Tag: <span>purification</span>

In-line conditioning (IC) is a form of dilution where a process buffer is formulated in-line from concentrated stock solutions of acids, bases, and salts that are mixed with the correct amount of water-for injection (WFI). This new buffer preparation strategy must prove its equivalency to buffers made the traditional way (i.e., weighing salts, stirring in water, titrating with acid or base). In this paper, such a demonstration is presented using two control modes: (1) ratio control with flow feedback; and (2) pH/conductivity feedback. To obtain the necessary parameters for an error propagation analysis, a robustness study has been performed. Our analysis showed that with low incoming variability, or when the uncertainty of the stock solutions is below 2%, the two modes of control give comparable performance. When the uncertainty increases, so does the uncertainty of ratio control with flow feedback, more with respect to conductivity than pH, while the precision of pH/conductivity feedback remains at the same level. The choice of control should therefore take into consideration the critical process parameters, their tolerances, and the input variability in the stock solution concentration. In situations where there are higher variabilities in stock solution concentrations or process temperatures, this study suggests that pH/conductivity feedback might be a better option.

Biologics Production

Tissue-derived products are a class of biological materials harvested directly from animal or human tissue, in contrast to recombinant DNA materials grown in cell culture bioreactors. Tissue-derived products are often used for structural purposes and are typically regulated as medical devices. However, when used to treat human patients, tissue-derived products are subject to many of the same concerns as recombinant DNA biotherapeutics, with viral safety being one of them. To address this, the tissue source material must undergo a risk analysis and testing regimen for the presence of viral contaminants. In addition, viral clearance studies must be performed to evaluate whether the purification process is robust enough to remove and/or inactivate viruses that may be present in the starting material.

The goals of viral clearance studies are the same for tissue-derived products and biotherapeutics, but the design and performance of these studies can be quite different because of the diverse nature of the materials. In this article, we will present an overview of viral clearance studies for tissue-derived products based on our experience in performing a large number of such studies. Rather than discussing the issues related to viral clearance in general, our focus will be on the unique challenges that tissue-derived products pose.

Biologics Production Regulatory Risk Analysis and Management

Bead matrices have been used in affinity chromatography to purify molecules in multiple applications. For instance, the hepatitis B surface antigen (HBsAg) is one of the molecules purified by this technique for human vaccine development programs. However, the use of monolithic supports have emerged as the advantageous choice for affinity chromatography based on convective mass transfer, a high number of channels, and low backpressures at high flow rates. For this reason, several experiments were conducted to determine the suitability of CB.Hep-1 monoclonal antibody (mAb) immunosorbent developed on carboxyimidazole (CDI)-monolithic supports (ligand concentrations: 0.5, 1.0, and 7.0 mg/mL) for HBsAg particle purification. Key results from this study show the highest amounts of HBsAg adsorbed (3059.31 ¬Ī 865.71 ¬Ķg HBsAg/mL immunosorbent, n = 2), and HBsAg eluted (2884.50 ¬Ī 541.01 ¬Ķg HBsAg/mL immunosorbent, n = 2), were estimated in the 1.0 mg/mL-CDI-CB. Hep-1 mAb monolithic support immunosorbents. In addition, the ligand leakage was always < 3 ng mAb/¬Ķg HBsAg (approved limit) in the 1.0 mg/ mL-CDI-CB.Hep-1 mAb immunosorbents. Experiments also evidenced the high purity and molecular homogeneity of purified HBsAg particles (< 95 %) across 20 purification cycles. Therefore, the ligand concentration could be reduced up to 1.0 mg/mL, which would enable a notable decrease in the mAb amount required for vaccine manufacturing, as compared to bead matrices (4.0 mg/mL). This study demonstrated that CDI-CB.Hep-1 mAb monolithic support immunosorbents are best suited for assessing the large-scale purification performance of HBsAg particles for human vaccine development programs at low ligand concentration and high flow rates...

Biologics Production

In this paper, we review the efficacy data for low and high pH inactivation of viruses in solutions (i.e., liquid inactivation) and discuss the mechanisms of action and the impact of temperature and treatment time, as these are the primary determinants of inactivation efficacy, besides pH, for different viruses. Only enveloped viruses were considered for low pH inactivation, as the literature concerning low pH inactivation of non-enveloped virus is not extensive and low pH is not considered to be an effective inactivation approach for most non-enveloped viruses. We conclude that for low pH treatment of enveloped viruses, and high pH treatment of both enveloped and non-enveloped viruses, an enteric flavivirus such as bovine viral diarrhea virus represents a worst-case model virus…

Biologics Production

Plantibody purification is not as efficient as antibody purification from serum, ascites, or mammalian cell cultures. It is characterized by the application of inefficient plantibody solid-liquid extraction systems, low plantibody recovery, and short lifetimes of expensive chromatography matrices. To overcome it, several protocols of liquid-liquid aqueous two-phase extraction (ATPE) combined with affinity chromatography were previously studied to purify the CB.Hep-1 monoclonal antibody, which showed an unexpectedly high recovery. However, a study of ATPE combined with several affinity chromatography matrices to purify plantibodies has not been reported so far. Therefore, a combination of the best ATPE protocol with five specific affinity chromatography matrices to purify a plantibody for vaccine manufacturing is described in this study. Positive outcomes from plantibody recovery (%), specific activity (%), yield (mg purified IgG/L of leaf extract), and productivity (mg purified IgG/L of leaf extract/h) were achieved. Plantibody purity did not show statistical differences among all samples (> 97%, p < 0.05), and protein A leakage was thousands of times smaller than toxic protein A for non-human primates. In summary, the combination of ATPE (10% PEG 4000/15% K2PO4, pH 5.5) with two specific affinity resins were well-suited for large-scale plantibody purification from tobacco plant leaves...

Biologics Production Manufacturing

Cancer is one of the leading causes of death worldwide, and the second leading cause of death in Cuba. To address this serious health problem, some research has involved suppressing tumor growth by inhibiting the angiogenesis process using several molecules including antibodies. A divalent version of antibody fragments, the CIGB-598a, with a molecular weight between 100 and 110 kDa, has been expressed in CHO cells specific for a novel epitope of the human vascular endothelium growth factor (VEGF). This material has been generated at the Center for Genetic Engineering and Biotechnology to support cancer research efforts. As in other studies involving the purification of recombinant molecules, CIGB-598a exhibited a high degree of aggregation in the CHO cell culture supernatant. This required the design of a downstream process capable of removing high levels of aggregates to obtain a highly pure target molecule for use in preclinical studies and human applications further down the road. We have developed a suitable downstream method based on the combination of three chromatography processes: affinity, cation-exchange, and anion-exchange that recover a relatively low level of CIGB-598a, but at a level of high purity (greater than 95 %) with fewer aggregates (below 1%)…

Biologics Production

Downstream processing is increasingly seen to be a capacity constraint for many biopharmaceutical manufacturing organizations. In our current study, nearly 75% of respondents reported that their facilities were experiencing some degree of capacity bottlenecks as a result of downstream processing. In comparison, 63.8% responded the same in the previous year. As the biopharmaceutical industry increases its focus on cost containment, product pricing, and healthcare reform, critical manufacturing operations have been pushed to center stage. Over the past few years, downstream processing, which includes complex operations such as filtration of final products and chromatography operations has become increasingly challenging, from budgetary and operational perspectives. As upstream operations continue to improve, the ability of current downstream facilities to handle the additional load has led to strains and constrictions. The industry is open to new solutions although few alternatives to current processes have been presented. A number of promising innovative technologies are on the horizon, but it will be a few years or more before they debut in clinical or commercial production operations….

Manufacturing

Amino acids are the most basic of building blocks in physiology, which is why peptides (oligomers of amino acids) are continuing to grow in prominence among pharmaceutical manufacturers. With inherent abilities to block and/or enhance signal transfers in the human body, peptides, when harnessed as active pharmaceutical ingredients, can treat a host of metabolic diseases, cardiovascular and heart conditions, and neurodegenerative disorders. Peptide-based drug targets are being identified at an increasingly rapid pace, both in terms of recently introduced therapies, and products in the development pipeline…

Manufacturing

Recombinant adeno-¬≠associated viral (rAAV) vectors have proven to be efficient vehicles for gene transfer in animal models. The attractive features of this vector system are long-term gene expression with little or no associated toxicities following administration to a variety of tissues. Previous and ongoing clinical trials in humans demonstrate a very good over-all safety profile. However, one of the caveats of this work that has been carried out by several ¬≠laboratories is the inability to normalize vector doses administered by different investigators to animals and humans. Most of the work to date has involved AAV serotype2 vectors, but vector systems based on other AAV ¬≠serotypes are being rapidly developed…

Viral Reference Materials Viral Vectors

With the ­development of bacterial fermen­tation and ­mammalian cell culture as the sources for new recombinant products came a standardization of raw feed stocks. Therefore, manufacturers came to share the same types of problems. This standardization allowed a more systematic approach to process development divided into upstream (bacterial and yeast fermentation or mammalian cell culture) and downstream processing activities…

Manufacturing