Syringe Filling of High-Concentration mAb Products Using Peristaltic Pump-Based Mechanism: Challenges and Mitigation Strategies.

Syringe filling of high-concentration mAb formulation during manufacturing of large-scale drug product batches may present challenges such as product deposition onto the area of the syringe barrel where the stopper is inserted, product splashing or dripping, droplets left after the fill cycle, filling needle clogging, product build-up inside the needle during line stoppages, variation in fill weight/volume, and potential impact on product quality attributes. In this article, a summary of these issues and approaches to overcome them are summarized. Potential failure modes of the syringe filling process and appropriate in-process controls are provided. In addition to developing the filling process or resolving manufacturing issues, the pharmaceutical company developing the product and associated drug product manufacturing process may want to implement long-term strategic approaches to support the portfolio progression. Potential long-term approaches such as use of a viscosity reducing formulation development approach, improving peristaltic filling technology performance, building small-scale filling capability and establishing a streamlined filling process management cycle are also summarized. The aspects summarized in this article may be used to develop a robust filling process and control strategy for high-concentration mAb products and implement long-term strategic approaches to support the portfolio progression.

Mixing of a mAb Formulation in a New Magnetically Coupled Single-Use Mixing System: Key Learnings of Preliminary Experimental and Computational Evaluation.

MilliporeSigma recently introduced a new magnetically coupled single-use mixing system (Mobius® Power MIX) for more efficient mixing of buffers and media in biopharmaceutical applications. Experimental and computational fluid dynamics (CFD) assessments were performed on the Power MIX 100 system to understand product quality impact, shear, and mixing efficiency. It was interesting to note slightly higher submicron (0.4-1 µm) and subvisible (1-54 µm) particle formation at the lower mixing speed (50 RPM) compared to higher mixing speeds (100/200 RPM). Mixing speed and time showed negligible impact on the other product quality attributes tested, including protein concentration, turbidity, general appearance, purity, and soluble aggregates. The CFD simulations provided useful information with respect to the impact of batch size (20-100 L), viscosity (2-50 cP), and impeller speed (100-300 RPM) on mixing time (mixing time ranged from 10 to 365 s) and shear (maximum shear rate was found to be localized around the impeller and it was about 30,260 s-1, whereas the average shear rate ranged from 4 to 36 s-1). Statistical analysis of the CFD results showed that natural-log transformation and quadratic fitting were found to be suitable statistical models to predict mixing time and shear within the design space of the parameters assessed in the present study.

Detailed analysis of modifications in lignin after treatment with cultures screened for lignin depolymerizing agents.

Termites, beetles, and other arthropods can digest living and decaying wood plus other lignocellulosic plant litter. Microbial sources like other wood-eating insect guts and wastewater treatment sludge were screened for lignin depolymerization. Near infrared spectroscopy and atomic force microscopy (AFM) along with high-performance liquid chromatography (HPLC), were used to track changes in functional groups, size, shape, and molecular weight of lignin molecules during incubations. Odontotaenius disjunctus (Betsy beetle) guts dissected whole or separately as midgut, foregut, and hindgut, consumed corn stover but did not show lignin depolymerization. The sludge-treated lignin did show some reduction in molecular weight on the HPLC, particle size (350-650 nm initially to 135-220 nm by day 30) and articles per field on AFM. pH and the presence of nutrients had a substantial effect on the extent of depolymerization. Cultures in lignin and nutrients showed higher growth than cultures with lignin only. Colony characteristics within the beetle gut and the sludge were also evaluated.

Determination of lignin by size exclusion chromatography using multi angle laser light scattering.

A method was developed using high-performance size exclusion liquid chromatography (HPSEC) with multi-angle laser light scattering (MALLS), quasi-elastic light scattering (QELS), interferometric refractometry (RI) and UV detection to characterize and monitor lignin. The combination proved very effective at tracking changes in molecular conformation of lignin molecules over time; i.e. changes in molecular weight distribution, radius of gyration, and hydrodynamic radius. Until this study, UV detection (280 nm) had been the primary lignin determination method for chromatography. Three different HPLC columns were used to study the effects of pH, flow conditions, and mobile phase compositions (dimethyl sulphoxide, water, 0.1M NaOH, and lithium bromide) on the chromatography of lignin. Since light scattering accuracy is highly dependent on solute concentration, both the UV and RI detectors were calibrated for use as concentration detectors. Shodex Asahipak GS-320 HQ column with 0.1M NaOH (pH 12.0) run at 0.5 ml/min was found to give the highest separation and most consistent recovery. The study also revealed that the lignin aggregated at pH below 8.5. This aggregation was detected only by MALLS and was not observed on UV or RI detectors. It is very important to take this loss in apparent concentration due to aggregation into consideration before collecting reliable depolymerization data.

Detailed analysis of modifications in lignin after treatment with cultures screened for lignin depolymerizing agents.

Termites, beetles, and other arthropods can digest living and decaying wood plus other lignocellulosic plant litter. Microbial sources like other wood-eating insect guts and wastewater treatment sludge were screened for lignin depolymerization. Near infrared spectroscopy and atomic force microscopy (AFM) along with high-performance liquid chromatography (HPLC), were used to track changes in functional groups, size, shape, and molecular weight of lignin molecules during incubations. Odontotaenius disjunctus (Betsy beetle) guts dissected whole or separately as midgut, foregut, and hindgut, consumed corn stover but did not show lignin depolymerization. The sludge-treated lignin did show some reduction in molecular weight on the HPLC, particle size (350-650 nm initially to 135-220 nm by day 30) and particles per field on AFM. pH and the presence of nutrients had a substantial effect on the extent of depolymerization. Cultures in lignin and nutrients showed higher growth than cultures with lignin only. Colony characteristics within the beetle gut and the sludge were also evaluated.