Applications of NIR spectroscopy to monitoring and analyzing the solid state during industrial crystallization processes

• Published in: International journal of pharmaceutics Vol. 273; no. 1; pp. 159 - 169
• Main Authors: Févotte, G., Calas, J., Puel, F., Hoff, C.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.04.2004; Elsevier
• Subjects: Biological and medical sciences; Calibration; Chemical and Process Engineering; Crystal habits; Crystallization; Drug Industry; Engineering Sciences; Filtration; General pharmacology; Life Sciences; Medical sciences; Near infrared spectroscopy; Pharmaceutical Preparations - analysis; Pharmaceutical sciences; Pharmaceutical technology. Pharmaceutical industry; Pharmacology. Drug treatments; Polymorphism; Process Analytical Technologies (PAT); Spectroscopy, Near-Infrared; Technology, Pharmaceutical - instrumentation; Technology, Pharmaceutical - methods; Near infrared spectroscopy; Crystal habits; Filtration; Process Analytical Technologies (PAT); Crystallization; Polymorphism; Solid state; Process; crystallization; filtration; near infrared spectroscopy; polymorphism; crystal habits
• ISSN: 0378-5173; 1873-3476
• DOI: 10.1016/j.ijpharm.2004.01.003

Fiber-optic near infrared (NIR) spectroscopy was used to investigate several key features of the polymorphic transitions observed during the crystallization and the filtration of SaC, an Active Pharmaceutical Ingredient (API) produced by Sanofi-Synthelabo. Using few samples, the spectroscopic data were calibrated to provide measurements of the polymorphic composition of the solid product which is likely to appear in two crystalline forms or in the amorphous state. Both qualitative and quantitative methods were successfully evaluated to characterize the API. The NIR spectroscopy measurement was then applied to investigate the kinetic behavior of the phase transition phenomena against various operating conditions. From the viewpoint of industrial process development several applications are presented. The effects of temperature and seed crystal habits on the rate of transition of filtration cakes are briefly investigated; and a study of the effect of residual water in the solvent on the transition occurring during filtration is more deeply analyzed. The experimental results demonstrate that highly valuable information can be provided by the NIR spectroscopy measurements, when one aims at understanding more deeply and optimizing the consequences of various and complex phenomena involved during the solid processing chain.