Raman spectroscopy of defected griseofulvin in powders and films

Raman spectroscopy is used to investigate possible defect formation in the pharmaceutical material, Griseofulvin, by milling. The appearance of a broad background in the spectra recorded with 785 nm excitation suggests the formation of defects which fluoresce in the near-infrared spectral region. Three different methods were used to anneal the crystalline defects formed in the powders. Exposure to high level of humidity, acetone dissolution followed by recrystallization, and laser irradiation, were all found to be effective and showed partial reduction of the induced defects and reduction of the background intensity. Detailed examination of the low frequency Raman spectra associated with molecular deformation, rocking and wagging modes in milled and reference samples of Griseofulvin, also showed significant relative intensity differences in the Raman lines. Thin film strips prepared with Griseofulvin, sodium dodecyl sulfate, hydroxypropylmethyl cellulose, and glycerol were also examined by chemical micro-Raman imaging coupled with multivariate analysis to determine the uniformity of the drug distribution and the presence or absence of defects on the drug particles.