Towards an Understanding of the Adsorption of Vaporized Hydrogen Peroxide (VHP) Residues on Glass Vials After a VHP Decontamination Process Using a Miniaturized Tool

Vaporized Hydrogen Peroxide Sterilization in the Production of Protein Therapeutics: Uptake and Effects on Product Quality

The aseptic filling of drug products is carried out in pharmaceutical isolators that have been sterilized. A commonly used method for achieving a high level of sterility assurance is vaporized hydrogen peroxide (VHP) sterilization, which is favorable to other methods, such as ethylene oxide sterilization, due to its low cycle times and nontoxic residuals. While VHP cycles are often employed to create a sterile environment within an isolator, they can leave residual levels of hydrogen peroxide behind that can enter the product during fill-finish operations. Due to the oxidizing potential of hydrogen peroxide and the multiple possible sources of uptake along filling lines, the extent of the potential impact on product quality needs to be understood during pharmaceutical development. Herein, different factors affecting hydrogen peroxide uptake, points of entry along the filling line, and possible impacts on product quality are reviewed.

Development of a multiplex-based immunoassay for the characterization of diphtheria, tetanus and acellular pertussis antigens in human combined DTaP vaccines

Routine batch quality testing before vaccine release, notably for potency evaluation, still relies on animal use for several animal and human vaccines. In this context, the VAC2VAC project is a public-private consortium of 22 partners funded by EU whose the main objective is to reduce the number of animal used for batch testing by developing immunoassays that could be implemented for routine potency assessment of vaccines. This paper focused on the development of a Luminex-based multiplex assay to monitor the consistency of antigen quantity and quality throughout the production process of DTaP vaccines from two human vaccine manufacturers. Indepth characterized monoclonal antibody pairs were used for development and optimization of the Luminex assay with non-adsorbed and adsorbed antigens and with complete vaccine formulations from both manufacturers. The multiplex assay demonstrated good specificity, reproducibility and absence of cross-reactivity. Analysis of over and underdosed formulations, heat and H2O2-degraded products as well as batch to batch consistency of vaccines from both manufacturers brought the proof of concept for a future application of the multiplex immunoassay as a useful tool in the frame of DTaP vaccine quality control.

Stress Factors in Protein Drug Product Manufacturing and Their Impact on Product Quality

Injectable protein-based medicinal products (drug products, or DPs) must be produced by using sterile manufacturing processes to ensure product safety. In DP manufacturing the protein drug substance, in a suitable final formulation, is combined with the desired primary packaging (e.g., syringe, cartridge, or vial) that guarantees product integrity and enables transportation, storage, handling and clinical administration. The protein DP is exposed to several stress conditions during each of the unit operations in DP manufacturing, some of which can be detrimental to product quality. For example, particles, aggregates and chemically-modified proteins can form during manufacturing, and excessive amounts of these undesired variants might cause an impact on potency or immunogenicity. Therefore, DP manufacturing process development should include identification of critical quality attributes (CQAs) and comprehensive risk assessment of potential protein modifications in process steps, and the relevant steps must be characterized and controlled. In this commentary article we focus on the major unit operations in protein DP manufacturing, and critically evaluate each process step for stress factors involved and their potential effects on DP CQAs. Moreover, we discuss the current industry trends for risk mitigation, process control including analytical monitoring, and recommendations for formulation and process development studies, including scaled-down runs.

Chemical-gas Sterilization of External Surface of Polymer-based Prefilled Syringes and Its Effect on Stability of Model Therapeutic Protein

To reduce the risk of infection during intravitreal injections, the external surface of prefilled syringes (PFSs) must be sterilized. Usually, ethylene oxide (EO) gas or vaporized hydrogen peroxide (VHP) is used for sterilization. More recently, nitrogen dioxide (NO₂) gas sterilization has been developed. It is known that gas permeability is approximately zero into glass-PFSs. However, polymer-PFSs (P-PFSs) have relatively high gas permeability. Therefore, there are concerns about the potential impact of external surface sterilization on drug solutions in P-PFSs. In this study, P-PFSs [filled with water for injection (WFI) or human serum albumin (HSA) solution] were externally sterilized using EO, VHP, and NO₂ gases. For the WFI-filled syringes, the concentration of each gas that ingressed into the WFI was measured. For the HSA solution-filled syringes, the physical and chemical degradation of HSA molecules by each sterilant gas was quantified. For the EO- or VHP-sterilized syringes, the ingressed EO or hydrogen peroxide (H₂O₂) molecules were detected in the filled WFI. Additionally, EO-adducted or oxidized HSA molecules were observed in the HSA-filled syringes. In contrast, the NO₂-sterilized WFI-filled syringes exhibited essentially immeasurable ingressed NO₂, and protein degradation was not detected in HSA-filled syringes.

Impact of H2O2 Sorption by Polymers on the Duration of Aeration in Pharmaceutical Decontamination

As part of manufacturing a sterile drug product, we quantified the impact of H₂O₂ sorption by polymers on the duration of aeration in pharmaceutical decontamination. Five polymers, which are typically used as materials/parts in sterile isolators, were investigated: polyethylene, polyvinyl chloride, Silicone, polyoxymethylene (POM), and chlorosulfonated polyethylene. Experiments were performed to estimate the storage capacity and diffusion coefficients of H₂O₂ in the polymer. Considering these key properties of sorption/desorption, mathematical models were developed to simulate the duration of aeration to achieve the target H₂O₂ concentration, which is the indicator to minimize. The models were used to create a map-out of the duration given the properties of the polymers, including the five polymers. In the simulated setup, POM and Silicone were found to require prolonged aeration. Thus, when using these polymers in the isolator, the size/amount should be carefully investigated. Another practical finding was that the superiority of the polymers changed depending on the target H₂O₂ concentration. This result motivates an early incorporation of the product information in the isolator design, to achieve a rapid decontamination/aeration cycle.