Development of automated metabolite control using mid-infrared probe for bioprocesses and vaccine manufacturing.

Automation of metabolite control in fermenters is fundamental to develop vaccine manufacturing processes more quickly and robustly. We created an end-to-end process analytical technology and quality by design-focused process by replacing manual control of metabolites during the development of fed-batch bioprocesses with a system that is highly adaptable and automation-enabled. Mid-infrared spectroscopy with an attenuated total reflectance probe in-line, and simple linear regression using the Beer-Lambert Law, were developed to quantitate key metabolites (glucose and glutamate) from spectral data that measured complex media during fermentation. This data was digitally connected to a process information management system, to enable continuous control of feed pumps with proportional-integral-derivative controllers that maintained nutrient levels throughout fed-batch stirred-tank fermenter processes. Continuous metabolite data from mid-infrared spectra of cultures in stirred-tank reactors enabled feedback loops and control of the feed pumps in pharmaceutical development laboratories. This improved process control of nutrient levels by 20-fold and the drug substance yield by an order of magnitude. Furthermore, the method is adaptable to other systems and enables soft sensing, such as the consumption rate of metabolites. The ability to develop quantitative metabolite templates quickly and simply for changing bioprocesses was instrumental for project acceleration and heightened process control and automation. ONE-SENTENCE SUMMARY: Intelligent digital control systems using continuous in-line metabolite data enabled end-to-end automation of fed-batch processes in stirred-tank reactors.

Interactions between Parenteral Lipid Emulsions and Container Surfaces.

OBJECTIVE: To evaluate the relationship between changes in emulsion globule size distributions and container uptake of lipid emulsions in total nutrient admixtures. METHODS: A total nutrient admixture was prepared from a commercial lipid emulsion, 20% ClinOleic®, separated into glass (borosilicate) and ethylene vinyl acetate (EVA) plastic containers, and then stored at ambient conditions for approximately 24 h. The large globule size distribution was monitored continuously for both containers, and the quantity of triglycerides associated with both containers was measured by liquid chromatography. The changes in mass of the EVA containers were also measured gravimetrically. RESULTS: The volume percent of globules greater than 5 microns in diameter (PFAT5) levels for an emulsion admixture in EVA containers showed a 75% reduction compared to a marginal decrease of PFAT5 when in the glass container. Extraction of the containers showed that the quantity of triglycerides associated with the EVA surfaces steadily increased with emulsion exposure time, while the glass showed a significantly lower triglyceride content compared to the EVA. Gravimetric measurements confirmed that the EVA containers gained significant mass during exposure to the emulsion admixture. CONCLUSION: A time-dependent decrease in PFAT5 values for an emulsion admixture was associated with container triglyceride absorption where EVA containers had a greater uptake than glass containers. The larger globules appear to absorb preferentially, and the admixture globule size distribution fraction represented by PFAT5 accounts for 15-20% of the total triglyceride adsorption to the container. LAY ABSTRACT: The goal of this work is to evaluate how emulsions in total nutrition admixtures are affected by the containers within which they are stored. Specifically, the study examines how the emulsion globule size distribution in different containers is related to adsorption or absorption of the lipids onto or into the container. The admixtures were prepared from a commercial lipid emulsion, 20% ClinOleic®, and the containers were either glass (borosilicate) or plastic (ethylene vinyl acetate, EVA). The large globule size distribution was monitored continuously for both containers over the course of 24 h, and the quantity of triglycerides taken up by both containers was measured by liquid chromatography. The lipid uptake by the EVA containers was also monitored by gravimetric methods. Briefly, the percent of fat globules greater than 5 micrometers (PFAT5) in EVA containers showed a 75% reduction compared to a marginal decrease of PFAT5 when in the glass container. Extraction of the lipids from the containers showed that the quantity of triglycerides associated with the EVA surfaces steadily increased with admixture exposure time, while the glass showed a significantly lower triglyceride content. Gravimetric measurements confirmed that the EVA containers gained measurable mass during exposure to the emulsion admixture.

Impact of Formulation and Processing Parameters on Silicone Extraction from Cyclic Olefin Copolymer (COC) Syringes.

The effect of various formulation and process parameters on the extraction of silicone from siliconized cyclic olefin copolymer (COC) syringes is reported. The impact of proprietary silicone curing process on COC syringe barrels was evaluated with respect to the rate and extent of silicone extraction. Similarly, the impact of formulation parameters such as pH, ionic species, and cosolvents on silicone extraction was also evaluated. The rate and extent of silicone extraction into contact solutions was inversely related to the degree of completion of the silicone curing process. The rate and extent of silicone extraction in solution were highest upon exposure to extreme pH solutions. The silicone extraction data indicate that the silicone curing process and formulation parameters have a profound effect on the rate and extent of silicone extraction into solutions. LAY ABSTRACT: Silicone oils are used in medical syringes to provide lubrication. Prefilled medical syringes contain solutions into which silicone oil components may migrate. This study examined the degree to which silicone components migrated into different solution matrices. The impact of different levels of proprietary silicone curing processes on the migration of silicone components in contact solutions was also examined. This study also examined the impact of various formulation parameters (pHionic strength and cosolvents) on the degree to which silicone components migrated into solutions. Solution pH had the greatest effect on silicone migration with higher levels of silicone measured in solutions at the pH extremes. Curing of the silicone (reaction of the silicone with the syringe materials) also had significant impact. High curing levels resulted in less silicone migrating into solution as compared to levels seen with syringes with low curing levels. Thus it was demonstrated that both the nature of the solution stored in the syringe and the degree of silicone curing on the syringe barrel had substantial impact on the amount of silicone that migrated from the syringe components into the solution contained within the syringe.