic supplementary materialThe online version of this article (doi:10.1007/s11095-015-1634-1) contains supplementary material, which is available to authorized users.

Highlights

The safety and efficacy of a therapeutic protein depends in part on its chemical and physical stability
Profound evidence that the presence of suspended particles is responsible for the interference signal comes from the results shown in Fig. 2a and b, where this signal in dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA) disappeared after ultrafiltration (0.02 μm)
In this study we demonstrated that sugar, even in pharmaceutical-grade quality, can contain up to 109 nanoparticles per gram in the 100–200 nm range, which can limit the use of techniques for subvisible particle analysis, such as DLS and NTA

Summary

Introduction

The safety and efficacy of a therapeutic protein depends in part on its chemical and physical stability. Degradation, such as aggregation, of a therapeutic protein can reduce the availability of the protein’s active form, can negatively affect its pharmacokinetic properties and might cause adverse effects, such as unwanted immunogenicity [1,2,3]. To enhance the chemical and physical stability of a protein therapeutic, biopharmaceutical drug products contain a combination of specific formulation additives to ensure the chemical and physical stability of the therapeutic protein. Sugars are extensively used for lyophilized protein formulations as cryoprotectors and lyoprotectors, e.g., Herceptin®, Serostim® and Remicade [7]. As with all reagents that are approved for the use in pharmaceutical drug products, testing procedures and purity criteria of sugars are defined and regulated by the respective pharmacopeias

Methods

Results

Discussion

Conclusion