Polysaccharide conjugate vaccines are typically comprised of several different polysaccharides produced with distinct and complex production processes. Clarification and primary recovery operations, such as particle conditioning are integral to purification. Efficient process development of these two unit operations has been constrained by lab-scale models that require large volumes and considerable time to evaluate. A modular approach to develop rapidly purification processes for polysaccharides at the micro-scale would greatly enhance productivity and speed the development of novel conjugate vaccines. To enable high throughput screening, a suite of high throughput analytics was assembled for polysaccharide-containing feedstreams. Three orthogonal generic assays were developed for the high throughput determination of product titre. Assays for clarity and impurity determination were also optimized. The final comprehensive suite of high throughput analytics was qualified for analysis of product titre, product quality, impurity clearance, clarification efficiency, and particle size characterisation. We developed a novel system for high throughput particle conditioning. With this system, 96 individual reaction conditions can be evaluated in parallel, including downstream centrifugal clarification. The scalability of particle conditioning was evaluated between USD reactors with less than 1 mL of volume up to Pilot-scale reactors of 14 L for several biological feedstreams derived from three host species. Product yield, impurity clearance, and product quality were comparable between scales. An engineering characterisation of the reactors was performed and several approaches for scaling particle conditioning processes were evaluated. To support this platform, a custom-built, modular system for depth filtration of eight conditions/filters in parallel was developed using 0.2 cm2 area of media per channel. The reproducibility and scalability of this technology was demonstrated with several filtration media. With this integrated approach to particle conditioning and depth filtration, we have shortened the process development time. The engineering scale up models developed in this thesis will facilitate the creation of more robust processes at pilot and commercial scales of operation.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:647190 |
| Date | January 2015 |
| Creators | Noyes, A. R. |
| Publisher | University College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://discovery.ucl.ac.uk/1555667/ |
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