A current trend in the production of biopharmaceuticals is the replacement of fixed stainless steel fluid-handling units with disposable plastic bags. Such single-use systems (SUS) offer numerous advantages, but also introduce a new set of materials into the production process and consequently expose biomanufacturers to a new set of risks related to those materials, not to mention reliance on an entirely new supply chain. In the course of developing and conducting a cell-growth-based test for suitability of disposable plastic components destined for use in cell culture operations, we discovered that the cytotoxic compound bis(2,4-di-tert-butylphenyl)phosphate (bDtBPP) leaches out of certain bags and into cell culture media in concentrations that are deleterious to cell growth. Specifically, media held in certain bags for several days at 37°C was found to contain bDtBPP, and use of those held-media samples in cell growth experiments provides data that overlap neatly with cell growth experiments using media spiked directly with bDtBPP, proving that bDtBPP leaching is responsible for the reduced growth attributable to those SUS bags. Overall, this issue represents a risk to the production of biopharmaceuticals in SUS, a risk that must be managed by diligent collaboration among companies along the entire supply chain for SUS components.

A rapid and sensitive approach was developed for direct detection of BdtbPP and other leachables from SUBs using DESI-TOFMS. The results are in high accordance with those from conventional approaches, which indicates the usefulness of the proposed method as a qualification tool for SUBs in biopharmaceutical development and also its great potential in the analysis of extractables/leachables in a wide variety of materials, process components, devices and containers used in the pharmaceutical industry.

The usage of single-use bioreactors has been increasing in biopharmaceutical industry because of the appealing advantages that it promises regarding to the cleaning, sterilization, operational flexibility, and so on, during manufacturing of biologics. However, compared to its conventional counterparts based mainly on stainless steel, single-use bioreactors are more susceptible to potential problems associated with compound leaching into the bioprocessing fluid. As a result, extractable profiling of the single-use system has become essential in the qualification of such systems for its use in drug manufacturing. The aim of this study is to evaluate the effectiveness of an extraction solvent system developed to study the extraction profile of single-use bioreactors in which aqueous-based systems are largely used. The results showed that with a non-targeted analytical approach, the extraction solvent allowed the generation and identification of an array of extractable compounds from four commercially available single-use bioreactors. Most of extractables are degradation products of polymer additives, among which was a compound that was later found to be highly detrimental to mammalian cell growth.