Fourier transform infrared (FTIR) spectra of syndiotactic polystyrene (s-PS) semicrystalline samples have been examined by using the spectral subtraction approach. For the crystalline forms including trans-planar chains (trigonal a and orthorhombic b) a number of conformational and structural order
Quantitative determination of amorphous cyclosporine in crystalline cyclosporine samples by Fourier transform infrared spectroscopy
β Scribed by Vittorio Bertacche; Elena Pini; Riccardo Stradi; Fabio Stratta
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 129 KB
- Volume
- 95
- Category
- Article
- ISSN
- 0022-3549
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β¦ Synopsis
The purpose of this study is the development of a quantification method to detect the amount of amorphous cyclosporine using Fourier transform infrared (FTIR) spectroscopy. The mixing of different percentages of crystalline cyclosporine with amorphous cyclosporine was used to obtain a set of standards, composed of cyclosporine samples characterized by different percentages of amorphous cyclosporine. Using a wavelength range of 450-4,000 cm(-1), FTIR spectra were obtained from samples in potassium bromide pellets and then a partial least squares (PLS) model was exploited to correlate the features of the FTIR spectra with the percentage of amorphous cyclosporine in the samples. This model gave a standard error of estimate (SEE) of 0.3562, with an r value of 0.9971 and a standard error of prediction (SEP) of 0.4168, which derives from the cross validation function used to check the precision of the model. Statistical values reveal the applicability of the method to the quantitative determination of amorphous cyclosporine in crystalline cyclosporine samples.
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