Choosing methods that yield more detailed results is essential for identifying subtle differences in conformational structure, and thus is critical to determine the optimal formulation of a drug.
This observation is confirmed when the same samples are analyzed by DSC (Figure 6), for which the PBS-formulated protein exhibited a lower melting temperature compared to the Tris-formulated protein.
Collectively, these data indicate that, although a portfolio of higher structure techniques available for analysis of protein APIs exists, not all of these are stability indicating, which is a key element required for formulation screening.
It is variable in its structure, as the many polymorphisms of the gene can lead to variable numbers of glutamine residues present in the protein.
In its wild-type (normal) form, it contains 6-35 glutamine residues.
It is important to consider that even superficial changes at initial timepoints can be exacerbated over time and become significant degradation events.
Unfortunately, these degradation events sometimes remain undetected until late in the drug development program, after significantly time-consuming and costly procedures have been completed.
Therefore, even small structural changes should be investigated and corrected through formulation design early in the drug development process so as to minimise potential problems at later stages.
Frequently used techniques for monitoring the conformational stability of a protein drug substance and drug product throughout manufacturing and storage include preformulation screening studies such as characterisation and comparability studies.
Similar to far-and near-UV DC, the results of second derivative analysis also indicate that the structural integrity of Ig G is similar when stored in PBS vs. These data collectively support the idea that the formulation buffers provide an equally stable environment for the protein.