Analysis of Forty-Two Psychoactive Substances in a Single Hair by Micro-Segmental Technique / 法医学杂志

OBJECTIVES@#To establish an LC-MS/MS method based on single hair micro-segmental technique, and verify the detection of 42 psychoactive substances in 0.4 mm hair segments.@*METHODS@#Each piece of single hair was cut into 0.4 mm segments and extracted by sonication and the segments were immersed in dithiothreitol-containing extraction medium. Mobile phase A was the aqueous solution containing 20 mmol/L ammonium acetate, 0.1% formic acid, and 5% acetonitrile. Mobile phase B was acetonitrile. An electrospray ionization source in positive ion mode was used for data acquisition in multiple reaction monitoring (MRM) mode.@*RESULTS@#The 42 psychoactive substances in hair had a good linear relationship within their respective linear ranges (r>0.99), the limits of detection were 0.2-10 pg/mm, the limits of quantification were 0.5-20 pg/mm, the intra-day and inter-day precisions were 1.5%-12.7%, the intra-day and inter-day accuracies were 86.5%-109.2%, the recovery rates were 68.1%-98.2%, and the matrix effects were 71.3%-111.7%. The method was applied to hair samples collected from one volunteer at 28 d after a single dose of zolpidem, with zolpidem detected in 5 hairs was 1.08-1.60 cm near the root tip, and the concentration range was 0.62-20.5 pg/mm.@*CONCLUSIONS@#The micro-segmental technique of single hair analysis can be applied to the investigation of drug-facilitated sexual assault cases.

UPLC-MS/MS Method for Detection of Etomidate and Its Metabolite Etomidate Acid Quantity in Blood / 法医学杂志

OBJECTIVES@#To establish a method for the simultaneous quantitative analysis of etomidate and its metabolite etomidate acid in blood, and to discuss its application value in actual cases.@*METHODS@#Acetonitrile precipitate protein method was used, and C18 column was selected. Gradient elution was performed with acetonitrile and 5 mmol/L ammonium acetate within 6 min. Electrospray ionization source in positive ion mode was used. The internal standard etomidate acid-d5 was obtained by etomidate-d5 alkaline hydrolysis reaction. Ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used for quantitative analysis. The methodological verification was conducted.@*RESULTS@#Etomidate and etomidate acid in blood showed good linear relationship in the quantitative linear range (r>0.999), with the lower limit of quantification was 2.5 ng/mL and 7.5 ng/mL, respectively. The accuracy, precision, recovery rate, and matrix effect of the method met the professional verification standards. The practical application results showed that etomidate and etomidate acid could be detected in the blood of the abusers, and their mass concentrations ranged from 17.24 to 379.93 ng/mL.@*CONCLUSIONS@#The method established in this study can simultaneously quantify etomidate and etomidate acid in blood, which is simple and convenient to operate with accuracy. It can meet the detection needs of actual cases and provide technical support for law enforcement to crack down on etomidate abuse.

Rapid Determination of Bucinnazine in Blood by UPLC-MS/MS / 法医学杂志

OBJECTIVES@#To establish a rapid method for the analysis of bucinnazine in blood by UPLC-MS/MS and to apply the method to the practical case.@*METHODS@#After the internal standard was added to blood, the protein was precipitated with 900 μL mixed solution (Vacetonitrile∶Vwater=8∶2). After vortex and centrifugation, the protein was measured through 0.22 μm filter membrane. The separation was performed on C18 chromatography column, with acetonitrile and 5 mmol/L ammonium acetate containing 0.1% formic acid aqueous as mobile phase gradient elution at the flow rate of 0.4 mL/min. Multiple reaction monitoring scan was performed in electrospray positive ion mode, quantitative measurement was performed by internal standard method, and methodological verification was carried out.@*RESULTS@#The linear relationship of bucinnazine in blood was good in the range of 0.5-200 μg/L, the correlation coefficient (r) was 0.999 7, the limit of detection was 0.1 μg/L, the limit of quantitation was 0.5 μg/L, and the recovery was 78.3%-83.8% at 1, 10 and 100 μg/L mass concentration levels. The matrix effect was 69.4%-73.8%, the intra-day precision was 1.9%-2.8%, and the inter-day precision was 2.8%-3.2%, the accuracy was 3.1%-3.5%. The stability test results of 1 and 100 μg/L mass concentrations at -25 ℃ showed that the accuracy (bias) of 10 d was less than 4.5%.@*CONCLUSIONS@#This method has the advantages of simple pre-treatment process, fast sample processing speed, high sensitivity of instrument analysis, good stability of content determination and reliable identification results, and can meet the needs of case identification.

Analysis and evaluation on Paeoniae Radix Alba from different cultivars by UPLC-Q-TOF-MS and HPLC / 中国中药杂志

In this study, an established ultra-high performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry(UPLC-Q-TOF-MS) method was combined with multivariate statistical analysis to investigate the commonality and difference of main chemical components in the medicinal parts of Paeonia lactiflora from different cultivars; in addition, a high performance liquid chromatography(HPLC) method was established to simultaneously determine the content of eight active components in Paeoniae Radix Alba. Non-targeted analysis was carried out by UPLC-Q-TOF-MS on a Waters ACQUITY UPLC BEH C_(18)(2.1 mm×100 mm, 1.7 μm) column with a gradient elution of 0.1% aqueous formic acid(A)-acetonitrile(B) as the mobile phase at a flow rate of 0.2 mL·min~(-1). The column temperature was 30 ℃, and an electrospray ionization source was used to acquire mass spectrometry data in positive and negative ion modes. According to the accurate molecular weight and fragment ion information provided by multi-stage mass spectrometry and by comparison with reference substances and literature reports, thirty-six identical components were identified in Paeoniae Radix Alba from different cultivars with positive and negative ion modes. In the negative ion mode, two groups of samples were well separated; specifically, seventeen components with significant differences in content were screened and identified, and one component unique in "Bobaishao" was obtained. Quantitative analysis was conducted by high-performance liquid chromatography(HPLC) on an Agilent HC-C_(18)(4.6 mm×250 mm, 5 μm) column with a gradient elution of 0.1% aqueous phosphoric acid(A)-acetonitrile(B) as the mobile phase at a flow rate of 1.0 mL·min~(-1). The column temperature was 30 ℃ and the detection wavelength was at 230 nm. An HPLC method was developed for the simultaneous determination of eight active components(gallic acid, oxypaeoniflorin, catechin, albiflorin, paeoniflorin, galloylpaeoniflorin, 1,2,3,4,6-O-pentagalloylglucose, benzoyl-paeoniflorin) in Paeoniae Radix Albaa from different cultivars. Satisfactory linearity was achieved within the investigated linear ranges and with fine coefficients(r>0.999 0), and the methodological investigation showed that the method had good precision, repeatability and stability. The mean recoveries were 90.61% to 101.7% with RSD of 0.12% to 3.6%(n=6). UPLC-Q-OF-MS provided a rapid and efficient qualitative analytical method for the identification of the chemical components in Paeoniae Radix Alba, and the developed HPLC method was simple, rapid and accurate, which could provide a scientific basis for the evaluation of the germplasm resources and herbal quality of Paeoniae Radix Alba from different cultivars.

Determination of acetochlor and its metabolites in urine using liquid chromatography-tandem mass spectrometry / 中华劳动卫生职业病杂志

Objective: A method for the determination of acetochlor and its metabolites in urine by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was established. Methods: After cleaned-up by a HLB extraction cartridges, the urine was eluted with 1% acetic acid acetonitrile solution. The target compounds were separated by ACQUITY UPLC®HSS T3 Column (2.1 mm×100 mm×1.8 μm) by using 1% formic acid solution and acetonitrile as mobile phase with gradient elution program, and analyzed in positive electrospray ionization mode by liquid chromatography tandem mass spectrometry. Results: All the target compounds showed good linear relationships in the range of 1-50 μg/L, and the correlation coefficients (r) were higher than 0.997. The recoveries rates at three different spiked levels for all target compounds in blank matrices were 107.6%-129.1%, and the relative standard deviations (RSD) were 1.5%-9.9% (n=6) . The limits of detection and quantitation of the method were 0.04-0.11 μg/L and 0.15-0.42 μg/L, respectively, and target substances were detected in all urine samples from occupational exposure workers to acetochlor. Conclusion: This method is suitable for rapid screening and analysis of acetochlor and metabolites in urine with the advantages of accuracy, rapidity, simplicity, high sensitivity and good specificity.

Detection of Phosphatidylethanol in Whole Blood by UPLC-MS/MS / 法医学杂志

OBJECTIVES@#To establish the ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method to detect ethanol metabolites phosphatidylethanol (PEth) in whole blood.@*METHODS@#An appropriate amount of aqueous solution including 1% formic acid was added to 100 μL whole blood, the protein was precipitated with acetone, centrifuged and the supernatant was purified and enriched by using Bond Elut Certify column. The eluent was redissolved with 1/1 isopropanol/acetonitrile (v/v) solution after nitrogen blowing and then tested by UPLC-MS/MS. Selective reaction monitoring scanning was carried out in negative ionization mode, and quantitative analysis was performed by external standard method.@*RESULTS@#PEth showed a linear relationship over the concentration range of 1-160 ng/mL in whole blood (r=0.999 9) with peak area. The detection limit was 0.2 ng/mL, the quantification limit was 1 ng/mL, the recovery rate was 97.43%-103.61%, the accuracy was 0.99%-1.77%, the intra-day precision was 0.4%-2.4%, and the inter-day precision was 1.1%-3.3%, and the matrix effect was 91.00%-99.55%. PEth was not detected in the in vitro blood samples supplemented with ethanol. PEth was detected positive in three drunk driving cases, and the concentration were 195.49, 83.67 and 876.12 ng/mL, respectively.@*CONCLUSIONS@#The established method has high sensitivity and specificity and the analysis results are accurate. It is suitable for the qualitative and quantitative analysis of PEth in whole blood.

Qualidade por Design Analítico (AQbD) aplicado no desenvolvimento e otimização de métodos cromatográficos / Analytical Quality by Design (AQbD) applied in the development and optimization of chromatographic methods

O guia Q8(R2) do guia ICH descreve Qualidade por Design (QbD) como "uma abordagem sistemática para desenvolvimento farmacêutico que começa com objetivos predefinidos e enfatiza produto, entendimento e controle dos processos, baseado em dados científicos sólidos e gestão do risco da qualidade". Os métodos analíticos são considerados parte integrante do desenvolvimento farmacêutico. Assim, a Qualidade por Design Analítico (AQbD) é justificável e recomendada para obter flexibilidade regulatória, reduzir os resultados fora de especificação, obter um alto grau de robustez e um método analítico econômico. O Planejamento de Experimentos (DoE) é um conjunto de ferramentas estatísticas que inclui delineamentos de triagem e otimização, no qual os fatores são sistematicamente variados para determinar seus efeitos nas respostas, o que permite a determinação de quais fatores são os mais significantes, a identificação de qual configuração de fatores resulta em respostas otimizadas e a identificação de interações entre os fatores. As abordagens QbD e AQbD permitem a melhoria contínua ao longo do ciclo de vida do produto farmacêutico e do método analítico, inclusive para reduzir a variabilidade do produto, melhorar o desempenho do processo, reduzir resultados fora da especificação, melhorar o desempenho analítico, entre outros. O Cloridrato de Verapamil foi escolhido como molécula teste para desenvolvimento do projeto. Na primeira etapa do estudo foi realizado uma triagem com 13 fatores e 20 experimentos, utilizando o delineamento Plackett-Burman, seguiu-se para a próxima etapa com 7 fatores e 16 experimentos através do delineamento fatorial fracionado (Res.: IV). A etapa de otimização foi realizada com 3 fatores e 20 experimentos utilizando o delineamento central composto. Após todas as etapas do estudo, as seguintes condições foram consideradas ideais: Fase móvel A - Tampão formiato de amônio 10 mM pH 3,0, Fase móvel B - Amoníaco 2,0% em acetonitrila, eluição do tipo gradiente, coluna cromatográfica XSelect CSH C18 (100mm x 4,6mm x 3,5 µm), fluxo de 0,7 mL/min, volume de injeção de 2 µL para teor e 10 µL para produtos de degradação. Os métodos desenvolvidos são robustos, validados e indicativos de estabilidade

The ICH guide Q8 (R2) describes Quality by Design as "a systematic approach to pharmaceutical development that begins with predefined goals and emphasizes product, understanding and control of processes, based on solid scientific data and Quality Risk Management ". Analytical methods are considered an integral part of pharmaceutical development. Thus, the application of QbD approach to analytical method development is justifiable and a recommended strategy to attain regulatory flexibility, to reduce out-of-specification results, to achieve a high degree of robustness and a cost-effective analytical method. DoE is a set of statistical tools which include screening designs and optimization designs. In DoE approach, the controlled input factors are systematically varied to determine their effects on the output responses, which allows the determination of the most important input factors, the identification of input factors setting leading to optimized output responses, and the identification of interactions between input factors. The QbD and AQbD approach allows the continuous improvement throughout the lifecycle of pharmaceutical product and analytical method, including to reduce product variability, to improve process performance, to reduce out-of-specification results, to improve analytical performance, among others. Verapamil Hydrochloride was chosen as a test molecule for the development of the project. In the first phase of the study, a 13-factor and 20-experiment screening was performed using the Plackett-Burman design, followed by the 7-factor and 16-experiment next stage through fractional factorial design (Res .: IV). The optimization step was performed with 3 factors and 20 experiments using the composite central design. After performing all the study steps, the following conditions were considered ideal: Mobile Phase A - 10 mM ammonium formate buffer pH 3.0, Mobile Phase B - 2.0% ammonia in acetonitrile, gradient elution, column chromatographic XSelect CSH C18 (100mm x 4.6mm x 3.5µm), flow rate of 0.7ml / min, injection volume of 2µL for assay and 10µL for degradation products. The methods developed are robust, validated and stability indicating

Establishment and application of HPLC-QAMS for quality evaluation of Chuanxiong Rhizoma / 药学学报

A quantitative analysis method of multi-components with a single marker (QAMS) for simultaneous determination of six marker compounds (one from phenolic acids and five from phthalides) in Chuanxiong Rhizoma was established by applying HPLC and using butylidenephthalide as the internal reference substance. And also the feasibility and accuracy of the established method for quality evaluation and application of Chuanxiong Rhizoma were investigated and validated. The analysis was performed with the mobile phase consisting of acetonitrile - 0.2% aqueous formic acid. The flow rate was 1.0 mL . min-1 and the column temperature was maintained at 30 °C. The detection wavelengths were set at 252 nm (for ferulic acid, Z-ligustilide, and butylidenephthalide) and 266 nm (for senkyunolide I, senkyunolide A, and coniferyl ferulate), separately, and 20 µL was injected for analysis with gradient elution. The results showed that there were no significant differences observed between the HPLC-QAMS method and the external standard method (RSD <5%). The relative correction factors were credible (RSD < 5%) in changed chromatographic conditions. The established HPLC-QAMS method can be accurately used for simultaneously evaluating and controlling the quality of Chuanxiong Rhizoma with multi-components.

Simultaneous estimation of rosuvastatin and amlodipine in pharmaceutical formulations using stability indicating HPLC method

A viable cost-effective and isocratic approach employing C-18 column (250 mm × 4.6 mm, 5 µm) based HPLC has been utilized to separate and estimate the drugs, rosuvastatin, amlodipine and their stress induced degradation products, simultaneously in pharmaceutical formulations. Focused on ICH guideline parameters, the efficient separation of both drugs and their degradation products was achieved by optimizing a 30:70 (v/v) solvent mixture of acetonitrile and 0.1 M ammonium acetate buffer (pH 5) as mobile phase. The flow rate of the mobile phase was 1.5 mL/min and all the detections were carried out at 240 nm using UV detector. The method was linear in the concentration range of 1-200 µg/mL for rosuvastatin with 0.996 coefficient of determination value. For amlodipine, linearity was in the range of 0.5-100 µg/ml with 0.994 coefficient of determination value. Both the drugs along with their degradation products were separated in less than twenty minutes. The results of within-day and between-day precision were varied from 0.72 to 1.81% for rosuvastatin and 0.83 to 1.88% for amlodipine. The results show that this ICH validated method can be employed successfully for the routine as well as stability quantification of both the active ingredients simultaneously in pharmaceutical formulations.

Utilizou-se abordagem de viabilidade custo-efetividade e isocrática, baseada em CLAE, empregando coluna C-18 (250 mm x 4,6 mm, 5 µm) para separar e avaliar os fármacos, rosuvastatina, anlodipino e seus produtos de degradação induzida por estresse, simultaneamente, em formulações farmacêuticas. Focada nos parâmetros das diretrizes da ICH, a separação eficiente de ambos os fármacos e de seus produtos de degradação foi obtida por meio da otimização da fase móvel com mistura de solventes 30:70 (v/v), respectivamente, acetonitrila e tampão acetato de amônio O,1 M (pH 5). A velocidade de fluxo da fase móvel foi de 1,5 mL/min e todas as detecções foram realizadas em 240 nm, utilizando detector de UV. O método foi linear no intervalo de concentração de 1-200 µg/mL para a rosuvastatina com coeficiente de determinação 0,996. Para o anlodipino, a linearidade ficou na faixa de 0.5-100 µg/mL, com coeficiente de determinação 0,994. Ambos os fármacos, junto com seus produtos de degradação, foram separados em menos de vinte minutos. Os resultados de precisão intra-dia e inter-dia variaram de 0,72 a 1,81% para a rosuvastatina e de 0,83 a 1,88%, para o anlodipino. Os resultados mostram que este método validado pelo ICH pode ser empregado com sucesso tanto para a rotina quanto para a quantificação simultânea da estabilidade de ambos os ingredientes ativos em formulações farmacêuticas.

Rapid simultaneous determination of ten major flavonoids in Tetrastigma hemsleyanum by UPLC-MS/MS / 药学学报

In this study, a rapid and sensitive analytical method was developed for the determination of 10 major compounds (procyanidin B1, catechin, procyanidin B2, rutin, isoquercitrin, kaempferol-3-O-rutinoside, astragalin, quercitrin, quercetin, and kaempferol) in Tetrastigma hemsleyanum by using ultra-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (UPLC-MS/MS) in multiple-reaction monitoring (MRM) mode. UPLC-MS/MS assay with negative ion mode was performed on a Waters CORTECS C18 (2.1 mm x 100 mm, 1.6 μm) with the mobile phase consisting of acetonitrile (A) and 0.1% aqueous formic acid (B) in gradient elution at a flow rate of 0.25 mL · min(-1) and the column temperature was set at 45 °C. Under the optimized chromatographic conditions, good separation for 10 target compounds were obtained including chiral isomer procyanidins B1 and B2 were completely separated within 8.5 min. Satisfactory linearity was achieved with wide linear range and fine determination coefficient (r > 0.996 6), the overall recoveries were ranged from 95.44%-110.40% with the RSD ranging from 2.37%-8.69%. It is the first report about simultaneous analysis of 10 major flavonoids components in Tetrastigma hemsleyanum by using UPLC-MS/MS method, which affords highly sensitive, specific, speedy and efficient method for quality control of Tetrastigma hemsleyanum

Qualitative and quantitative analysis of major constituents in Tetrastigma hemsleyanum by HPLC-Q-TOF-MS and UPLC-QqQ-MS / 中国中药杂志

A qualitative analytical method of liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (HPLC-Q-TOF-MS) was developed for identification of multi-constituents and an analytical method was developed for simultaneously determining 4 major compounds (rutin, isoquercitrin, kaempferol-3-0-rutinoside, and astragalin) in Tetrastigma hemsleyanum Diels et Gilg. The HPLC-Q-TOF-MS assay was performed on a Welch Ultimate XB-C18 column (4.6 mm x 150 mm, 5 microm) with the mobile phase consisting of acetonitrile (A) and water containing 0.1% Formic acid (B) in gradient mode at a flow rate of 0.8 mL x min(-1). The column temperature was at 30 degrees C, and negative ion mode was used for TOF-MS. The UPLC-QqQ-MS assay was performed on a Waters CORTECS C18 (2.1 mm x 100 mm, 1.6 microm) with the mobile phase consisting of acetonitrile (A) and water containing 0.1% formic acid (B) in gradient mode at a flow rate of 0.25 mL x min(-1). The column temperature was at 45 degrees C, and MRM mode was used for QqQ-MS. Based on the retention time and MS spectra, 24 compounds were identified or tentatively characterized by comparing with reference substances or literatures. For quantitative the linear range of 4 detected compounds were good (r > 0.9966), and the overall recoveries ranged from 98.27% to 101.58%, with the RSD ranging from 3.15% to 5.88%. The results indicated that new approach conbined HPLC-Q-TOF-MS and UPLC-QqQ-MS was applicable in qualitative and quantitative quality control of Tetrastigma hemsleyanum.

Determination of equilibrium solubility and n-octanol/water partition coefficient of pulchinenosiden D by HPLC / 中国中药杂志

<p><b>OBJECTIVE</b>To determine the equilibrium solubility of pulchinenosiden D in different solvents and its n-octanol/water partition coefficients.</p><p><b>METHOD</b>Combining shaking flask method and high performance liquid chromatography (HPLC) to detect the n-octanol/water partition coefficients of pulchinenosiden D, the equilibrium solubility of pulchinenosiden D in six organic solvents and different pH buffer solution were determined by HPLC analysis.</p><p><b>RESULT</b>n-Octanol/water partition coefficients of pulchinenosiden D in different pH were greater than zero, the equilibrium solubility of pulchinenosiden D was increased with increase the pH of the buffer solution. The maximum equilibrium solubility of pulchinenosiden D was 255.89 g x L(-1) in methanol, and minimum equilibrium solubility of pulchinenosiden D was 0.20 g x L(-1) in acetonitrile.</p><p><b>CONCLUSION</b>Under gastrointestinal physiological conditions, pulchinenosiden D exists in molecular state and it has good absorption but poor water-solubility, so increasing the dissolution rate of pulchinenosiden D may enhance its bioavailability.</p>

Quantitative determination of 5 active ingredients in different harvest periods of Ligusticum chuanxiong by HPLC / 中国中药杂志

A simple and quick method is described for the determination of ferulic acid, senkyunolide I, senkyunolide H, senkyunolide A and ligustilide in rhizomes of Ligusticum chuanxiong. The 5 active ingredients in the sample was extracted using 40% ethanol and analyzed by reversed-phase high performance liquid chromatography (HPLC). Chromatography separation was performed using Agilent 1100 series HPLC system with a Symmetry C18 column and gradient elution with a mixture of three solvents : solvent A, acetonitrile, solvent B, methanol and solvent C, 1% aqueous acetic acid, 0 min to 5 min A: B: C 20: 40: 40, 5 min to 30 min A: B: C 60 to 100 : 0 : 40 to 0. The effluent was monitored using a VWD detector set at 321 nm (0-4.3 min) and 275 nm (4.31-30 min). The flow rate was set at 1 mL x min(-1) and the injection volume was 10 microL. The column temperature was maintained at 35 degrees C. The calibration curve was linear (r > or = 0.99) over the tested ranges. The average recovery was 94.44%-103.1% (n = 6). The method has been successfully applied to the analysis in different harvest periods of L. chuanxiong samples. In this paper, single-factor randomized block design to study the 5 components content of L. chuanxiong on ten collecting stages. For the L. chuanxiong collected from April 15th to May 30rd, the content of 5 ingredients increased primarily, and then decreased. Determine the appropriate harvest time has important significance to the promotion of the quality of L. chuanxiong.

RP-HPLC analytical method development and optimization for quantification of donepezil hydrochloride in orally disintegrating tablet

An easy, fast and validated RV-HPLC method was invented to quantify donepezil hydrochloride in drug solution and orally disintegrating tablet. The separation was carried out using reversed phase C-18 column [Agilent Eclipse Plus C-18] with UV detection at 268 nm. Method optimization was tested using various composition of organic solvent. The mobile phase comprised of phosphate buffer [0.01M], methanol and acetonitrile [50:30:20, v/v] adjusted to pH 2.7 with phosphoric acid [80%] was found as the optimum mobile phase. The method showed intraday precision and accuracy in the range of 0.24% to -1.83% and -1.83% to 1.99% respectively, while interday precision and accuracy ranged between 1.41% to 1.81% and 0.11% to 1.90% respectively. The standard calibration curve was linear from 0.125 micro g/mL to 16 micro g/mL, with correlation coefficient of 0.9997 +/- 0.00016. The drug solution was stable under room temperature at least for 6 hours. System suitability studies were done. The average plate count was > 2000, tailing factor <1, and capacity factor of 3.30. The retention time was 5.6 min. The HPLC method was used to assay donepezil hydrochloride in tablet and dissolution study of in-house manufactured donepezil orally disintegrating tablet and original Aricept

Mechanisms of hepatotoxicity of chloroacetonitrile: an end product of water chlorination

Chloroacetonitrile is a disinfectant by-product of chlorination of drinking water and is considered as a directacting mutagenic and carcinogenic agent. Time-course and dose-response studies were performed to examine the mechanism of chloroacetonitrile-induced hepatotoxicity. In the time-course study, animals were scarified at 2, 4, 6 and 12 h after a single oral dose of chloroacetonitrile [38 mg/kg, p.o.]. In the dose-response study, rats were scarified at 2 h after a single oral dose of chloroacetonitrile [9, 19, 38, and 76 mg/kg]. In the time-course study chloroacetonitrile induced a significant decrease of hepatic glutathione, and activities of glutathione-S-transferase, glutathione proxidase and superoxide dismutase accompanied with an increase of hepatic malondialdehyde, plasma cytokines [IL-6 and 10 and TNF-alpha], serum aminotransferases and total bilirubin after 2 h of administration. Maximal alteration of the estimated parameters was observed at 4 h and returned to normal value at 6 h and/or 12 h after chloroacetonitrile treatment. Moreover, the alterations in oxidant, antioxidant parameters, inflammatory cytokines and the liver function tests were dose dependant. Histopathological findings supported the biochemical results. These data indicate that the mechanism of chloroacetonitrile-induced hepatotoxicity may be mediated through depletion of antioxidants, induction of oxidative stress and inflammatory cytokines

Development and Validation of a Liquid Chromatography-Tandem Mass Spectrometry Method for the Determination of epsilon-Acetamidocaproic Acid in Rat Plasma

A simple and rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantification of epsilon-acetamidocaproic acid (AACA), the primary metabolite of zinc acexamate (ZAC), in rat plasma by using normetanephrine as an internal standard. Sample preparation involved protein precipitation using methanol. Separation was achieved on a Gemini-NX C18 column (150 mm x 2.0 mm, i.d., 3 microm particle size) using a mixture of 0.1% formic acid-water : acetonitrile (80 : 20, v/v) as the mobile phase at a flow rate of 200 microl/min. Quantification was performed on a triple quadrupole mass spectrometer employing electrospray ionization and operating in multiple reaction monitoring (MRM) and positive ion mode. The total chromatographic run time was 4.0 min, and the calibration curves of AACA were linear over the concentration range of 20~5000 ng/ml in rat plasma. The coefficient of variation and relative error at four QC levels were ranged from 1.0% to 5.8% and from -8.4% to 6.6%, respectively. The present method was successfully applied for estimating the pharmacokinetic parameters of AACA following intravenous or oral administration of ZAC to rats.

Methylparaben concentration in commercial Brazilian local anesthetics solutions

OBJECTIVE: To detect the presence and concentration of methylparaben in cartridges of commercial Brazilian local anesthetics. MATERIAL AND METHODS: Twelve commercial brands (4 in glass and 8 in plastic cartridges) of local anesthetic solutions for use in dentistry were purchased from the Brazilian market and analyzed. Different lots of the commercial brands were obtained in different Brazilian cities (Piracicaba, Campinas and São Paulo). Separation was performed using high performance liquid chromatography (HPLC) with UV-Vis detector. The mobile phase used was acetonitrile:water (75:25 - v/v), pH 4.5, adjusted with acetic acid at a flow rate of 1.0 ml.min-1. RESULTS: When detected in the solutions, the methylparaben concentration ranged from 0.01% (m/v) to 0.16% (m/v). One glass and all plastic cartridges presented methylparaben. CONCLUSION: 1. Methylparaben concentration varied among solutions from different manufacturers, and it was not indicated in the drug package inserts; 2. Since the presence of methylparaben in dental anesthetics is not regulated by the Brazilian National Health Surveillance Agency (ANVISA) and this substance could cause allergic reactions, it is important to alert dentists about its possible presence.

UPLC characteristic chromatographic profile of Poria / 中国中药杂志

To establish a UPLC characteristic chromatographic profile analysis method to quickly assess Poria quality and provide basis fro controlling Poria quality. The UPLC characteristic chromatographic profiles of fifteen batches of Poria were determined by ACQUITY UPLC, with HSS T3 Column (2.1 mm x 100 mm, 1.8 microm) eluted with the mobile phases of water containing 0.05% phosphoric acid and acetonitrile in gradient mode. The detection wavelength was set at 243 nm. The common mode of the UPLC characteristic chromatographic profile was set up. There were 20 common peaks, seven of which were identified, and the similar degrees of the fifteen samples to the common mode were between 0.787 and 0.974. The method was so time-saving that it can be used for the quality control of Poria.

Measurement of acetonitrile in blood and urine by head-space gas chromatography / 法医学杂志

OBJECTIVE@#To establish the method for measurement of acetonitrile in blood and urine by head-space gas chromatography.@*METHODS@#DB-ALC1 (30 m x 320 microm x 1.8 microm) and DB-ALC2 (30 m x 320 microm x 1.2 microm) capillary column were used to measure the acetonitrile in blood and urine with the isopropanol as internal standard reference.@*RESULTS@#The limits of detection of acetonitrile in both blood and urine were 0.5 microg/mL, with a linear range of 5-1000 microg/mL (r = 0.999).The accuracy of this method was 93.2%-98.0%. The RSD for the intra-day and inter-day were less than 3.7%.@*CONCLUSION@#The method is capable for measurement analysis of acetonitrile in blood and urine.

Microscopic trends in methanol/water and acetonitrile/water systems

The most practical measure of therapeutic equivalence between two commercially available and generic formulation of a certain drug is to determine their in vivo bioavailability. However, for the oral dosage from that is not intended to be absorbed [e.g. orlistat], in vivo bioavailability studies are irrelevant to the achievement of the product's intended purposes. However, specific requirements for these drug products may be set in a way that they should meet acceptable in vitro standards. For this purpose, a comparative enzymatic inhibition assay of the target enzyme, pancreatic lipase, was developed to demonstrate orlistat products' pharmaceutical and potency equivalence. In this study we compared the pancreatic lipase inhibition that is achieved by two orlistat formulations: a generic product manufactured by local company [Jordan Sweden Medical Company, JOSWE] and the reference one Xenical [Registered sign] manufactured by Roche. The inhibition was expressed by the concentration of product which inhibits 50% of the activity of the pancreatic lipase enzyme [1C[50]]. The results of these studies showed that both formulations have equivalent potency that was demonstrated by in vitro studies