A Facile Raman Spectroscopy Method for Online Monitoring of Crystal Plane Orientation of Favipiravir

by Selleckchem | Jul 09 2023

The efficiency of pharmacotherapy is significantly influenced by the crystal habit and polymorphic form of the drugs. Especially due to the anisotropy of different facets in crystalline material, crystal habit impacts the physicochemical properties and behaviors of a drug, which has been rarely reported. This paper describes a facile method for online monitoring of crystal plane orientation of favipiravir(T-705) by Raman spectroscopy. Firstly, we investigated the synergy of multiple physicochemical fields (solvation, agitated flow fields, etc.), and then prepared favipiravir crystals with different orientations in a controllable manner. Secondly, to establish the connection between crystal planes and Raman spectra, the favipiravir crystals were theoretically analyzed at the molecular and structural levels using density functional theory (DFT) and 3D visualization tools. Finally, we based on standard samples and applied it to 12 actual samples to evaluate the crystal habit of favipiravir. The results are similar to the classical XRD method. Additionally, the XRD method is difficult to be monitored online, while the Raman method is non-contact, fast, and requires no sample preparation, showing a great application prospect in the pharmaceutical process.

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The mentioned paper describes a method for online monitoring of the crystal plane orientation of a drug called favipiravir (also known as T-705) using Raman spectroscopy. The crystal habit and polymorphic form of drugs can significantly impact their efficiency in pharmacotherapy. The anisotropy of different facets in crystalline materials influences the physicochemical properties and behaviors of a drug.

In this study, the researchers investigated the synergy of multiple physicochemical fields, such as solvation and agitated flow fields, to control the crystal orientations of favipiravir. They developed a facile method to prepare favipiravir crystals with different orientations in a controllable manner.

To establish the connection between crystal planes and Raman spectra, the researchers conducted theoretical analyses at the molecular and structural levels using density functional theory (DFT) and 3D visualization tools. By analyzing the theoretical data, they were able to correlate specific crystal planes with distinct Raman spectra.

The researchers then applied this method to evaluate the crystal habit of favipiravir in both standard samples and 12 actual samples. The results obtained from the Raman method were found to be similar to those obtained from the classical X-ray diffraction (XRD) method, which is commonly used for crystal structure determination. However, unlike XRD, the Raman method can be monitored online, is non-contact, fast, and requires no sample preparation. These advantages make Raman spectroscopy a promising tool for pharmaceutical processes.

In summary, this paper presents a method for online monitoring of crystal plane orientation in favipiravir using Raman spectroscopy. The method allows for the evaluation of crystal habit without the need for complex sample preparation and offers advantages over traditional techniques like XRD in terms of speed and non-contact nature.