The effects of tableting with potassium bromide on the infrared absorption spectra of indomethacin

Abstract

The effects of tableting with KBr on the IR absorption spectra of molecular crystals were studied at room temperature. Study substances were mechanically activated mixtures of crystalline indomethacin and the excipient polyethylene glycol at ratios of 1:1 and 1:3. There was a marked widening of absorption bands in the range 2000 -500 cm -1 in the IR spectra of mechanically activated mixtures in tablets with KBr. These experimental results are assessed within the framework of possible interactions between study samples and the KBr matrix during tableting and storage as powered mixtures.

Multicomponent Chemical Imaging of Pharmaceutical Solid Dosage Forms with Broadband CARS Microscopy

“…Many tools are commonly used to characterize API phase and distribution, including chromatography, solid state NMR, X-ray diffraction crystallography, and differential scanning calorimetry . Spontaneous Raman scattering and IR spectroscopy have recently become increasingly prevalent in this industry due to their ability to obtain chemically specific information and to nondestructively characterize compounds. − Attenuated total reflectance IR spectroscopy can be used to chemically map tablet surfaces over small areas, and IR microscopy can be used to obtain chemical maps of larger areas at low spatial resolution, but these techniques require sample preparation and suffer from Mie scattering and from absorption by water in the atmosphere. − Spontaneous Raman spectroscopy and microspectroscopy also probe bulk properties rapidly or provide high-resolution chemical mapping but at a much slower rate. − The drawback inherent to spontaneous Raman techniques is in their inability to simultaneously measure a sample rapidly and with high spatiochemical resolution. On the other hand, nonlinear optical methods have proven their ability to image pharmaceuticals with high-spatial resolution very rapidly …”

Synergistic intrafibrillar/extrafibrillar mineralization of collagen fibrils and scaffolds enhanced by introducing polyacrylamide to PILP for osteogenic differentiation

“…The IR spectra was recorded by pressing the dried precipitate into a tablet with KBr (1 mg of sample per 100 mg of KBr). IR spectra of the tablet was recorded over the range 4000–500 cm −1 with a resolution of 4 cm −1 at room temperature using a Fourier transform infrared spectrometer (FT‐IR) (6700, Thermo‐Fisher, USA) 49 . About 10 mg of the dried precipitate was taken, dissolved in heavy water (D 2 O) and subjected to 1 H‐nuclear magnetic resonance (NMR) spectroscopy (AVANCE III 500 MHz, Bruker, USA).…”

“…IR spectra of the tablet was recorded over the range 4000-500 cm À1 with a resolution of 4 cm À1 at room temperature using a Fourier transform infrared spectrometer (FT-IR) (6700, Thermo-Fisher, USA). 49 About 10 mg of the dried precipitate was taken, dissolved in heavy water (D 2 O) and subjected to 1 H-nuclear magnetic resonance (NMR) spectroscopy (AVANCE III 500 MHz, Bruker, USA). The dried precipitate was dissolved in water to a concentration of 4.0 mg mL À1 and passed through a microfilter with an average pore size of 0.22 μm.…”

Modification, Structural Characterizations, and Biological Activities of Sulfated Polysaccharides: A Review

“…Hence, infrared absorption spectroscopy has been widely used for the preliminary identification of polysaccharides structure. [47,50] Growing evidences have indicated that the stretching vibration of S═O was reflected at about 1260 cm −1 on the infrared spectrum, and the vibration containing C─O─S showed absorption at about 810 cm −1 . Both stretching vibrations fully proved that the polysaccharides had been successfully sulfated and contained sulfated groups.…”

“…A large number of studies have confirmed that two typical peaks of sulfated polysaccharides at 1260 cm −1 (S═O) and 814 cm −1 (C─O─S). [47,50] If the two vibrations mentioned above exist in the polysaccharide derivatives, indicating that the sulfation modification of polysaccharides is successful. In addition, ultraviolet absorption spectroscopy is also commonly used to measure the chemical composition of sulfated polysaccharides.…”