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papers from the latest issue:
Identification and analysis of an impurity inducing clinical adverse effect in anti-adhesion carboxymethyl chitosan products
08 August 2013,
21:21:53
Publication date: November
2013
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 85
Author(s): Ming-Ming Yu , Ting-Fu Jiang , Yuan-Hong Wang , Dong-Yan Wang , Zhi-Hua Lv
Controlling and minimizing the adverse effects of drugs are the key issues in ensuring the safety of drug therapy. Carboxymethyl chitosan has been widely used as an anti-adhesion material. However, recently in China there have been several reported instances of conjunctival hyperemia associated with the use of carboxymethyl chitosan containing products. Through MS, FTIR, and GC analysis, an impurity, diglycolic acid, was discovered in carboxylmethyl chitosan products. Pharmacological tests further indicated diglycolic acid has antithrombogenicity properties and induces vasodilation, both of which can cause conjunctival hyperemia. Thus, through these tests it was ascertained that diglycolic acid was the culprit responsible for the adverse clinical effects. Next, emphasis shifted to trying to discover the mechanism responsible for generating the diglycolic acid. Under strong basic conditions, chloroacetic acid can generate glycolic acid, which, upon etherification, can become diglycolic acid. In order to avoid future adverse effects, we have established an HPLC method to detect and determine diglycolic acid in carboxymethyl chitosan products. This method is specific, accurate, and precise, and can be easily implemented into routine monitoring practice. Concurrently, a refined method has also been established in order to eliminate diglycolic acid from carboxymethyl chitosan.
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 85
Author(s): Ming-Ming Yu , Ting-Fu Jiang , Yuan-Hong Wang , Dong-Yan Wang , Zhi-Hua Lv
Controlling and minimizing the adverse effects of drugs are the key issues in ensuring the safety of drug therapy. Carboxymethyl chitosan has been widely used as an anti-adhesion material. However, recently in China there have been several reported instances of conjunctival hyperemia associated with the use of carboxymethyl chitosan containing products. Through MS, FTIR, and GC analysis, an impurity, diglycolic acid, was discovered in carboxylmethyl chitosan products. Pharmacological tests further indicated diglycolic acid has antithrombogenicity properties and induces vasodilation, both of which can cause conjunctival hyperemia. Thus, through these tests it was ascertained that diglycolic acid was the culprit responsible for the adverse clinical effects. Next, emphasis shifted to trying to discover the mechanism responsible for generating the diglycolic acid. Under strong basic conditions, chloroacetic acid can generate glycolic acid, which, upon etherification, can become diglycolic acid. In order to avoid future adverse effects, we have established an HPLC method to detect and determine diglycolic acid in carboxymethyl chitosan products. This method is specific, accurate, and precise, and can be easily implemented into routine monitoring practice. Concurrently, a refined method has also been established in order to eliminate diglycolic acid from carboxymethyl chitosan.
Graphical abstract
An analytical approach based on ESI-MS, LC–MS and PCA for the quali–quantitative analysis of cycloartane derivatives in Astragalus spp.
08 August 2013,
21:21:53
Publication date: November
2013
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 85
Author(s): Assunta Napolitano , Seref Akay , Angela Mari , Erdal Bedir , Cosimo Pizza , Sonia Piacente
Astragalus species are widely used as health foods and dietary supplements, as well as drugs in traditional medicine. To rapidly evaluate metabolite similarities and differences among the EtOH extracts of the roots of eight commercial Astragalus spp., an approach based on direct analyses by ESI-MS followed by PCA of ESI-MS data, was carried out. Successively, quali–quantitative analyses of cycloartane derivatives in the eight Astragalus spp. by LC-ESI-MS n and PCA of LC-ESI-MS data were performed. This approach allowed to promptly highlighting metabolite similarities and differences among the various Astragalus spp. PCA results from LC-ESI-MS data of Astragalus samples were in reasonable agreement with both PCA results of ESI-MS data and quantitative results. This study affords an analytical method for the quali–quantitative determination of cycloartane derivatives in herbal preparations used as health and food supplements.
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 85
Author(s): Assunta Napolitano , Seref Akay , Angela Mari , Erdal Bedir , Cosimo Pizza , Sonia Piacente
Astragalus species are widely used as health foods and dietary supplements, as well as drugs in traditional medicine. To rapidly evaluate metabolite similarities and differences among the EtOH extracts of the roots of eight commercial Astragalus spp., an approach based on direct analyses by ESI-MS followed by PCA of ESI-MS data, was carried out. Successively, quali–quantitative analyses of cycloartane derivatives in the eight Astragalus spp. by LC-ESI-MS n and PCA of LC-ESI-MS data were performed. This approach allowed to promptly highlighting metabolite similarities and differences among the various Astragalus spp. PCA results from LC-ESI-MS data of Astragalus samples were in reasonable agreement with both PCA results of ESI-MS data and quantitative results. This study affords an analytical method for the quali–quantitative determination of cycloartane derivatives in herbal preparations used as health and food supplements.
Graphical abstract
Optimisation methodology in the chiral and achiral separation in electrokinetic chromatography in the case of a multicomponent sample of dansyl amino acids
08 August 2013,
21:21:53
Publication date: November
2013
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 85
Author(s): Alessandro Giuffrida , Marianna Messina , Annalinda Contino , Vincenzo Cucinotta
Two different chiral selectors synthesised in our laboratory were used to test the possibility of separation for a sample consisting of ten different enantiomeric pairs of dansyl-derivatives of α-amino acids in electrokinetic chromatography. It was possible to observe all the peaks, though only partly resolved, due to the twenty analytes through an accurate strategy of choice of the experimental conditions. As a part of this strategy, a procedure of identification of the single peaks in the electropherograms called LACI (lastly added component identification) has been developed.
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 85
Author(s): Alessandro Giuffrida , Marianna Messina , Annalinda Contino , Vincenzo Cucinotta
Two different chiral selectors synthesised in our laboratory were used to test the possibility of separation for a sample consisting of ten different enantiomeric pairs of dansyl-derivatives of α-amino acids in electrokinetic chromatography. It was possible to observe all the peaks, though only partly resolved, due to the twenty analytes through an accurate strategy of choice of the experimental conditions. As a part of this strategy, a procedure of identification of the single peaks in the electropherograms called LACI (lastly added component identification) has been developed.
Graphical abstract
Quantitative capillary zone electrophoresis method for the precise determination of charge differences arising from the manufacture of heparan-N-sulfatase
08 August 2013,
21:21:53
Publication date: November
2013
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 85
Author(s): Daniel S. Roseman , Robert Weinberger
A rapid and reproducible high-resolution capillary zone electrophoresis (CZE) method capable of resolving the charge isoforms of intact heparan-N-sulfatase (HNS) has been developed to monitor the charge consistency across different batches of HNS. Separation was carried out using a bare fused silica capillary with a buffer system composed of 25mM Tris, pH 8.0. This CZE method allowed the separation and integration of 14 peaks, each arising from differences in the amount of sialic-acid and mannose-6-phosphate bearing glycoforms, which were confirmed using enzymatically modified samples. Standard conditioning and rinsing conditions of the capillary were used to achieve optimal repeatability. Excellent day-to-day precision was obtained for migration times of each peak relative to the electroosmotic flow marker with relative standard deviation (RSD)≤0.5%. The precision of the relative peak areas (peak area percentages) ranged from 0.6% to 2.8% RSD for the major isoforms (peaks 3–12), from 4.0% to 5.0% RSD for peaks 1 and 2, and from 7.4% to 23.2% RSD for peaks 13 and 14. The method was able to discriminate charge variation across different batches of HNS, including those with both significant and minor process changes.
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 85
Author(s): Daniel S. Roseman , Robert Weinberger
A rapid and reproducible high-resolution capillary zone electrophoresis (CZE) method capable of resolving the charge isoforms of intact heparan-N-sulfatase (HNS) has been developed to monitor the charge consistency across different batches of HNS. Separation was carried out using a bare fused silica capillary with a buffer system composed of 25mM Tris, pH 8.0. This CZE method allowed the separation and integration of 14 peaks, each arising from differences in the amount of sialic-acid and mannose-6-phosphate bearing glycoforms, which were confirmed using enzymatically modified samples. Standard conditioning and rinsing conditions of the capillary were used to achieve optimal repeatability. Excellent day-to-day precision was obtained for migration times of each peak relative to the electroosmotic flow marker with relative standard deviation (RSD)≤0.5%. The precision of the relative peak areas (peak area percentages) ranged from 0.6% to 2.8% RSD for the major isoforms (peaks 3–12), from 4.0% to 5.0% RSD for peaks 1 and 2, and from 7.4% to 23.2% RSD for peaks 13 and 14. The method was able to discriminate charge variation across different batches of HNS, including those with both significant and minor process changes.
Graphical abstract
Simultaneous investigation of sesquiterpenes, pyrrolizidine alkaloids and N-oxides in Butterbur (Petasites hybridus) with an offline 2D-combination of HPLC-UV and LC-MMI-ToF-MS
08 August 2013,
21:21:53
Publication date: November
2013
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 85
Author(s): Ahmet Alper Aydın , Thomas Letzel
With the worldwide rapid increasing interest in the use of natural products as dietary supplements, medical remedies and functional foods, it has been accepted that omitting the plant constituents with potential adverse effects was a huge fault of the past. Several countries developed regulations to limit the consumption of such products in the markets. Among these natural products, butterbur (Petasites) has been used for years as herbal supplement for its anti-spasmodic and anti-inflammatory effects. However, its hepatotoxic alkaloid content limits the direct usage. In this study, investigation of sesquiterpenes and pyrrolizidine alkaloids (PAs) together with their N-oxide forms has been conducted with an offline 2D-combination using high-performance liquid chromatography with UV detection (HPLC-UV) and liquid chromatography – multi mode ionization – time-of-flight mass spectrometry (LC-MMI-ToF-MS) for plant screening. The content has been qualitatively investigated to provide information on the constituents of the plant rhizomes extracted using ethanol. Besides the reported hepatotoxic and medically bio-active plant constituents, a strategy has been suggested for estimating the retention order and retention times with respect to calculated log D (distribution coefficient) and hydrophobicity distributions on C18 reversed-phase column when all standard compounds are not available in laboratory. In this sense, the influence of calculated log D and hydrophobicity distributions on retention time has been clarified via available PA and PA-N-oxide standards. The ethanolic extract of Petasites hybridus has been used for examination of the strategy in a real-sample model. Additionally, the advantages of the developed HPLC-UV and LC-MMI-ToF-MS combination have been discussed with respect to the presented results.
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 85
Author(s): Ahmet Alper Aydın , Thomas Letzel
With the worldwide rapid increasing interest in the use of natural products as dietary supplements, medical remedies and functional foods, it has been accepted that omitting the plant constituents with potential adverse effects was a huge fault of the past. Several countries developed regulations to limit the consumption of such products in the markets. Among these natural products, butterbur (Petasites) has been used for years as herbal supplement for its anti-spasmodic and anti-inflammatory effects. However, its hepatotoxic alkaloid content limits the direct usage. In this study, investigation of sesquiterpenes and pyrrolizidine alkaloids (PAs) together with their N-oxide forms has been conducted with an offline 2D-combination using high-performance liquid chromatography with UV detection (HPLC-UV) and liquid chromatography – multi mode ionization – time-of-flight mass spectrometry (LC-MMI-ToF-MS) for plant screening. The content has been qualitatively investigated to provide information on the constituents of the plant rhizomes extracted using ethanol. Besides the reported hepatotoxic and medically bio-active plant constituents, a strategy has been suggested for estimating the retention order and retention times with respect to calculated log D (distribution coefficient) and hydrophobicity distributions on C18 reversed-phase column when all standard compounds are not available in laboratory. In this sense, the influence of calculated log D and hydrophobicity distributions on retention time has been clarified via available PA and PA-N-oxide standards. The ethanolic extract of Petasites hybridus has been used for examination of the strategy in a real-sample model. Additionally, the advantages of the developed HPLC-UV and LC-MMI-ToF-MS combination have been discussed with respect to the presented results.
Graphical abstract
Application of an innovative design space optimization strategy to the development of LC methods for the simultaneous screening of antibiotics to combat poor quality medicines
08 August 2013,
21:21:53
Publication date: November
2013
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 85
Author(s): J.K. Mbinze , A. Dispas , P. Lebrun , J. Mavar Tayey Mbay , V. Habyalimana , N. Kalenda , E. Rozet , Ph. Hubert , R.D. Marini
The poor quality of medicines is a crucial problem of public health. Therefore, it is important to have analytical tools to attend decisions of the legal authorities while combating this offense. In this context, the main objective of this study was to develop generic methods able to trace, screen and determine several antibiotics and common associated molecules by mean of liquid chromatographic techniques. For that purpose, an innovative Design Space optimization strategy was applied, targeting 16 antibiotics and 3 beta-lactamase inhibitors. The robustness of the developed method allowed using its use in an environment where operational factors such as temperature are not easy to control and eased its transfer to Ultra High Performance Liquid Chromatography. To demonstrate its ability to quantify the targeted molecules, the developed and transferred method was fully validated for two active ingredients commonly used in association, sulbactam and ceftriaxone, using the accuracy profile as decision tool. Based on this successful step, the method was then used for the quantitative determination of these two active ingredients in three pharmaceutical brands marketed in the Democratic Republic of Congo. Two out of the three pharmaceutical products did not comply with the specifications.
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 85
Author(s): J.K. Mbinze , A. Dispas , P. Lebrun , J. Mavar Tayey Mbay , V. Habyalimana , N. Kalenda , E. Rozet , Ph. Hubert , R.D. Marini
The poor quality of medicines is a crucial problem of public health. Therefore, it is important to have analytical tools to attend decisions of the legal authorities while combating this offense. In this context, the main objective of this study was to develop generic methods able to trace, screen and determine several antibiotics and common associated molecules by mean of liquid chromatographic techniques. For that purpose, an innovative Design Space optimization strategy was applied, targeting 16 antibiotics and 3 beta-lactamase inhibitors. The robustness of the developed method allowed using its use in an environment where operational factors such as temperature are not easy to control and eased its transfer to Ultra High Performance Liquid Chromatography. To demonstrate its ability to quantify the targeted molecules, the developed and transferred method was fully validated for two active ingredients commonly used in association, sulbactam and ceftriaxone, using the accuracy profile as decision tool. Based on this successful step, the method was then used for the quantitative determination of these two active ingredients in three pharmaceutical brands marketed in the Democratic Republic of Congo. Two out of the three pharmaceutical products did not comply with the specifications.
Graphical abstract
Characterization of currently marketed heparin products: Key tests for LMWH quality assurance
08 August 2013,
21:21:53
Publication date: November
2013
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 85
Author(s): Hongping Ye , Timothy K. Toby , Cynthia D. Sommers , Houman Ghasriani , Michael L. Trehy , Wei Ye , Richard E. Kolinski , Lucinda F. Buhse , Ali Al-Hakim , David A. Keire
During the 2007–2008 heparin crisis it was found that the United States Pharmacopeia (USP) testing monograph for heparin sodium or low molecular weight heparins did not detect the presence of the contaminant, oversulfated chondroitin sulfate (OSCS). In response to this concern, new tests and specifications were developed by the Food and Drug Administration (FDA) and USP and put in place to detect not only the contaminant OSCS, but also to improve assurance of quality and purity of these drug products. The USP monographs for the low molecular weight heparins (LMWHs) approved for use in the United States (dalteparin, tinzaparin and enoxaparin) are also undergoing revision to include many of the same tests used for heparin sodium, including; one-dimensional (1D) 500MHz 1H NMR, SAX-HPLC, percent galactosamine in total hexosamine and anticoagulation time assays with purified Factor IIa or Factor Xa. These tests represent orthogonal approaches for heparin identification, measurement of bioactivity and for detection of process impurities or contaminants in these drug products. Here we describe results from a survey of multiple lots from three types of LMWHs in the US market which were collected after the 2009 heparin sodium monograph revision. In addition, innovator and generic versions of formulated enoxaparin products purchased in 2011 are compared using these tests and found to be highly similar within the discriminating power of the assays applied.
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 85
Author(s): Hongping Ye , Timothy K. Toby , Cynthia D. Sommers , Houman Ghasriani , Michael L. Trehy , Wei Ye , Richard E. Kolinski , Lucinda F. Buhse , Ali Al-Hakim , David A. Keire
During the 2007–2008 heparin crisis it was found that the United States Pharmacopeia (USP) testing monograph for heparin sodium or low molecular weight heparins did not detect the presence of the contaminant, oversulfated chondroitin sulfate (OSCS). In response to this concern, new tests and specifications were developed by the Food and Drug Administration (FDA) and USP and put in place to detect not only the contaminant OSCS, but also to improve assurance of quality and purity of these drug products. The USP monographs for the low molecular weight heparins (LMWHs) approved for use in the United States (dalteparin, tinzaparin and enoxaparin) are also undergoing revision to include many of the same tests used for heparin sodium, including; one-dimensional (1D) 500MHz 1H NMR, SAX-HPLC, percent galactosamine in total hexosamine and anticoagulation time assays with purified Factor IIa or Factor Xa. These tests represent orthogonal approaches for heparin identification, measurement of bioactivity and for detection of process impurities or contaminants in these drug products. Here we describe results from a survey of multiple lots from three types of LMWHs in the US market which were collected after the 2009 heparin sodium monograph revision. In addition, innovator and generic versions of formulated enoxaparin products purchased in 2011 are compared using these tests and found to be highly similar within the discriminating power of the assays applied.
Graphical abstract
Analyses of marketplace tacrolimus drug product quality: Bioactivity, NMR and LC–MS
08 August 2013,
21:21:53
Publication date: November
2013
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 85
Author(s): Cynthia D. Sommers , Eric S. Pang , Houman Ghasriani , Robert T. Berendt , Vincent L. Vilker , David A. Keire , Michael T. Boyne II
Tacrolimus (FK506) is a potent, narrow therapeutic index, immunosuppressive drug used to avoid organ rejection in patients that have undergone organ transplantation. Recent clinical reports suggested a significant reduction in the tacrolimus concentration/dose ratio in the plasma of liver and kidney recipients when the reference listed drug was substituted with a generic drug. In response to these concerns about switching between tacrolimus from different approved manufacturers during treatment, the FDA initiated purity, potency and quality studies of the innovator and generic tacrolimus products available in the US marketplace. A combination of analytical methods, including mass spectrometry (LC–MS), nuclear magnetic resonance (NMR) and bioactivity assay were developed and validated to assess the quality of tacrolimus. These tests measured the identity, impurities and activity of tacrolimus from active pharmaceutical ingredient (API) sources and with formulated drug product from five different approved manufactures. In addition, some testing was performed on tacrolimus capsules obtained from a non US approved Indian source. The data obtained showed no discernible difference in the impurity profiles and potency between the generic and innovator tacrolimus products.
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 85
Author(s): Cynthia D. Sommers , Eric S. Pang , Houman Ghasriani , Robert T. Berendt , Vincent L. Vilker , David A. Keire , Michael T. Boyne II
Tacrolimus (FK506) is a potent, narrow therapeutic index, immunosuppressive drug used to avoid organ rejection in patients that have undergone organ transplantation. Recent clinical reports suggested a significant reduction in the tacrolimus concentration/dose ratio in the plasma of liver and kidney recipients when the reference listed drug was substituted with a generic drug. In response to these concerns about switching between tacrolimus from different approved manufacturers during treatment, the FDA initiated purity, potency and quality studies of the innovator and generic tacrolimus products available in the US marketplace. A combination of analytical methods, including mass spectrometry (LC–MS), nuclear magnetic resonance (NMR) and bioactivity assay were developed and validated to assess the quality of tacrolimus. These tests measured the identity, impurities and activity of tacrolimus from active pharmaceutical ingredient (API) sources and with formulated drug product from five different approved manufactures. In addition, some testing was performed on tacrolimus capsules obtained from a non US approved Indian source. The data obtained showed no discernible difference in the impurity profiles and potency between the generic and innovator tacrolimus products.
Graphical abstract
Characterization of degradation products of idarubicin through LC-UV, MSn and LC–MS-TOF studies
08 August 2013,
21:21:53
Publication date: November
2013
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 85
Author(s): Dheeraj Kaushik , Gulshan Bansal
Idarubicin was subjected to forced degradation under the ICH recommended conditions of hydrolysis, oxidation, dry heat and photolysis to characterize its possible impurities and/or degradation products. The drug was found unstable to acid hydrolysis at 85°C and to alkaline hydrolysis, and oxidation at room temperature. The hydrolytic and oxidative degradation products were resolved with gradient and isocratic elution, respectively on an Inertsil RP18 (250mm×4.6mm; 5μ) column with HCOONH4 (20mM, pH 3.0) and acetonitrile. The drug degraded to two products (O-I and O-II) in oxidative condition, two products (K-I and K-II) in alkaline hydrolytic, and one product (A-I) in acidic hydrolytic conditions. The purity of each in the LC-UV chromatogram was ascertained through LC-PDA analysis. The products were characterized through +ESI-MS n studies on the drug and LC–MS-TOF studies on the degraded drug solutions. Based on the multistage mass fragmentation pattern of idarubicin and accurate mass analysis of the degradation products, the O-I, O-II and A-I were characterized as desacetylidarubicin hydroperoxide, desacetylidarubicin and deglucosaminylidarubicin, respectively. The products K-I and K-II were not characterized due to their low concentrations and/or extremely weak ionization. The mechanisms of degradation of idarubicin to these products were proposed and discussed.
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 85
Author(s): Dheeraj Kaushik , Gulshan Bansal
Idarubicin was subjected to forced degradation under the ICH recommended conditions of hydrolysis, oxidation, dry heat and photolysis to characterize its possible impurities and/or degradation products. The drug was found unstable to acid hydrolysis at 85°C and to alkaline hydrolysis, and oxidation at room temperature. The hydrolytic and oxidative degradation products were resolved with gradient and isocratic elution, respectively on an Inertsil RP18 (250mm×4.6mm; 5μ) column with HCOONH4 (20mM, pH 3.0) and acetonitrile. The drug degraded to two products (O-I and O-II) in oxidative condition, two products (K-I and K-II) in alkaline hydrolytic, and one product (A-I) in acidic hydrolytic conditions. The purity of each in the LC-UV chromatogram was ascertained through LC-PDA analysis. The products were characterized through +ESI-MS n studies on the drug and LC–MS-TOF studies on the degraded drug solutions. Based on the multistage mass fragmentation pattern of idarubicin and accurate mass analysis of the degradation products, the O-I, O-II and A-I were characterized as desacetylidarubicin hydroperoxide, desacetylidarubicin and deglucosaminylidarubicin, respectively. The products K-I and K-II were not characterized due to their low concentrations and/or extremely weak ionization. The mechanisms of degradation of idarubicin to these products were proposed and discussed.
Graphical abstract
Reversed-phase thin-layer chromatography technique for the comparison of the lipophilicity of selected non-steroidal anti-inflammatory drugs
08 August 2013,
21:21:53
Publication date: November
2013
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 85
Author(s): Małgorzata Starek , Łukasz Komsta , Jan Krzek
The chromatographic behavior of a series of coxibs and oxicams, drugs from a group of non-steroidal anti-inflammatory drugs, was studied by reversed-phase thin-layer chromatography with binary mobile phases containing water and the organic modifiers: methanol, acetone, 1,4-dioxane, acetonitrile and 2-propanol. Linear relationships were obtained between the retention R M values of the compounds and the concentration of organic modifier in the mobile phase. Values of R M0, represent the theoretical R M values at 0% organic solvent in the mobile phase were calculated by extrapolation. These experimental lipophilicity values were correlated with lipophilicity (logP) from databases. The obtained results show that reversed-phase chromatography (experimental parameters) may be a good instrument for analytics in describing the lipophilic nature of investigated compounds as well as the activity.
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 85
Author(s): Małgorzata Starek , Łukasz Komsta , Jan Krzek
The chromatographic behavior of a series of coxibs and oxicams, drugs from a group of non-steroidal anti-inflammatory drugs, was studied by reversed-phase thin-layer chromatography with binary mobile phases containing water and the organic modifiers: methanol, acetone, 1,4-dioxane, acetonitrile and 2-propanol. Linear relationships were obtained between the retention R M values of the compounds and the concentration of organic modifier in the mobile phase. Values of R M0, represent the theoretical R M values at 0% organic solvent in the mobile phase were calculated by extrapolation. These experimental lipophilicity values were correlated with lipophilicity (logP) from databases. The obtained results show that reversed-phase chromatography (experimental parameters) may be a good instrument for analytics in describing the lipophilic nature of investigated compounds as well as the activity.
Graphical abstract
Analysis and detection of the chemical constituents of Radix Polygalae and their metabolites in rats after oral administration by ultra high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry
08 August 2013,
21:21:53
Publication date: November
2013
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 85
Author(s): Yun Ling , Zhixiong Li , Mingcang Chen , Zhaolin Sun , Mingsong Fan , Chenggang Huang
Radix Polygalae (RP), the dried root of Polygala tenuifolia Willd., is a well-known traditional Chinese medicine to mediate sedative, antipsychotic, cognitive improving, neuroprotective, and anti-inflammatory therapeutic effects on the central nervous system. In this work, ultra high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC/ESI-Q-TOF-MS/MS) was established for the separation and characterization of the chemical constituents in Radix Polygalae and their metabolites in rat plasma and urine after oral administration. Samples were separated on an Agilent Zorbax Eclipse Plus-C18 column (100mm×2.1mm, 1.8μm) with 0.1% formic acid aqueous solution and acetonitrile as the mobile phase under gradient conditions. Overall, 50 compounds were characterized from the RP, 9 of which are to our knowledge reported for the first time. In vivo, 10 components and 2 metabolites were observed in rat plasma, and 27 components and 7 metabolites were detected in rat urine. The results from this work improve our understanding on the chemical constituents of RP and their metabolic profiling.
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 85
Author(s): Yun Ling , Zhixiong Li , Mingcang Chen , Zhaolin Sun , Mingsong Fan , Chenggang Huang
Radix Polygalae (RP), the dried root of Polygala tenuifolia Willd., is a well-known traditional Chinese medicine to mediate sedative, antipsychotic, cognitive improving, neuroprotective, and anti-inflammatory therapeutic effects on the central nervous system. In this work, ultra high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC/ESI-Q-TOF-MS/MS) was established for the separation and characterization of the chemical constituents in Radix Polygalae and their metabolites in rat plasma and urine after oral administration. Samples were separated on an Agilent Zorbax Eclipse Plus-C18 column (100mm×2.1mm, 1.8μm) with 0.1% formic acid aqueous solution and acetonitrile as the mobile phase under gradient conditions. Overall, 50 compounds were characterized from the RP, 9 of which are to our knowledge reported for the first time. In vivo, 10 components and 2 metabolites were observed in rat plasma, and 27 components and 7 metabolites were detected in rat urine. The results from this work improve our understanding on the chemical constituents of RP and their metabolic profiling.
Graphical abstract
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