The use of net analyte signal orthogonalization in the separation of multi-component diffraction patterns obtained from X-ray powder diffraction of intact compacts

Determination of three dyes in commercial soft drinks using HLA/GO and liquid chromatography

“…After that, NAS concept was extended to inverse calibration methods that only need the concentration of the target analyte in the calibration set (Lorber, Faber, & Kowalski, 1997). Recently, new families of multivariate calibration methods have been proposed based on the concept of NAS which are know as NAS-based calibration methods (Berger, Koo, Itzkan, & Feld, 1998;Espinosa-Mansilla, Merás, Rodríguez Gómez, Muñoz de la Peña, & Salinas, 2002;Ferré & Faber, 2003;Goicoechea & Olivieri, 2000;Mirmohseni, Abdollahi, & Rostamizadeh, 2007;Moore, Cogdill, Short, Hair, & Wildfong, 2008;Xu & Schechter, 1997).…”

Application of Partial Least-Squares (PLS) modeling in quantifying drug crystallinity in amorphous solid dispersions

“…Such methods include differential scanning calorimetry (DSC), infrared and Raman spectroscopy, and powder X-ray diffractometry (PXRD) (Clas et al, 1995;Taylor and Zografi, 1998;Pan et al, 2006;Shah et al, 2006;Seyer and Luner, 2001;Lehto et al, 2006;Bertacche et al, 2006;Bai et al, 2004;Yoshioka et al, 1994Yoshioka et al, , 1995Suda et al, 2008;Chieng et al, 2009). In addition, quantitative determination of crystalline API in the presence of other components has also been reported (Suryanarayanan and Herman, 1991;Moore et al, 2008Moore et al, , 2009). However, quantitative determination of the amount of crystalline API present in an otherwise amorphous molecular-level solid dispersion system (where the drug and the polymer are intimately mixed) has not been widely reported.…”

Quantifying API polymorphs in formulations using X-ray powder diffraction and multivariate standard addition method combined with net analyte signal analysis

“…The NAS algorithm consists in projecting the pureanalyte signal onto a new mathematic space, while the interfering signal (due to the matrix) is projected onto a perpendicular independent space. Two recent papers (Moore et al, 2008;Palermo et al, 2012) applied NAS to XRPD data to quantify crystal and amorphous forms in poly-component mixtures; in this case, the total amount of analyte in standard samples was taken as independent variable (interpolation mode).…”