Exploring features in chromatographic profiles as a tool for monitoring column performance.

In the biopharmaceutical industry, chromatography resins have a finite number of uses before they start to age and degrade, typically due to losses of ligand integrity and/or density. The "health" of a column is predicted and validated by running multiple cycles on representative scale-down models and can be followed by real-time on-going validation during commercial production. Principal Component Analysis (PCA), Partial Least Square (PLS), Similarity Scores and Single One Point-MultiParameter Technique (SOP-MPT) along with machine learning principles were applied to explore the hypothesis that there is predictive capability of latent variables in chromatography absorbance profiles for process performance (step yield) and product quality (aggregates, fragments, host cell proteins (HCP) and DNA, and Protein A ligand). The first stage of this study is described in this paper: a MabSelect SuRe™ chromatography column was cycled with a method to establish the "normal" baseline for process performance and product quality, followed by runs using a harsher NaOH Cleaning in Place (CIP) procedure (with a higher NaOH concentration than that recommended by the vendor) to accelerate resin degradation. The different mathematical analytical tools correlated with resin degradation of the column (reflected in decreasing step yield and binding capacity with increasing running cycle), specifically when using the Wash, Elution and Strip phases of the chromatography method. Monomer, HCP and DNA content were not significantly impacted and therefore a correlation with product quality was inconsequential. Importantly, this work shows proof-of-concept that while more traditional methods of measuring resin integrity such as the height equivalent to a theoretical place (HETP) and Asymmetry (As) measurements could not detect changes in the integrity of the resin, PCA, PLS, Similarity Scores and SOP-MPT (to a lesser extent) applied to the absorbance data were capable of anticipating issues in the chromatography bed by identifying atypical outcomes.

Evaluating multiproduct chromatography Protein A resin reuse for monoclonal antibodies in biopharmaceutical manufacturing.

In good manufacturing practice (GMP) facilities in the biopharmaceutical industry, chromatography resins are largely underutilized during purification of single drug products during clinical production. Chromatography resins are dedicated to a specific product and disposed of, after only a fraction of their lifetime due to concerns of potential product carryover from one program to another. In this study, we follow a resin lifetime methodology typically used for commercial submissions and apply it to determine the feasibility of purifying different products on a Protein A MabSelect PrismA™ resin. Three distinct monoclonal antibodies were used as model molecules. Column performance was monitored through chromatogram profiles, yield, clearance capability of selected media components, pressure and product quality. A protein carryover study was designed to demonstrate that the column cleaning procedures reduced protein carryover to safe cleanliness levels regardless of multiple product contact cycles and the order in which the mAbs are captured. Data show that up to 90 total cycles (30 cycles per antibody), there was negligible protein carryover and impact on process performance. Product quality was consistent, with the only meaningful trends found for the leached Protein A ligand, without affecting the conclusion of the study. While the study was restricted to three antibodies, the proof of concept for resin reuse was demonstrated.

In Vitro Performance Testing of Legacy and ENFit Gastrostomy Tube Devices Under Gravity Flow Conditions.

BACKGROUND: Changes in connector design for the gastrostomy tube were implemented to reduce the risk of misconnections. This study aimed to determine whether there are differences in gravity flow rates between legacy devices and the ENFit devices intended to replace them. MATERIALS AND METHODS: We compared 5 legacy gastrostomy tube brands with 3 corresponding ENFit brands, sized between 14 French (Fr) and 24 Fr. Seven commercial diets were used. One comparison involved low-profile devices. RESULTS: Whether an ENFit device manifested a lower flow rate than a legacy device was not a strong function of diet. One 14-Fr ENFit device, because of its reduced distal inner tube diameter, produced an average feeding time of 56 (±13) minutes from a 20-minute baseline. For other 14-Fr ENFit devices, the increase was much less pronounced (25 ± 4 minutes). At larger sizes, both decreases and increases in feeding time were observed, depending on device type; on average, the 20-minute feeding time increased to 25 (±7) minutes. For low-profile devices, across all sizes, an increase in 20-minute feeding time occurred, but the difference was small (23 ± 2). CONCLUSION: Statistically lower flow rates were observed for 70% of ENFit devices relative to their legacy counterparts. We estimate that 30% of the differences may be noticeable. In the scenarios studied, lower flow rates (relative to other devices at the same Fr number) arise from energy losses in straight tubing. This difference can be reduced by increasing the tube inner diameters in distal end of ENFit tubes.