Analytical

eBook: Product Variants in Bioprocesses

Product variants are contaminants because they bear properties that are different from those of desired biological products with respect to activity, efficacy, and safety. Thus, such variants can compromise product quality and consistency. In this eBook, Yuval Shimoni explores different types of variants — including primary-sequence variants, undesirable posttranslational modifications, aggregates, and degraded proteins — and explains how their presence can diminish the performance and quality of drug substances and products. He also discusses how product variants form at different…

eBook: Process-Related Impurities — Emerging Strategies for Detection, Identification, and Management of Host-Cell Proteins

Host-cell proteins (HCPs) represent a major class of process-related impurities (PRIs) that are generated during biopharmaceutical manufacture. Although the vast majority of such proteins are removed from a drug substance during downstream purification, residual HCPs can remain in a finished drug product. Even in minimal concentrations, copurifying HCPs can pose safety risks and compromise protein-product yield, efficacy, and stability. Thus, regulatory agencies consider the presence of HCPs to be a critical quality attribute (CQA). Sufficient clearance of these impurities helps…

Contractor Perspectives: Best Practices for Transfer, Handling, Testing, and Storage of Cell Banks

For comments about how contract development and manufacturing organizations (CDMOs) manage their cell-banking quality assurance (QA) practices. I contacted long-time member of BPI’s Editorial Advisory Board Scott M. Wheelwright, PhD, for his perspectives. Wheelwright brings many years of experience to this discussion, with insights into the evolution of technologies and practices extending back to the early launch of the biopharmaceutical industry. Currently, he provides consulting support for companies with manufacturing and sourcing in China and other Asian countries. He also…

Measuring Viral Titer in AAV-Mediated Gene Therapy Using a PCR Technique for Absolute Quantitation

Gene therapies have reemerged as promising treatments to a number of genetic illnesses. Nearly 400 gene therapy clinical trials are recruiting or ongoing in the United States for diseases such as hemophilia and spinal muscular atrophy (1). The primary vehicles used today to deliver such therapies to patients’ cells are viral vectors such as adenoassociated viruses (AAVs), but producing biologically active vectors for gene therapy can be problematic. One difficulty is generating vectors at the correct concentration to yield a…

Analytical Methods for Cell Therapies: Method Development and Validation Challenges

Advanced-therapy medicinal product (ATMP) characterization and analysis play important roles in providing chemistry, manufacturing, and controls (CMC) information for regulatory applications as well as in supporting product-release and stability studies. Each type of advanced therapy presents different analytical development challenges, so each requires specific characterization, potency, purity and identity assays. Variability in cells and among patients, multiple and complex mechanisms of action (MoAs), a general lack of readily available reference materials, and complicated analytical methods and instruments underlie the major…

Validation of a Next-Generation Single-Use Turbidity System

Turbidity describes the relative clarity of a liquid as the result of suspended solids. Instruments that measure turbidity typically use a beam of light to detect particles by measuring the difference between the amount of light emitted from the light source and the amount that is received by a detector. Such measurements are affected by the size, shape, and number of particles in a sample of liquid because those solids scatter the incoming light, which provides an apparent absorbance that…

The Five Heresies of Cell Culture: Debunking Conventional Wisdom

Cell culture and bioprocessing conventional wisdom remains a hurdle for the wider adoption of more precise tools. It has been more than 60 years since any real progress has been made towards creating a more accurate and reliable way of performing cell culture monitoring to better understand the effects of things like pH and oxygen at the pericellular level. At SBI, we’re developing optical sensing technologies that unlock the “black box” of cell culture to bring actionable insights to scientists…

Cell-Line Development: Accelerating Antibody Discovery By Monitoring Titer and Glycosylation with the Octet Platform

Cell line development involves the screening of thousands of clones in an effort to find the few optimal clones that are stable, grow as expected, and produce high yields of the bioproduct. The time it takes from engineering an optimal cell line to the production of the target biologic can be prohibitive and may differ from molecule to molecule. While expression-level analysis like titer screening is carried out early, other critical quality attributes (CQAs) such as glycan characterization are often…

Cell Banking in the Spotlight: Advising Biologics Developers About Cell Bank Preparation and Characterization

Living cells are at the heart of biotechnology, and cell lines for production and testing of biopharmaceuticals are highly valuable assets. The process of banking cells generally moves from development of a research cell bank (RCB) based on a clone of interest to establishment of a master cell bank (MCB), from which working cell banks (WCBs) can be produced. Especially for biotechnology startups, preparation of an MCB can involve a significant jump from work performed in standard laboratory conditions to…

Ask the Expert: Considerations for Mass Spectrometric HCP Analysis During Process Development

Host-cell proteins (HCPs) must be assessed early in biopharmaceutical product development to establish the efficiency of a purification process. Liquid chromatography coupled with mass spectrometry (LC-MS) is a strong orthogonal method for HCP identification and quantitation. During an 18 March 2021 “Ask the Expert” presentation, Christina Morris (senior scientist at BioPharmaSpec) explained how MS analyses can enhance process development (PD), then presented considerations for generating spectral libraries, selecting samples for quantitation, and reviewing data. Morris’s Presentation Spectral Libraries: A typical…