In Situ Raman Spectroscopy for In-Line Control of Pharmaceutical Crystallization and Solids Elaboration Processes: A Review

As Raman spectroscopy enables complex, in situ, non-destructive and fast quantitative measurements of the solid state of pharmaceutical compounds, this technique is expected to allow the development of innovative future industrial applications for monitoring and controlling solids elaboration processes. This review presents important features of Raman spectroscopy, keeping industrial applications in view. The main potential applications of the technique, its advantages and drawbacks, and studies reporting on the real-time use of Raman spectroscopy for monitoring solid pharmaceutical elaboration processes are presented. A particular attention is focused on the in-line monitoring of crystallization processes. As far as routine exploitation of the Raman technology is concerned, it is shown that many problems remain unsolved, which were not fully addressed in published studies.