A new issue of this journal has just
been published. To see abstracts of the papers it contains (with links through
to the full papers) click here:
Selected
papers from the latest issue:
Microdialysis combined with liquid chromatography–tandem mass spectrometry for the determination of levo-tetrahydropalmatine in the rat striatum
04 April 2012,
10:36:45
Publication year:
2012
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
Chen Wang, Shu Li, Yuanjun Tang, Shuowen Wang, Yalin Zhang, Guorong Fan, Liqin Li, Yi Zhang
Levo-tetrahydropalmatine (l-THP), one of the main active alkaloids isolated from Rhizoma corydalis, was recently found to elicit profound effects on the dopaminergic system in the striatum, which plays an important role in regulating nociception. A rapid and sensitive method based on microdialysis combined with liquid chromatography–tandem mass spectrometry was developed for the determination of l-THP in the rat striatum. Microdialysis probes were stereotactically placed in the striatal hemisphere, and l-THP was measured from the microdialysates collected using LC–MS/MS. Reverse-phase LC separation was accomplished on a Diamonsil™ C18 column (50mm×2.1mm ID, 5μm) with the mobile phase composed of methanol–water (50:50, v/v) at a flow rate of 0.2ml/min. The method had a chromatographic total run time of 5min. Detection was performed in electrospray positive mode and quantification was executed in selected reaction monitoring mode. The following transitions were monitored: m/z 356.0→191.9 for l-THP and 256.0→167.1 for the internal standard diphenhydramine. The method was sensitive with a lower limit of quantitation (LLOQ) of 0.1ng/ml for l-THP, with good linearity in the range of 0.1–1000ng/ml (r 2 ≥0.999). All the validation data, such as accuracy, precision, and inter-day repeatability were within the required limits. The method was successfully applied to pharmacokinetic study of the l-THP in the rat striatum.
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
Chen Wang, Shu Li, Yuanjun Tang, Shuowen Wang, Yalin Zhang, Guorong Fan, Liqin Li, Yi Zhang
Levo-tetrahydropalmatine (l-THP), one of the main active alkaloids isolated from Rhizoma corydalis, was recently found to elicit profound effects on the dopaminergic system in the striatum, which plays an important role in regulating nociception. A rapid and sensitive method based on microdialysis combined with liquid chromatography–tandem mass spectrometry was developed for the determination of l-THP in the rat striatum. Microdialysis probes were stereotactically placed in the striatal hemisphere, and l-THP was measured from the microdialysates collected using LC–MS/MS. Reverse-phase LC separation was accomplished on a Diamonsil™ C18 column (50mm×2.1mm ID, 5μm) with the mobile phase composed of methanol–water (50:50, v/v) at a flow rate of 0.2ml/min. The method had a chromatographic total run time of 5min. Detection was performed in electrospray positive mode and quantification was executed in selected reaction monitoring mode. The following transitions were monitored: m/z 356.0→191.9 for l-THP and 256.0→167.1 for the internal standard diphenhydramine. The method was sensitive with a lower limit of quantitation (LLOQ) of 0.1ng/ml for l-THP, with good linearity in the range of 0.1–1000ng/ml (r 2 ≥0.999). All the validation data, such as accuracy, precision, and inter-day repeatability were within the required limits. The method was successfully applied to pharmacokinetic study of the l-THP in the rat striatum.
Development and validation of an alpha fetoprotein immunoassay using Gyros technology
04 April 2012,
10:36:45
Publication year:
2012
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
Allison M. Given, Pamela M. Whalen, Peter J. O’Brien, Chad A. Ray
Circulating alpha fetoprotein (AFP) is a diagnostic and prognostic biomarker for hepatocellular carcinoma (HCC) with potential utility as a pharmacodynamic endpoint in rodent tumor models. This application is limited, however, by low sample volumes, highlighting the need for sensitive, sample-sparing biomarker assay methods. In order to improve the utility of AFP as an oncology biomarker, we developed a method for AFP using the Gyrolab™, an automated microimmunoassay platform. Commercially available antibodies were screened to identify optimal combinations that were then used in a multi-factorial design of experiments (DOE) to optimize reaction conditions. Analytical validation included assessments of accuracy and precision (A&P), and dilutional linearity/hook effect, as well as reagent and sample stability. The method is reliable, with total error, a measure of accuracy and precision, less than 30% for all concentrations tested. AFP concentrations were measurable in diseased mice and undetectable in normal mice. Therefore, this novel, low volume AFP immunoassay is suitable for pre-clinical drug development, where its miniaturized format facilitates serial sampling in rodent models of cancer.
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
Allison M. Given, Pamela M. Whalen, Peter J. O’Brien, Chad A. Ray
Circulating alpha fetoprotein (AFP) is a diagnostic and prognostic biomarker for hepatocellular carcinoma (HCC) with potential utility as a pharmacodynamic endpoint in rodent tumor models. This application is limited, however, by low sample volumes, highlighting the need for sensitive, sample-sparing biomarker assay methods. In order to improve the utility of AFP as an oncology biomarker, we developed a method for AFP using the Gyrolab™, an automated microimmunoassay platform. Commercially available antibodies were screened to identify optimal combinations that were then used in a multi-factorial design of experiments (DOE) to optimize reaction conditions. Analytical validation included assessments of accuracy and precision (A&P), and dilutional linearity/hook effect, as well as reagent and sample stability. The method is reliable, with total error, a measure of accuracy and precision, less than 30% for all concentrations tested. AFP concentrations were measurable in diseased mice and undetectable in normal mice. Therefore, this novel, low volume AFP immunoassay is suitable for pre-clinical drug development, where its miniaturized format facilitates serial sampling in rodent models of cancer.
Simultaneous determination of antidementia drugs in human plasma: Procedure transfer from HPLC–MS to UPLC–MS/MS
04 April 2012,
10:36:45
Publication year:
2012
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
Muriel Noetzli, Nicolas Ansermot, Maria Dobrinas, Chin B. Eap
A previously developed high performance liquid chromatography mass spectrometry (HPLC–MS) procedure for the simultaneous determination of antidementia drugs, including donepezil, galantamine, memantine, rivastigmine and its metabolite NAP 226-90, was transferred to an ultra performance liquid chromatography system coupled to a tandem mass spectrometer (UPLC–MS/MS). The drugs and their internal standards ([2H7]-donepezil, [13C,2H3]-galantamine, [13C2,2H6]-memantine, [2H6]-rivastigmine) were extracted from 250μL human plasma by protein precipitation with acetonitrile. Chromatographic separation was achieved on a reverse phase column (BEH C18 2.1mm×50mm; 1.7μm) with a gradient elution of an ammonium acetate buffer at pH 9.3 and acetonitrile at a flow rate of 0.4mL/min and an overall run time of 4.5min. The analytes were detected on a tandem quadrupole mass spectrometer operated in positive electrospray ionization mode, and quantification was performed using multiple reaction monitoring. The method was validated according to the recommendations of international guidelines over a calibration range of 1–300ng/mL for donepezil, galantamine and memantine, and 0.2–50ng/mL for rivastimgine and NAP 226-90. The trueness (86–108%), repeatability (0.8–8.3%), intermediate precision (2.3–10.9%) and selectivity of the method were found to be satisfactory. Matrix effects variability was inferior to 15% for the analytes and inferior to 5% after correction by internal standards. A method comparison was performed with patients’ samples showing similar results between the HPLC–MS and UPLC–MS/MS procedures. Thus, this validated UPLC–MS/MS method allows to reduce the required amount of plasma, to use a simplified sample preparation, and to obtain a higher sensitivity and specificity with a much shortened run-time.
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
Muriel Noetzli, Nicolas Ansermot, Maria Dobrinas, Chin B. Eap
A previously developed high performance liquid chromatography mass spectrometry (HPLC–MS) procedure for the simultaneous determination of antidementia drugs, including donepezil, galantamine, memantine, rivastigmine and its metabolite NAP 226-90, was transferred to an ultra performance liquid chromatography system coupled to a tandem mass spectrometer (UPLC–MS/MS). The drugs and their internal standards ([2H7]-donepezil, [13C,2H3]-galantamine, [13C2,2H6]-memantine, [2H6]-rivastigmine) were extracted from 250μL human plasma by protein precipitation with acetonitrile. Chromatographic separation was achieved on a reverse phase column (BEH C18 2.1mm×50mm; 1.7μm) with a gradient elution of an ammonium acetate buffer at pH 9.3 and acetonitrile at a flow rate of 0.4mL/min and an overall run time of 4.5min. The analytes were detected on a tandem quadrupole mass spectrometer operated in positive electrospray ionization mode, and quantification was performed using multiple reaction monitoring. The method was validated according to the recommendations of international guidelines over a calibration range of 1–300ng/mL for donepezil, galantamine and memantine, and 0.2–50ng/mL for rivastimgine and NAP 226-90. The trueness (86–108%), repeatability (0.8–8.3%), intermediate precision (2.3–10.9%) and selectivity of the method were found to be satisfactory. Matrix effects variability was inferior to 15% for the analytes and inferior to 5% after correction by internal standards. A method comparison was performed with patients’ samples showing similar results between the HPLC–MS and UPLC–MS/MS procedures. Thus, this validated UPLC–MS/MS method allows to reduce the required amount of plasma, to use a simplified sample preparation, and to obtain a higher sensitivity and specificity with a much shortened run-time.
Tentative identification of phase I metabolites of HU-210, a classical synthetic cannabinoid, by LC–MS/MS
04 April 2012,
10:36:45
Publication year:
2012
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
Unyong Kim, Ming Ji Jin, Jaeick Lee, Sang Beom Han, Moon Kyo In, Hye Hyun Yoo
(6aR,10aR)-9-(Hydroxymethyl)-6,6-dimethyl-3-(2-methyloctan-2-yl)-6a,7,10,10a-tetrahydrobenzo[c]chromen-1-ol (HU-210) is a synthetic cannabinoid, with a classical cannabinoid structure similar to Δ9-tetrahydrocannabinol (Δ9-THC). In this study, the in vitro metabolism of HU-210 was investigated in human liver microsomes to characterize associated phase I metabolites. HU-210 was incubated with human liver microsomes, and the reaction mixture was analyzed using LC–MS/MS. HU-210 was metabolized in human liver microsomes, yielding about 24 metabolites. These metabolites were structurally characterized on the basis of accurate mass analyses and MS/MS fragmentation patterns. The major metabolic route for HU-210 was oxygenation. Metabolites M1–M7 were identified as mono-oxygenated metabolites; M8–M15, mono-hydroxylated metabolites; M16–M20, di-oxygenated metabolites; and M21–M24, di-hydroxylated metabolites. These results provide evidence for in vivo HU-210 metabolism, and they may be applied to the analysis of HU-210 and its relevant metabolites in biological samples.
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
Unyong Kim, Ming Ji Jin, Jaeick Lee, Sang Beom Han, Moon Kyo In, Hye Hyun Yoo
(6aR,10aR)-9-(Hydroxymethyl)-6,6-dimethyl-3-(2-methyloctan-2-yl)-6a,7,10,10a-tetrahydrobenzo[c]chromen-1-ol (HU-210) is a synthetic cannabinoid, with a classical cannabinoid structure similar to Δ9-tetrahydrocannabinol (Δ9-THC). In this study, the in vitro metabolism of HU-210 was investigated in human liver microsomes to characterize associated phase I metabolites. HU-210 was incubated with human liver microsomes, and the reaction mixture was analyzed using LC–MS/MS. HU-210 was metabolized in human liver microsomes, yielding about 24 metabolites. These metabolites were structurally characterized on the basis of accurate mass analyses and MS/MS fragmentation patterns. The major metabolic route for HU-210 was oxygenation. Metabolites M1–M7 were identified as mono-oxygenated metabolites; M8–M15, mono-hydroxylated metabolites; M16–M20, di-oxygenated metabolites; and M21–M24, di-hydroxylated metabolites. These results provide evidence for in vivo HU-210 metabolism, and they may be applied to the analysis of HU-210 and its relevant metabolites in biological samples.
Pharmacokinetics and disposition study of calf thymus DNA in rats by applying 3H-labeling method
04 April 2012,
10:36:45
Publication year:
2012
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
Shuoye Yang, Qiuyang Zhang, Jiayin Chen, Deen Han, Di Zhao, Xijing Chen
A tritium(3H)-labeling method with high specificity was established to investigate the pharmacokinetics and disposition of the calf thymus DNA (ctDNA) in rats. The plasma pharmacokinetics, tissue distribution, mass balance and excretion were characterized in SD rats, respectively. Rats were injected i.v. with radiolabeled ctDNA with the dose of 40μCi/kg in each independent experiment. 3H-labeled ctDNA was eliminated rapidly in plasma, with the half-life estimated from 9 to 13h and preferentially accumulated in liver and lung, its concentration in all the tissues investigated decreased to very low level after 24h. ctDNA exhibited 80.8% accumulative recovery, excretion of radiolabel in urine and bile was nearly complete by 72h, which shown as the main excretion pathways, and the total recovery of excretion reached 77.9% within three days. In conclusion, ctDNA was rapidly eliminated in plasma and would not accumulate in tissues, parent ctDNA and its radioactive metabolites can be recovered almost completely in schedule time. All the results indicated that the in vitro use of ctDNA is safe and will not bring out potential risk.
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
Shuoye Yang, Qiuyang Zhang, Jiayin Chen, Deen Han, Di Zhao, Xijing Chen
A tritium(3H)-labeling method with high specificity was established to investigate the pharmacokinetics and disposition of the calf thymus DNA (ctDNA) in rats. The plasma pharmacokinetics, tissue distribution, mass balance and excretion were characterized in SD rats, respectively. Rats were injected i.v. with radiolabeled ctDNA with the dose of 40μCi/kg in each independent experiment. 3H-labeled ctDNA was eliminated rapidly in plasma, with the half-life estimated from 9 to 13h and preferentially accumulated in liver and lung, its concentration in all the tissues investigated decreased to very low level after 24h. ctDNA exhibited 80.8% accumulative recovery, excretion of radiolabel in urine and bile was nearly complete by 72h, which shown as the main excretion pathways, and the total recovery of excretion reached 77.9% within three days. In conclusion, ctDNA was rapidly eliminated in plasma and would not accumulate in tissues, parent ctDNA and its radioactive metabolites can be recovered almost completely in schedule time. All the results indicated that the in vitro use of ctDNA is safe and will not bring out potential risk.
Development of a rapid method for the determination and confirmation of nitroimidazoles in six matrices by fast liquid chromatography–tandem mass spectrometry
04 April 2012,
10:36:45
Publication year:
2012
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
Ádám Tölgyesi, Virender K. Sharma, Szabolcs Fekete, Jenő Fekete, Andrea Simon, Szilvia Farkas
A rapid liquid chromatography–tandem mass spectrometric (LC–MS/MS) method was developed to identify and to quantify nitroimidazoles, metronidazole (MNZ), ronidazole (RNZ) and dimetridazole (DMZ) and their corresponding hydroxy metabolites, MNZ-OH and 2-hydroxymethyl-1-methyl-5-nitroimidazole (HMNNI) in plasma, milk, muscle, egg, honey and feed samples. The same sample clean-up procedure including a novel solid-phase extraction (SPE) on polymeric Strata-SDB cartridges was used for each matrix. The analytes were separated on Kinetex XB C-18 core–shell type HPLC column using isocratic elution mode with a mobile phase containing 0.1% formic acid in water/methanol (88/12, v/v, pH 2.6) at a flow rate of 0.7ml/min. The main advantage of the developed method is that the analysis time of only 3min, which is about three to ten times shorter than in other reported HPLC methods. The developed method was validated using a matrix-comprehensive in-house validation strategy. The matrix effect of LC–MS/MS analysis was also investigated. Results are presented from the successful application of the developed method to an incurred pork meat certified reference material and to incur porcine plasmas in a proficiency test in year 2011.
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
Ádám Tölgyesi, Virender K. Sharma, Szabolcs Fekete, Jenő Fekete, Andrea Simon, Szilvia Farkas
A rapid liquid chromatography–tandem mass spectrometric (LC–MS/MS) method was developed to identify and to quantify nitroimidazoles, metronidazole (MNZ), ronidazole (RNZ) and dimetridazole (DMZ) and their corresponding hydroxy metabolites, MNZ-OH and 2-hydroxymethyl-1-methyl-5-nitroimidazole (HMNNI) in plasma, milk, muscle, egg, honey and feed samples. The same sample clean-up procedure including a novel solid-phase extraction (SPE) on polymeric Strata-SDB cartridges was used for each matrix. The analytes were separated on Kinetex XB C-18 core–shell type HPLC column using isocratic elution mode with a mobile phase containing 0.1% formic acid in water/methanol (88/12, v/v, pH 2.6) at a flow rate of 0.7ml/min. The main advantage of the developed method is that the analysis time of only 3min, which is about three to ten times shorter than in other reported HPLC methods. The developed method was validated using a matrix-comprehensive in-house validation strategy. The matrix effect of LC–MS/MS analysis was also investigated. Results are presented from the successful application of the developed method to an incurred pork meat certified reference material and to incur porcine plasmas in a proficiency test in year 2011.
Development and validation of non-aqueous capillary electrophoresis methods to analyze boronic esters and acids
04 April 2012,
10:36:45
Publication year:
2012
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
Mindy B. Forst, Anne M. Warner
Boronic esters and acids are potential intermediates in the manufacture of many active pharmaceutical ingredients (API). Accurate quantitation of the intermediate is necessary to assure the stoichiometry of the reaction. The analysis of these compounds is challenging due to their labile nature. For example, the boronic ester can hydrolyze to the acid during storage, when exposed to moisture in the air, during sample preparation and analysis, and thus give erroneous ester results. Traditional analytical techniques like gas chromatography (GC), normal phase chromatography (NPLC), hydrophilic interaction chromatography (HILIC), and reversed phase liquid chromatography (RPLC) have been utilized but with noted limitations such as poor peak shape, variation in retention times, and evidence of hydrolysis. All of these limitations impact accurate quantitation needed for selected situations. For the proprietary boronic ester evaluated here, these traditional techniques were insufficient for the accurate determination of assay and residual boronic acid. Non-aqueous capillary electrophoresis (NACE) is an accurate quantitative technique that can be used to analyze boronic esters and their corresponding acids without the limitations noted for traditional analytical techniques. The present study describes the development of methodology for the determination of the potency of a proprietary boronic ester as well as methodology for the determination of residual boronic acid in the ester. In addition, nine model boronic ester and acid pairs with a range in polarity, based on the electronic properties of the attached side group, were tested to evaluate and demonstrate the general applicability of these conditions. Under the conditions used for potency, all ten pairs had a resolution between the boronic ester and acid of greater than 1.5, acceptable peak shape for the boronic ester (tailing factor of less than 2.0), and a run time of less than 3min. In addition, this work describes the development of methodology to determine residual levels of boronic acids in the corresponding boronic ester. Using the ten boronic ester and acid pairs, eight of the ten pairs were shown to have acceptable sensitivity (S/N of 10 or better at 0.5%) and spike recoveries (within the range of 80–120%). The potential for hydrolysis during analysis was also addressed by using a subset of the ten boronic ester and acid pairs and spiking water into the diluent. There was no observed conversion of the ester to the acid. The lack of hydrolysis during analysis and the high success in separating and validating these methods for the boronic ester and acid pairs supports the utility of NACE as a technique for the analysis of boronic esters and acids.
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
Mindy B. Forst, Anne M. Warner
Boronic esters and acids are potential intermediates in the manufacture of many active pharmaceutical ingredients (API). Accurate quantitation of the intermediate is necessary to assure the stoichiometry of the reaction. The analysis of these compounds is challenging due to their labile nature. For example, the boronic ester can hydrolyze to the acid during storage, when exposed to moisture in the air, during sample preparation and analysis, and thus give erroneous ester results. Traditional analytical techniques like gas chromatography (GC), normal phase chromatography (NPLC), hydrophilic interaction chromatography (HILIC), and reversed phase liquid chromatography (RPLC) have been utilized but with noted limitations such as poor peak shape, variation in retention times, and evidence of hydrolysis. All of these limitations impact accurate quantitation needed for selected situations. For the proprietary boronic ester evaluated here, these traditional techniques were insufficient for the accurate determination of assay and residual boronic acid. Non-aqueous capillary electrophoresis (NACE) is an accurate quantitative technique that can be used to analyze boronic esters and their corresponding acids without the limitations noted for traditional analytical techniques. The present study describes the development of methodology for the determination of the potency of a proprietary boronic ester as well as methodology for the determination of residual boronic acid in the ester. In addition, nine model boronic ester and acid pairs with a range in polarity, based on the electronic properties of the attached side group, were tested to evaluate and demonstrate the general applicability of these conditions. Under the conditions used for potency, all ten pairs had a resolution between the boronic ester and acid of greater than 1.5, acceptable peak shape for the boronic ester (tailing factor of less than 2.0), and a run time of less than 3min. In addition, this work describes the development of methodology to determine residual levels of boronic acids in the corresponding boronic ester. Using the ten boronic ester and acid pairs, eight of the ten pairs were shown to have acceptable sensitivity (S/N of 10 or better at 0.5%) and spike recoveries (within the range of 80–120%). The potential for hydrolysis during analysis was also addressed by using a subset of the ten boronic ester and acid pairs and spiking water into the diluent. There was no observed conversion of the ester to the acid. The lack of hydrolysis during analysis and the high success in separating and validating these methods for the boronic ester and acid pairs supports the utility of NACE as a technique for the analysis of boronic esters and acids.
The effects of dynamic changes of malonyl ginsenosides on evaluation and quality control of Panax ginseng C.A. Meyer
04 April 2012,
10:36:45
Publication year:
2012
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
Zhi Liu, Yu Li, Xiang Li, Chang-Chun Ruan, Li-Juan Wang, Guang-Zhi Sun
To clarify the effects of malonyl ginsenosides (MGR) on evaluation and quality control of Panax ginseng, the contents of neutral and malonyl ginsenosides from P. ginseng were examined by high-performance liquid chromatography equipped with UV-VIS detector (HPLC-UV) during extraction, processing and storage. Several solvents, including water, ethanol, methanol, and n-butanol were used in the cold-soaked extraction (CSE). Among the four extraction solvents, methanol was found to be the most efficient. CSE was compared with other extraction methods such as Soxhlet extraction (SE), heat reflux extraction (HRE), ultrasonic-assisted extraction (UAE), and microwave-assisted extraction (MAE). The content of MGR showed significant differences, higher in CSE and UAE; lower in MAE and HRE; no MGR could be detected after SE. However, the total contents of neutral and malonyl ginsenosides were not different. Meanwhile, white ginseng, stored at 25°C in air of low humidity, showed a marked decrease in the concentration of MGR from 1.19% to 0.63% but with an increase in the neutral ginsenosides from 1.12% to 1.53% after 0–9-month storage. The results indicated that MGR changed dynamically in P. ginseng with different extraction solvents, extraction methods and increasing storage time. The total ginsenosides was not only underestimated but also determined imprecisely by ignoring malonyl ginsenosides. On the basis of our results, we suggest that malonyl ginsenosides should be transformed into the corresponding neutral ginsenosides during sample preparation for quality control and evaluation of P. ginseng. Then the content of six neutral ginsenosides in samples was used as the true level of total ginsenosides. The results reported here might provide useful information for accurate evaluation and quality control of P. ginseng.
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
Zhi Liu, Yu Li, Xiang Li, Chang-Chun Ruan, Li-Juan Wang, Guang-Zhi Sun
To clarify the effects of malonyl ginsenosides (MGR) on evaluation and quality control of Panax ginseng, the contents of neutral and malonyl ginsenosides from P. ginseng were examined by high-performance liquid chromatography equipped with UV-VIS detector (HPLC-UV) during extraction, processing and storage. Several solvents, including water, ethanol, methanol, and n-butanol were used in the cold-soaked extraction (CSE). Among the four extraction solvents, methanol was found to be the most efficient. CSE was compared with other extraction methods such as Soxhlet extraction (SE), heat reflux extraction (HRE), ultrasonic-assisted extraction (UAE), and microwave-assisted extraction (MAE). The content of MGR showed significant differences, higher in CSE and UAE; lower in MAE and HRE; no MGR could be detected after SE. However, the total contents of neutral and malonyl ginsenosides were not different. Meanwhile, white ginseng, stored at 25°C in air of low humidity, showed a marked decrease in the concentration of MGR from 1.19% to 0.63% but with an increase in the neutral ginsenosides from 1.12% to 1.53% after 0–9-month storage. The results indicated that MGR changed dynamically in P. ginseng with different extraction solvents, extraction methods and increasing storage time. The total ginsenosides was not only underestimated but also determined imprecisely by ignoring malonyl ginsenosides. On the basis of our results, we suggest that malonyl ginsenosides should be transformed into the corresponding neutral ginsenosides during sample preparation for quality control and evaluation of P. ginseng. Then the content of six neutral ginsenosides in samples was used as the true level of total ginsenosides. The results reported here might provide useful information for accurate evaluation and quality control of P. ginseng.
Characterization and identification of baccharane glycosides in Impatientis Semen by rapid-resolution liquid chromatography with electrospray ionization quadrupole time-of-flight tandem mass spectrometry
04 April 2012,
10:36:45
Publication year:
2012
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
Yu Fu, Wen Gao, Jun-jie Yu, Jun Chen, Hui-jun Li, Ping Li
Baccharane glycosides represent a group of rare saponins in plant kingdom and have been regarded as chemical marker for quality control of Impatientis Semen. Based on the structural skeleton, the baccharane glycosides were classified into three types: hosenkol A, hosenkol B and hosenkol C type. In this study, a rapid-resolution liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (RRLC/ESI-Q-TOF MS/MS) was performed to investigate the fragmentation behaviours of baccharane glycosides from Impatientis Semen. In full scan mass spectrum, the accurate determination of molecular formula was obtained by the predominant ion [M+COO]− in negative mode. In the MS/MS spectrum, fragmentation reactions of the [M+H]+ acquired in positive mode were recorded to provide abundant structural information on the aglycone and glycosyl moieties. The characteristic ion for hosenkol A and hosenkol B type glycosides was at m/z 399, while for hosenkol C type glycosides the diagnostic ion was at m/z 381. Neutral losses of monosaccharide, disaccharide, H2O and C3H4 were observed for stepwise structural characterization. As a result, 19 compounds including 9 target saponins and 10 non-target saponins were rapidly screened out in ethanol extract of Impatientis Semen, and 5 of them were found to be novel baccharane glycosides.
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
Yu Fu, Wen Gao, Jun-jie Yu, Jun Chen, Hui-jun Li, Ping Li
Baccharane glycosides represent a group of rare saponins in plant kingdom and have been regarded as chemical marker for quality control of Impatientis Semen. Based on the structural skeleton, the baccharane glycosides were classified into three types: hosenkol A, hosenkol B and hosenkol C type. In this study, a rapid-resolution liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (RRLC/ESI-Q-TOF MS/MS) was performed to investigate the fragmentation behaviours of baccharane glycosides from Impatientis Semen. In full scan mass spectrum, the accurate determination of molecular formula was obtained by the predominant ion [M+COO]− in negative mode. In the MS/MS spectrum, fragmentation reactions of the [M+H]+ acquired in positive mode were recorded to provide abundant structural information on the aglycone and glycosyl moieties. The characteristic ion for hosenkol A and hosenkol B type glycosides was at m/z 399, while for hosenkol C type glycosides the diagnostic ion was at m/z 381. Neutral losses of monosaccharide, disaccharide, H2O and C3H4 were observed for stepwise structural characterization. As a result, 19 compounds including 9 target saponins and 10 non-target saponins were rapidly screened out in ethanol extract of Impatientis Semen, and 5 of them were found to be novel baccharane glycosides.
Analysis of cycloserine and related compounds using aqueous normal phase chromatography/mass spectrometry
04 April 2012,
10:36:45
Publication year:
2012
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
Joseph J. Pesek, Maria T. Matyska, Andy Dang
A new approach is evaluated for the analysis of cycloserine, a strongly hydrophilic drug. The method utilized is aqueous normal phase chromatography with a silica hydride-based stationary phase and mass spectrometry for detection. The samples are analyzed to determine the number of components and they are identified when possible. In addition, the composition change is monitored with respect to time and sample solvent. Analyses using both gradient and isocratic conditions are presented. The repeatability of inter- and intraday analyses is also determined.
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
Joseph J. Pesek, Maria T. Matyska, Andy Dang
A new approach is evaluated for the analysis of cycloserine, a strongly hydrophilic drug. The method utilized is aqueous normal phase chromatography with a silica hydride-based stationary phase and mass spectrometry for detection. The samples are analyzed to determine the number of components and they are identified when possible. In addition, the composition change is monitored with respect to time and sample solvent. Analyses using both gradient and isocratic conditions are presented. The repeatability of inter- and intraday analyses is also determined.
Comparative determination of sibutramine as an adulterant in natural slimming products by HPLC and HPTLC densitometry
04 April 2012,
10:36:45
Publication year:
2012
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
Etil Ariburnu, Mehmet Fazli Uludag, Huseyin Yalcinkaya, Erdem Yesilada
A new validated method for the identification and quantification of the sibutramine was developed by HPTLC-densitometry at 225nm and advantages and disadvantages compared with HPLC-FLD at 225nm emission and 316nm excitation. Both methods were applied to the analysis of three natural slimming products in the market for the quantitative analysis of illegally added sibutramine. HPTLC separations were performed on (20cm×10cm) glass HPTLC plates coated with silica gel 60 F 254 using a mobile phase, n-hexane–acetone–ammonia (10:1:0.1, v/v/v). For HPLC analysis, a phenyl column (5.0μm, 150mm×4.6mm, i.d.) and an isocratic mobile phase of acetonitrile–water–formic acid (pH 3.0; 0.19M) (45:55:0.78, v/v/v) was used. The calibration curve area versus concentration was found to be linear in the range of 250–2000ng/spot−1 and 5–200μg/ml for HPTLC and HPLC, respectively. Both methods were validated for accuracy, precision, linearity, selectivity, recovery and short term stability. As a conclusion, these methods were found to be useful for the routine analysis of illegally added sibutramine in the marketed products.
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
Etil Ariburnu, Mehmet Fazli Uludag, Huseyin Yalcinkaya, Erdem Yesilada
A new validated method for the identification and quantification of the sibutramine was developed by HPTLC-densitometry at 225nm and advantages and disadvantages compared with HPLC-FLD at 225nm emission and 316nm excitation. Both methods were applied to the analysis of three natural slimming products in the market for the quantitative analysis of illegally added sibutramine. HPTLC separations were performed on (20cm×10cm) glass HPTLC plates coated with silica gel 60 F 254 using a mobile phase, n-hexane–acetone–ammonia (10:1:0.1, v/v/v). For HPLC analysis, a phenyl column (5.0μm, 150mm×4.6mm, i.d.) and an isocratic mobile phase of acetonitrile–water–formic acid (pH 3.0; 0.19M) (45:55:0.78, v/v/v) was used. The calibration curve area versus concentration was found to be linear in the range of 250–2000ng/spot−1 and 5–200μg/ml for HPTLC and HPLC, respectively. Both methods were validated for accuracy, precision, linearity, selectivity, recovery and short term stability. As a conclusion, these methods were found to be useful for the routine analysis of illegally added sibutramine in the marketed products.
Risk analysis of analytical validations by probabilistic modification of FMEA
04 April 2012,
10:36:45
Publication year:
2012
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
D.M. Barends, M.T. Oldenhof, M.J. Vredenbregt, M.J. Nauta
Risk analysis is a valuable addition to validation of an analytical chemistry process, enabling not only detecting technical risks, but also risks related to human failures. Failure Mode and Effect Analysis (FMEA) can be applied, using a categorical risk scoring of the occurrence, detection and severity of failure modes, and calculating the Risk Priority Number (RPN) to select failure modes for correction. We propose a probabilistic modification of FMEA, replacing the categorical scoring of occurrence and detection by their estimated relative frequency and maintaining the categorical scoring of severity. In an example, the results of traditional FMEA of a Near Infrared (NIR) analytical procedure used for the screening of suspected counterfeited tablets are re-interpretated by this probabilistic modification of FMEA. Using this probabilistic modification of FMEA, the frequency of occurrence of undetected failure mode(s) can be estimated quantitatively, for each individual failure mode, for a set of failure modes, and the full analytical procedure.
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
D.M. Barends, M.T. Oldenhof, M.J. Vredenbregt, M.J. Nauta
Risk analysis is a valuable addition to validation of an analytical chemistry process, enabling not only detecting technical risks, but also risks related to human failures. Failure Mode and Effect Analysis (FMEA) can be applied, using a categorical risk scoring of the occurrence, detection and severity of failure modes, and calculating the Risk Priority Number (RPN) to select failure modes for correction. We propose a probabilistic modification of FMEA, replacing the categorical scoring of occurrence and detection by their estimated relative frequency and maintaining the categorical scoring of severity. In an example, the results of traditional FMEA of a Near Infrared (NIR) analytical procedure used for the screening of suspected counterfeited tablets are re-interpretated by this probabilistic modification of FMEA. Using this probabilistic modification of FMEA, the frequency of occurrence of undetected failure mode(s) can be estimated quantitatively, for each individual failure mode, for a set of failure modes, and the full analytical procedure.
Importance of retention data from affinity and reverse-phase high-performance liquid chromatography on antitumor activity prediction of imidazoacridinones using QSAR strategy
04 April 2012,
10:36:45
Publication year:
2012
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
Marcin Koba, Tomasz Bączek, Michał Piotr Marszałł
Quantitative structure–activity relationships (QSAR) studies for prediction of cytotoxic and antitumor activity of imidazoacridinones (IA) based on experimentally obtained high-performance liquid chromatography (HPLC) retention data and calculated parameters using computational (molecular modeling) medicinal chemistry methods were proposed. The RP-HPLC and affinity-HPLC chromatographic techniques with four diversified HPLC systems applying columns with octadecylsilanes (C18), phosphatidylcholine (IAM), as well as α1-glycoprotein (AGP) and albumin (HSA) were used for the determination of the retention constants log k and log k w which characterize lipophilicity and protein affinity of IA. Moreover, molecular modeling studies were performed using HyperChem and Dragon software's, and structural descriptors were calculated and subsequently used. The QSAR equations using multiple linear regression (MLR) analysis method were derived which indicated that in vivo antileukemia activity of IA depends on cytotoxic activity against leukemia cells, whereas this cytotoxic activity depends on log k and log k w parameters obtained on all HPLC systems. Moreover, the QSRR equations were derived and indicated that log k and log k w parameters depend on calculated non-empirical structural parameters. The predictive power of obtained QSAR and QSRR equations allowed the prediction of cytotoxic and antitumor activity of IA and also their HPLC retention parameters. Finally, the equations can be used for prediction of antileukemia activity of IA without the necessity of carrying out experimental measurements.
Source:Journal of Pharmaceutical and Biomedical Analysis, Volumes 64–65
Marcin Koba, Tomasz Bączek, Michał Piotr Marszałł
Quantitative structure–activity relationships (QSAR) studies for prediction of cytotoxic and antitumor activity of imidazoacridinones (IA) based on experimentally obtained high-performance liquid chromatography (HPLC) retention data and calculated parameters using computational (molecular modeling) medicinal chemistry methods were proposed. The RP-HPLC and affinity-HPLC chromatographic techniques with four diversified HPLC systems applying columns with octadecylsilanes (C18), phosphatidylcholine (IAM), as well as α1-glycoprotein (AGP) and albumin (HSA) were used for the determination of the retention constants log k and log k w which characterize lipophilicity and protein affinity of IA. Moreover, molecular modeling studies were performed using HyperChem and Dragon software's, and structural descriptors were calculated and subsequently used. The QSAR equations using multiple linear regression (MLR) analysis method were derived which indicated that in vivo antileukemia activity of IA depends on cytotoxic activity against leukemia cells, whereas this cytotoxic activity depends on log k and log k w parameters obtained on all HPLC systems. Moreover, the QSRR equations were derived and indicated that log k and log k w parameters depend on calculated non-empirical structural parameters. The predictive power of obtained QSAR and QSRR equations allowed the prediction of cytotoxic and antitumor activity of IA and also their HPLC retention parameters. Finally, the equations can be used for prediction of antileukemia activity of IA without the necessity of carrying out experimental measurements.
No comments:
Post a Comment