Factors Governing the Precision of Subvisible Particle Measurement Methods – A Case Study with a Low-Concentration Therapeutic Protein Product in a Prefilled Syringe

Abstract

Purpose The current study was performed to assess the precision of the principal subvisible particle measurement methods available today. Special attention was given to identifying the sources of error and the factors governing analytical performance. Methods The performance of individual techniques was evaluated using a commercial biologic drug product in a prefilled syringe container. In control experiments, latex spheres were used as standards and instrument calibration suspensions. ResultsThe results reported in this manuscript clearly demonstrated that the particle measurement techniques operating in the submicrometer range have much lower precision than the micrometer size-range methods. It was established that the main factor governing the relatively poor precision of submicrometer methods in general and inherently, is their low sampling volume and the corresponding large extrapolation factors for calculating final results. ConclusionsThe variety of new methods for submicrometer particle analysis may in the future support product characterization; however, the performance of the existing methods does not yet allow for their use in routine practice and quality control.KEY WORDS subvisible particles . precision . particle counting methods . protein particles ABBREVIATIONS CC Coulter counter CV Coefficient of variance ECD Equivalent circular diameter MFI Micro flow imaging LO Light obscuration NTA Nanoparticle tracking analysis PFS Pre-filled syringe r.h. Relative humidity RMM Resonant mass measurement RMM (+) Positively buoyant particles detected by RMM RMM (−) Negatively buoyant particles detected by RMM

Factors Governing the Accuracy of Subvisible Particle Counting Methods

“…Consequently, the different technical principle of each methodology implies different outcomes, both in terms of analytical performance 26 (and this publication) and particle assessments. 9 This highlights the importance of developing a more complete understanding of the analytical performance of particle counting methodologies.…”

“…Recently, we reported on the factors governing the precision of subvisible particle measurement methods 26 in a detailed analysis of such an extensive analytical toolbox for subvisible particle characterization. In contrast, the aim of the present article was to study the accuracy of these methods and analyze the factors controlling it in a realistic, integrative, and systematic approach.…”

Evaluation of aggregate and silicone-oil counts in pre-filled siliconized syringes: An orthogonal study characterising the entire subvisible size range

“…The substantial differences in sampled volumes across the three techniques in the present study: RICS (~2 x 10 -9 mL) < RMM (~4 x 10 -6 mL and ~1 x 10 -4 mL by the nano and micro sensors, respectively) < MFI (3 x 10 -1 mL), may explain the differences observed in the data in the overlapping size ranges between the techniques. Low sampled volumes reduce the likelihood of detecting larger particles present in low concentrations (Anacelia Ríos Quiroz 2015). On the other hand, a significant sample volume is required to generate statistically significant particle counts per dose unit.…”

“…between protein and foreign matter, such as silicone-oil. In response to this predicament, in the last decade several new analytical technologies have been introduced in order to detect and characterise aggregates; offering the capability to extend the detectable size range of particles from 30 nm to 10 m, through combining orthogonal technologies (Anacelia Ríos Quiroz 2015). For example, the recently developed Resonance Mass Measurement (RMM) system (Archimedes) has been utilised alongside MFI, as a particle metrology tool to bridge the analytical size 'gap' for particulates in the 0.5-5 µm size range, and similar to MFI, discriminate between silicone-oil droplets and protein aggregates.…”

“…However, the focus of the study was on large sub-micron and micron-sized particles through the utilisation of the RMM 'micro sensor', with a lower detection limit of 0.5 m (Pharmacopeia, 2011;Weinbuch et al, 2013b). Table 1: Common terminology used for various protein aggregate size ranges Narhi et al, 2012;Ríos Quiroz et al, 2015;Zolls et al, 2012).…”