Comparison of pyrogen assays by testing products exhibiting low endotoxin recovery.

The use of pyrogen tests to assess the risk of endotoxin in biological products has increased recently due to concerns of some regulatory authorities about products exhibiting low endotoxin recovery (LER). Manufacturers increasingly seek to reduce the use of animals unless essential to assure patient safety. The current study compares the ability of the monocyte activation test (MAT) and the bacterial endotoxin test (BET) to the rabbit pyrogen test (RPT) to detect endotoxin spikes in samples of products shown to exhibit LER. Product samples or water were spiked with endotoxin and held for three days or tested immediately in the BET, the RPT, and two variations of the MAT at the same time. Results show high sensitivity to endotoxin of both the BET and MAT, and much lower sensitivity of the RPT, indicating that much higher levels of reference standard endotoxin are required to induce pyrogenicity in the RPT than the 5 endotoxin units (EU) per kg common threshold. The results of the BET and MAT correlated well for the detection of endotoxin spike in water. We also show that LER (masking of endotoxin) found in the BET is also seen in the MAT and RPT, suggesting that the products themselves elicit a biological inactivation of spiked endotoxin over time, thereby rendering it less or non-pyrogenic. We conclude that the non-animal MAT option is a suitable replacement for the RPT to measure spiked endotoxin in biopharmaceuticals.

Study on equivalence between micro kinetic chromogenic assay and kinetic chromogenic assay / 中国药理学通报

Aim To evaluate the equivalence between micro kinetic chromogenic assay anrl kinetic chromogenic assay in order to provide data support for the use of alternative methods.Methods Detection conditions; micro kinetic chromogenic assay and kinetic chromogenic assay limulus reagent were used, sample amount of each well and limulus reagent was 25 jxL ( kinetic chromogenic assay was 100 jxL) , detection wavelength was 405 nm, ONSET OD value was 0.03, and half- well elisa plate was used for detection ( kinetic chromogenic assay was ordinary ELISA plate).The equivalence of the two methods was evaluated by various statistical methods, such as equivalence test, in collaboration with four laboratories in China.Results The results of one-way an OVA, paired T test and equivalence test were consistent, indicating that there were some differences between the existing kinetic chromogenic assay of different manufacturers, while there was no significant difference between the trace or conventional amount of reagent used by each manufacturer.Conclusions Micro kinetic chromogenic assay is e- quivalent to existing reagents in terms of accuracy and recoverv.J.

Standardized pyrogen testing of medical products with the bacterial endotoxin test (BET) as a substitute for rabbit Pyrogen testing (RPT): A scoping review.

The Bacterial Endotoxin Test (BET) is a method for exclusion of endotoxin-related pyrogen contamination in pharmaceutical products, as an alternative to the Rabbit Pyrogen Test (RPT). However, BET does not detect a broad range of biologically relevant pyrogens, and interferences can limit its practical use for different medical products. This work aimed to scope the evidence in the scientific literature for case-by-case validity assessments of BET in different uses for medical products. A search strategy was conducted in PubMed, Scopus, and Web of Science in April 2020, according to the PRISMA-ScR statement. Twenty-two references were included, evaluating medical products for endotoxin contamination through both BET and RPT according to standardized protocols. A critical appraisal was performed through ToxRTool, followed by data extraction and qualitative synthesis of outcomes and methodological issues. Four classes of products assessed by BET were identified, including nanoparticles, drugs, blood and biological products. A considerable variation was observed on the BET methods used. Collectively, the evidence indicates different factors influencing the outcome of BET, including the chemical nature of samples that may cause interference depending on the selected method. While some applications to medical products appear adequate, others, such as nanoparticles, may require the use of different in vitro pyrogen testing methods, reinforcing the need for case-by-case validation for each BET method and type of medical product.

Pyrogen testing revisited on occasion of the 25th anniversary of the whole blood monocyte activation test.

The whole blood pyrogen test invented 25 years ago, and its variant based on cryo-preserved blood one year later, brought momentum into the field of pyrogen testing, which, despite the broad application of the Limulus amebocyte lysate (LAL) assay, aka bacterial endotoxin test (BET), consumed several hundred thousand rabbits per year world-wide. The resulting international validation and lengthy acceptance and implementation process of what are called now monocyte activation tests (MATs) finally is impacting on animal numbers - at least in Europe - reducing them by more than 70% and counting. The author sees no reason for continuing any regulatory rabbit testing for pyrogens except the lack of acceptance of MATs in some regions of the world. The availability of MATs has opened also the discussion about the shortcomings of LAL/BET, namely its restriction to Gram-negative pyrogens, non-reflection of the potency of these in humans, interference and masking by many products, and animal welfare concerns for horseshoe crabs. The obvious advantages of MATs in all these respects should lead to a shift from LAL/BET to MATs. We are starting to see this for vac-cines and medical devices, but other areas like safety testing of blood transfusions, cell therapies and nanomaterials, and the assessment of air-borne pyrogens still need to grasp the opportunity provided by MATs. While the different MATs can jointly serve these needs, the whole blood MAT has some advantages as discussed here.

Using the monocyte activation test as a stand-alone release test for medical devices.

Monocyte activation tests (MAT) are widely available but rarely used in place of animal-based pyrogen tests for safety assessment of medical devices. To address this issue, the National Toxicology Program Interagency Center for the Evaluation of Alternative Toxicological Methods and the PETA International Science Consortium Ltd. convened a workshop at the National Institutes of Health on September 18-19, 2018. Participants included representatives from MAT testing laboratories, medical device manufacturers, the U.S. Food and Drug Administration's Center for Devices and Radiologic Health (CDRH), the U.S. Pharmacopeia, the International Organization for Standardization, and experts in the development of MAT protocols. Discussions covered industry experiences with the MAT, remaining challenges, and how CDRH's Medical Device Development Tools (MDDT) Program, which qualifies tools for use in evaluating medical devices to streamline device development and regulatory evaluation, could be a pathway to qualify the use of MAT in place of the rabbit pyrogen test and the limulus amebocyte lysate test for medical device testing. Workshop outcomes and follow-up activities are discussed.

Establishment of Bacterial Endotoxin Test for an Insoluble Drug Substance / 中国药师

Objective:To establish the bacterial endotoxin test for HSSYO-001-3S. Methods: HSSYO-001-3S was dissolved in dimethylsulfoxide,diluted by BET water and centrifuged,and then the supernatant was used for the bacterial endotoxin test. The ex-periment was carried out according to the gel-clot technique for bacterial endotoxin inspection and the related regulations in Chinese Pharmacopoeia (2015 edition,volumeⅣ,general rule 1443). Results:HSSYO-001-3S was added with cosolvent and diluted by BET water to 1 mg·ml-1,and there was no interference effects to bacterial endotoxin test from the supernatant diluted four times or more. Conclusion:Bacterial endotoxin test can be used to control the quality of HSSYO-001-3S.

Determination of Bacterial Endotoxin in Fat Emulsion(10%)/Amino Acid (15)/Glucose (20%) Injection by Gel Method / 中国药房

OBJECTIVE:To adopt gel method for the determination of bacterial endotoxin in Fat emulsion(10%)/amino acid (15)/glucose (20%) injection. METHODS:According to the gel method in term ofbacterial endotoxin test methodin Chinese Pharmacopeia(2015 edition),the maximal valid dilution(MVD)of samples were determined through interference test and the vali-dated. The results were compared with chromogenic method. RESULTS:In gel method,the interference to agglutination reaction of TAL and bacterial endotoxin can be excluded when samples were diluted 24 times or less. In chromogenic method,the samples should be diluted 76 times or less. CONCLUSIONS:Gel method can be used for bacterial endotoxin test of Fat emulsion(10%)/amino acid(15)/glucose(20%)injection.

Feasibility Study on Bacterial Endotoxin Test for Safflower Yellow for Injection / 中国药师

Objective:To establish a bacterial endotoxin test for safflower yellow for injection to control the drug quality and reduce the incidence of clinical pyrogenic reaction. Methods:The bacterial endotoxin test was carried out according to the methods and guid-ing principles in Chinese Pharmacopoeia ( 2015 edition, volumeⅣ) . A systematic study was carried out to investigate the interference of safflower yellow for injection with limulus reagent and agglutination reaction to bacterial endotoxin in order to detect the non-interfer-ence concentration of bacterial endotoxin. Results: Safflower yellow for injection with the concentration below or equal to 0. 4 mg· ml-1 had no interference with tachypiens amebocyte lysate. Conclusion: Bacterial endotoxin test ( gel method) can be used for the limit test of bacterial endotoxin of safflower yellow for injection, and the results are accurate and reproducible.

Endotoxin recovery using limulus amebocyte lysate (LAL) assay.

A phenomenon initially reported by Chen and Vinther in 2013 [1], and now commonly referred to as low endotoxin recovery (LER), has prompted the Food and Drug Administration (FDA) to request specific data demonstrating the capability of the LAL BET method (i.e., USP <85>) to recover endotoxin from spiked samples over time. The results of these spike/hold recovery studies are expected to be included in the Biologics License Applications (BLA) for review by the Center for Drug Evaluation and Research (CDER) Hughes (2014) and Hughes et al. (2015) [2,3]. Such studies involve spiking a known amount of a surrogate endotoxin, such as purified lipopolysaccharide (LPS), into undiluted biological products and then testing at different time points to determine the recovery over time. We report here the experience and learning gained from conducting spike/hold recovery studies for a monoclonal antibody (Mab) product. Results from initial hold studies spiked with purified LPS showed rapid loss of endotoxin activity in the drug substance (DS) and significant batch-to-batch variation in the drug product (DP). After careful review and examination of the experimental details, it was determined that the study design and execution differed from the routine batch release USP <85> BET method with regard to mixing time and sampling scheme. The hold study design was subsequently revised so that the mixing time and sampling were the same as the verified USP <85> BET method used for routine batch release testing. The spike/hold recovery studies were repeated and the results demonstrated that LPS could be consistently recovered over time. These findings highlight the importance of carefully controlling sample preparation procedures in a spike/hold recovery study in order to demonstrate the suitability of using the LAL BET method for endotoxin detection.

Implementing the Principle of the 3 Rs Through the Indian Pharmacopoeia.

Quality and safety tests are required for regulatory approval of drugs and pharmaceuticals in the country to guarantee minimum safety standards, and most of these tests include animal usage. In the case of biological medicines, these safety and quality tests have to be performed on a batch-to-batch basis and require a large number of animals. Russell and Burch's 1959 principle of the 3 Rs- replacement, reduction, and refinement-is now being increasingly adopted worldwide, and various national and international pharmacopoeias have taken initiatives to safeguard animals. This article details the Indian Pharmacopoeia Commission's initiative to implement the 3 Rs through the Indian Pharmacopoeia. Explored are the deletion of animal tests, such as the abnormal toxicity test at final lot for biologicals; the replacement of in vivo methods by in vitro methods; the reduction in the number of animals used where deletion of the animal test is not possible; and the refinement of tests to cause minimal suffering to the animals. In Indian Pharmacopoeia 2014, pyrogen testing using rabbits has been replaced by the bacterial endotoxin test in the majority of biological monographs-keeping in view international trends and, especially for vaccine monographs, validated in vitro tests such as the bacterial endotoxin test as an alternative to the pyrogen test where justified and authorized. Steps are taken for introducing a single-dilution assay for the potency testing of diphtheria and tetanus vaccine (adsorbed) with the aim of minimizing number of animals used. The justified and authorized use of animals in drug manufacturing, analytic laboratories, and research will not only help in the expedited development/production of drugs but also be useful in protecting and promoting animal health.

Establishment of Bacterial Endotoxin Test Method for Peramivir Hydrate and Sodium Chloride Injection / 中国药房

OBJECTIVE:To establish a method for bacteria1 endotoxin test for Peramivir hydrate and sodium chloride injec-tion. METHODS:Maximum non-interference concentration of the sample with different batohes were used for interference test. was determined by interference test according to endotoxin gel method stated in Chinese Pharmacopiea (2010 edition)and bacterial en-edotoxintest by tachypleus amebocyte lysate from 2 manufact urers. RESULTS:The interference on bacterial endotoxin test could be excluded when the sample was diluted to 2.5 mg/ml and the limit of bacterial endotoxins was 0.5 EU/ml. CONCLUSIONS:The established method can be used to detect the bacterial endotoxin of Peramivir hydrate and sodium chloride injection.

Analysis of the factors of how to build the bacterial endotoxin test laboratory with GPCL quality management concepts / 中国药学杂志

OBJECTIVE: To summarize and analyze the factors of building the bacterial endotoxin test laboratory. These factors should meet the GPCL quality management concepts. METHODS: Give Some specific methods and experience in five aspects were given, which combine the GPCL quality management concepts with the characteristics of bacterial endotoxin test. RESULTS AND CONCLUSION: Summarizes The applications of GPCL concept for bacterial endotoxin test laboratory is summarized.

Establishment of Bacterial Endotoxins Test for Brozopine / 中国药师

Objective:To establish bacterial endotoxin test for brozopine. Methods: Interference pre-test and interfering factors test were conduced on 3 batches of samples from 2 manufacturers to confirm the applicability of bacterial endotoxin test and the non-in-terfering concentration. The bacterial endotoxin test was carried out based on the method described in the second part of Chinese Phar-macopeia (2010 edition) and relevant standards and guidelines. Results: The three batches of brozopine showed no interference in bacterial endotoxin test at the concentration less than or equal to 2. 5 mg·ml-1 . The bacterial endotoxin test of the three bathes of samples all met the requirements. Conclusion:Bacterial endotoxin test can be used for the quality control of brozopine.

Gel clot bacterial endotoxin test of FDG: Indian scenario.

BACKGROUND: The bacterial endotoxin test (BET) performed using gel clot method is a 60-min test and typically performed after the decay of the 2-((18)F) fluoro-2-deoxy-d-glucose (F18-FDG) sample to determine the endotoxin content. The objective of this study protocol was to perform BET testing of F18-FDG by gel clot method. MATERIALS AND METHODS: Ten random decayed samples of the F18-FDG were subjected to the gel clot BET. The assay was performed with undiluted F18-FDG and at four different maximum valid dilutions of 1:10, 1:100, 1:350 and 1:700 (total number of tests = 100). The sensitivity of the LAL reagent used was 0.125 EU/ml. Endotoxin dilutions were freshly prepared from control standard endotoxin (CSE) stock solution for each F18-FDG batch testing. If the gel had formed and remained intact in the bottom of the reaction tube after an inversion of 180°, the test was considered positive. Any other state of the reaction mixture constituted a negative test. RESULTS: In the undiluted samples, the measured pH (7.05) was well within the acceptable range (i.e. 6.0-8.0) for the gel clot assay. Of the 10 undiluted F18-FDG batches and all the diluted samples, none gelled after 60-min incubation period at 37°C. However, the undiluted F18-FDG did inhibit gel formation at the lysate sensitivity of 0.125 EU/ml. CONCLUSION: The total volume of FDG produced was 16 ml in the synthesis module. The total F18-FDG preparation at any time did not contain more than 8 EU (0.5 EU/ml × 16 ml). Thus, the product is safe for human administration.

Improvement of the Method of Positive Control Test in Bacterial Endotoxin Test / 中国药房

OBJECTIVE:To improve the method of positive control test in bacterial endotoxin test.METHODS:A new method rather than a routine method was adopted for the bacterial endotoxin test in which the tachyplens amebocyte lysate(TAL)was dissolved directly by sample solutions or its diluted solution,which was then added with 2.0 ? endotoxins solution for positive control test for the common injections including metronidazole and glucose saline etc.RESULTS:The Et values of all the test samples detected by the improved method were similar to those by the routine method,which stood at 2.0 Es～0.5 Es,suggesting that the improved method has no interfere on the bacterial endotoxin test.CONCLUSION:The method is simple and time-saving.

Method of Bacterial Endotoxin Test of Fluorescein Sodium Injection / 中国药房

OBJECTIVE: To establish a bacterial endotoxin test method for fluorescein sodium injection.METHODS: Based on the bacterial endotoxin test method stated in Chinese Pharmacopoeia 2005 edition(second part),an interference test was conduced on different batches of fluorescein sodium samples using tachypleus amebocyte lysate from different companies.RESULTS: At a concentration of no more than 0.75 mg?mL-1,fluorescein sodium showed no interfere with the bacterial endotoxin test.CONCLUSION: It is feasible for bacterial endotoxin test of fluorescein sodium injection be conducted in a limit value of 0.15 EU?mL-1.

Detection of Bacterial Endotoxin in Floxuridine Injection / 中国药房

OBJECTIVE:To investigate the feasibility of bacterial endotoxin test(BET) for floxuridine(FuDR) injection and to perform the test.METHODS:To refer to BET in appendix of China Pharmacopoeia,edition 2000.RESULTS:Bacterial endotoxin could be detected in 60 times dilution of FuDR injection by limulus lysate with a sensitivity of 0.5EU/ml.CONCLUS_ION:BET for FuDR injection is feasible.

Experimental studies on bacterial endotoxin test of SAFFLOR INJECTION / 中草药

Object To establish a method for the determination of bacterial endotoxin in SAFFLOR INJECTION * Methods Thirty batches of SAFFLOR INJECTION were subjected to Limulus lysate test in comparison with pyrogen test to ascertain whether there are any interference between the lysate and SAFFLOR INJECTION Results SAFFLOR INJECTION showed no inhibition or enhancement actions in bacterial endotoxin test with Limulus lysate, while showed a 100% coincidental rate with pyrogen test Conclusion This method was found to be simple, quick, accurate and is suitable for the determination of bacterial endotoxin in SAFFLOR INJECTION

Interference test in bacterial endotoxins detection of Shenmai Freeze-dried Powder Injection / 中草药

Object To prove the feasibility of bacterial endotoxin test (BET) in Shenmai Freeze-dried Powder Injection by interference test. Methods Interference primary screening test and interference test were conducted in BET of Shenmai Freeze-dried Powder Injection to detect whether the interference existed or not and to explore the method of removing the interference. Results There was inhibition on BET with 0.5 EU/mL tachypleus amebocyte lysate (TAL). Interference could be excluded by using 0.25 EU/mL TAL and diluting the samples. Conclusion It is feasible to use 0.25 EU/mL TAL or TAL with more sensitivity in BET of Shenmai Freeze-dried Powder Injection.

Bacterial Endotoxins Test for Ilex Pubescens Compound Injection / 中药新药与临床药理

Objective To establish a method for the determination of bacterial endotoxin in Ilex pubescens compound injection(LPCJ) .Methods According to China Pharmacopoeia (second part,2000),interference test was carried out to detect the endotoxins in LPCJ with limulus lysate agents (?was 0.25 EU/mL).Results Inhibition action was found in bacterial endotoxin test for LPCJ and in the 10-,20-,30-and 40-fold diluted liquid of LPCJ.It was proved that the maximum noninterference concentration was the 50-fold dilution.The inspection results are the same as that of rabbit pyrogen test.Conclusion The 50-fold diluted LPCJ is suitable for the determination of bacterial endotoxin and can be used as the quality control standard for its preparation.