Biopharmaceutical Analysis

The biopharmaceutical industry has gained a lot of experience in monitoring glycosylation, but still has a lot to learn about the structure–function relationship.

The United States Pharmacopeia (USP, Rockville, MD, www.usp.org) and the UK's National Institute for Biological Standards and Control (NIBSC, Hertfordshire, UK, www.nibsc.ac.uk) are seeking participants in a study of analytical methods used by the industry to characterize and quantify oligosaccharides.

These articles encapsulate the past, present, and possible future of process-scale chromatography in biopharmaceutical production.

This article discusses how on-line high-performance liquid chromatography (HPLC) can measure product purity in the column eluent stream in near–real time. These data can then enable the automation and control of a purification column operation, thus reducing product variability, shortening process cycle time, and increasing yield. An example application demonstrates how on-line HPLC is used as a process analytical technology to ensure the process can accommodate variability in the separation while ensuring the product meets its critical quality attributes.

Affinity purification schemes for antibody production have certain limitations keeping up with cell culture expression levels as they reach and exceed 10 g/L. New downstream purification processes are based on low cost, long lasting, and high binding (40–100 mg/mL) cation exchange resins.

ABSTRACT

Vagueness in the ICH Q2A and Q2B guidelines necessitates effective protocol design and data analysis. For specificity (detection in the presence of interfering substances), the goal is statistical differences with meaningful implications on assay performance. Linearity (results directly proportional to concentration of analyte in the sample) is typically demonstrated via least squares regression. Accuracy (difference between measured and true values) usually is presented as a percent of nominal. Precision analysis is vital because it supports claims of accuracy and linearity. A well-designed experiment and statistically relevant methods will facilitate method validation in accordance with ICH guidelines.

Conducting an analysis of the 4 Ms-man, machine, methods, and materials-enables companies to identify the true root causes of deviations.

Increased resin stability can extend the number of cleaning cycles that can be performed in situ.

This article shows how Probabilistic Tolerance Intervals of the form, "We are 99% confident that 99% of the measurements will fall within the calculated tolerance limits" can be used to set acceptance limits using production data that are approximately Normally distributed. If the production measurements are concentrations of residual compounds that are present in very low concentrations, it may be appropriate to set acceptance limits by fitting a Poisson or an Exponential Distribution.

The first part of this article, published in the September 2006 issue, discussed general strategies for validation extensions to other test method components, laboratories and even different test methods.1This second part provides practical tips on how to maintain test method suitability long after the formal completion of analytical method validation (AMV) studies.

PerkinElmer Inc. (Wellesley, MA, www.perkinelmer.com) has acquired Avalon Instruments Limited (Belfast, Northern Ireland).

SOPs are written job aids that detail the procedure of how to do a specific job task correctly.

Reserve samples of test and control articles must be retained for at least one stability time point after the completion of the study.

Good risk management tools dictate how much assay performance characteristics can deviate from ideal.

Nothing beats a good dictionary. It can clarify doubts, settle an argument, or prompt exploration into new areas of learning.

Case studies were run to test Process Analytical Technology applications for protein refolding, diafiltration, and cation exchange chromatography. It is shown that it is feasible to design control schemes that rely on measurement of product quality attributes and thereby enable real-time decisions.

A novel calibration approach was developed that not only calibrates the X-axis, but also calibrates the peak shape.

For decades now, it has been said that "the process is the product" for biologics. Great care and consistency must be applied in their upstream manufacture-during fermentation, harvest, and early purification-to preserve their complex structure, which confers their activity and specificity. As the product moves to late-stage purification, however, the relative concentration of impurities and altered product forms is diminished. Also, the final dosage form of most large molecule biopharmaceuticals is the relatively simple liquid formulation of parenteral dosage form. In contrast, manufacturing the solid dosage forms common for small-molecule drugs involves more complex processes, such as mixing dry powders, granulation, manufacturing controlled-release matrices, and tableting.

"Clinical data is the gold standard" for setting manufacturing specifications, said Patrick Swann, PhD, acting deputy director of the Division of Monoclonal Antibodies at FDA, at a session on specification setting at the AAPS National Biotechnology Conference that was held June 19-21 in Boston.

Protein aggregation is a term that can include many types of aggregation, from rapidly reversible aggregation caused by non-covalent bonds to irreversible aggregation in the form of covalent oligomers.

Using packed columns in process development activities limits the scope for appraising a large and diverse range of media.

Signal-to-noise ratios are useful in robust engineering to design products and processes that consistently deliver on target.

Extra column effects must be accounted for to make a valid comparison

Over the last three decades, numerous protein expression systems have been developed with various quality requirements on large and small scales. Huge steps have been made in large-scale protein production in mammalian systems while the small-scale mammalian systems are expensive and inflexible. Thus, small-scale production is done in simpler expression systems, sometimes sacrificing the quality of the proteins. However, relief is on the way.