1.1 本规范涵盖了应用自动膜显微镜（AMM）测量胃肠外药物生产过程和药品中存在的外来固体不溶性微粒的测试方法的验证要求。有关AMM测试方法开发的广泛指导，请参见指南 E3425 . 1.2 在AMM测试方法中，通过膜过滤器过滤含有悬浮颗粒的测试液体，颗粒保留在膜过滤器的表面上，用光学显微镜和数码相机对膜过滤器表面成像，并应用图像分析软件确定颗粒计数和颗粒尺寸。 1.3 AMM测试方法可应用于亚可见（<100µm）或可见（ ≥ 100µm）或在肠胃外药物生产的任何阶段存在的颗粒物。 1.4 由AMM测试方法表征的测试液体可以是工艺流体、药物物质或药物产品，或来自加工设备、药物容器、递送装置及其部件表面的液体提取物。 1.5 该实践不适用于肠胃外悬浮液固有颗粒(例如细胞、蛋白质聚集体或疫苗佐剂)的表征或液滴(例如硅油)的表征。 1.6 单位- 以SI单位表示的值将被视为标准值。本标准不包括其他计量单位。 1.7 本标准并不旨在解决与其使用相关的所有安全性问题（如果有）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践并确定法规限制的适用性。 1.8 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ======意义和用途====== 4.1 从质量风险管理角度（ICH Q9），最终胃肠外制剂中的外来固体和不溶性微粒是一种潜在危害，除了可能降低制剂质量、疗效和可用性外，还可能对接受制剂的患者造成伤害。药品中微粒发生概率的最小化取决于从起始成分到最终药品的整个药品生产过程中是否符合现行药品生产质量管理规范（cGMP）。如USP<788>和相关USP以及等效协调欧洲（EP 2.9.19）和日本（JP 6.07）专论中所述，100%目视检查以及最终药品的不溶性（<100µm）微粒取样和破坏性检测可实现肠胃外药品中微粒的良好可检测性。 4.2 在USP<788>方法2显微颗粒计数测试中，悬浮在液体中的颗粒被过滤到膜过滤器上，并且在受控的照明条件下，在显微镜下使用由限定的检查区域和参考圆组成的标线对收集在膜过滤器上的颗粒进行手动计数和尺寸分类直径为10 μ m和25 μ m的颗粒。发现的粒子数 ≥ 10µm和 ≥ 25µm。方法2是劳动密集型的，并且容易出现人为错误，因为每个颗粒都由人工分析员单独进行尺寸分类和计数。 4.3 药典章节还描述了测量悬浮在液体中的颗粒物的自动化方法。在USP<788>方法1光遮蔽颗粒计数测试中，将悬浮在液体中的颗粒吸入管中，通过光束检测器，并且当光束由于颗粒对光的散射或吸收或两者而衰减时，对颗粒进行计数。通过与用球形粒度标准获得的校准进行比较，由颗粒衰减的光与粒度相关。因此，USP<788>方法1的输出是等效圆直径。请注意，USP<1788.1>指出，根据仪器和配置，光遮蔽可用于1µm至300µm的近似粒径范围。或者，USP<1788>、<1788.3>和指南 E3060 描述流动成像，其中探测器是成像系统，图像分析确定颗粒大小。USP<1787>中描述了具体适用于治疗性蛋白质注射的测量技术。 4.4 此外，USP<1788.2>第6节讨论了测量膜过滤器表面颗粒物的“自动化方法”。在USP<1788.2>中，指出随着自动化，根据USP<788>方法2对颗粒进行手动尺寸分类所需的“与主观人为决策和制表相比，客观准确度和精密度的潜力增加”。4.5 本实施规程描述了自动膜显微镜（AMM）测试方法的验证要求，该测试方法旨在计数和确定胃肠外药物生产中存在的微粒。在AMM测试方法中，通过膜过滤器过滤含有悬浮颗粒的测试液体，颗粒保留在膜过滤器的表面上，用光学显微镜和数码相机对膜过滤器表面成像，并应用图像分析软件确定颗粒计数和颗粒尺寸。 4.6 将AMM应用于肠胃外药物生产中可能存在的各种颗粒物的计数和尺寸测定的测试方法的验证存在重大挑战。在肠胃外药物制造的各个阶段中，可以发现由不同材料组成、大小和形态不同的颗粒。固体和不溶性颗粒物质可包括但不限于纺织纤维、毛发纤维、纸纤维、塑料和弹性体颗粒、金属和陶瓷颗粒、皮肤薄片、灰尘、昆虫部分和其他有机物。半固体颗粒(例如蛋白质聚集体)或液滴(例如硅油)可能部分或完全穿透膜过滤器，因此通常不能通过AMM测试方法测量。AMM测试方法可用于测量细胞和基因疗法中药物产品、疫苗佐剂和细胞固有的颗粒物质。然而，固有颗粒的AMM测试方法的开发和验证超出了本实践的范围。 4.7 颗粒物质可从制剂成分和加工设备带入最终药物产品中。颗粒物质也可以经由最终容器和药物递送装置连同其部件(例如，玻璃容器、弹性体封闭件、注射器组件和输液袋)一起被携带到最终药物产品中。各种指南和标准文件描述了通过一次性工艺设备表面的液体萃取产生适用于AMM测试方法的测试液体的方法（实践 E3230 ）、最终容器材料（ISO 8871）、 10 和药物输送装置（VDI 2083第21部分），以及“难以检查”药品中颗粒物的分析程序。 11 4.8 本规范适用于AMM测试方法的验证，用于测量通常定义的亚可见（<100µm）和可见（ ≥ 100µm)颗粒，如药典所述。在本实践中，建议使用最大费雷特直径作为特征粒度参数。其他颗粒形态参数的测定不在本实施范围内。

1.1 This practice covers the requirements for validation of test methods that apply automated membrane microscopy (AMM) to the measurement of extraneous solid insoluble particulate matter present in parenteral pharmaceutical manufacturing processes and drug products. For extensive guidance on the development of AMM test methods see Guide E3425 . 1.2 In an AMM test method, a test liquid containing suspended particles is filtered through a membrane filter, the particles are retained on the surface of the membrane filter, the membrane filter surface is imaged with an optical microscope and digital camera, and application of image analysis software determines particle count and particle sizes. 1.3 AMM test methods may be applied to the measurement of the commonly defined size categories of subvisible (<100 µm) or visible ( ≥ 100 µm) or both particulate matter present during any stage of the manufacturing of parenteral pharmaceuticals. 1.4 The test liquid characterized by an AMM test method may be a process fluid, drug substance or drug product, or liquid extracts from the surfaces of processing equipment, drug containers, delivery devices, and components thereof. 1.5 This practice does not apply to the characterization of particles inherent to parenteral suspensions (for example, cells, protein aggregates, or vaccine adjuvants) or the characterization of liquid droplets (for example, silicone oil). 1.6 Units— The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 4.1 From a quality risk management perspective (ICH Q9), extraneous solid and insoluble particulate matter in a final parenteral drug product is a potential hazard that may cause harm to the patient receiving the drug product in addition to potentially reducing drug product quality, efficacy, and availability. Minimization of the probability of occurrence of particulate matter in a drug product depends upon conformance to current good manufacturing practices (CGMPs) along the entire pharmaceutical manufacturing process from starting ingredients to final drug product. Good detectability of particulate matter in parenteral drug products results from the required combination of 100 % visual inspection, along with sampling and destructive testing of final drug products for subvisible (<100 µm) particulate matter as described in USP <788> and related USP and equivalent harmonized European (EP 2.9.19) and Japanese (JP 6.07) monographs. 4.2 In the USP <788> Method 2 microscopic particle count test, particles suspended in liquid are filtered onto a membrane filter, and under controlled illumination conditions, the particles collected on the membrane filter are manually counted and size classified under a microscope using a reticule consisting of a defined inspection field and reference circles (graticules) of 10 µm and 25 µm diameter. The number of particles found ≥ 10 µm and ≥ 25 µm are reported. Method 2 is labor intensive and susceptible to human error since each particle is individually size classified and counted manually by the human analyst. 4.3 The pharmacopoeial chapters also describe automated methods for the measurement of particulate matter suspended in liquid. In the USP <788> Method 1 light obscuration particle count test, a particle suspended in liquid is drawn into a tube, passes through a light beam detector, and the particle is counted when the light beam is attenuated because of scattering or absorption or both of light by the particle. The light attenuated by the particle is related to a particle size via comparison with a calibration obtained with spherical particle size standards. Thus, the output of USP <788> Method 1 is an equivalent circular diameter. Note that USP <1788.1> indicates that light obscuration is useful for an approximate particle size range from 1 µm to 300 µm depending upon instrument and configuration. Alternately, USP <1788>, <1788.3>, and Guide E3060 describe flow imaging, in which the detector is an imaging system, and image analysis determines particle size. Measurement techniques specifically applicable to therapeutic protein injections are described in USP <1787>. 4.4 In addition, “automated approaches” to the measurement of particulate matter on the surface of a membrane filter are discussed in Section 6 of USP <1788.2>. In USP <1788.2>, it is noted that, with automation, “there is increased potential for objective accuracy and precision versus subjective human decision and tabulation” required in the manual size classification of particles as per USP <788> Method 2. 4.5 This practice describes the requirements for validation of automated membrane microscopy (AMM) test methods designed to count and size particulate matter present in the manufacturing of parenteral pharmaceuticals. In an AMM test method, a test liquid containing suspended particles is filtered through a membrane filter, the particles are retained on the surface of the membrane filter, the membrane filter surface is imaged with an optical microscope and digital camera, and application of image analysis software determines particle count and particle sizes. 4.6 Significant challenges arise in the validation of test methods applying AMM to the counting and sizing of the wide variety of particulate matter potentially present in parenteral pharmaceutical manufacturing. Particles composed of different materials, varying in size and morphology, may be found in the various stages of parenteral pharmaceutical manufacturing. Solid and insoluble particulate matter may include, but is not limited to, textile fibers, hair fibers, paper fibers, plastic and elastomeric particles, metal and ceramic particles, skin flakes, dust, insect parts, and other organic matter. Semi-solid particles (for example, protein aggregates) or liquid droplets (for example, silicone oils) may partially or completely penetrate membrane filters and, thus, are not usually measurable by an AMM test method. An AMM test method may be useful for the measurement of particulate matter inherent to drug products, vaccine adjuvants, and cells in cell and gene therapies. However, the development and validation of AMM test methods for inherent particles is out of the scope of this practice. 4.7 Particulate matter may be carried into the final drug product from formulation ingredients and processing equipment. Particulate matter may also be carried into the final drug product via final containers and drug delivery devices, along with components thereof (for example, glass containers, elastomeric closures, syringe assemblies, and infusion bags). Various guidance and standards documents describe methods for generation of test liquids suitable for AMM test methods via liquid extraction of the surfaces of single-use process equipment (Practice E3230 ), final container materials (ISO 8871), 10 and drug delivery devices (VDI 2083 Part 21), along with procedures for the analysis of particulate matter in “difficult to inspect” drug products. 11 4.8 This practice is applicable to the validation of AMM test methods for measurement of particles in both the commonly defined size categories of subvisible (<100 µm) and visible ( ≥ 100 µm) particles as described in the pharmacopoeias. In this practice, the use of the maximum Feret diameter as a characteristic particle size parameter is recommended. Determination of other particle morphology parameters is out of the scope of this practice.