Process Analytical Technology (PAT) for Bioprocesses

Improving Quality through Precise Process Analytics and Process Optimization

Analytical methods are used almost universally across bioprocess applications such as biopharmaceutical development, enzyme or amino acid production, and other applications where consistently monitoring and controlling product quality is essential.

Conventionally, scientists collected samples at the end of each batch and analyzed them in a quality control (QC) laboratory, away from the process, before deciding about the product's acceptance, rejection, or reprocessing.

Precise Process Analytics and Process Optimization

With the FDA's introduction of the process analytical technology (PAT) framework in 2004, process analytical tools are constantly evolving.

The bioprocess industry is moving toward applying process analytics to analyze raw materials and final products, and to monitor and control the bioprocesses.

Precise analytics, monitoring, and control to optimize bioprocess operations ensure ideal cell viability, oxygen, carbon dioxide and nutrient feeding strategies, corrective actions and consistent productivity from process development to full manufacturing scale.

With over 60 years of experience as a leader in process analytics and laboratory instruments, METTLER TOLEDO understands that reliable instrumentation is vital to trustworthy bioprocess monitoring leading to maximizing yield and productivity rates.

The PAT Framework

The idea behind the PAT framework is that a well-understood process leads to a predefined final product quality that reduces regulatory concerns and increases process efficiency in the least amount of time with the least operational costs.

With PAT, quality is built into the process design and is not tested into the products. This is how PAT opens the door for Quality by Design (QbD) strategies, paving the path to lean manufacturing principles.

Researchers identify and explain the sources of variability, the process manages the variability, and the scientists can accurately and reliably predict product quality over the design space, critical process parameters (CPPs), and manufacturing conditions.

When life scientists use analytical methods to develop biopharmaceuticals or produce enzymes and amino acids, they also must ensure the conditions are consistently monitored so that the products meet strict regulatory requirements for the final molecules to inherit vital attributes such as purity, identity, safety, and potency.

Understanding PAT Framework

To understand the importance of PAT in biotechnology, it is first essential to understand the existing types of analytical processes:

Offline monitoring

Offline measurements require the collection of a sample, which is taken to a lab to be analyzed.

At-Line measurements

At-line measurements are at the side of the process but are not directly integrated. The sample has to be actively removed and delivered to the analytical method.

In-Line analysis

In-Line analysis uses sensors placed in the process vessel to conduct in situ measurements.

Online monitoring

Online sensors are placed on a side stream of the process and measured continuously.

Since they are built on a bypass, there will be a delay in the reported measurement versus in-line.

PAT for Water Quality

In biotechnology, water is a multifunctional resource.

It is used as a raw material, solvent, ingredient, reagent, and cleaning agent, and it is produced in various “pure” forms.

The wide variety of water grades and water systems means their production is becoming an increasingly specialized process and requires highly dependable instrumentation.

Online measurement of total organic carbon (TOC), oxidation reduction potential (ORP), and conductivity are essential for continuous and reliable water quality assurance.

Having precise quantities of nutrients in the medium is a prerequisite for the cells to grow and express products optimally.

When developing a medium, researchers typically test several combinations of amino acids, glucose, and ions, as well as other supplements such as serum extracts, tissue extracts or hydrolysates, growth factors, hormones, carrier proteins like albumin and transferrin, lipids, metals, vitamins, polyamines, and reductants.

The number of possible combinations is nearly infinite, and the different ingredients often interact with each other.

Media optimization requires a lot of effort, time, and cost. An optimal growth medium cannot be designed by simply trying arbitrary combinations of ingredients randomly.

Media optimization and preparation are perceived as simple operations; however, key parameters such as temperature, mixing time, and pH can significantly affect media and can maintain cell metabolism consistency and performance.

PAT is often necessary to develop a robust process.

With ReactIR and ReactRaman, you can quantify in-line the concentration of the critical components during media preparation and monitor key ingredients during dissolution and under varying pH and temperature conditions.

Those results can be validated offline using HPLC or UV-Vis spectrometry.

With In-line particle analysis, you can monitor the rate and degree of change to particle count and size of the dry-powder and media dissolutions, while with EasyMax, you have a simple and robust process development platform available where you can control and precisely document the influence of process parameters such as pH, dosing, conductivity, oxidation-reduction potential (ORP), or dissolved oxygen on your new media.

pH is one of the most critical parameters for cultivated cells and must be carefully controlled to maintain cell growth.

The InLab® Max Pro ISM pH electrodes are ideal for measuring pH while preparing and optimizing cell culture and fermentation media.

For larger scales or in-line monitoring, the InPro pH and ORP electrodes ensure confident and reproducible measurements during media preparation while high-range conductivity probes indicate complete dissolution of the ingredients. In single-use platforms, the InSUS sensors deliver these inline monitoring just as reliably.

METTLER TOLEDO manufacturing guide below explains biopharmaceutical manufacturing at commercial scale and covers the role of analytics and weighing in understanding crucial parameters in upstream and downstream process steps.

Biopharmaceutical Manufacturing Guide

The Biopharmaceutical Manufacturing Guide discusses the importance analytics and weighing related to:

Media & Buffer Preparation
Process Development, Characterization & Scale-up Studies
Commercial Fermentation & Cell Culture Operations
Separation, Harvest & Clarification
Purification & Bioconjugation
Formulation, Fill & Finish

PAT in Upstream Processing (USP)

The main variables affecting a bioprocess are temperature, pH, dissolved oxygen (DO), carbon dioxide, biomass, glucose and lactate, and other metabolites.

Each of these variables play a critical role in the bioreactor in optimizing the cell-based production of large molecules, polymers, oligomers, and small molecules.

In-line sensors of the InPro family (reusable format, heat sterilizable) and the InSUS family (single-use format, irradiation sterilizable) are designed for reliable and accurate measurements in these applications.

While in-line monitoring of temperature, pH, ORP, DO, and CO2 in the bioreactor has been an industry standard for years, the direct measurement of cell density and viability using probes still needs to be improved.

Although solutions exist for microbial fermentation, cell viability measurement for cell cultures is still mainly done through sampling and counting.

Common analytical approaches to investigate the media nutrient profile involve offline methods such as chromatographyor enzymatic quantification assays while there are now also inline single-use glucose and lactate sensors based on the latter technologies.

Research is, however, developing methods to measure glucose and metabolites in-line using Raman spectroscopy or other infrared spectroscopy technologies such as Fourier transform infrared (FTIR) spectroscopy.

These sensors are valuable as they can be used continually and don’t have any chemical interactions with the analytes.

Precise analytics, monitoring, and control to optimize bioprocess operations ensure optimal cell viability, a consistent oxygen and nutrient feeding strategy, and consistent productivity from process development to full manufacturing scale.

PAT in Downstream Processing (DSP)

The most important goals of downstream processing (DSP) are to recover the final product and reduce impurities to a level that is accepted and complies with the regulatory quality criteria.

If possible, impurities should be monitored after each downstream processing step or unit operation, or at least after the steps aiming at reducing specific contaminants.

With in-line or online monitoring applied at each critical step of the downstream processing, PAT would have a real impact on bioprocesses so that impurities can be monitored rapidly, and time will be available to correctly adjust the DSP step in question before the next processing step starts.

Measurements using FTIR, UV-Vis, and Raman spectrometry, as well as pressure, flow, pH, conductivity, and turbidity in-line measurements, can replace conventional offline analyses and help monitor downstream processing steps such as harvest, centrifugation and filtration, primary capture, buffer exchange, up concentration, purification, bioconjugation, and formulation.

Pressure and flow sensors, control systems, and software for measuring, monitoring, and collecting data also ensure efficiency in downstream processes.

METTLER TOLEDO Solutions for Bioprocesses

Analytical Sensors for Bioreactors

METTLER TOLEDO produces in-line analytical sensors for monitoring and controlling key analytical par...

Dynochem Biologics

Fit-for-purpose simulation software to support bioprocessing upstream and downstream unit operations...

Automated Lab Reactors and In-Situ Analysis

Particle size analyzers, FTIR and Raman spectrometers, chemical synthesis reactors, reactor control...

CytoDirect automated cell counting used in the biolab under the hood

Cell Analysis

METTLER TOLEDO now offers CytoDirect, an automated stain-free cell counter, ensuring a consistent nu...

Industrial Weighing Scales and Systems

Bench Scales, Portable Scales, Floor Scales, Counting and Mixing Scales, Terminals, Weigh Modules, L...

Useful Documentation. Biopharmaceutical Manufacturing Guide

Biopharmaceutical manufacturing at commercial scale requires the ability to see, understand and make quick decisions on critical process parameters. This guide covers the role of analytics and weighing in understanding these parameters in upstream and downstream process steps.

This guide discusses how the right tools to monitor and understand your biological process, from process development to full-scale manufacturing, help optimize productivity while minimizing time-to-market.

The Biopharmaceutical Manufacturing Guide discusses the importance analytics and weighing related to:

Media & Buffer Preparation
Process Development, Characterization & Scale-up Studies
Commercial Fermentation & Cell Culture Operations
Separation, Harvest & Clarification
Purification & Bioconjugation
Formulation, Fill & Finish

Calibration, Qualification and Maintenance for Your Solutions

METTLER TOLEDO Service is your one-stop shop for all your balance service, scale service, and inspection device service needs. From installation and initial calibration to preventive maintenance and timely upgrades, we ensure your operations run smoothly and efficiently.

Achieve and maintain compliance through consistent procedures and adhere to local and global regulations and standards, such as:

ISO 17025

EURAMET

USP, GLP and GMP

NIST Handbook 44 and OIML

Measuring Instruments Directive (MID)

Ensure a perfect start and ongoing, worry-free use with immediate and long-term benefits:

Assurance that the equipment is fit for use

Cost-savings through manufacturer's qualification services

Confidence that the equipment meets process requirements

Identification of needed calibration and maintenance

Pre-plan your periodic maintenance that provides you with complete trust that your equipment achieves:

Consistent, accurate results

Safe and reliable operation

Optimal performance possible

A longer equipment lifespan, resulting in a higher ROI

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Process Analytical Technology (PAT) for Bioprocesses

Improving Quality through Precise Process Analytics and Process Optimization

The PAT Framework