Process Development for Lyophilized Products

A common approach to process development for lyophilized products is to thermally characterize the solution formulation to determine the critical product temperature that should not be exceeded during primary drying. This is conducted using differential scanning calorimetry (DSC) and freeze-dry microscopy (FDM). The approach to development of the lyophilization cycle is often less precise. Some scientists may choose intentionally conservative conditions to avoid failure of the product during primary drying. This can lead to long processing times that are inefficient for routine production. Another approach is to choose the shelf temperature and chamber pressure for primary drying and then conduct a few experiments that utilize temperatures and pressures near those set points to propose an operating range. The challenge with both approaches is that there is no way to know if the process is operating near the failure point for the product. This can be catastrophic when transferring the process to full-scale.