Freeze-Drying of Pharmaceuticals in Vials Nested in a Rack System-Part I: Freezing Behaviour

Area of Science:

• Pharmaceutical Science
• Bioprocessing Engineering
• Materials Science

Background:

• Biopharmaceutical distribution often necessitates ultra-cold conditions or lyophilization, involving freezing that can compromise drug quality.
• Formulation and freezing design are critical for mitigating stress during the freezing process.

Purpose of the Study:

• To investigate the impact of key freezing parameters (ice nucleation temperature and cooling rate) on a sucrose-based formulation.
• To analyze how different vial loading configurations influence freezing behavior and product morphology.

Main Methods:

• Controlled freezing experiments were conducted on a sucrose-based formulation.
• Two loading configurations were tested: vials directly on the shelf and vials nested in a rack.
• Scanning Electron Microscopy (SEM) and specific surface area measurements were used to characterize product morphology.
• The effect of freezing on lactate dehydrogenase bioactivity was assessed.

Main Results:

• Loading configuration significantly affected product freezing rates and ice nucleation temperature distribution.
• Vials nested in a rack system exhibited larger ice crystals compared to those directly on the shelf.
• Product morphology differences were confirmed by SEM and surface area measurements.
• Altered product morphology correlated with variations in lactate dehydrogenase bioactivity recovery.

Conclusions:

• Freezing parameters and loading configurations critically influence the physical state and quality of biopharmaceuticals.
• Optimizing freezing design and formulation can mitigate detrimental effects of freezing, preserving drug bioactivity.
• Understanding these factors is essential for developing robust biopharmaceutical manufacturing and storage processes.