E56.08 - Nano-Enabled Medical Products

SIGNIFICANCE AND USE
5.1 Lipid composition in a liposomal formulation is an important aspect during synthesis of liposomes, which determines stability, surface characteristics, drug encapsulation, and drug release capabilities. The cholesterol component plays a key role in controlled drug release by adding stability to the liposome. A small variation in the lipid composition can significantly alter the parameters mentioned above (15).  
5.2 Variation in the lipid composition in the liposomal formulation may influence the safety and efficacy of the product. Therefore, chemical composition of the liposomes shall be determined.  
5.3 The pharmaceutical industry and regulatory agencies require QC, QA, specifications, thorough characterization, and quantification of lipid components (16, 17).  
5.4 This test method can be used to ascertain variations in the lipid component profiling of various liposomal formulations. However, this test method does not intend to identify chemical degradation products (18).  
5.5 Analyzing the stability of analytes and their chemical degradation profiles as a result of oxidation or hydrolysis is beyond the scope of this test method (18, 19).
SCOPE
1.1 This test method describes an analytical technique to quantify lipid components that are often present in liposomal formulations as major components.  
1.2 This test method uses high performance liquid chromatography (HPLC) to separate lipids in liposomal formulations and evaporative light-scattering detection (ELSD) to quantify the individual components.  
1.3 This test method quantifies three major organic components in liposomal formulations: cholesterol, 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DSPE-PEG 2000), and hydrogenated soy L-α-phosphatidylcholine (HSPC).  
1.4 This test method can estimate the absolute concentration of cholesterol, DSPE-PEG 2000, and HSPC and their ratio (DSPE-PEG 2000: HSPC: cholesterol) in liposomal formulations.  
1.5 This test method describes preparation of calibration standards and samples, HPLC and ELSD instrumentation, method development and method validation, sample analysis, and data reporting.  
1.6 The detection limits and quantitation limits for the analytes (lipid components) in this test method are in the range of 2 µg/g to 4 µg/g and 7 µg/g to 10 μg/g, respectively. The analytical measurement ranges for cholesterol, DSPE-PEG 2000, and HSPC are 10 µg/g to 165 µg/g, 10 µg/g to 300 µg/g, and 10 µg/g to 200 µg/g, respectively.  
1.7 Significant digits and rounding of all reported values have been performed according to the guidelines as established in Practice D6026.  
1.8 Units—The values stated in SI units are to be regarded as the standard. Where appropriate, c.g.s units in addition to SI units are included in this standard.  
1.9 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.  
1.10 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
5.1 This test method is designed to evaluate nanomaterial capacity to induce nitric oxide production by macrophages.  
5.2 Activated macrophages generate large quantities of NO. NO generated from activated macrophages is a cytostatic/cytotoxic agent (3-6).  
5.3 The production of NO in excessive amounts leads to the generation of peroxynitrite by its spontaneous reaction with superoxide. Peroxynitrite causes tissue injury through its capability to damage lipids, proteins, and DNA (2).  
5.4 NO is a proinflammatory mediator and it is an important marker for activation of inflammation (5, 6).  
5.5 Testing the capacity of a nanomaterial to induce NO production in vitro helps in predicting the nanomaterial’s biocompatibility through anticipating and understanding the potential problems that might be encountered during its in vivo administration.
SCOPE
1.1 This test method delivers a protocol for a quantitative measure of nitrite (NO2–), a stable end-product of nitric oxide (NO), in cell culture medium due to exposure to nanomaterial(s).  
1.2 NO has a critical role in several pathological conditions in addition to its role in many physiological processes.  
1.3 This test method uses murine macrophage cell line RAW 264.7 as an in vitro model.  
1.4 The nitrite is measured in the cell culture medium by a colorimetric analysis using Griess reagent as shown in Fig. 1.
FIG. 1 Summary of Nitric Oxide Production Assay  
1.5 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.  
1.6 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
5.1 Liposomes are vesicles of nanoscale dimensions, composed of lipid bilayers, which are used for various diagnostic and therapeutic applications (9). The growing interest in liposomal formulations in the delivery of various drugs, antisense oligonucleotides, cloned genes, or recombinant proteins by the biopharmaceutical industry, warrants QC and thorough characterization of the constituent lipids. Lipid structure, composition, and concentration are key attributes in determining the quality and efficacy of a liposomal drug product as they influence the stability of liposomes, drug loading, release kinetics, biodistribution, and pharmacokinetic properties (9). Cholesterol modulates the lipid membrane fluidity, elasticity, and permeability; hence, it plays a key role in controlled drug release and increased stability of the liposome (10).  
5.2 This test method provides a rapid and reliable protocol for the determination of cholesterol, DSPE-PEG 2000, and HSPC in liposomal formulations using UHPLC-TQMS. Assessment of the stability of the analytes in terms of their degradation profiles is not included in this test method (11). This test method will benefit the biopharmaceutical industry in ascertaining quality assessment of liposomal formulations and monitoring batch-to-batch consistency for large-scale production, thereby facilitating safe and efficient drug development and regulatory review.  
5.3 UHPLC-MS/MS measurements are analytically more sensitive and specific for lipid analysis compared to other contemporary techniques using universal detectors, such as a charged aerosol or an evaporative light-scattering detector. For liposomes, MS/MS has further advantages over ultraviolet detectors, as lipids lack chromophores for detection. In this test method, TQMS has been used as the MS/MS technique of choice because of its high selectivity, sensitivity, S/N, accuracy, and broad linear range of quantitation, thereby allowing reproducible quantitation of the analytes,...
SCOPE
1.1 This test method describes the determination of lipid components in liposomal formulations, which includes sample solubilization in methanol followed by separation of the analytes using ultra-high-performance liquid chromatography (UHPLC) and detection with tandem mass-spectrometry (MS/MS). This test method adheres to multiple reaction monitoring (MRM) mass spectrometry on a triple quadrupole mass spectrometer (TQMS).  
1.2 This test method is specific for liposomal formulations containing cholesterol, 1,2- distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy (polyethylene glycol)-2000] (DSPE- PEG 2000), and hydrogenated (soy) L-α-phosphatidylcholine (HSPC).  
1.3 This test method is applicable to report the absolute concentrations of cholesterol, DSPE-PEG 2000, and HSPC and their ratio (DSPE-PEG 2000: HSPC: cholesterol) in liposomal formulations. Assessment of the stability of the analytes in terms of their degradation as a result of oxidation or hydrolysis is beyond the scope of this test method.  
1.4 This test method includes calibration and standardization, sample preparation, UHPLC-TQMS instrumentation, potential interferences, method validation with acceptance criteria, sample analysis, and data reporting.  
1.5 The detection limits for cholesterol, DSPE-PEG 2000, and HSPC using this test method are 5.3, 0.5, and 0.5 ng/g, respectively. In addition, the quantitation limits for cholesterol, DSPE-PEG 2000, and HSPC are 10.6, 0.8, and 0.5 ng/g, respectively.  
1.6 This test method is intended for concentration ranges of 8-1600 ng/g for cholesterol, and of 2-400 ng/g for DSPE-PEG 2000 and HSPC.  
1.7 All observed and calculated values shall conform to the guidelines for significant digits and rounding as established in Practice D6026.  
1.8 Units—The values stated in SI units are to be regarded as the standard. Where appropriate, c.g.s units in addition to SI units are included in this standard.  
1.9 Th...

SIGNIFICANCE AND USE
5.1 The growing interest in liposomal formulations in the pharmaceutical industry requires QC and thorough characterization and quantification of lipids that form liposomes (6). Lipid composition has proven to be a critical attribute of the liposomal formulation; it directly influences the stability of the formulation, drug loading, performance, size, and surface characteristics of the liposome. Cholesterol plays a key role in controlled drug release by adding stability to the liposome (7). Significant variation in the lipid composition and ratio of the components will influence the safety, biodistribution, drug efficacy, and drug release kinetics of the liposomal formulation (8-11).  
5.2 This test method is a fast and reliable procedure for the quantification of cholesterol, DSPE-PEG 2000, and HSPC in liposomal formulations using HPLC-CAD.  
5.3 This test method can be used for QC and QA and to ascertain variations in component profiling of liposomal formulations.
SCOPE
1.1 This test method is for the separation of lipids in liposomal formulations through high performance liquid chromatography (HPLC) and their quantitation using a mass-flow sensitive charged aerosol detector (CAD).  
1.2 This test method is specifically for liposomal formulations containing cholesterol, 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DSPE-PEG 2000) and hydrogenated soy L-α-phosphatidylcholine (HSPC).  
1.3 This test method is applicable to report the absolute concentrations and ratio of cholesterol, DSPE-PEG 2000, and HSPC in liposomal formulations. Assessment of the stability of the analytes in terms of their degradation profiles as a result of oxidation or hydrolysis is beyond the scope of this test method.  
1.4 This test method includes calibration standards preparation, sample preparation, method validation, and sample analysis. This method also contains specifications for instrumentation and the chromatography experimental procedure.  
1.5 The detection limit and quantitation limit for the analytes in this test method is in the range of 0.1–2.0 µg/g and 1.0–5.0 μg/g respectively. The analytical measurement range for cholesterol, DSPE-PEG 2000, and HSPC is 5–300 µg/g.  
1.6 All observed and calculated values shall conform to the guidelines for significant digits and rounding as established in Practice D6026.  
1.7 Units—The values stated in SI units are to be regarded as the standard. Where appropriate, c.g.s units in addition to SI units are included in this standard.  
1.8 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.  
1.9 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
5.1 The information and recommendations in this guide are relevant for imaging and identifying ENMs in cells and other biological (for example, fixed tissues, whole plants) and nonbiological (for example, drug formulations, filter media, soil, and wastewater) matrices after appropriate sample preparation procedures have been performed (3-5). DFM/HSI is a recently developed analytical tool; however, the relative simplicity of sample preparation combined with the potential to acquire high-contrast ENM images and high-content ENM spectral responses facilitates the increasing use of the tool for diverse applications in drug delivery, toxicology, environmental science, biology, and medicine.  
5.2 Verification of the uptake and spatial distribution of ENMs in cells, for example, is necessary for evaluating and understanding the biological effects of ENMs on living systems. Similarly, the closeness of the spatial distribution of ENMs in complex drug formulations can be an important criterion in establishing physicochemical similarity between formulations (6). Complex products are described in the most recent version of the Generic Drug User Fee Act (GDUFA) reauthorization commitment letter: (7). This guide covers the criteria and general considerations for performing DFM/HSI analyses on samples of biological and nonbiological origins containing ENMs (for example, metal and metal oxide nanoparticles, or carbon nanotubes, or both). This guide does not cover or address provisions for imaging or identifying, or both, non-engineered (natural) nanoparticles/nanomaterials in cells or other matrices, nor does this guide describe or discuss the application of DFM/HSI for determining the dimensions of ENMs.
SCOPE
1.1 This guide has been prepared to familiarize laboratory scientists with the background information and technical content necessary to image and identify engineered nanomaterials (ENMs) in cells via darkfield microscopy/hyperspectral imaging (DFM/HSI) methodology.  
1.2 DFM/HSI is a hyphenated bioanalytical technique/tool that combines optical microscopy with high-resolution spectral imaging to both spatially localize the distribution of and identify ENMs within a suitably prepared test sample.  
1.2.1 In the context of mammalian cells, ENMs will have distinctive light-scattering properties in comparison to subcellular organelles and cell structural features, which can allow one to discriminate between the spectral profiles of ENMs and cellular components.  
1.2.2 The light-scattering properties of ENMs in other test samples, such as fixed tissues, plants, complex drug product formulations, filter media, and so forth, will also be different from the native matrix component scattering signals inherent to these other types of samples, thus allowing for ENM visualization and identification.  
1.3 This guide is applicable to the use of DFM/HSI for identifying ENMs in the matrices mentioned.  
1.4 This guide describes and discusses basic practices for setting up and using DFM/HSI instrumentation, sample imaging techniques, considerations for optics, image analysis, and the use of reference spectral libraries (RSLs). DFM/HSI is routinely used in industry, academia, and government as a research and development and quality control tool in diverse areas of nanotechnology.  
1.5 The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.  
1.6 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.  
1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of Internati...

SIGNIFICANCE AND USE
5.1 This test method will assess whether the test nanoparticulate material has chemoattractant activity.  
5.2 This test method will provide a rapid and quantitative measure of the ability of nanoparticulate material to recruit immune cells.  
5.3 Recruitment of immune cells by chemotaxis plays an important part in all phases of both humoral and cell-mediated immune responses.  
5.4 Testing the capacity of a nanoparticulate material to recruit immune cells in vitro helps in predicting the influence of such material on the immune cell response.
SCOPE
1.1 This test method provides a protocol for rapid and quantitative measurement of the chemoattractant capacity of a nanoparticulate material (nanoparticles and their aggregates and agglomerates).  
1.2 Immune cells recruitment (by chemotaxis) plays a central role in the immune system function especially in the inflammatory process.  
1.3 This test method uses an in vitro model. In this model, peripheral blood human acute promyelocytic leukemia cells HL-60 are separated from control chemoattractant or test nanoparticulate material by a 3-µm pore size filter; the cell migration through the filter is monitored and quantified using the fluorescent dye calcein AM (Figs. 1 and 2).
FIG. 1 Chemotaxis Chamber (Boyden Chamber)
FIG. 2 Chemotaxis Assay
a (left)—Parts of the chemotaxis assay assembly.
b (right)—Procedure for testing the chemoattractant capacity of a nanoparticulate material.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 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.  
1.6 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
5.1 Lipid composition in a liposomal formulation is an important aspect during synthesis of liposomes, which determines stability, surface characteristics, drug encapsulation, and drug release capabilities. The cholesterol component plays a key role in controlled drug release by adding stability to the liposome. A small variation in the lipid composition can significantly alter the parameters mentioned above (15).  
5.2 Variation in the lipid composition in the liposomal formulation may influence the safety and efficacy of the product. Therefore, chemical composition of the liposomes shall be determined.  
5.3 The pharmaceutical industry and regulatory agencies require QC, QA, specifications, thorough characterization, and quantification of lipid components (16, 17).  
5.4 This test method can be used to ascertain variations in the lipid component profiling of various liposomal formulations. However, this test method does not intend to identify chemical degradation products (18).  
5.5 Analyzing the stability of analytes and their chemical degradation profiles as a result of oxidation or hydrolysis is beyond the scope of this test method (18, 19).
SCOPE
1.1 This test method describes an analytical technique to quantify lipid components that are often present in liposomal formulations as major components.  
1.2 This test method uses high performance liquid chromatography (HPLC) to separate lipids in liposomal formulations and evaporative light-scattering detection (ELSD) to quantify the individual components.  
1.3 This test method quantifies three major organic components in liposomal formulations: cholesterol, 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DSPE-PEG 2000), and hydrogenated soy L-α-phosphatidylcholine (HSPC).  
1.4 This test method can estimate the absolute concentration of cholesterol, DSPE-PEG 2000, and HSPC and their ratio (DSPE-PEG 2000: HSPC: cholesterol) in liposomal formulations.  
1.5 This test method describes preparation of calibration standards and samples, HPLC and ELSD instrumentation, method development and method validation, sample analysis, and data reporting.  
1.6 The detection limits and quantitation limits for the analytes (lipid components) in this test method are in the range of 2 to 4 µg/g and 7 to 10 μg/g, respectively. The analytical measurement ranges for cholesterol, DSPE-PEG 2000, and HSPC are 10 to 165 µg/g, 10 to 300 µg/g, and 10 to 200 µg/g, respectively.  
1.7 Significant digits and rounding of all reported values have been performed according to the guidelines as established in Practice D6026.  
1.8 Units—The values stated in SI units are to be regarded as the standard. Where appropriate, c.g.s units in addition to SI units are included in this standard.  
1.9 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.  
1.10 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.