Extractables and Leachables Risk Assessment for Single-Use Systems

Single-use systems can be used to improve efficiency and productivity in the bioprocessing workflow. In addition, they reduce capital investment, cleaning requirements, facility set-up time, and lower the risk of product contamination.

When adopting single-use technologies, the drug manufacturer must conduct an assessment of the risk from potential leachables, which could alter the safety, identity, strength, quality, and purity of the drug product. 

This technical article describes approaches to assess the risks associated with E&L from single-use systems. These risk-assessment approaches are aligned with general and informational chapters recently published by the United States Pharmacopeia (USP).

Section Overview

• Using a Risk-Based Approach for Evaluating Extractables and Leachables
• Compendial Standards for Extractables and Leachables Testing
• Considerations when Evaluating Extractables and Leachables from Single-Use Components
  
• Application of USP <665> and <1665> to Extractables and Leachables Testing
• Assessing Risk to the Patient
• Emprove^® Program: Your Technical, Regulatory and Supply Information
• Related Products

Using a Risk-Based Approach for Evaluating Extractables and Leachables

The Center for Biologics Evaluation and Research (CBER) recommends¹ a risk-based approach for evaluating E&L in drug products. Any evaluation should consider the indication, safety issues, product characteristics, dosage, formulation and stability profile.

An E&L assessment of the single-use system must consider each component in the fluid path; components with similar material of construction, identity and manufacturing process may be grouped for analysis. If there is no relevant risk associated with the single-use materials in question, supplier data and information can be referenced and used to justify no additional testing to regulatory authorities. If a risk is identified, the drug manufacturer may have to determine toxicity based on the maximum dosage of potential leachables using extractables data. If this dosage is a safety risk, leachable evaluation and testing may be necessary. In addition, if product quality could be affected by a potential leachable, studies may need to be performed to assess the impact on product quality, including efficacy.

While extractables data may be generated by the supplier, it is the responsibility of the drug manufacturer to ensure the data are representative of their process.

The first step in evaluating the level of risk presented by extractables is an assessment of the manufacturing process to determine which components are in scope and an initial risk assessment. Based on the risk level, standard extractables data, based on USP <665>, are compiled for the contact materials in the process; guidelines published by Biophorum are also used. By interpreting extractables data, process-specific extractables in the drug product are identified. Finally, the potential risk associated with drug intake is calculated. If negligible risk cannot be demonstrated, a leachables or flush study or a change in the process design is needed. 

Compendial Standards for Extractables and Leachables Testing

The United States Pharmacopeia (USP) has published several chapters providing guidance and recommendations related to extractables and leachables. Chapter <665>, entitled "Plastic Components and Systems Used to Manufacture Pharmaceutical Drug Products and Biopharmaceutical Drug Substances and Products", effective May 2026, is the first USP chapter dedicated to this topic. It provides a framework for assessing plastic materials used in bioprocessing including the chemical suitability of components for their intended use based on a standard bracketed extractables protocol.

USP <1665>, entitled "Characterization and Qualification of Plastic Components and Systems Used to Manufacture Pharmaceutical Drug Products and Biopharmaceutical Drug Substances and Products", is a companion document that provides a risk assessment approach and additional analytical details.

The Scope of USP <665>

USP <665> is related to single-use manufacturing processes that involve liquids and covers all drug substances and products including small molecules and biologics. It includes bags, bioreactors, cassettes, chromatographic columns, chromatographic devices, connectors, filling needles, filters, sensors, stir bars, tubing, valves, and vessels. It also covers multi-use products such as plastic filters in stainless steel housings. The chapter does not cover active pharmaceutical ingredients or auxiliary items for dispensing and transferring ingredients that have a relatively short contact time with the process. Non-product contact materials such as O-rings and diaphragm gaskets are also excluded.

For product contact components in scope of USP <665> the end-user must determine the risk level of the components and systems used in the manufacturing process.  Table 1 classifies the three risk levels to be evaluated, based on USP <655>.

Use of USP <1665> and/or BioPhorum Best Practice Guide Leachables Assessment for Establishing the Level of Risk

It is the responsibility of the drug manufacturer to evaluate the risk of the single-use components, using a risk assessment.  There are two published risk assessments:  USP <1665> appendix and the BioPhorum Leachables Risk assessment. These assessments are similar, but have some different dimensions as listed in Table 2. Each dimension is then broken down further based on the risk of generating E&L.

Considerations when Evaluating Extractables and Leachables from Single-Use Components

The evaluation of E&L begins with single-use assembly drawings and an understanding of the product flow path through the single-use components. Components in single-use systems should be compatible and non-reactive with the process stream under the specified process conditions. If a component material with limited compatibility must be used, process conditions should be adjusted to minimize the risk to patient safety; this may include minimizing temperature or duration of contact. 

When selecting components for multiple single-use systems, it is preferable to use components with the same materials of construction to minimize the number of evaluations needed and potentially streamline extractables testing. If you need support in the evaluation of components, performing the E&L risk assessment, patient safety evaluation and/or custom testing then our Validation Services team can support your needs. 

Application of USP <665> and <1665> to Extractables and Leachables Testing

Assessing the risk that a polymeric compound from the single-use component will be leached to an extent that the extractables may be impactful include assessing temperature of contact, material of construction, the chemical nature of the process stream, and the duration of contact (Table 3).

The example below considers a mixing assembly that can be used for the drug product. The drug product comprises 2% active pharmaceutical ingredient (API), 0.02% polysorbate 80, 2% dextrose, in water at pH 5. Filter contact time is 8 hours, and the filtration temperature is 25 °C.

Based on the process information and the risk dimensions, a risk level can be established for this single-use assembly (Table 4). The table „Linking the Numerical Risk Sequence with a Level of Characterization“ in USP <1665> is used to determine the risk level.

Based on the material assessment of “3” for high reactivity due to sterilization using gamma radiation, “2” for process stream and temperature,“2” for short term duration, characterization of the process step is Level B with a numerical risk sequence of 3222 according to USP <1665>. Level B relates to a moderate risk and organic testing with 50% Ethanol is needed.

To reduce risk ,migation actions such as flushing, can be implemented to reduce the reactivity parameter. Other mitigation actions, such as ultraflitration/diafiltration, act as clearance steps and may change the overall risk score from medium to low.

Assessing Risk to the Patient

Once the risk has been established and extractables results are obtained, the next step is to assess the risk. Assessing the risk to the patient includes identification of extractables, an exposure assessment, and a safety evaluation. Identifying the extractables includes the following:

• Determining the risk of potential leachables based on the total quantity below the Analytical Evaluation Threshold (AET)
• Individual quantitation
• Scaling the data to the surface area of the assemblies
• Sum the quantitation for each component 

The exposure assessment is then performed to determine how the compounds are generated and how the drug is going to be used in terms of dosage and duration. The safety evaluation includes assessment based on the threshold of toxicological concern (TTC) and establishing a permitted daily exposure (PDE). 

• If the quantity of each extractable is above the TTC/PDE, risk mitigation is needed and can include leachables testing, dilution, and a material or process change.
• If the quantity is lower than the TTC/PDE, the risk is acceptable.

Emprove^® Program: Your Technical, Regulatory and Supply Information

The Emprove^® Program provides convenient online access to comprehensive documentation needed for implementation of single use systems in pharmaceutical manufacturing. Detailed product information contained within the Emprove^® Dossiers reduces the time and investment typically needed to gather and/or prepare documentation and enables more agile, risk-based decisions. The Emprove^® Program includes single use components, filters, connectors, and film, as well as a wide range of other products used in bioprocessing such as chromatography resins, cell culture media and chemicals. The description for the filter and single-use dossiers are below.

• The Emprove^® Material Qualification Dossiers (MQD) include product test specifications, release criteria, and regulatory information for the components as well as materials used for component qualification. 
• The Emprove^® Quality Management Dossiers (QMD) includes quality and validation information including site qualification, irradiation sterilization process and packaging validations and site qualification.  
• The Emprove^® Operational Excellence Dossier (OED) includes extractables data following BioPhorum and USP <665> guidance to support patient safety evaluation. OED’s are available for individual filters, 
• The Emprove^® Component Extractable Reports includes extractables data following USP <665> to support patient safety evaluation. The reports are for single-use component made by third-party suppliers. 

Special considerations for single-use assemblies

As single-use assemblies are comprised of multiple components, qualification can be more complex.  Extractables which are compounds migrating from the fluid contact layer of polymeric plastics used in single-use assemblies into the process stream, are a key consideration during qualification of single-use systems for manufacturing. USP general chapter <665>, effective in May 2026, is the first compendial standard for plastic components and systems used to manufacture pharmaceutical drug products and biopharmaceutical drug substances and products. This data is the first step in evaluating patient safety and Table 3 provides an overview of a workflow.   

The Emprove^® Advanced Qualification Dossier (AQD) was developed to provide biomanufacturers with the information they need to support risk assessments on single use assemblies containing multiple components. This first-of-its-kind dossier supports custom and configurable assemblies and includes: 

• All available component qualification information along with extensive USP <665> extractables data for all the components in the assembly. 
• Information on extractables, bills of material, regulatory statements, component surface area information, original manufacturer information, shelf-life statements, and customer-approved drawings of the assemblies.  
• The data needed for end users to conduct risk assessments and patient safety evaluations of their assemblies.   

If you are interested in Emprove^® premium content, Demo dossiers are available to download including data for custom assemblies.