Investigation of the API distribution homogeneity in lyophilized product-pemetrexed disodium for injection by confocal micro-Raman spectroscopy mapping / 药学学报

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.

The impurity profiling of paclitaxel and its injection by UPLC-MS/MS / 药学学报

An ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS) method was developed to elucidate the impurity profiles of paclitaxel and paclitaxel injections from different Chinese pharmaceutical companies. The fragmentation patterns for paclitaxel and the related impurities were analyzed and summarized. To remove the interference from auxiliary materials, such as hydrogenated castor oil, paclitaxel was dissolved in ethanol for acid, base, peroxide, and light induced forced degradation analysis, which could produce all the impurities exist in the paclitaxel injection. A total of 10 impurities were characterized, such as cephalomannine (1), 7-epi-10-deacetylpaclitaxel (2), 7-epipaclitaxel (3), baccatin Ⅲ (4), ethyl ester side chain (5), 7-epi-baccatin Ⅲ (6), 10-deacetylpaclitaxel (7), paclitaxel isomer (C3-C11 bridge) (8), paclitaxel isomer (9), and N-benzoyl-(2R, 3S)-3-phenylisoserine (10), respectively. Among them, compounds 1-3 could be introduced during manufacture processing. In the forced degradation studies, while acid induced degradation products included 3-7, base induced degradation could produce 2-7 and 10; while 7 is the main compound produced by hydrogen peroxide treatment, 4 compounds (3-5 and 7) were produced by high temperature environment and 5 compounds (2-5 and 9 which is the first reported) from intensity light exposure. Furthermore, 8 was the main impurity came from intensity light exposed paclitaxel powder. The results from this study provide an important reference in processing, optimization, quality control and evaluation of paclitaxel.

The impurity profiling of simvastatin and its tablets by UPLC-MS/MS / 药学学报

Investigation of simvastatin and its related substances was carried out using a reversed phase ultra performance liquid chromatography/tandem mass spectrometry method. The identification of impurities in simvastatin was performed with a triple-quadrupole mass spectrometer, with an electrospray ionization (ESI) source in the negative/positive ion mode. A total of 12 compounds were characterized in commercial samples, among which 2 impurities had never been reported. All the impurities were deduced based on the MS fragment pathways of simvastatin and the biosynthetic pathway of lovastatin. This work provides very useful information for quality control of simvastatin.

Polymorphs of clopidogrel bisulfate / 药学学报

This paper is to report the polymorphism of raw materials of clopidogrel bisulfate at home and abroad. By the analysis of Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction (p-XRD), samples are roughly classified into two groups, except one patent material. And the differential scanning calorimeter (DSC) examination showed more detailed information for these materials. The results of the study could provide comprehensive basis for the quality evaluation of clopidogrel bisulfate.

Study on pharmaceutical screening of representative components of Salvia miltiorrhiza diterpene quinones / 中国中药杂志

<p><b>OBJECTIVE</b>To screen out the main components with no significant difference with Salvia miltiorrhiza diterpene quinones pharmacological action, in order to determine the compatible form of representative components that can describe the overall property of S. miltiorrhiza diterpene quinones.</p><p><b>METHOD</b>According to the results of the in vitro pharmacological experiment, the myocardial ischemia model of rats was induced through intraperitoneal injection of isoproterenol. The pharmacologic effects of S. miltiorrhiza diterpene quinones, combination with principal component A and combination with principal component B were compared in electrocardiogram (changes in J point), enzymology indicators (SOD, MDA, CK, LDH) and pathology (myocardial histological changes), so as to screen out the compatible form of representative components that can describe the overall property of S. miltiorrhiza diterpene quinones.</p><p><b>RESULT</b>The S. miltiorrhiza diterpenoid quinone high-dose group and the B high-dose group were similar in all pharmacological effects, with equal efficacy but no significant difference.</p><p><b>CONCLUSION</b>The S. miltiorrhiza diterpenoid quinone high-dose group and the B high-dose group showed a certain therapeutic effect on ISO-induced myocardial ischemia. Therefore, the four components in the B high-dose group can be used as representative components of S. miltiorrhiza diterpene quinones.</p>

Analysis and evaluation of the impurity of felodipine and its tablets / 药学学报

The paper reports the systematic study on felodipine and its impurities in tablets, to improve its quality standards for the control of the related substances. HPLC-DAD, UPLC-MS, IR and NMR methods were used for the isolation of felodipine and its impurities in tablets, their identification and the zebrafish animal model was used for the analysis of the toxic impurities. In felodipine material and its tablets, three impurities are isolated and identified. They are impurity 1 [dimethyl 4-(2, 3-dichlorophenyl)-2, 6-dimethyl-1, 4-dihydropyridine-3, 5-dicarboxylate], impurity 2 [ethyl methyl 4-(2, 3-dichlorophenyl)-2, 6-dimethylpyridine-3, 5-dicarboxylate] and impurity 3 [diethyl 4-(2, 3-dichlorophenyl)-2, 6-dimethyl-1, 4-dihydropyridine-3, 5-dicarboxylate], separately. The result of zebrafish animal model analysis showed that the teratogenic effects of four compounds were: impurity 3 > or = felodipine > impurity 1 > impurity 2, lethal effects were as follows: impurity 2 = impurity 3 > felodipine > or = impurity 1. This study confirmed the toxicity of three impurities in felodipine. According to the results, the paper suggested the amendments to the standard of the medicine and provided the support to the control of impurities in the manufacturing process.