Spatial distribution and content detection of gefitinib in tablets using confocal micro-raman spectroscopy mapping

In this study, we aim at establishing a method to evaluate the spatial distribution and content of gefitinib in tablets without destroying the tablets. The content of gefitinib tablets was determined by HPLC. Using confocal micro-Raman spectroscopy, with a wavelength of 785 nm and power of 10%, gefitinib, starch, and hydrated magnesium silicate were scanned. Tablets with five concentrations of gefitinib (15.63–31.25%) were scanned with a 1000 × 1000 μm spectral resolution and live video imaging was performed. The surfaces of gefitinib tablets were scanned and images were obtained by a continuous scanning method. Characteristic Raman spectra of tablets were obtained after surface scanning and map reviews of tablets with five concentrations of gefitinib for rapid and accurate identification. The characteristic spectral bands of gefitinib, starch, and hydrated magnesium silicate were 1620 cm–1, 480 cm–1, 1350 cm–1 respectively. Comparing the surfaces of the tablets, it was found that the tablets with a flat and round surface are more suitable for Raman spectroscopy. Live video imaging and scanning maps of five concentrations of gefitinib were performed. The results showed that the product with the content of 16.12% had a good mixing homogeneity. In conclusion, confocal micro-Raman spectroscopy can detect the spatial distribution and content of gefitinib tablets without destroying tablets.

Low-Cost Investment with High Quality Performance. Bleaching Earths for Phosphorus Reduction in the Low-Temperature Bleaching Process of Rapeseed Oil

Rapeseed oils are a valuable component of the diet. Mostly, there are refined oils deprived of valuable nutrients in the market, hence in recent times cold-pressed and unrefined oils have been available and popular among consumers. However, the low yield of this oil makes this product expensive. The aim of the study was to analyse the effectiveness of phosphorus reduction in crude oils, cold- and hot-pressed in the low-temperature bleaching process. Eight market-available bleaching earths was compared. The effectiveness of 90% was found with 2% (m/m) of Kerolite with hydrated magnesium silicate. An increase in the share of earths to 4% (m/m) resulted in the effectiveness of phosphorus reduction >90% in seven out of eight analysed cases. Bentonite activated with acid with the lowest MgO content was characterised by low efficiency <64%. The research shows that the effectiveness of phosphorus reduction was significantly affected by the composition of earths applied in the bleaching process at ambient temperature. The results of research confirm the high effectiveness of the process as it is not necessary to heat up the oil before the bleaching process. This method is recommended for existing and new industrial plant for two-stage rapeseed oil pressing.

Synthetic ‘deweylite’

SummaryMaterials similar to the natural hydrated magnesium silicate mineral deweylite have been synthesized hydrothermally under low-temperature-low-pressure conditions from magnesia-silica gels. Optical, X-ray, infra-red, and DTA examinations have shown that both the natural and synthetic materials are mixtures of badly crystallized talc and badly crystallized serpentine. The mineral is thought to be a coarse mixture of these two components while the synthetic products are intimately interlayered. These materials are believed to be closely related to the hydrated magnesium silicates detected in high-magnesia cement hydration products.