Structural identification of the related substances in phloroglucinol injection by two-dimensional liquid chromatography-quadrupole time-of-flight mass spectrometry / 药学学报

This study aimed to identify the related substances of phloroglucinol injection by two-dimensional liquid chromatography quadrupole time-of-flight mass spectrometry (2D-LC-Q-TOF/MS). The first-dimensional separation was carried out on an HSS T3 (250 mm × 4.6 mm, 5 μm) column by gradient elution using 1.36 g·L-1 potassium dihydrogen phosphate buffer solution (pH adjusted to 3.0 with diluted phosphoric acid) and acetonitrile as the mobile phases. The separated components were then trapped in switch valve tube lines respectively and delivered to the second-dimensional desalting gradient elution which was performed with a BDS C18 (100 mm × 4.6 mm, 2.4 μm) column using 0.1% formic acid and methanol as the mobile phases. After rapid desalting, electrospray-ionization quadrupole time-of-flight high resolution mass spectrometry was used for determining the accurate masses and elemental compositions of the parents and their product ions for both phloroglucinol and its related substance. Structures of the related substances were then figured out by mass spectrometry elucidation, organic reaction mechanism analysis, and/or comparison with reference substances. Under the established analytical conditions, phloroglucinol and its related substances were adequately separated, 17 main related substances were detected and identified in the injection and its stressed samples for the first time. The identification results can provide reference for the quality control of phloroglucinol injection.

Effect of added halide ions and pH on the solubility of nebivolol hydrochloride and the evaluation of selected, discriminating dissolution media / 药学学报

The solubility of nebivolol hydrochloride was determined in acidic aqueous media in the absence and presence of different concentration of NaCl, NaBr, or NaI at 37 ℃ in order to facilitate proper selection of dissolution media that have adequate discriminating power for enhancing the likelihood of a generic drug product to successfully pass in-vivo bioequivalence test. In the range of pH 5.0 to pH 1.0, the solubility of nebivolol hydrochloride decreased with the decrease in the pH of aqueous solution, and the solubility of nebivolol hydrochloride further decreased with the increase in the concentration of added sodium chloride. The solubility decrease of a few weakly basic drug molecules in acidic media and in higher concentration of added chloride was published previously by other researchers, and the observed decrease in the solubility in the presence of higher chloride concentration was interpreted in terms of common-ion effect. However, the results in this paper showed that the solubility of nebivolol hydrochloride also decreased when sodium chloride was replaced with sodium bromide or iodide. The approach described in this paper (i.e. substituting sodium chloride with sodium bromide or iodide) provides an effective method to verify whether common-ion effect is the true (or at least the sole) driving force behind the observed decrease in the solubility of nebivolol hydrochloride in the presence of sodium chloride. The solubility decrease reported in this paper can be interpreted in terms of salting-out effect of sodium chloride, bromide, and iodide. For hydrochloride salt of a weakly basic drug molecule like nebivolol hydrochloride, its solubility in an acidic dissolution medium can be purposely decreased to the lower end of sink condition by adding sodium chloride to make the resulting medium more discriminating. As shown in this paper, a medium at pH 1.2 with added sodium chloride is discriminating and this medium is shown to be bio-relevant to the in-vivo data collected under fasting condition (in-vivo study protocol was approved by Institutional Review Board).

Identification of the related substances of vortioxetine hydrobromide by LC-MS techniques / 药学学报

The study was aimed to identify the related substances of vortioxetine hydrobromide by hyphenated techniques. The separation of the six related substances was performed on a Phenomenex Luna Phenyl- Hexyl column (150 mm×4.6 mm, 3 μm) by linear gradient elution of acetonitrile and ammonium formate solution. Electrospray and atmospheric pressure chemical ionization were interfaced respectively with high resolution Q-TOF/MS for the determination of the accurate mass and elemental composition of the parent ions of the related substances, and triple quadrupole tandem mass was employed for the product mass spectra determination. The structures of the related substances were identified through elucidation of the fragment ions. Vortioxetine hydrobromide and its related substances were adequately separated under the established HPLC conditions. Six major related substances were detected and identified for the first time. The data provides a reference for optimization of the synthetic process and quality assurance of vortioxetine hydrobromide.

Pharmacokinetics of mercury after oral administration of cinnabaris and Fufang Niuhuang Xiaoyan capsule in rats / 中国中药杂志

Fufang Niuhuang Xiaoyan capsule was a classical compound prescription with the efficacy of heat-clearing, detoxification, sedation and anti-inflammation, with cinnabaris as one of its active ingredients. The study focuses on the pharmacokinetics of mercury in rats after oral administration of cinnabaris and Fufang Niuhuang Xiaoyan capsule, in order to explore the effect of combined traditional Chinese medicines on mercury metabolism. In this study, the method of nitric-perchloric acid digestion system coupled with cold atomic-atomic fluorescence spectroscopy (CV-AFS) was adopted to accurately determine mercury in whole blood of rats. Fufang Niuhueng Xiaoyan capsule had three dose schemes of oral administration, namely equivalent clinical dose, 3 times of equivalent clinical dose and 10 times of equivalent clinical dose; And the doses of oral administration of cinnabaris was calculated according to that of Fufang Niuhuang Xiaoyan capsule. SPF grade healthy SD rats were fasted overnight before the oral administration with cinnabaris suspension (or Fufang Niuhuang Xiaoyan capsule suspension). After oral administration of different doses of cinnabaris, no obvious changes in tmax and MRT were observed, while Cmax/dose, AUC0-48 h/dose and AUC0-∞/dose decreased with the increase in dose, indicating that total mercury absorption in body was declining. As the dose increased, Ke, CL/F decreased, and t1/2 increased, indicating that the elimination slowed down, and mercury metabolism showed non-linear dynamic characteristics within a certain range of dose (22-220 mg•kg⁻¹). The total mercury metabolism in the whole blood of rats after oral administration with different doses of Fufang Niuhuang Xiaoyan capsule also showed non-linear dynamic characteristics. The results were correlated with the low solubility of cinnabaris in the body. Compared with cinnabaris, Fufang Niuhuang Xiaoyan capsule showed no obvious changes in V/F and MRT, while Ke, CL/F, tmax decreased, and t1/2, Cmax/dose, AUC0-48 h/dose, AUC0-∞/dose increased significantly. The results showed that Fufang Niuhuang Xiaoyan capsule accelerated absorption, slowed down elimination and improved the total absorption of mercury in the whole blood, indicating that Fufang Niuhuang Xiaoyan capsule may contain components for promoting absorption and alleviating elimination of mercury. Fufang Niuhuang Xiaoyan capsule had an impact on the pharmacokinetics of cinnabaris, and long-term administration of cinnabaris (Fufang Niuhuang Xiaoyan capsule) was possible to cause accumulation of mercury in the body. This study could explain changes in efficacy of Fufang Niuhuang Xiaoyan capsule, evaluate the rationality of compound medicines containing toxic elements and provide scientific basis for the rational and safe use of Fufang Niuhuang Xiaoyan capsule.

Arsenic speciation in rat plasma after oral administration of realgar and Niu Huang Jie Du Pian / 药学学报

The arsenic species in rat plasma were studied after oral administration of realgar and Niu Huang Jie Du Pian (NHJDP) and the possible compatible effects of realgar was evaluated by comparing the pharmacokinetics of arsenic species after administration of realgar and NHJDP. The separation of the arsenicals was performed by a high performance liquid chromatography-hydride generation-atomic fluorescence spectrometry (HPLC-HG-AFS) technique. Dimethylarsinic acid (DMA) was found to be the main species in rats' plasma after dosing. No traces of arsenite[As(Ⅲ)], monomethylarsonic acid (MMA) or arsenate[As(V)] were detected at any sampling time points. Compared with realgar administration alone, dose-normalized peak concentration (Cmax) and AUC0-t of DMA were significantly decreased by NHJDP administration, while the tmax was significantly delayed with the clearance and apparent volume of distribution significantly increased, indicating that the pharmacokinetics of As from realgar was affected by other ingredients in the compound prescription of NHJDP.

Identification of related substances in nicergoline by HPLC-MS / 药学学报

To study the related substances in nicergoline, electrospray positive ionization high resolution TOF/MS was used for the determination of the accurate mass and elemental composition of the related substances. Triple quadrupoles tandem MS/MS was employed for the determination of the fragmentations of the parent ions. 16 related substances were detected and identified to be eight synthetic by-products and eight degradation products, by using impurity references matching, product mass spectra fragmentations elucidation, and verified further according to synthetic processes and stress testing results. The results obtained are valuable for nicergoline manufacturing process control and quality assurance.

Identification of the related substances in fasudil hydrochloride with hyphenated techniques / 药学学报

The study aims to identify the related substances in fasudil hydrochloride by hyphenated techniques. A WondaSil C18 (250 mm x 4.6 mm, 5 microm) column was used for the separation of the related substances with a mixture of methanol and ammonium acetate buffer solution as the mobile phase by gradient elution. The structures of the related substances were speculated by electrospray positive ionization LC-TOF/MS accurate ion mass and MS/MS determination and elucidation, and verified further through synthesis and spectroscopic analysis. Fasudil hydrochloride and the related substances were separated under the established HPLC condition. Three related substances in fasudil hydrochloride were characterized by hyphenated techniques. The hyphenated LC-MS method is useful for the identification of related substances in fasudil hydrochloride and the results obtained are valuable for its manufacturing process and quality control.

Effects of combination of Salvia miltiorrhiza and Panax notoginseng on the pharmacokinetics of their major bioactive components in Beagle dog / 药学学报

After oral administration of Salvia miltiorrhiza (Danshen in Chinese), Panax notoginseng (Sanqi in Chinese) and Danshen Sanqi combination suspensions to Beagle dogs, the plasma concentration-time profiles of danshensu, tanshinone II(A), cryptotanshinone, notoginsenoside R1, ginsenoside Rg1 and Rb1 were analyzed by LC-MS/MS. Pharmacokinetic parameters were calculated and analyzed with BAPP 2.0 software. The results showed that the Cmax and AUC of danshensu, notoginsenoside R1, ginsenoside Rg1 and Rb1 in Danshen Sanqi combination group all decreased in comparison with those of Danshen or Sanqi given alone, while the CLz/F and Vz/F increased to some extent. No significant differences of the pharmacokinetics of tanshinone II(A) and cryptotanshinone were observed between groups.

HPLC tandem-mass spectrometric analysis of the chemical components and decomposition products of allicin extract of garlic / 药学学报

To analyze the chemical components and decomposition products in allicin extract of garlic, the chemical components screening and identification were made with HPLC-MS/MS method by full scan TIC MS, HPLC retention time, product MS spectra and chemical reference standards. The stability of the extract in water and alcoholic solutions was also investigated. There were five major components in allicin extract which were all identified as thiosulfinates. The extract was stable for at least 3 months when stored at -20 degrees C as water solution, but obvious decomposition was observed with the increase of alcoholic concentration. The decomposition products were also identified by HPLC-MS/MS.

Metabonomic study on the effects of allicin on rats / 药学学报

To investigate the effects of allicin on rats by NMR-based metabonomic method, the changes of endogenous metabolites in normal rat urine and the influences on metabolism were analyzed with bio-nuclear magnetic resonance (NMR) method and partial least-squares discriminant analysis (PLS-DA) after intraperitoneal administration of allicin solution. The identified biochemical effects associated with allicin dosing included elevated then gradually recovered urinary levels of Kreb's cycle intermediates, such as citrate, alpha-ketoglutarate and succinate and increased concentrations of ketones. Meanwhile, decreased urinary concentrations of glucose, lactate, alanine, hippurate and trimethylamine oxide were observed. The PLS-DA revealed that the metabonomic profiles of allicin treated groups were obviously different from those of the control group. Allicin may change metabolism significantly in normal rats. The study of the pharmacologic mechanism of allicin by metabonomic method is practicable and it could be explored further.

Quantitative determination and pharmacokinetics of retinamido-ester in rat plasma by liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry / 药学学报

A highly sensitive, rapid and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantitative determination of retinamido-ester in rat plasma was developed and validated. A simplified protein precipitation with acetonitrile was employed for the sample preparation. The separation was carried out on an Agilent TC C18 column (150 mm x 4.6 mm ID, 5 microm particle size) with the mobile phase consisted of methanol-water-formic acid (93: 7: 0.1). Simvastatin was used as internal standard. The detection was performed on a trap-quadrupole tandem mass spectrometer by selected reaction monitoring (SRM) scan mode via atmospheric pressure chemical ionization (APCI). The range of calibration curve was 0.05-50 ng x mL(-1) and the limit of quantification was 10 pg x mL(-1). The intra- and inter-day precision values were between 95.97% and 104.43%, and RSD was between 4.63% and 10.69%, respectively. This method was applied to determine the pharmacokinetic parameters. The main pharmacokinetic parameters of retinamido-ester after oral administration via gastric gavage of 2.5, 5, 10 mg x kg(-1) were as follows, T(1/2): (11.28 +/- 7.23), (8.90 +/- 3.82), (8.01 +/- 5.65) h; AUC(0-infinity): (103.41 +/- 61.46), (190.23 +/- 74.99), (421.66 +/- 229.20) ng x h x mL(-1); MRT: (6.31 +/- 0.75), (5.98 +/- 0.71), (6.18 +/- 0.97) h; CL/F: (30.10 +/- 13.67), (29.58 +/- 10.59), (31.18 +/- 17.51) L x h(-1) x kg(-1); Vd/F: (414.94 +/- 159.82), (356.16 +/- 139.85), (369.28 +/- 322.72) L x kg(-1), respectively.

Pharmacokinetic interactions between the main components in the extracts of Salvia miltiorrhiza Bge. in rat / 药学学报

The pharmacokinetics of the main components of protocatechualdehyde, salvianolic acid B, tanshinone II(A), cryptotanshinone, and the hydrophilic or lipophilic extracts of Salvia Miltiorrhiza Bge., in rat plasma were studied after oral administration separately to explore the interactions between them. Some components in the hydrophilic extract depress the absorption of the protocatechualdehyde, on the contrary, enhance the absorption of the salvianolic acid B and depress its elimination rate. The concomitant components in the lipophilic extract might enhance the absorption of cryptotanshinone and its distribution from the centre compartment to the peripheral compartment, and the metabolism to tanshinone II(A). The 'concomitant components' in the extract of Chinese material medica had significant effect on the pharmacokinetics of its 'marker components'. It can not only be rival, synergic, but also have the effects on metabolism. Therefore the traditional Chinese medicine was a complicated system, It should be taken a scientific and dialectic view in the research and development processes.

Related substances in purified alliin determined by HPLC-MS/MS / 药学学报

To study the related substances in purified alliin, HPLC-MS/MS method carried out on a Phenomenex NH2 column was used for screen and identification of the related substances with full scan MS spectra determination of their [M + H] + ions and then the analyses of the retention time, product MS spectra and/or chemical reference standards. The full scan HPLC-MS chromatogram showed that there were seven major related substances in the purified alliin and their m/z of the [M + H] + ions with increasing retention were 116, 133, 147, 152, 175, 178 and 178, separately. And they were identified as proline, asparagine, glutamine, methiin, arginine, isoalliin and cycloalliin (both were isomers of alliin), respectively. The major related substances in purified alliin are amino acids, homologen and the isomers of alliin.

Photo-degradation products of 1-1-(6-methoxy-2-naphthyl)ethyl-2-(4-nitrobenzyl)-6,7-dimethoxyl-1,2,3,4-tetrahydroisoquinoline hydrobromide / 药学学报

To study the photo-degradation products of 1-[1-(6-methoxy-2-naphthyl) ethyl]-2-(4-nitrobenzyl)-6,7-dimethoxyl-1,2,3,4-tetrahydroisoquinoline hydrobromide (code designation: P91024). The chemical structures of the major photo-degradation products of P91024 were identified by HPLC-MS and spectroscopic methods, and their reference substances were also synthesized for confirmation. The three major photo-degradation products were identified to be N-(4-nitrobenzyl)-6,7-dimethoxyl-3, 4-dihydroisoquinoline bromide, 1-[1-(6-methoxyl-2-naphthyl) ethyl]-6, 7-dimethoxyl-1, 2, 3, 4-tetrahydroisoquinoline and 2-isopropyl-6-methoxyl-naphthalene, respectively.

Metabolites of 1-(1-(6-methoxyl-2-naphthyl)ethyl)-2-(4-nitrobenzyl)-6,7-dimethoxyl-1,2,3,4-tetrahydroisoquinoline hydrobromide in rat by LC-MS/MS method / 药学学报

To investigate the principal metabolites of 1-(1-(6-methoxyl-2-naphthyl) ethyl)-2-(4-nitrobenzyl)-6,7-dimethoxyl-1,2,3,4-tetrahydroisoquinoline hydrobromide (code designation: P91024) in rats after ig administration by LC-MS/MS, the phase I metabolites were discovered by comparing the fullscan and SIM chromatograms of the test samples with the corresponding blanks. The structures of phase I metabolites were identified by ESI-MS spectra and the product spectra of the corresponding adduct ions. The phase II metabolites were identified in the test samples after the phase I metabolites were completely removed with solvent extraction and then treated with glucuronidase for enzymolysis of phase II glucuronide conjugates and the hydrolysates. Two phase I metabolites of P91024 were identified in rat feces, one phase I and five phase II in bile, one phase I and three phase II in urine, and four phase I and one phase II in plasma. Their structures were elucidated, separately. P91024 was extensively metabolized in rat. The metabolites can be easily screened and identified by LC-MS/MS method.

Correlation of bacteria in the contaminated drug and the environmental microbes in the clean room for pharmaceutical microbial test investigated by FTIR / 药学学报

The FTIR method was used to investigate the correlation of bacteria in the contaminated drug and the environmental microbes in the clean room for pharmaceutical microbial test. The similarity of bacteria in the contaminated drug and environmental microbes was compared by critical hit value method and cluster analysis method. This constructed the FTIR spectra library of clean room environmental microbe, and determined the criterion to promptly judge if the bacteria isolated from pharmaceuticals were contaminated by environment or not, hence the exactness of "one-off report" of sterile test result can be guaranteed, and can be used for the dynamic monitoring of environmental bacteria of clean room. The method is proven to be simple, accurate and rapid, and can be easily spread to the pharmaceutical microbial control.

Structures of leucogen and its related substances in solution state / 药学学报

<p><b>AIM</b>To study the four diastereomers of leucogen and structure of the related substances.</p><p><b>METHODS</b>LC-DAD, LC-MS/MS and LC- 1H NMR were used. LC was carried out with a Phenomnex Luna C18 (250 mm x 4.60 mm ID, 5 microm) column and a mobile phase of water-acetonitrile-glacial acetic acid (58:42: 0.3).</p><p><b>RESULTS</b>The structures of leucogen and its related substances were identified. Leucogen and the related substances were found to have four diastereomers in solution state separately. The stability and transformation of the four diastereomers were analyzed and 3R4S5R was found to be more stable than the others according to quantum calculations.</p><p><b>CONCLUSION</b>Leucogen have four diastereomers in solution state and it can transform from one diastereomer to the others, and the 3R4S5R is more stable than the others.</p>

Excretion of (-)-clausenamide in rats / 药学学报

<p><b>AIM</b>To study the excretion of (-)-clausenamide in rats.</p><p><b>METHODS</b>The urine, feces and bile were collected at predetermined time points after (-)-clausenamide was orally administrated to 6 rats (30 mg x kg(-1)). The concentrations of (-)-clausenamide and its metabolite 6-OH-(-)-clausnamide were determined by HPLC-MS/MS method using glipzide as the internal reference, and the accumulative excretion amount of (-)-clausenamide and 6-OH-(-)-clausenamide was calculated in the urine, feces and bile, separately.</p><p><b>RESULTS</b>(-)-Clausenamide was recovered mostly (44%) from feces in 112 hours, 7.1% was found from urine in 120 hours and 0.013% was detected from bile in 24 hours. The accumulative excretions of 6-OH-(-)-clausenamide were 0.92% , 0.46% and 0.0003% of the administered dose from feces, urine and bile, respectively.</p><p><b>CONCLUSION</b>The major amount of (-)-clausenamide was recovered from feces after (-)-clausenamide was orally administrated to rats (30 mg kg(-1)).</p>

Pharmacokinetics of (-)-clausenamide and its major metabolite 6-hydroxyl-clausenamide in beagle dogs by HPLC/MS / 药学学报

<p><b>UNLABELLED</b>To establish a sensitive and accurate method to study the pharmacokinetics of (-)-clausenamide [(-)-clau] and its major metabolite 6-hydroxyl-clausenamide (6-OH-clau) in the plasma of the Beagle dog.</p><p><b>METHODS</b>(-)-Clau was orally administered to six Beagle dogs at the dose of 30 mg x kg(-1), venous blood from front leg was sampled and plasma was separated for analysis. After extraction with ethyl acetate, the plasma samples were analyzed by HPLC/MS and the mobile phase was a mixture of methanol-water-acetic acid (60: 40: 0. 8) at the flow rate of 1.0 mL x min(-1). The API-ES positive ion SIM detection was carried out for the detection of both (-)-clau ([M + H] (+), m/z 298 ) and 6-OH-clau ([M + H - H2 O](+), m/z 296) with glipzide (glip) ([M + H](+), m/z 446) as internal standard. The pharmacokinetic parameters were calculated by 3P97 software.</p><p><b>RESULTS</b>There was good linear relationship ( r > 0. 999) between the SIM responses and the concentrations for (-)-clau and 6-OH-clau at the range from 1.0 to 200 ng x mL(-1) and 0.2 to 40.0 ng x mL(-1), respectively. The absolute recovery was greater than 85%. The plasma concentration-time curves of (-)-clau and 6-OH-clau were both best fitted to a two-compartment model. The C(max) of (-)-clau and 6-OH-clau were (21 +/- 10) ng x mL(-1) and (3.9 +/- 2.2) ng x mL(-1), T(max) were (0.8 +/- 0.5) h and (1.3 +/- 0.5) h, T 1/2 alpha were (0.9 +/- 0.6) hand (1.4 +/- 0.6) h, T 1/2 beta were (19 +/- 23) hand (13 +/- 12) h, AUC(0-24 h) were (69 +/- 14) h x ng x mL(-1) and (12 +/- 7) h x ng x mL(-1) respectively.</p><p><b>CONCLUSION</b>The established HPLC/MS method was sensitive and specific for the determination of (-)-clau. It was shown that the absorption and first phase elimination of (-)-clau were very quick in Beagle dogs, but the terminal elimination was very slow. The plasma concentration profile of its major metabolite 6-OH-clau was similar to (-)-clau and the AUC was relatively small in comparison with (-)-clau.</p>