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.

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.

Evidence against a bacterial endotoxin masking effect in biologic drug products by limulus amebocyte lysate detection.

The inability to detect endotoxin using compendia methods is a potential safety concern for patients due to the lack of endotoxin removal capabilities at the fill-finish stage in typical aseptic biologic drug product manufacturing. We have successfully demonstrated endotoxin challenge study recovery methodology using mammalian cell-produced biologic drug products and drug substances in citrate, histidine, phosphate, and sodium acetate buffer formulations containing polysorbate, challenged with an endotoxin analyte, for up to 6 months of storage. Successful recovery was similarly demonstrated for a preserved, peptide-containing drug product formulation. To isolate a potential masking-or low-endotoxin recovery-source, additional studies were performed to evaluate factors including product manufacturing contact surfaces, drug product matrix with and without polysorbate, individual matrix components, protein concentration, reagent suppliers, an orthogonal test method, and storage conditions. In all cases, acceptable recoveries were observed. Bacterial endotoxin is known to be chemically stable at physiological conditions. Purified endotoxin in aqueous conditions is likely to self-aggregate or bind to surfaces. Neither the nature of, nor the storage conditions of, the studied formulation matrices were shown experimentally to render the challenge endotoxin biologically inactive. The results highlight the importance of appropriate study design in assessing the recovery of endotoxins. LAY ABSTRACT: Bacterial endotoxin is a Gram-negative bacterial cell wall component that is harmful to humans at threshold concentrations, and it is not expected to be in aseptically-produced pharmaceutical medicines. It has been suggested that endotoxin cannot be detected over time in certain biopharmaceutical drug product formulations containing citrate, phosphate, and polysorbate components via an unknown masking mechanism. We have generated and present data here that indicate that endotoxin can be recovered in a variety of matrices, and under various experimental conditions.