A polysaccharide is a complex glycan with at least 10 monosaccharide units. It can be formed by the multiples of the same monosaccharide (a homopolysaccharide) or by two or more monosaccharides combined (heteropolysaccharide). Two homopolysaccharides can have completely different conformations — and thus properties — based on the position and type of glycosidic linkages in the structure (Figure 9). Polyglucose ranges from cellulose — β(1,2,3,4) glucan, with its zig-zag chains regularly superimposed to each other and bound tightly by hundreds…
Product Characterization
Bioassay Survey 2006–2007
Bioassays are required for a variety of purposes in the development and production of biopharmaceuticals including drug candidate selection, product releases, product stability assessment, and comparability to support proposed process changes. However, because of their complexity and susceptibility to many variables, bioassays often prove problematic and difficult to develop. Timely development of suitable assay systems represents a major investment on the part of the biopharmaceutical industry — but late development often results in even more costly clinical holds. PRODUCT FOCUS:…
Demonstrating Comparability for Well-Characterized Biotechnology Products
Challenges and approaches in demonstrating comparability of a well-characterized biotechnology product after manufacturing changes can be as varied and complex as the products themselves. Participants at the January 2005 CMC Strategy Forum sought to discuss and agree on common implementation strategies for different manufacturing change scenarios. Development of flexible, comprehensive approaches in strategy development addressed evaluation of critical product characteristics, appropriate process steps to test, numbers of lots and levels of testing required, and assessment of product comparability (e.g., trending…