Characterization of Solid-State Drug Polymorphs and Real-Time Evaluation of Crystallization Process Consistency by...

Area of Science:

• Pharmaceutical Science
• Analytical Chemistry
• Process Engineering

Background:

• Pharmaceutical crystallization processes are critical for drug quality and efficacy.
• Polymorphism, the existence of multiple crystal forms, significantly impacts drug properties.
• Real-time monitoring of crystallization consistency is essential for quality control.

Purpose of the Study:

• To develop a strategy for real-time evaluation of pharmaceutical crystallization process consistency.
• To focus on two common polymorphic cases: cefazolin sodium pentahydrate (α-CEZ-Na) and cephathiamidine (CETD).
• To establish a rapid technique for assessing crystallization behavior and process consistency.

Main Methods:

• Theoretical analysis combining 13C solid-state nuclear magnetic resonance (NMR) spectroscopy with other polymorphism analysis techniques.
• Identification of marker signals indicative of different structural orientations (lattices/conformations).
• Real-time analysis using chemometrics-assisted near-infrared spectroscopy (NIR) with spectral pretreatment (first derivative, vector normalization) and standard deviation calculations.

Main Results:

• Marker signals revealed the presence of multiple structural orientations in both α-CEZ-Na and CETD.
• Proportions of polymorphic forms were identified as batch-dependent critical quality attributes (CQAs).
• NIR spectroscopy successfully identified vibrational responses sensitive to CQAs in both compounds, enabling accurate discrimination models.

Conclusions:

• A novel technique for rapid evaluation of crystallization process consistency was established.
• Near-infrared spectroscopy, combined with polymorphism analysis, provides valuable insights into crystallization behavior.
• The developed method allows for real-time monitoring and control of critical quality attributes in pharmaceutical manufacturing.