Quantitative analysis of amorphous content of lactose using CCD-Raman spectroscopy

Lactose characteristics and the generation of the aerosol

“…However, Chen et al have reported an improved XRPD technique with a LOQ for amorphous lactose decreased to 1% [134]. Other techniques have been used to study the amorphous lactose content of powders: Raman [135][136][137][138] and near infrared spectroscopy [139], high speed DSC [140], isothermal microcalorimetry [141,142] and solution calorimetry [135,143,144].…”

Mapping amorphous material on a partially crystalline surface: Nanothermal analysis for simultaneous characterisation and imaging of lactose compacts

“…A number of different methods have been utilized for the detection and quantification of the amorphous components of pharmaceuticals including Xray powder diffraction (XRPD), 7 isothermal microcalorimetry (IMC), 8 Raman spectroscopy, 9 near infrared spectroscopy (NIRS), 10 solid state nuclear magnetic resonance (SS-NMR), 11 conventional differential scanning calorimetry (DSC), 12 modulated temperature DSC (MTDSC), 13 high speed DSC (hyper-DSC) 14 and solution calorimetry. 15 However many of these are bulk techniques and are therefore not sufficiently surface sensitive to determine whether the amorphous material is indeed located at the surface.…”

Detection of Low Levels of Amorphous Lactose using H/D Exchange and FT-Raman Spectroscopy

“…Even very low levels (a few %) of amorphous material can have a dramatic effect on both the physical and chemical properties of pharmaceuticals and techniques capable of reliably quantifying such amorphous content to low levels are not routinely available (9)(10)(11). The characterisation methods commonly used for determining amorphous content in pharmaceutical materials include powder X-ray diffraction (PXRD) (5), calorimetric methods such as differential scanning calorimetry (DSC) (12)(13)(14), isothermal microcalorimetry (IMC) (15,16) and solution calorimetry (17), and spectroscopic methods such as solid-state NMR (18,19), near-infrared (12) and Raman (20,21). In general, the limit of detection and limit of quantification of the PXRD and DSC are >5%, and the determination of experimental parameters for calorimetric methods can also be time consuming (9).…”