Sterilization Validation Research Articles

Characterization and optimization of continuous ohmic thermal sterilization based on the development of a predictive computational toolbox

Continuous thermal processing (CTP) is a common method for sterilizing food. However, it can result in an uneven temperature distribution, which can lead to a varying degree of processing intensity. Ohmic heating (OH) can be advantageous in this regard, as it enables volumetric heating for more homogenous treatments. However, evaluating the processing intensity distribution inside the equipment for OH is challenging due to the complex interaction between electrical, mechanical and thermal phenomena. Furthermore, the comparison of OH and conventional heating treatments often lack a profound basis of comparable treatment intensity considerations. To gain a deeper mechanistic understanding of the technology, a numerical computational fluid dynamics model for the OH sterilization of a clear carrot juice from the heating region to the cooling process was developed. The model was validated with thermal and electrical measurements and showed an error rate below 2.5% in its prediction capacities. Moreover, the model was implanted for the validation of the products sterilization and compared to a conventional validation approach, reviling a 33.3% underestimation of the thermal load by conventional manners, which can lead to faulty sterilization of the food product. Additionally, the model was expanded to also be able to predict the microbial inactivation ratio of the system with an average error of 1.10±0.74%. In addition, results indicate that the numerical calculation of the F0 values and their validation with the microbial inactivation ratio have a notable potential for localization and evaluation of hotspots in OH simulations. Therefore, it can be seen as a promising step for establishing a foundation for computer-assisted optimization of CTP and targeted processing.

Synergistic effects of pressure, temperature, shear, and their interactions on Clostridium sporogenes PA3679 spore inactivation during ultra-shear processing

Ultra-shear technology (UST) is a semi-continuous high-pressure method for processing liquid foods. By pressurizing liquid foods up to 400 MPa and decompressing them through a shear valve, UST is designed for pasteurizing or sterilizing foods and modifying their structure and rheological characteristics. This study evaluated the lethal effects of pressure, holding time, temperature, shear, and their interactions for inactivating endospores of Clostridium sporogenes PA3679 suspended in pressure-stable 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) buffer solution (0.1 M, pH 7.0, initial concentration = 6.3 log CFU/mL). Results indicated while thermal treatment at 105 °C did not have appreciable spore inactivation, isostatic treatment at 400 MPa and 105 °C for 5 min resulted in a 3.3-log inactivation. UST treatment at 400 MPa and 85 °C for 5 min, followed by 125 °C shear discharge resulted in 3.3-log reduction. Our analysis also revealed that thermal-pressure treatment history as well as their intensities also influence magnitude of spore reduction. This study revealed the sporicidal capability of UST and evaluated the relative importance of different lethal factors on spore inactivation. Industrial relevanceUltra-shear technology (UST) is a novel processing method that has a potential to help produce value-added liquid foods, sauces, gels, and nanoemulsions, while helping to preserve the foods by inactivating undesirable microorganisms using the combination of pressure, shear, and temperature. This research provided an insight on the effects of key UST lethal factors on spores of C. sporogenes PA3679 for commercial sterilization validation. The results of this study could help the industry select the safe-harbor UST processing parameters for sterilizing food products in the future.

Power of Parametric: Methods to Validate Ethylene Oxide Sterilization Parametric Release.

When approaching an ethylene oxide (EO) sterilization validation, medical device manufacturers traditionally have two choices. They can use biological indicators (BIs) to monitor each production run or establish a parametric release process in which sterile release is based on the monitoring and control of physical process parameters that ensure process specifications are met. In ISO 11135:2014, parametric release was brought to the forefront as an acceptable release method; however, a perception exists that implementing parametric release is challenging and time consuming. This article will demonstrate that the opposite is true. It presents a streamlined approach in which parametric release is addressed through the various stages of validation: product definition, process definition, performance qualification, routine release, and process control. Considerations for establishing specifications directly from validation versus "run and record" and trending critical process parameters (e.g., relative humidity, temperature, EO concentration) are discussed. In addition, the benefits of parametric release (active monitoring) over BI release (passive monitoring), including improvements to turnaround time, process control, risk mitigation, reduction of resource investment, and elimination of microbiological release testing, are highlighted. With multiple benefits, parametric release should be the gold standard for EO sterilization processes. It is not novel and has been widely accepted by regulatory agencies globally and notified bodies. The article further describes how the data collection and process capability that is central to process control and parametric release is more powerful than the information provided by a BI, which is merely a catastrophic indicator when used in routine processing.

Equipment Validation of Moist Heat Sterilization

Equipment Validation of Moist Heat Sterilization

Equipment Validation of Moist Heat Sterilization

Equipment Validation of Moist Heat Sterilization

Comparison of one-step with two-step production of Bacillus atrophaeus spores for use as bioindicators.

The production method of spores significantly influences the resistance of spores used as bioindicators (BI) in the validation of sterilization of packaging material surfaces in aseptic food manufacturing. Therefore, the standardization of the spore production method represents an important and desirable goal in industrial BI production to ensure reliable validation test results. Previously, we recommended a two-step production approach for submerged spore production, in which the cultivation phase to obtain high cell mass was separate from the sporulation phase. In this work, a one-step manufacturing process was investigated to reduce production complexity and facilitate standardization of spore production. It was found that one-step BI production is technically possible but at the expense of spore yield. The two-step manufacturing process can realize almost 10-fold higher spore yields.

Validation of ethylene oxide sterilization of disposable electronic analgesia infusion pumps

Validation of ethylene oxide sterilization of disposable electronic analgesia infusion pumps

Basic prerequisites for on-line, high-volume hemodiafiltration.

High-volume hemodiafiltration involves filtration of >23 L/treatment and its replacement by sterile non-pyrogenic substitution fluid, while maintaining the patient's fluid balance. That volume of substitution fluid precludes the use of prepackaged sterile fluid. Instead, substitution fluid must be prepared on-line using machines that incorporate a series of bacteria- and endotoxin-retentive filters. The sterilizing ultrafilters are validated to deliver sterile, non-pyrogenic fluid to the patient when operated according to the machine manufacturer's instructions and in compliance with international standards and regulatory oversight. A successful hemodiafiltration program also places important responsibilities on the user. Specifically, the user is responsible for ensuring that the dialysis water or dialysis fluid delivered to the sterilizing filters of the hemodiafiltration machine meets the machine manufacturer's specifications and is consistent with the quality used in the sterilization validation process. The user is also responsible for ensuring that the treatment prescription allows a filtration volume >23 L/treatment to be achieved by careful selection of a dialyzer, blood flow rate and treatment time. Questions related to assurance that the substitution fluid will routinely be sterile and non-pyrogenic have limited the uptake of on-line hemodiafiltration as a therapeutic option in some countries, such as the United States.

Achieving Success by Validation! Decontamination Protocols of Category A Medical Waste for Patients with Serious Communicable Diseases

<h3>Purpose</h3> During the 2014 Ebola outbreak, treatment centers for Ebola and special pathogens had to determine safe handling protocols for the management of category A infectious substances. There have been challenges achieving validation of adequate sterilization with autoclaving. To achieve successful inactivation requires alteration of cycle parameters (temperature, pressure, and time), and packaging methods. Successful inactivation is verified through the use of biological indicators, data loggers, and the evaluation of drain and exhaust lines. We aim to describe a successful waste sterilization process utilizing an autoclave in Emory University Hospital's biocontainment unit where we maintained appropriate safe handling waste processes. <h3>Methods & Materials</h3> Waste was differentiated by type to include patient general waste, linens, liquids, and sharps (including continuous renal replacement therapy cartridges). This helped us to determine appropriate packing methods and cycle parameters to ensure adequate inactivation by autoclaves. A biological indicator (BI) was used to monitor the efficacy of the autoclave sterilization process. Waste was double bagged with autoclave bags using the "gooseneck" method and secured with autoclave tape. This allowed for waste packaging to maintain closure of biohazard bags and contain leaks and aerosols. Following failed loads, action plans were generated until achieving successful inactivation. In order to determine the effectiveness of autoclave sterilization parameters, repeat loads were performed to ensure reliability. Once cycle specifications were finalized, each cycle type was repeated to achieve three successful runs with all passing biological indicators. <h3>Results</h3> We achieved effective inactivation of waste by altering autoclave factory settings. Following separation of waste and determine appropriate packing methods, we ran 26 total cycles achieving passing biological loads in 17 cycles. Failed loads occurred primarily in liquids and sharps where parameters were readjusted until achieving three successful cycles. <h3>Conclusion</h3> Safe handling of category A infectious waste requires validation of inactivation of waste by autoclave. Validation of autoclave parameters need to be assessed with particular attention to waste loads and packaging prior to treatment. We achieved successful inactivation of infectious medical waste with simulated patient waste loads while maintaining the integrity of waste packaging to ensure no leakage of liquid or aerosol particles occurred.

Assessment of Various Process Parameters for Optimized Sterilization Conditions Using a Multi-Sensing Platform.

In this study, an online multi-sensing platform was engineered to simultaneously evaluate various process parameters of food package sterilization using gaseous hydrogen peroxide (H2O2). The platform enabled the validation of critical aseptic parameters. In parallel, one series of microbiological count reduction tests was performed using highly resistant spores of B. atrophaeus DSM 675 to act as the reference method for sterility validation. By means of the multi-sensing platform together with microbiological tests, we examined sterilization process parameters to define the most effective conditions with regards to the highest spore kill rate necessary for aseptic packaging. As these parameters are mutually associated, a correlation between different factors was elaborated. The resulting correlation indicated the need for specific conditions regarding the applied H2O2 gas temperature, the gas flow and concentration, the relative humidity and the exposure time. Finally, the novel multi-sensing platform together with the mobile electronic readout setup allowed for the online and on-site monitoring of the sterilization process, selecting the best conditions for sterility and, at the same time, reducing the use of the time-consuming and costly microbiological tests that are currently used in the food package industry.

The Preparation of Dye-Acrylamide/Itaconic Acid Gel Dosimeters for Process Validation of Medical Device Sterilization

The Preparation of Dye-Acrylamide/Itaconic Acid Gel Dosimeters for Process Validation of Medical Device Sterilization

Wanted: Dead or Alive.

Sterilization validation practices in the United States rely heavily on the destruction of microorganisms to establish that sufficient lethality has been delivered. The objective in many instances is demonstration of the poorly defined attainment of "overkill" throughout the load. The complete destruction of resistant spore formers is assumed to support the attainment of a minimum probability of a nonsterile unit (PNSU). In reality, the absence of recoverable microorganisms in sterilization cycle development and validation does not allow for accurate PNSU determination. This article outlines how a strategy inspired by that used for ISO 11137-2, VDMAX, with positive results can be used to fully support sterilization cycle efficacy. This article is intended to spark interest in a potentially novel approach to sterilization cycle development and can be refined once sufficient experience has been gained with it.

Alternate Approach for Defining Worst Case in Steam Sterilization Validation of Porous/Hard Goods Loads.

For steam sterilization load validation of porous/hard goods loads, regulatory guidelines state to identify and validate the worst-case challenge that is the most difficult to sterilize. The maximum load and the minimum load are usually considered as worst-case challenges, and both are validated. This article demonstrated with examples how the control strategy determined the worst-case load in the steam sterilizer. It further established with examples how a suitably designed control strategy could nullify the impact of varying load characteristics (e.g., mass, configuration, and air removal challenges) in porous/hard goods loads and make it load size independent.

Quantitative and Fast Sterility Assurance Testing of Surfaces by Enumeration of Germinable Endospores

A fast Endospore Germinability Assay (EGA) was validated with traditional plate counts to enumerate single endospore germination events for monitoring surface sterilization. The assay is based on a time-gated luminescence microscopy technique enabling visualization and enumeration of individual germinating endospores. Germinating endospores release calcium dipicolinate to form highly luminescent terbium dipicolinate complexes surrounding each germinating endospore. EGA and heterotrophic plate counting (HPC) were used to evaluate the swab/rinse recovery efficiency of endospores from stainless steel surfaces. EGA and HPC results were highly correlated for endospore recovery from stainless steel coupons inoculated with range of 1,000 endospores per coupon down to sterility. Dosage-dependent decrease of surface endospore germinability were observed in dry heat, UV irradiation, oxygen plasma and vaporized hydrogen peroxide treatments, measured with EGA and HPC. EGA is a fast and complementary method to traditional HPC for quantitative sterility assurance testing of surfaces. This work introduces and validates a 15-minute or faster assay for germinable endospores to complement the conventional lengthy, culture-based surface sterility validation, which is critical in hospitals, food and pharmaceutical industries to help minimize nosocomial infection, food spoilage, and pharmaceutical contamination.

Validation of sterilization of Lucilia cuprina larvae using raw honey through scanning electron microscope

Background: In the application of Maggot Debridement Therapy (MDT), sterilized maggots (Lucilia cuprina) by standard chemicals were used. Recent potential demands for using a procedure with allnatural products, raw honey has been proposed as a natural sterilization technique to replace the chemical products.

The Princess Margaret Cancer Centre Experience: Transitioning to GCSF Alone for Stem Cell Mobilization in Myeloma Patients

Historically at Princess Margaret Cancer Centre, cyclophosphamide and GCSF was the standard stem cell mobilization regimen used for transplant eligible multiple myeloma patients. Limitations to this regimen included chemotherapy associated toxicity such as febrile neutropenia, and unpredictability regarding the ideal planned apheresis start date. With the recent validation of open-vial sterility of plerixafor allowing for broader access at our centre (Seki et al. Can J Hosp Pharm 2017;70:270), an opportunity was identified to transition to a less toxic GCSF alone mobilization regimen.

The Bugs Don't Lie.

Sterilization is a critical process in the preparation of many drug products. Its execution and validation are addressed in numerous regulatory, pharmacopeial, and industry documents. EMA Annex 1: Manufacture of Sterile Medicinal Products stands alone in giving clear preference to physical measurements over those obtained from biological indicators. This paper reviews principles behind sterilization processes outlining the differences between physical and biological measurements as well as their relationship to each other. The assumptions associated with the use of physical measurement are explored and their derivation from microbiological results is traced with the intent of reaffirming the primacy of biological evidence. The arguments and objections to the use of biological indicators in sterilization are reviewed and deconstructed.LAY ABSTRACT: Sterilization validation is required by regulatory agencies around the globe. The accepted principles are derived from those originally established in the United States and the United Kingdom during the 1970s. Unfortunately, these have evolved into conflicting expectations. The U.K. placed greater emphasis on physical measurements initially in HTM-10, and this is reflected in the European Medicines Agency's Annex 1 statements for their preeminence over biological data. Practices, primarily in the U.S., give preference to microbiological challenges as confirmation of lethality. This paper reviews sterilization fundamentals and describes the relationship between physical and biological data. It critiques the various arguments for the superiority of physical measurements and supports why microbiological evidence should take precedence.

Influence of aseptic surge tank venting on equipment sterilization

Abstract Aseptic surge tank (AST) systems are applied to aseptic production in order to store sterile product until aseptic filling, maintaining the commercial sterility condition achieved from previous production steps. To avoid microbial recontamination of the product, a sterility condition must be achieved in the aseptic tank system through the application of a heating, venting, and sterilization cycle. This cycle must follow specific validation protocols to ensure operational integrity - FDA 21 CFR Part 113.40g (ii). The demand for larger capacity systems and the implication of this volume increase on sterilization efficiency require a review of results obtained from current validation protocols. The purpose of this work was to evaluate aseptic surge tank’s venting cycles, studying internal pressure and temperature distribution to better understand this operation and its efficiency. Tests carried out at an industrial setting showed that the venting cycle was insufficient, with 13%-23% of air remaining inside the tank. Consequently, the subsequent sterilization process was not conducted under saturated steam condition. This different condition may change the kinetics for thermal destruction of microorganism spores from a moist heat state to a drier state in which its thermal resistance is higher. This finding raises a question regarding the true efficacy of the sterilization process and validation protocols currently used by the industry. The apparent success of current sterilization processes could be due to the application of excessive temperature and longer times. New operational and validation criteria will result in improvements in product integrity protection and operational cost reductions.

Sterilization Validation of Pharmaceuticals

Sterilization Validation of Pharmaceuticals

Investigation of a Contaminated, Nationally Distributed, Organ Transplant Preservation Solution — United States, 2016–2017

BackgroundIn December 2016, bacterial contamination of an organ preservation solution (OPS) was reported by Transplant Center A in Iowa. Annually, >20,000 abdominal organs are transplanted in the United States; OPS is used for organ storage. We investigated the scope of OPS contamination and its association with adverse events in patients.MethodsWe assessed infection control practices related to OPS at Transplant Centers A and B in Iowa and the local organ procurement organization (OPO). We issued national notifications about OPS contamination and requested transplant centers to report product-related concerns or potential patient harm. Among transplant recipients at Center A, we compared adverse events (fever, bacteremia, surgical site infection, peritonitis, or pyelonephritis within 14 days of transplantation) during October–December 2015 with October–December 2016, the presumed window of exposure to contaminated OPS. Isolates from OPS were characterized.ResultsNo infection control deficiencies were identified at Transplant Centers A, B, or the OPO. In January 2017, contaminated OPS from the same manufacturer was reported by Transplant Center C in Texas. Nationally, there were no reports of patient harm definitively linked to OPS. Post-transplant adverse events at Center A did not increase between fourth quarter 2015 (5/12 [42%]) and 2016 (2/15 [13%]). Organisms recovered from OPS included Pantoea agglomerans and Enterococcus gallinarum (Center A) and Pseudomonas koreensis (Center C). Five Pantoea isolates from ≥3 opened OPS bags were indistinguishable by pulsed-field gel electrophoresis. The OPS distributor issued recalls and suspended production. The US Food and Drug Administration identified deficiencies in current good manufacturing practices at manufacturing and distribution facilities, including inadequate validation of OPS sterility.ConclusionBacterial contamination of a nationally distributed product was identified by astute clinicians. The investigation found no illnesses were directly linked to the product. Prompt reporting of concerns about potentially contaminated healthcare products, which might put patients at risk, is critical for swift public health action.Disclosures All authors: No reported disclosures.