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.

A Discussion on Bio-Fluorescent Particle Counters: Summary of the Process and Environmental Monitoring Methods Working Group Meeting with the FDA Emerging Technology Team.

The Process and Environmental Monitoring Methods Working Group, composed of members from industry and instrument manufacturers, met with the FDA Emerging Technology Team to discuss bio-fluorescent particle counting technology, a type of rapid microbiological method. This is a summary of the meeting including submitted questions and answers, and the Process and Environmental Monitoring Methods Working Group's understanding of the FDA Emerging Technology Team's points made.

Disinfectant Efficacy: Understanding the Expectations and How to Design Effective Studies That Include Leveraging Multi-Site Data to Drive an Efficient Program.

For manufacturers of both sterile and nonsterile pharmaceuticals, there is an expectation that the manufacturing process is performed in a manner that prevents extraneous contamination so that the products are provided in a safe, integral, pure, and unadulterated form. As part of that process, cleaning and disinfection are an absolute necessity. Although cleaning and disinfection support control of microbial contamination through preventive and corrective action, specific compendia methods do not currently exist. The intent of this paper is to provide a general guidance on how to perform disinfectant efficacy validation and implementation. This includes how to make sure the concepts are understood, how to interpret facility data and utilize it to demonstrate control awareness for your facilities, and how to leverage the data to reduce redundancies in validation or verification. This paper represents the thoughts and best practices of the authoring team and their respective companies and provides an efficient way to qualify disinfectants without impacting the quality of the study. If you choose to follow the recommendations in this paper, you must ensure that the appropriate rationale is sound and the scientific data is documented. It is the belief of the authoring team that only then will this approach meet regulatory requirements.

Practical Applications of Biofluorescent Particle Counting in Environmental Monitoring Investigations.

Investigations into environmental monitoring (EM) excursions can be prolonged and do not always result in clear root causes or corrective and preventative actions. This article outlines how biofluorescent particle counting (BFPC) can be used in investigations to eliminate the inherent delays of culture-based methods. The application for investigations supplements routine EM, acting as a risk-reduction tool enabling real-time detection of viable microorganisms in air samples and supporting root cause analysis and remedial actions. The article includes guidance on how to use the technology, a real case study involving a mold excursion, and examples of business benefits achieved by various companies.

Continuous Microbiological Environmental Monitoring for Process Understanding and Reduced Interventions in Aseptic Manufacturing.

This paper provides recommendations for quality oversight, manufacturing operations, and industry perspective of regulatory expectations to enable aseptic facilities to move toward real-time and continuous microbiological environmental monitoring, thereby reducing interventions and future replacement of Grade A settle plates and nonremote active air sampling. The replacement of traditional monitoring with biofluorescent particle-counting systems provides an improvement in process understanding and product safety and reduces operator manipulations, assuring product quality and real-time process verification. The future state pharmaceutical technology roadmaps include gloveless isolators with real-time and continuous monitoring for aseptic manufacturing.LAY ABSTRACT: This paper advocates the use of an alternative and relatively new method of monitoring the air for contamination in biopharmaceutical manufacturing facilities. The alternative method is based on a type of instrument the authors refer to as a biofluorescent particle counter (BFPC). The BFPC method has the advantage of being able to detect airborne microorganisms continuously and to record the actual time of detection. The replacement of traditional monitoring with BFPC systems can provide better data, which can be used to improve the understanding of contamination risks in complex manufacturing processes, ultimately providing more confidence in product safety. The authors present data showing the suitability of BFPC. This immediate result is very useful for picking up early any possible contamination and should, therefore, provide a better way to monitor and control the risk of contamination. As traditional monitoring methods require manual manipulation, an additional advantage of BFPC systems is that they can reduce manual manipulations. Elimination of all interventions is a goal in the industry, because although they are tightly controlled, interventions are an unwanted potential source of contamination.

Microbiological Control for Affinity Capture Chromatography Processing: An Industry Perspective.

The purpose of this paper is to provide a summary of a BPOG-led industry survey of the microbiological control aspects of affinity chromatography processing in the biopharmaceutical industry. The document provides a summary of historical microbiological control concerns, coupled with industry-derived best practices, for material, equipment, and storage controls required to mitigate the potential for microbial ingress and contamination of chromatography resin and equipment. These best practice guidelines, which are derived from the members of the BPOG Bioburden Working Group, are intended to assist biopharmaceutical manufacturers to enhance microbial control and monitoring strategies for chromatography systems.

High-dose gamma irradiation for soft tissue allografts: High margin of safety with biomechanical integrity.

Screening and processing methods currently in place have made the risk of bacterial and viral infections from allograft tissues extremely low. However, the development of a terminal sterilization method that does not adversely affect tissue function would provide an added safety to tissues for transplantation. We assessed whether high-dose gamma irradiation could be used as an effective terminal sterilization method for allografts without impairing the preimplantation mechanical integrity of the tissues. Semitendinosus tendons were pretreated with a radioprotectant solution and then irradiated to 50 kGy under well-defined conditions that included a tight dose range and maintained low temperatures. Maximum force, strain, stress, modulus, and strain energy density for tendons irradiated to 50 kGy were compared to nonirradiated control tendons and tendons irradiated to 18 kGy by a commercial tissue bank using their existing method. The preimplantation biomechanical properties of the 50-kGy group compared favorably to the nonirradiated and 18 kGy groups. A study to evaluate the postimplantation mechanical and biological performance of grafts irradiated to 50 kGy is ongoing. Pathogen inactivation was also quantified following 50 kGy of irradiation, with > or =4.5 logs of Sindbis virus and 4.9 logs of parvovirus kill achieved. Analysis of Clostridium sordellii inactivation kinetics indicated that a 16 log10 reduction is predicted with 50 kGy of irradiation. A high dose of gamma irradiation using the described conditions can reduce infectious risks associated with soft tissue allografts while maintaining the preimplantation biomechanical performance of the tissues.

Effective use of optimized, high-dose (50 kGy) gamma irradiation for pathogen inactivation of human bone allografts.

The safety of tissue allografts has come under increased scrutiny due to recent reports of allograft-associated bacterial and viral infections in tissue recipients. We report that 50 kGy of gamma irradiation, nearly three times the dose currently used, is an effective pathogen inactivation method when used under optimized conditions that minimize damage to the tissue. Cancellous bone dowels treated with a radioprotectant solution and 50 kGy of optimized irradiation had an ultimate compressive strength and modulus of elasticity equal to conventionally irradiated (18 kGy) and non-irradiated control bone grafts. We subjected bone dowels treated with this pathogen inactivation method to an in vitro cytotoxicity test using three different mammalian cell lines and concluded that the treated grafts were not cytotoxic. The log reduction of nine pathogens spiked into radioprotectant-treated bone irradiated to 50 kGy was also tested. We achieved 4.9 logs of inactivation of a model virus for HIV and hepatitis C and 5 logs inactivation of a model virus for human parvovirus B-19. Complete inactivation (6.0-9.2 logs) of seven clinically relevant microorganisms was demonstrated. The results show that a combination of radioprotectants and optimized, high-dose gamma irradiation is a viable method for producing safer cancellous bone grafts that have the mechanical strength of existing grafts.

Controlled gamma-irradiation mediated pathogen inactivation of human urokinase preparations with significant recovery of enzymatic activity.

Human sources of urokinase have led to the contamination of in-process lots of commercially available material with human pathogens. Effective pathogen inactivation of urokinase preparations can be achieved through the use of gamma-irradiation. Additionally, the presence of a free radical scavenger (ascorbate) and the control of temperature have resulted in maintenance of the enzymatic activity of urokinase without a significant effect on the pathogen inactivation properties of gamma-irradiation. In this study we have optimized the conditions during gamma-irradiation to achieve inactivation of porcine parvovirus by 5 logs and vaccinia virus to levels below the limits of detection, while maintaining 92% of urokinase activity. Product specific optimization of gamma-irradiation has the potential to provide effective pathogen inactivation while maintaining substantial functional activity for many therapeutic proteins.

Effective use of gamma irradiation for pathogen inactivation of monoclonal antibody preparations.

Gamma irradiation has been used for decades as an effective method of pathogen inactivation of relatively inert materials. Until recently, its application to biologicals has resulted in unacceptable losses in functional activity. In this report we demonstrate that the damaging secondary effects of gamma irradiation can be controlled while maintaining the pathogen inactivation properties due to damage by primary effects. Control is achieved by a combination of protection from free radical damage to a monoclonal antibody through the use of the antioxidant ascorbate and by freeze-drying to minimize the potential for generating free radicals. The data demonstrate a synergy of these two approaches that results in quantitative recovery of functional activity while maintaining the ability to inactivate greater than 5 logs of porcine parvovirus infectivity.