Vapor-Phase Hydrogen Peroxide Uptake by Silicone Tubing and Primary Packaging Components during Protein Drug Product Aseptic Filling: Impact of Pretreatment and Sterilization Process.

In the vapor-phase hydrogen peroxide (VPHP)-sanitized environment, VPHP uptake by product-contacting components could eventually lead to undesired oxidation of biological drug products. Silicone tubing and primary packaging materials are prominent examples of such product-contacting surfaces that are typically processed/sterilized prior to use. This study investigated the VPHP-uptake tendency of these components and how their respective processing/sterilization methods affect the uptake behaviors. Silicone tubing that was sterilized via autoclave or gamma irradiation exhibited different VPHP uptake patterns-decreased uptake rates post autoclaving vs. increased uptake rates post gamma irradiation. The reduced uptake tendency of autoclaved tubing is maintained for 14 days after sterilization, whereas the uptake tendency of irradiated tubing was mostly reversed to normal levels 1 month after irradiation. Empty glass vials adsorbed hydrogen peroxide via the diffusion of VPHP into the vial with high vial-to-vial variability. Vial pretreatment (i.e., depyrogenation) and surface hydrophilicity/hydrophobicity impacted the uptake tendency. Stoppers and empty syringes also adsorbed hydrogen peroxide but at a relatively low level. The uptake behavior of these components appeared to correlate with water levels at the surface (i.e., hydrophilicity). This study provides process development scientists and engineers an in-depth understanding of the VPHP uptake by critical product-contacting surfaces so that they can mitigate the impact on drug product quality.LAY ABSTRACT: This study investigated vapor-phase hydrogen peroxide (VPHP) absorption by biopharmaceutical drug products via VPHP uptake by critical product-contacting components during the aseptic manufacturing process with a focus on various pretreatments and processing of these components. Sterilization of silicone tubing by gamma irradiation or autoclaving resulted in different VPHP uptake profiles with different effect durations. Primary packaging components, such as vials, syringes, and stoppers, also showed different levels of VPHP uptake with surface hydrophilicity/hydrophobicity playing a critical role. These outcomes suggested that VPHP uptake is a complex phenomenon and should be carefully considered to minimize its impact on product quality. The approach and outcome of this study can benefit scientists and engineers who develop biological product manufacturing processes by providing an in-depth understanding of drug product process risks.

Vapor Phase Hydrogen Peroxide Decontamination or Sanitization of an Isolator for Aseptic Filling of Monoclonal Antibody Drug Product-Hydrogen Peroxide Uptake and Impact on Protein Quality.

A monoclonal antibody drug product manufacturing process was transferred to a different production site, where aseptic filling took place within an isolator that was decontaminated (sanitized) using vapor phase hydrogen peroxide (VPHP). A quality-by-design approach was applied for study design to understand the impact of VPHP uptake on drug product quality. Both small-scale and manufacturing-scale studies were performed to evaluate the sensitivity of the monoclonal antibody to hydrogen peroxide (H2O2) and characterize VPHP uptake mechanisms in the filling process. The acceptable H2O2 uptake level was determined to be 100 ng/mL for the antibody in the H2O2 spiking study; protein oxidation was observed above this threshold. The most prominent sources of VPHP uptake were identified to be the silicone tubing assembly (associated with the peristaltic pumps) and open, filled vials. Silicone tubing, an effective depot to H2O2, absorbs VPHP during different stages of the filling process and transmits H2O2 into the drug product solution during filling interruptions. A small-scale isolator model, established to simulate manufacturing-scale conditions, was a useful tool in understanding H2O2 uptake in relation to tubing dimensions and VPHP concentration in the isolator air (or atmosphere). Although the tubing assembly had absorbed a substantial amount of VPHP during the decontamination phase, the majority of H2O2 could be removed during tubing cleaning and sterilization in the subsequent isolator aeration phase, demonstrating that H2O2 in the final drug product solution is primarily taken up from residual VPHP in the isolator during filling. Picarro sensor monitoring demonstrated that the validated VPHP aeration process generates reproducible residual VPHP profiles in isolator air, allowing small-scale studies to provide relevant recommendations on tubing size and interruption time limits for commercial manufacturing. The recommended process parameters were demonstrated to be acceptable and rendered no product quality impact in six consecutive manufacturing batches in the process validation campaign. Overall, this case study provides process development scientists and engineers an in-depth understanding of the VPHP process and a science-based approach to mitigating drug product quality impact.LAY ABSTRACT: While the use of vapor phase hydrogen peroxide as a sanitizing agent for isolator and cleanroom decontamination has gained popularity in recent years, its impact on product quality during aseptic manufacturing of biopharmaceutical drug products is yet to be fully understood. With this scope in mind, this case study offers a detailed account of defining process parameters and developing their operating ranges to ensure that the impact to product quality is minimized. Both small-scale and manufacturing-scale studies were performed to assess the sensitivity of a monoclonal antibody to hydrogen peroxide, to characterize hydrogen peroxide uptake sources and mechanisms, and to eventually define process parameters and their ranges critical for minimizing product quality impact. The approach and outcome of this study is expected to benefit scientists and engineers who develop biologic product manufacturing processes by providing a better understanding of drug product process challenges.

Filling of high-concentration monoclonal antibody formulations into pre-filled syringes: filling parameter investigation and optimization.

Syringe filling, especially the filling of high-concentration/viscosity monoclonal antibody formulations, is a complex process that has not been widely published in literature. This study sought to increase the body of knowledge for syringe filling by analyzing and optimizing the filling process from the perspective of a fluid's physical properties (e.g., viscosity, concentration, surface tension). A bench-top filling unit, comprising a peristaltic pump unit and a filling nozzle integrated with a linear actuator, was utilized; glass nozzles were employed to visualize liquid flow inside the nozzle with a high-speed camera. The desired outcome of process optimization was to establish a clean filling cycle (e.g., absence of splashes, bubbles, and foaming during filling and absence of dripping from the fill nozzle post-fill) and minimize the risk of nozzle clogging during nozzle idle time due to formulation drying at or near the nozzle tip. The key process variables were determined to be nozzle size, airflow around the nozzle tip, pump suck-back (SB)/reversing, fluid viscosity, and protein concentration, while pump velocity, acceleration, and fluid/nozzle interphase properties were determined to be relatively weak parameters. The SB parameter played an especially critical role in nozzle clogging. This study shows that an appropriate combination of optimal SB setting, nozzle size, and airflow conditions could effectively extend nozzle idle time in a large-scale filling facility and environment. LAY ABSTRACT: Syringe filling can be considered a well-established manufacturing process and has been implemented by numerous contract manufacturing organizations and biopharmaceutical companies. However, its technical details and associated critical process parameters are rarely published. The information on high-concentration/viscosity formulation filling is particularly lacking. The purpose of this study is three-fold: (1) to reveal design details of a bench-top syringe filling unit; (2) to identify and optimize critical process parameters; (3) to apply the learning to practical filling operation. The outcomes of this study will benefit scientists and engineers who develop pre-filled syringe products by providing a better understanding of HC formulation filling principles and challenges.

Syringe siliconization process investigation and optimization.

The interior barrel of the prefilled syringe is often lubricated/siliconized by the syringe supplier or at the syringe filling site. Syringe siliconization is a complex process demanding automation with a high degree of precision; this information is often deemed "know-how" and is rarely published. The purpose of this study is to give a detailed account of developing and optimizing a bench-top siliconization unit with nozzle diving capabilities. This unit comprises a liquid dispense pump unit and a nozzle integrated with a Robo-cylinder linear actuator. The amount of coated silicone was determined by weighing the syringe before and after siliconization, and silicone distribution was visually inspected by glass powder coating or characterized by glide force testing. Nozzle spray range, nozzle retraction speed, silicone-coated amount, and air-to-nozzle pressure were found to be the key parameters affecting silicone distribution uniformity. Distribution uniformity is particularly sensitive to low-target silicone amount where the lack of silicone coating on the barrel near the needle side often caused the syringes to fail the glide force test or stall when using an autoinjector. In this bench-top unit we identified optimum coating conditions for a low silicone dose, which were also applicable to a pilot-scale siliconization system. The pilot unit outperformed the bench-top unit in a tighter control (standard deviation) in coated silicone amount due to the elimination of tubing flex. Tubing flex caused random nozzle mis-sprays and was prominent in the bench-top unit, while the inherent design of the pilot system substantially limited tubing flux. In summary, this bench-top coating unit demonstrated successful siliconization of the 1 mL long syringe with ∼0.2 mg of silicone oil using a spraying cycle also applicable to larger-scale siliconization. LAY ABSTRACT: Syringe siliconization can be considered a well-established manufacturing process and has been implemented by numerous syringe providers. However, its technical details and associated critical process parameters are rarely published. The purpose of this study is three-fold: (1) to reveal design details of a bench-top siliconization unit, (2) to identify critical process parameters and determine their optimum range to provide consistent and even silicone coating, and (3) to demonstrate the applicability of the optimum process condition derived from the bench-top unit to a pilot siliconization unit. The outcomes of this study will benefit scientists and engineers developing pre-filled syringe products by helping them to better understanding silicone spray coating principles and their relationship to siliconization processes in a large-scale manufacturing setting.

Root Cause Investigation of Rubber Seal Cracking in Pre-filled Cartridges: Ozone and Packaging Effects.

Pre-filled syringes/cartridges as primary packaging for parenterally delivered biopharmaceutical liquids consist of multiple components, including containers made of glass or plastic, and stoppers/plungers and disk seals (septa) made of rubber materials. Cracking of rubber components may be cosmetically unacceptable and in extreme cases may compromise enclosure integrity. The purpose of this study was to investigate the root cause of septum cracking and evaluate parameters/solutions to delay or prevent cracking from occurring. Custom-made chambers capable of tightly controlling ozone levels were assembled to deliberately create septum cracks. Cracks were qualitatively assessed by optical microscopy and quantified using image analysis by ImageJ. The results confirmed that ozone attack is the root cause of septum cracking during storage, and the stress-the result of crimping on the glass cartridge by the aluminum lined seal-made the septum particularly vulnerable to ozone attack. Ozone concentration as low as 10-40 ppb (levels routinely detected on a busy street) could crack the stressed septum in hours while days of ozone exposure at 50 ppm could not cause the unstressed septum to crack. Under ozone attack cracks initially grow in length and width uniformly across the stressed area and then stop progressing, perhaps due to residual stress release. Although the use of impermeable barriers could prevent cracking completely, this study suggested that any form of packaging barriers, including a highly permeable Tyvek® sheet, could postpone cracking by slowing down ozone diffusion and convection. We demonstrate that simple double packaging-placing the Tyvek®-lidded blister tray in a cardboard carton-could sufficiently protect the stressed septum for years in a surrounding environment with ozone at normal indoor levels (≤2 ppb). LAY ABSTRACT: Pre-filled syringes/cartridges as primary packaging for parenterally delivered biopharmaceutical liquids contain multiple components, including a disk seal (septum) made of rubber materials. Cracking of rubber components may be cosmetically unacceptable and in extreme cases may compromise enclosure integrity. The septum, if not appropriately packaged, might crack under uncontrolled storage environment. The purpose of this study was to investigate the root cause of septum cracking and evaluate parameters/solutions to delay or prevent cracking from occurring. Custom-made chambers capable of tightly controlling ozone levels were assembled to deliberately create septum cracks. The results confirmed that ozone attack is the root cause of septum cracking during storage, and the stress-the result of crimping on the glass cartridge by the aluminum lined seal-made the septum particularly vulnerable to ozone attack. Ozone concentration as low as 10-40 ppb (levels routinely detected on a busy street) could crack the stressed septum in hours. Although the use of impermeable barriers could prevent cracking completely, this study suggested that any form of packaging barriers, including a highly permeable Tyvek® sheet, could postpone cracking by slowing down ozone diffusion and convection. This investigation will raise awareness of manufacturers of pre-filled cartridge/syringe parenteral products to storage and packaging requirements for the long-term physical stability of cartridge components as small as the rubber septum.