Zhou Chen, Krueger Aaron B, Barnard James G, Qi Wei, Carpenter John F
Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, 80045.
J Pharm Sci. 2015 Aug;104(8):2441-50. doi: 10.1002/jps.24510. Epub 2015 May 27.
Submicron particles may play important roles in therapeutic protein product quality, stability, and adverse effects in patients. However, quantitation of these particles has been challenging. Nanoparticle tracking analysis (NTA) is capable of both sizing and counting submicron particles. We investigated the effects of product and instrument parameters on NTA results for nanoparticle standards and therapeutic protein samples. To obtain proper particle size distributions, complete tracking numbers of at least 200 and 400 were required for latex nanobeads and protein nanoparticles, respectively. In addition, when set at suboptimal values, the minimum expected particle size parameter led to inaccurate sizing and counting for all particles types investigated. A syringe pump allowed for higher sampling volumes, and results were reproducible for nanoparticle sizing and counts at flow rates ≤7 μL/min. Finally, because therapeutic protein products are being formulated at relatively high protein concentrations, we investigated the effects of protein concentration on nanoparticle characterization. With high protein concentrations, nanoparticle sizing was not affected, whereas particle concentrations were significantly reduced. Linear relationships between particle count and dilution factor were obtained when a high protein concentration formulation was diluted into particle-free solutions at the same protein concentrations, but not when dilutions were made into buffer.
亚微米颗粒可能在治疗性蛋白质产品质量、稳定性以及对患者的不良反应中发挥重要作用。然而，对这些颗粒进行定量分析一直具有挑战性。纳米颗粒跟踪分析（NTA）能够对亚微米颗粒进行大小测定和计数。我们研究了产品和仪器参数对纳米颗粒标准品和治疗性蛋白质样品NTA结果的影响。为了获得合适的颗粒大小分布，乳胶纳米珠和蛋白质纳米颗粒分别需要至少200和400的完整跟踪数。此外，当设置为非最佳值时，最小预期颗粒大小参数会导致所研究的所有颗粒类型的大小测定和计数不准确。注射泵可实现更高的进样体积，并且在流速≤7 μL/min时，纳米颗粒大小测定和计数结果具有可重复性。最后，由于治疗性蛋白质产品的配方中蛋白质浓度相对较高，我们研究了蛋白质浓度对纳米颗粒表征的影响。在高蛋白浓度下，纳米颗粒大小不受影响，而颗粒浓度显著降低。当将高蛋白浓度配方稀释到相同蛋白质浓度的无颗粒溶液中时，颗粒计数与稀释因子之间呈线性关系，但稀释到缓冲液中时则不然。
