ABSTRACT
Diffraction and spectroscopic methods were evaluated for quantitative analysis of binary powder mixtures of FII(6.403) and FIII(6.525) piracetam. The two polymorphs of piracetam could be distinguished using powder X-ray diffraction (PXRD), Raman and near-infrared (NIR) spectroscopy. The results demonstrated that Raman and NIR spectroscopy are most suitable for quantitative analysis of this polymorphic mixture. When the spectra are treated with the combination of multiplicative scatter correction (MSC) and second derivative data pretreatments, the partial least squared (PLS) regression model gave a root mean square error of calibration (RMSEC) of 0.94 and 0.99%, respectively. FIII(6.525) demonstrated some preferred orientation in PXRD analysis, making PXRD the least preferred method of quantification.
Subject(s)
Crystallography, X-Ray , Nootropic Agents/chemistry , Piracetam/chemistry , Powder Diffraction , Spectroscopy, Near-Infrared , Spectrum Analysis, Raman , Technology, Pharmaceutical/methods , Calibration , Chemistry, Pharmaceutical , Crystallization , Crystallography, X-Ray/standards , Least-Squares Analysis , Limit of Detection , Multivariate Analysis , Powder Diffraction/standards , Spectroscopy, Near-Infrared/standards , Spectrum Analysis, Raman/standards , Technology, Pharmaceutical/standardsABSTRACT
The principles of social and biological evolution have been combined in a Cultural Differential Evolution hybrid global optimization technique and applied to crystal structure solution.
