RESUMEN
The properties of dry-coated paracetamol particles(fast-dissolving model drug)with carnauba wax particles as the coating agent(dissolution retardant)were investigated.Raman mapping technique was used to non-destructively examine the thickness and homogeneity of coated particles.The results showed that the wax existed in two forms on the surface of the paracetamol particles,forming a porous coating layer:i)whole wax particles on the surface of paracetamol and glued together with other wax surface particles,and ii)deformed wax particles spread on the surface.Regardless of the final particle size fraction(between 100 and 800 μm),the coating thickness had high variability,with average thickness of 5.9±4.2 μm.The ability of carnauba wax to decrease the dissolution rate of paracetamol was confirmed by dissolution of powder and tablet formulations.The dissolution was slower for larger coated particles.Tableting further reduced the dissolution rate,clearly indicating the impact of subsequent formulation processes on the final quality of the product.
RESUMEN
The method of homogeneity evaluation for active pharmaceutical ingredient (API) spatial distribution in lyophilized product was investigated for the first time with confocal micro-Raman spectroscopy mapping, using pemetrexed disodium for injection as a model drug. Certain areas of the lyophilized product were scanned to obtain Raman spectra. The classical method ("peak clipping" method) was employed for mapping with characteristic Raman peaks of the API and the excipient. Due to the API being finely dispersed in the excipient in lyophilized products, the classical method cannot discriminate between the two ingredients making the distribution homogeneity difficult to evaluate. The "ratio of characteristic peak intensities" method was then utilized. Using this method, the relative intensity of the characteristic Raman peaks of the API to the excipient was applied for mapping and the relative content of API to excipient was calculated for a homogeneity evaluation of the drug distribution. The validation of this method showed a good linear relationship between the relative intensity and the relative content of API to excipient (r2 > 0.99), and the precision and recovery were adequate for homogeneity evaluation of API by Raman spectroscopy mapping. Five products of pemetrexed disodium for injection from different manufacturers were tested through Raman maps applying this method and the histograms of relative Raman intensity were also plotted by frequency to help the homogeneity evaluation of drug distribution. The results showed that there were obvious differences in the drug distribution homogeneity from different products, where a more homogeneous API distribution was found in the brand product. This research provides a reliable method for the homogeneity evaluation of API distribution, which facilitates quality evaluation and process optimization of lyophilized products.
RESUMEN
Objective: Colorectal cancer is a commonly encountered cancer worldwide about 1.4 million new cases diagnosed and 693,900 deaths occurred per year. Colorectal cancer could be stopped and highly curable if diagnosed early. In this proposed study, the main goal is to develop accurate, sensitive and rapid Raman spectroscopy method in colorectal cancer diagnosis of formalin-fixed paraffin embedded tissue samples. Methods: In the proposed method, samples were deparaffinized and prepared as 20 microns of dimension that was located on a coverslip. The instrument produces a continuum laser at 785 nm that were applied to both healthy and cancer tissues. Wavenumber of 50-1800 cm-1 was scanned to get information about the metabolic variation in each group. Results: Accuracy of the method was calculated by comparing the results regarding the histopathological evaluation. Healthy and cancer tissues formed two unique clusters via chemometrics algorithm. The rapid, easy and precise diagnosis was achieved for colorectal cancer diagnosis. By this method, some beneficial information regarding the variation in several metabolites was also obtained from the spectrum. Conclusion: It is reported that the optimized method represents an important opportunity for clustering and separating cancer tissues from healthy ones. This novel, rapid, precise and numerical approach may be an effective alternative for the conventional methods.