A highly sensitive, rapid and rugged liquid chromatography-tandem mass spectrometw （LC-ESI-MS/MS） method was developed for reliable estimation of amantadine （AMD）, an antiviral drug in human plasma. The analyte an...A highly sensitive, rapid and rugged liquid chromatography-tandem mass spectrometw （LC-ESI-MS/MS） method was developed for reliable estimation of amantadine （AMD）, an antiviral drug in human plasma. The analyte and internal standard （IS）, amantadine-d6 （AMD-d6）, were extracted from 200μL plasma by solid phase extraction on Phenomenex Strata-X-C 33 ~t cartridges. Chromatography was performed on Synergi^TM Hydro-RP C18 （150 mm×4.6 mm, 4 μm） analytical column using a mixture of acetonitrile and 10 mM ammonium formate, pH 3.0 （80：20, v/v） as the mobile phase. Detection and quantitation was done by multiple reaction monitoring in the positive ionization mode for AMD （m/z 152.1→ 135.1 ） and IS （m/z 158.0 → 141.1） on a triple quadrupole mass spectrometer. The assay was linear in the concentration range of 0.50-500 ng/mL with correlation coefficient （r^2） 〉 0.9969. The limit of detection of the method was 0.18 ng/mL The intra-batch and inter-batch precisions were 〈 5.42% and the accuracy varied from 98.47% to 105.72%. The extraction recovery of amantadine was precise and quantitative in the range of 97.89%-100.28%. IS-normalized matrix factors for amantadine varied from 0.981 to 1.012. The stability of AMD in whole blood and plasma was evaluated under different conditions. The developed method was successfully applied for a bioequivalence study with 100 mg of AMD in 32 healthy volunteers. The reproducibility of the assay was determined by reanalysis of 134 subject samples.展开更多
A highly sensitive liquid chromatography-tandem mass spectrometry（LC-MS/MS） method was developed for the determination of tadalafil（TAD） in human plasma. TAD and its deuterated internal standard（IS）, tadalafil-d...A highly sensitive liquid chromatography-tandem mass spectrometry（LC-MS/MS） method was developed for the determination of tadalafil（TAD） in human plasma. TAD and its deuterated internal standard（IS）, tadalafil-d3, were extracted from 200 mL plasma using Phenomenex Strata-X-C 33 m extraction cartridges. Chromatographic analysis was carried out on Synergi Hydro-RP C18（100 mm × 4.6 mm, 4 mm）column with a mobile phase consisting of methanol and 10 m M ammonium formate, p H 4.0（90：10, v/v）,delivered at a flow rate of 0.9 m L/min. Quantitation of the protonated analyte was done on a triple quadrupole mass spectrometer using multiple reaction monitoring via electrospray ionization. The precursor to product ions transitions monitored for TAD and TAD-d3 were m/z 390.3-268.2 and m/z393.1-271.2, respectively. The calibration curve was linear over the concentration range of 0.50–500 ng/m L with correlation coefficient, r2 Z 0.9994. Acceptable intra-batch and inter-batch precision（r3.7%） and accuracy（97.8% to 104.1%） were obtained at five concentration levels. The recovery of TAD from spiked plasma was highly precise and quantitative（98.95% to 100.61%）. Further, the effect of endogenous matrix components was minimal. TAD was found to be stable under different storage conditions in human plasma and also in whole blood samples. The validated method was successfully used to determine TAD plasma concentration in a bioequivalence study with 20 mg TAD tablets in 24 healthy volunteers. Method performance was evaluated by reanalyzing 115 study samples.展开更多
A selective, sensitive and high throughput liquid chromatography-tandem mass spectro-metry （LC-ESI-MS/MS） method has been developed for separation and quantification of metoprolol enantiomers on a chiral Lux Amylose...A selective, sensitive and high throughput liquid chromatography-tandem mass spectro-metry （LC-ESI-MS/MS） method has been developed for separation and quantification of metoprolol enantiomers on a chiral Lux Amylose-2 （250 mm＆#215;4.6 mm, 5 mm） column. Solid phase extraction of （S）-（-）- and （R）-（t）-metoprolol and rac-metoprolol-d6 as an internal standard （IS） was achieved on Lichrosep DVB HL cartridges employing 200 mL human plasma. Both the analytes were chromatographically separated with a resolution factor of 2.24 using 15 mM ammonium acetate in water, pH 5.0 and 0.1% （v/v） diethyl amine in acetonitrile （50：50, v/v） as the mobile phase within 7.0 min. The precursor-product ion transitions for the enantiomers and IS were monitored in the multiple reaction monitoring and positive ionization mode. The method was validated over the concentration range of 0.500-500 ng/mL for both the enantiomers. Matrix effect was assessed by post-column analyte infusion experiment and the mean extraction recovery was greater than 94.0% for both the enantiomers at all quality control levels. The stability of analytes was evaluated in plasma and whole blood under different storage conditions. The method was successfully applied to a clinical study in 14 healthy volunteers after oral administration of 200 mg metoprolol tablet under fasting conditions. The assay reproducibility is shown by reanalysis of 68 incurred samples. The suitability of the developed method was assessed in comparison with＆amp;nbsp;different chromatographic methods developed for stereoselective analysis of metoprolol in biological matrices.展开更多
The aim of the proposed research work was to develop and validate a simple, selective high sensitive and high-throughput assay for the simultaneous estimation of Atorvastatin and Glimepiride in human plasma using liqu...The aim of the proposed research work was to develop and validate a simple, selective high sensitive and high-throughput assay for the simultaneous estimation of Atorvastatin and Glimepiride in human plasma using liquid chromatography tandem mass spectrometry (LC-MS/MS). Atorvastatin–Glimepiride combines a competitive inhibitor of HMG-CoA reductase and a sulfonylurea anti-diabetic drug. The purpose of this study was to develop single method for Atorvastatin and Glimepiride in plasma by liquid chromatography-tandem mass spectrometry (LC-MS/MS) that would result into a simultaneous estimation of Atorvastatin and Glimepiride avoiding acid –lactone inter conversions right from sample collections to analysis on the LC-MS/MS. Sample collection procedure optimized for Atorvastatin holds good for Glimepiride, hence resulting into a simultaneous estimation of Atorvastatin and Glimepiride. Liquid-liquid extraction and liquid chromatography coupled to positive ion mode tandem mass spectrometry was used to develop the method and was validated according to US FDA guidelines. The calibration curves for two analytes were linear (R2 ≥ 0.9950, n = 4) over the concentration range of 0.2 - 30 ng/mL for Atorvastatin and 1 - 250 ng/mL for Glimepiride. Mean extraction recoveries 80.34 ± 9.43 for Atorvastatin and 88.19 ± 7.13 for Glimepiride. Intra- and inter-run mean percent accuracy was between 85% - 115% and percent imprecision was ≤15%. Stability studies revealed that Atorvastatin and Glimepiride were stable in plasma during bench top (10.5 h at room temperature), in Injector (47.5 h), at the end of three successive freeze and thaw cycles and long term at -65℃ ± 15℃ for 114 days. The method was successfully applied to the study of pharmacokinetics of Atorvastatin and Glimepiride in healthy volunteers. Simultaneous estimation of Atorvastatin and Glimepiride is cost effective, reduces analysis cycle time, enables effective utilization of resources and reduces bleeding burden on human volunteers.展开更多
A simple, precise and rapid liquid chromatography-tandem mass spectrometry （LC-MS/MS） method has been developed and validated for the simultaneous determination of oseltamivir and oseltamivir carboxylate, a neuramin...A simple, precise and rapid liquid chromatography-tandem mass spectrometry （LC-MS/MS） method has been developed and validated for the simultaneous determination of oseltamivir and oseltamivir carboxylate, a neuraminidase inhibitor, using their deuterated analogs as internal standards （ISs）. The method involved solid phase extraction of the analytes and ISs from 200 μL human plasma with no reconstitution and drying steps. The chromatographic separation was achieved on a Symmetry C18 （100 mm × 4.6 mm, 5 μm） column using 10 mM ammonium formate and acetonitrile （30：70, v/v） as the mobile phase in a run time of 2.0 min. Quantitation of analytes and ISs were done by multiple reaction monitoring on a triple quadrupole mass spectrometer in the positive ionization mode. The linearity of the method was established in the concentration range of 0.5-200 ng/mL and 2.0-800 ng/mL for oseltamivir and oseltamivir carboxylate respectively. The mean extraction recovery for oseltamivir （94.4%） and oseltamivir carboxylate （92.7%） from spiked plasma samples was consistent and reproducible. The application of this method was demonstratedby a bioequivalence study in 42 healthy Indian subjects with 75 mg oseltamivir phosphate capsules. The assay reproducibility was established by reanalysis of 151 incurred subject samples.展开更多
An accurate, sensitive and selective method is developed for determination of ergoealeiferol （vitamin D2） in human plasma using LC-MS/MS. After liquid-liquid extraction with n-hexane, ergoealeiferol was derivatized ...An accurate, sensitive and selective method is developed for determination of ergoealeiferol （vitamin D2） in human plasma using LC-MS/MS. After liquid-liquid extraction with n-hexane, ergoealeiferol was derivatized by reacting with 4-phenyl-l,2,4-triazoline-3,5-dione （PTAD）, a strong dienophile based on Diels-Alder reaction. Ergocalciferol and its deuterated internal standard, ergocalciferol-d6, were analyzed on X Select CSH Cls （100 mmx4.6 mm, 2.5 lam） column using acetonitrile and 0.1% （v/v） formic acid in water containing 0.14% methylamine within 6.0 min under gradient elution mode. Tandem mass spectrometry in positive ionization mode was used to quantify ergocalciferol by multiple reaction monitoring （MRM）. Entire data processing was done using Watson LIMSTM software which provided excellent data integrity and high throughput with improved operational efficiency. The major advantage of this method includes higher sensitivity （0.10 ng/mL）, superior extraction efficiency （〉83%） and small sample volume （100 ~tL） for processing. The method was linear in the concentration range of 0.10-100 ng/mL for ergoealciferol. The intra-batch and inter-batch accuracy and precision （% CV） values varied from 97.3% to 109.0% and 1.01% to 5.16%, respectively. The method was successfully applied to support a bioequivalence study of 1.25 mg ergoealciferol capsules in 12 healthy subjects.展开更多
The objective of current study was to develop a validated specific stability indicating reversed-phase liquid chromatographic method for the quantitative determination of desvenlafaxine in bulk sample and pharmaceutic...The objective of current study was to develop a validated specific stability indicating reversed-phase liquid chromatographic method for the quantitative determination of desvenlafaxine in bulk sample and pharmaceutical dosage form in the presence of degradation products. Forced degradation studies were performed on bulk sample of desvenlafaxine as per ICH prescribed stress conditions using acid, base, oxidative and photolytic degradation to show the stability indicating power of the method. Significant degradation was observed under acidic stress condition and the degradation product formed was identified by LC-MS and a degradation pathway for drug has been proposed. Successful separation of drug from degradation products formed under stress conditions was achieved on a SymmetryShield column C 18 (5 mm, 250 mm 4.6 mm, i.d.) using the mobile phase consisting of a mixture of 0.2% (v/v) triethylamine in ammonium acetate (0.05 M; pH 6.5) and methanol using isocratic gradient.展开更多
A highly sensitive, selective, and precise ultra-performance liquid chromatography tandem mass spectrometry method was developed and validated for simultaneous quantification of itraconazole and hydroxy itraconazole i...A highly sensitive, selective, and precise ultra-performance liquid chromatography tandem mass spectrometry method was developed and validated for simultaneous quantification of itraconazole and hydroxy itraconazole in human plasma by a single liquid-liquid extraction step. The precursor to product ion transitions of m/z 705.3/392.3, m/z 721.2/408.3 and m/z 708.2/435.4 were used to detect and quantify itraconazole, hydroxy itraconazole and itraconazole-d3 respectively. The lower limit of quantitation was found to be 0.500 ng/mL for itraconazole and 1.00 ng/mL for hydroxy itraconazole. The mean recoveries for itraconazole and hydroxy itraconazole were found to be 100.045% and 100.021%, respectively. This developed method with a chromatographic run time of 2.0 min was successfully applied to a bioequivalence study of 100 mg itraconazole capsule.展开更多
A rapid and sensitive ultra performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS） method is described for determination of letrozole in human plasma.Following solid phase extraction（SPE） of letroz...A rapid and sensitive ultra performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS） method is described for determination of letrozole in human plasma.Following solid phase extraction（SPE） of letrozole and letrozole-d4 on Orochem DVB-LP cartridges,chromatography was performed on Acquity UPLC BEH C_（18）（50 mm × 2.1 mm.1.7 μm） column using methanol-0.1%formic acid in water（85：15,v/v） as the mobile phase.Detection was carried out on a triple quadrupole mass spectrometer with an electrospray source,operated under positive ionization mode.Quantitation of letrozole and letrozole-d4 was done using multiple reaction monitoring（MRM） following the transitions at m/z286.2→217.0 and m/z 290.2→221.0,respectively.The calibration plots were linear through the concentration range of 0.10-100 ng/mL（r^2 ≥ 0.9990） using 100 μL human plasma.The extraction recovery of letrozole ranged from 94.3%to 96.2%and the intra-batch and inter-batch precision was ≤ 5.2%.The method was successfully applied to a bioequivalence study of letrozole after oral administration of2.5 mg tablet formulation to 16 healthy postmenopausal Indian women.The assay reproducibility was also established through incurred sample reanalysis（ISR） of 74 subject samples.展开更多
An improved high performance liquid chromatography-tandem mass spectrometry（LC-MS/MS） method has been developed for sensitive and rapid determination of albendazole（ABZ） and its active metabolite,albendazole sulfo...An improved high performance liquid chromatography-tandem mass spectrometry（LC-MS/MS） method has been developed for sensitive and rapid determination of albendazole（ABZ） and its active metabolite,albendazole sulfoxide（ABZSO）,in the positive ionization mode.The method utilized solid phase extraction（SPE） for sample preparation of the analytes and their deuterated internal standards（ISs） from100 μL human plasma.The chromatography was carried out on Hypurity C_（18） column using acetonitrile-2.0 mM ammonium acetate,pH 5.0（80：20,v/v） as the mobile phase.The assay exhibited a linear response over the concentration range of 0.200-50.0 ng/mL for ABZ and 3.00-600 ng/mL for ABZSO.The recoveries of the analytes and ISs ranged from 86.03%-89.66%and 89.85%-98.94%,respectively.Matrix effect,expressed as IS-normalized matrix factors,ranged from 0.985 to 1.042 for the both analytes.The method was successfully applied for two separate studies in healthy subjects using single dose of 400 mg conventional tablets and 400 mg chewable ABZ tablets,respectively.展开更多
Pramipexole belongs to a class of nonergot dopamine agonist recently approved for the treatment of early and advanced Parkinson＇s disease.A validated specific stability indicating reversed-phase liquid chromatographi...Pramipexole belongs to a class of nonergot dopamine agonist recently approved for the treatment of early and advanced Parkinson＇s disease.A validated specific stability indicating reversed-phase liquid chromatographic method has been developed for the quantitative determination of pramipexole in bulk as well as in pharmaceutical dosage forms in the presence of degradation products.Forced degradation studies were performed by exposition of drug to hydrolytic（acidic and basic）,oxidative and photolytic stress conditions,as defined under ICH guideline Q1A（R2）.Significant degradation was observed under hydrolytic,oxidative and photolytic conditions and the degradation products formed were identified by LC-MS.展开更多
The present study describes a simple, reliable and reproducible liquid chromatography–tandem mass spectrometry method(LC–MS/MS) for the simultaneous determination of allopurinol and its active metabolite,oxypurinol ...The present study describes a simple, reliable and reproducible liquid chromatography–tandem mass spectrometry method(LC–MS/MS) for the simultaneous determination of allopurinol and its active metabolite,oxypurinol in human plasma for a pharmacokinetic/bioequivalence study. After protein precipitation(PPT) of100 μL plasma sample with 1.0% formic acid in acetonitrile, the recovery of the analytes and allopurinol-d2 as an internal standard ranged from 85.36% to 91.20%. The analytes were separated on Hypersil Gold(150 mm×4.6 mm, 5 μm) column using 0.1% formic acid-acetonitrile(98:2, v/v) as the mobile phase.Quantification was done using electrospray ionization in the positive mode. The calibration concentration range was established from 60.0 to 6000 ng/m L for allopurinol and 80.0–8000 ng/m L for oxypurinol. Matrix effect in human plasma, expressed as IS-normalized matrix factors ranged from 1.003 to 1.030 for both the analytes. The developed method was found suitable for a clinical study with 300 mg allopurinol tablet formulation in healthy subjects.展开更多
The objective of the present research work is to develop a gradient, reversed-phase liquid chromatographic (RP-UPLC) method for the determination of Finasteride in pharmaceutical bulk drugs for assay and its related i...The objective of the present research work is to develop a gradient, reversed-phase liquid chromatographic (RP-UPLC) method for the determination of Finasteride in pharmaceutical bulk drugs for assay and its related impurities. The chromatographic separation was achieved on a Waters ACQUITY UPLC BEH Phenyl Column (150 mm × 2.1 mm, 1.7 μm), The gradient LC method employs solutions A and B as mobile phase. The solution A Contains 2.5 mM ortho phosphoric acid (Buffer) and solution B contains a mixture of acetonitrile and water in the ratio of (90:10 v/v). The flow rate was 0.22 ml/min and the detection wavelength was 210 nm. In the developed UPLC method, the resolution between Finasteride and its potential impurities, namely Imp-1, Imp-2, Imp-3 and Imp-4 was found to be greater than 2.0. The drug was subjected to stress conditions of hydrolysis, oxidation, photolysis and thermal degradation. Considerable degradation was found to occur in alkaline medium and oxidative stress conditions. Degradation product formed during oxidative hydrolysis was found to be Imp-1. The stress samples were assayed against a qualified reference standard and the mass balance was found close to 99.5%. The developed RP-UPLC method was validated with respect to linearity, accuracy, precision and robustness. The limit of quantification of Imp-1, Imp-2, Imp-3 and Imp-4 were 0.06, 0.06, 0.05 and 0.036% (of analyte concentration, i.e. 0.5 mg/ml) with 1μl injection volume. The developed method was found to be linear in the range of 2.5 - 15 μg/mL with correlation coefficient of 0.999 for assay procedures and found to be linear in the range of 0.05 - 3 μg/mL with correlation coefficient of 0.999 for related impurities.展开更多
A selective and rapid high-performance liquid chromatography–tandem mass spectrometry method was developed and validated for the quantification of raltegravir using raltegravir-d3 as an internal standard（IS）. The a...A selective and rapid high-performance liquid chromatography–tandem mass spectrometry method was developed and validated for the quantification of raltegravir using raltegravir-d3 as an internal standard（IS）. The analyte and IS were extracted with methylene chloride and n-hexane solvent mixture from 100 mL human plasma. The chromatographic separation was achieved on a Chromolith RP-18 e endcapped C18（100 mm 4.6 mm） column in a run time of 2.0 min. Quantitation was performed in the negative ionization mode using the transitions of m/z 443.1-316.1 for raltegravir and m/z 446.1-319.0 for IS. The linearity of the method was established in the concentration range of 2.0–6000 ng/m L.The mean extraction recovery for raltegravir and IS was 92.6% and 91.8%, respectively, and the IS-normalized matrix factors for raltegravir ranged from 0.992 to 0.999. The application of this method was demonstrated by a bioequivalence study on 18 healthy subjects.展开更多
A highly sensitive and selective high performance liquid chromatography–tandem mass spectrometry method was developed and validated for the quantification of alverine（ALV） and its active metabolite, para hydroxy al...A highly sensitive and selective high performance liquid chromatography–tandem mass spectrometry method was developed and validated for the quantification of alverine（ALV） and its active metabolite, para hydroxy alverine（PHA）, in human plasma. For sample preparation, solid phase extraction of analytes was performed on Phenomenex Strata-X cartridges using alverine-d5 as the internal standard. The analytes were separated on Symmetry Shield RP18（150 mm×3.9 mm, 5 μm） column with a mobile phase consisting of acetonitrile and10 mM ammonium formate（65：35, v/v）. Detection and quantitation was done by electrospray ionization mass spectrometry in the positive mode using multiple reaction monitoring. The assay method was fully validated over the concentration range of 15.0–15,000 pg/mL for ALV and 30.0–15,000 pg/mL for PHA. The intra-day and inter-day accuracy and precision（% CV） ranged from 94.00% to 96.00% and 0.48% to 4.15% for both the analytes. The mean recovery obtained for ALV and PHA was 80.59% and 81.26%, respectively. Matrix effect,expressed as IS-normalized matrix factor ranged from 0.982 to 1.009 for both the analytes. The application of the method was demonstrated for the specific analysis of ALV and PHA for a bioequivalence study in 52 healthy subjects using 120 mg ALV capsules. The assay reproducibility was also verified by reanalysis of 175 incurred subject samples.展开更多
A rapid and sensitive ultra-performance liquid chromatography–tandem mass spectrometry（UPLC–MS/MS） method was developed and validated for the estimation of 17-desacetyl norgestimate in human plasma using solid-pha...A rapid and sensitive ultra-performance liquid chromatography–tandem mass spectrometry（UPLC–MS/MS） method was developed and validated for the estimation of 17-desacetyl norgestimate in human plasma using solid-phase extraction technique. 17-desacetyl norgestimate D6 was used as the internal standard. Simple gradient chromatographic conditions and mass spectrometric detection enabled accurate and precise measurement of 17-desacetyl norgestimate at sub-picogram levels. The proposed method was validated for a linear range of 20–5000 pg/m L with a correlation coefficient Z 0.9988. The intra-run and inter-run precision and accuracy were within 10%. The overall recoveries for 17-desacetyl norgestimate and 17-desacetyl norgestimate D6 were 96.30% and 93.90%, respectively. The total run time was 4.5 min. The developed method was applied for the determination of the pharmacokinetic parameters of 17-desacetyl norgestimate following a single oral administration of a norgestimate and ethinyl estradiol0.250 mg/0.035 mg tablets in 35 healthy female volunteers.展开更多
文摘A highly sensitive, rapid and rugged liquid chromatography-tandem mass spectrometw （LC-ESI-MS/MS） method was developed for reliable estimation of amantadine （AMD）, an antiviral drug in human plasma. The analyte and internal standard （IS）, amantadine-d6 （AMD-d6）, were extracted from 200μL plasma by solid phase extraction on Phenomenex Strata-X-C 33 ~t cartridges. Chromatography was performed on Synergi^TM Hydro-RP C18 （150 mm×4.6 mm, 4 μm） analytical column using a mixture of acetonitrile and 10 mM ammonium formate, pH 3.0 （80：20, v/v） as the mobile phase. Detection and quantitation was done by multiple reaction monitoring in the positive ionization mode for AMD （m/z 152.1→ 135.1 ） and IS （m/z 158.0 → 141.1） on a triple quadrupole mass spectrometer. The assay was linear in the concentration range of 0.50-500 ng/mL with correlation coefficient （r^2） 〉 0.9969. The limit of detection of the method was 0.18 ng/mL The intra-batch and inter-batch precisions were 〈 5.42% and the accuracy varied from 98.47% to 105.72%. The extraction recovery of amantadine was precise and quantitative in the range of 97.89%-100.28%. IS-normalized matrix factors for amantadine varied from 0.981 to 1.012. The stability of AMD in whole blood and plasma was evaluated under different conditions. The developed method was successfully applied for a bioequivalence study with 100 mg of AMD in 32 healthy volunteers. The reproducibility of the assay was determined by reanalysis of 134 subject samples.
文摘A highly sensitive liquid chromatography-tandem mass spectrometry（LC-MS/MS） method was developed for the determination of tadalafil（TAD） in human plasma. TAD and its deuterated internal standard（IS）, tadalafil-d3, were extracted from 200 mL plasma using Phenomenex Strata-X-C 33 m extraction cartridges. Chromatographic analysis was carried out on Synergi Hydro-RP C18（100 mm × 4.6 mm, 4 mm）column with a mobile phase consisting of methanol and 10 m M ammonium formate, p H 4.0（90：10, v/v）,delivered at a flow rate of 0.9 m L/min. Quantitation of the protonated analyte was done on a triple quadrupole mass spectrometer using multiple reaction monitoring via electrospray ionization. The precursor to product ions transitions monitored for TAD and TAD-d3 were m/z 390.3-268.2 and m/z393.1-271.2, respectively. The calibration curve was linear over the concentration range of 0.50–500 ng/m L with correlation coefficient, r2 Z 0.9994. Acceptable intra-batch and inter-batch precision（r3.7%） and accuracy（97.8% to 104.1%） were obtained at five concentration levels. The recovery of TAD from spiked plasma was highly precise and quantitative（98.95% to 100.61%）. Further, the effect of endogenous matrix components was minimal. TAD was found to be stable under different storage conditions in human plasma and also in whole blood samples. The validated method was successfully used to determine TAD plasma concentration in a bioequivalence study with 20 mg TAD tablets in 24 healthy volunteers. Method performance was evaluated by reanalyzing 115 study samples.
文摘A selective, sensitive and high throughput liquid chromatography-tandem mass spectro-metry （LC-ESI-MS/MS） method has been developed for separation and quantification of metoprolol enantiomers on a chiral Lux Amylose-2 （250 mm＆#215;4.6 mm, 5 mm） column. Solid phase extraction of （S）-（-）- and （R）-（t）-metoprolol and rac-metoprolol-d6 as an internal standard （IS） was achieved on Lichrosep DVB HL cartridges employing 200 mL human plasma. Both the analytes were chromatographically separated with a resolution factor of 2.24 using 15 mM ammonium acetate in water, pH 5.0 and 0.1% （v/v） diethyl amine in acetonitrile （50：50, v/v） as the mobile phase within 7.0 min. The precursor-product ion transitions for the enantiomers and IS were monitored in the multiple reaction monitoring and positive ionization mode. The method was validated over the concentration range of 0.500-500 ng/mL for both the enantiomers. Matrix effect was assessed by post-column analyte infusion experiment and the mean extraction recovery was greater than 94.0% for both the enantiomers at all quality control levels. The stability of analytes was evaluated in plasma and whole blood under different storage conditions. The method was successfully applied to a clinical study in 14 healthy volunteers after oral administration of 200 mg metoprolol tablet under fasting conditions. The assay reproducibility is shown by reanalysis of 68 incurred samples. The suitability of the developed method was assessed in comparison with＆amp;nbsp;different chromatographic methods developed for stereoselective analysis of metoprolol in biological matrices.
文摘The aim of the proposed research work was to develop and validate a simple, selective high sensitive and high-throughput assay for the simultaneous estimation of Atorvastatin and Glimepiride in human plasma using liquid chromatography tandem mass spectrometry (LC-MS/MS). Atorvastatin–Glimepiride combines a competitive inhibitor of HMG-CoA reductase and a sulfonylurea anti-diabetic drug. The purpose of this study was to develop single method for Atorvastatin and Glimepiride in plasma by liquid chromatography-tandem mass spectrometry (LC-MS/MS) that would result into a simultaneous estimation of Atorvastatin and Glimepiride avoiding acid –lactone inter conversions right from sample collections to analysis on the LC-MS/MS. Sample collection procedure optimized for Atorvastatin holds good for Glimepiride, hence resulting into a simultaneous estimation of Atorvastatin and Glimepiride. Liquid-liquid extraction and liquid chromatography coupled to positive ion mode tandem mass spectrometry was used to develop the method and was validated according to US FDA guidelines. The calibration curves for two analytes were linear (R2 ≥ 0.9950, n = 4) over the concentration range of 0.2 - 30 ng/mL for Atorvastatin and 1 - 250 ng/mL for Glimepiride. Mean extraction recoveries 80.34 ± 9.43 for Atorvastatin and 88.19 ± 7.13 for Glimepiride. Intra- and inter-run mean percent accuracy was between 85% - 115% and percent imprecision was ≤15%. Stability studies revealed that Atorvastatin and Glimepiride were stable in plasma during bench top (10.5 h at room temperature), in Injector (47.5 h), at the end of three successive freeze and thaw cycles and long term at -65℃ ± 15℃ for 114 days. The method was successfully applied to the study of pharmacokinetics of Atorvastatin and Glimepiride in healthy volunteers. Simultaneous estimation of Atorvastatin and Glimepiride is cost effective, reduces analysis cycle time, enables effective utilization of resources and reduces bleeding burden on human volunteers.
文摘A simple, precise and rapid liquid chromatography-tandem mass spectrometry （LC-MS/MS） method has been developed and validated for the simultaneous determination of oseltamivir and oseltamivir carboxylate, a neuraminidase inhibitor, using their deuterated analogs as internal standards （ISs）. The method involved solid phase extraction of the analytes and ISs from 200 μL human plasma with no reconstitution and drying steps. The chromatographic separation was achieved on a Symmetry C18 （100 mm × 4.6 mm, 5 μm） column using 10 mM ammonium formate and acetonitrile （30：70, v/v） as the mobile phase in a run time of 2.0 min. Quantitation of analytes and ISs were done by multiple reaction monitoring on a triple quadrupole mass spectrometer in the positive ionization mode. The linearity of the method was established in the concentration range of 0.5-200 ng/mL and 2.0-800 ng/mL for oseltamivir and oseltamivir carboxylate respectively. The mean extraction recovery for oseltamivir （94.4%） and oseltamivir carboxylate （92.7%） from spiked plasma samples was consistent and reproducible. The application of this method was demonstratedby a bioequivalence study in 42 healthy Indian subjects with 75 mg oseltamivir phosphate capsules. The assay reproducibility was established by reanalysis of 151 incurred subject samples.
文摘An accurate, sensitive and selective method is developed for determination of ergoealeiferol （vitamin D2） in human plasma using LC-MS/MS. After liquid-liquid extraction with n-hexane, ergoealeiferol was derivatized by reacting with 4-phenyl-l,2,4-triazoline-3,5-dione （PTAD）, a strong dienophile based on Diels-Alder reaction. Ergocalciferol and its deuterated internal standard, ergocalciferol-d6, were analyzed on X Select CSH Cls （100 mmx4.6 mm, 2.5 lam） column using acetonitrile and 0.1% （v/v） formic acid in water containing 0.14% methylamine within 6.0 min under gradient elution mode. Tandem mass spectrometry in positive ionization mode was used to quantify ergocalciferol by multiple reaction monitoring （MRM）. Entire data processing was done using Watson LIMSTM software which provided excellent data integrity and high throughput with improved operational efficiency. The major advantage of this method includes higher sensitivity （0.10 ng/mL）, superior extraction efficiency （〉83%） and small sample volume （100 ~tL） for processing. The method was linear in the concentration range of 0.10-100 ng/mL for ergoealciferol. The intra-batch and inter-batch accuracy and precision （% CV） values varied from 97.3% to 109.0% and 1.01% to 5.16%, respectively. The method was successfully applied to support a bioequivalence study of 1.25 mg ergoealciferol capsules in 12 healthy subjects.
文摘The objective of current study was to develop a validated specific stability indicating reversed-phase liquid chromatographic method for the quantitative determination of desvenlafaxine in bulk sample and pharmaceutical dosage form in the presence of degradation products. Forced degradation studies were performed on bulk sample of desvenlafaxine as per ICH prescribed stress conditions using acid, base, oxidative and photolytic degradation to show the stability indicating power of the method. Significant degradation was observed under acidic stress condition and the degradation product formed was identified by LC-MS and a degradation pathway for drug has been proposed. Successful separation of drug from degradation products formed under stress conditions was achieved on a SymmetryShield column C 18 (5 mm, 250 mm 4.6 mm, i.d.) using the mobile phase consisting of a mixture of 0.2% (v/v) triethylamine in ammonium acetate (0.05 M; pH 6.5) and methanol using isocratic gradient.
文摘A highly sensitive, selective, and precise ultra-performance liquid chromatography tandem mass spectrometry method was developed and validated for simultaneous quantification of itraconazole and hydroxy itraconazole in human plasma by a single liquid-liquid extraction step. The precursor to product ion transitions of m/z 705.3/392.3, m/z 721.2/408.3 and m/z 708.2/435.4 were used to detect and quantify itraconazole, hydroxy itraconazole and itraconazole-d3 respectively. The lower limit of quantitation was found to be 0.500 ng/mL for itraconazole and 1.00 ng/mL for hydroxy itraconazole. The mean recoveries for itraconazole and hydroxy itraconazole were found to be 100.045% and 100.021%, respectively. This developed method with a chromatographic run time of 2.0 min was successfully applied to a bioequivalence study of 100 mg itraconazole capsule.
基金Department of Chemistry,St.Xavier's College,Ahmedabad,India for supporting this work
文摘A rapid and sensitive ultra performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS） method is described for determination of letrozole in human plasma.Following solid phase extraction（SPE） of letrozole and letrozole-d4 on Orochem DVB-LP cartridges,chromatography was performed on Acquity UPLC BEH C_（18）（50 mm × 2.1 mm.1.7 μm） column using methanol-0.1%formic acid in water（85：15,v/v） as the mobile phase.Detection was carried out on a triple quadrupole mass spectrometer with an electrospray source,operated under positive ionization mode.Quantitation of letrozole and letrozole-d4 was done using multiple reaction monitoring（MRM） following the transitions at m/z286.2→217.0 and m/z 290.2→221.0,respectively.The calibration plots were linear through the concentration range of 0.10-100 ng/mL（r^2 ≥ 0.9990） using 100 μL human plasma.The extraction recovery of letrozole ranged from 94.3%to 96.2%and the intra-batch and inter-batch precision was ≤ 5.2%.The method was successfully applied to a bioequivalence study of letrozole after oral administration of2.5 mg tablet formulation to 16 healthy postmenopausal Indian women.The assay reproducibility was also established through incurred sample reanalysis（ISR） of 74 subject samples.
基金support and necessary facilities provided by Accutest Research Lab,Ahmedabad,to carry out this work
文摘An improved high performance liquid chromatography-tandem mass spectrometry（LC-MS/MS） method has been developed for sensitive and rapid determination of albendazole（ABZ） and its active metabolite,albendazole sulfoxide（ABZSO）,in the positive ionization mode.The method utilized solid phase extraction（SPE） for sample preparation of the analytes and their deuterated internal standards（ISs） from100 μL human plasma.The chromatography was carried out on Hypurity C_（18） column using acetonitrile-2.0 mM ammonium acetate,pH 5.0（80：20,v/v） as the mobile phase.The assay exhibited a linear response over the concentration range of 0.200-50.0 ng/mL for ABZ and 3.00-600 ng/mL for ABZSO.The recoveries of the analytes and ISs ranged from 86.03%-89.66%and 89.85%-98.94%,respectively.Matrix effect,expressed as IS-normalized matrix factors,ranged from 0.985 to 1.042 for the both analytes.The method was successfully applied for two separate studies in healthy subjects using single dose of 400 mg conventional tablets and 400 mg chewable ABZ tablets,respectively.
文摘Pramipexole belongs to a class of nonergot dopamine agonist recently approved for the treatment of early and advanced Parkinson＇s disease.A validated specific stability indicating reversed-phase liquid chromatographic method has been developed for the quantitative determination of pramipexole in bulk as well as in pharmaceutical dosage forms in the presence of degradation products.Forced degradation studies were performed by exposition of drug to hydrolytic（acidic and basic）,oxidative and photolytic stress conditions,as defined under ICH guideline Q1A（R2）.Significant degradation was observed under hydrolytic,oxidative and photolytic conditions and the degradation products formed were identified by LC-MS.
基金the support and necessary facilities provided by Accutest Research Lab, Ahmedabad, for this work
文摘The present study describes a simple, reliable and reproducible liquid chromatography–tandem mass spectrometry method(LC–MS/MS) for the simultaneous determination of allopurinol and its active metabolite,oxypurinol in human plasma for a pharmacokinetic/bioequivalence study. After protein precipitation(PPT) of100 μL plasma sample with 1.0% formic acid in acetonitrile, the recovery of the analytes and allopurinol-d2 as an internal standard ranged from 85.36% to 91.20%. The analytes were separated on Hypersil Gold(150 mm×4.6 mm, 5 μm) column using 0.1% formic acid-acetonitrile(98:2, v/v) as the mobile phase.Quantification was done using electrospray ionization in the positive mode. The calibration concentration range was established from 60.0 to 6000 ng/m L for allopurinol and 80.0–8000 ng/m L for oxypurinol. Matrix effect in human plasma, expressed as IS-normalized matrix factors ranged from 1.003 to 1.030 for both the analytes. The developed method was found suitable for a clinical study with 300 mg allopurinol tablet formulation in healthy subjects.
文摘The objective of the present research work is to develop a gradient, reversed-phase liquid chromatographic (RP-UPLC) method for the determination of Finasteride in pharmaceutical bulk drugs for assay and its related impurities. The chromatographic separation was achieved on a Waters ACQUITY UPLC BEH Phenyl Column (150 mm × 2.1 mm, 1.7 μm), The gradient LC method employs solutions A and B as mobile phase. The solution A Contains 2.5 mM ortho phosphoric acid (Buffer) and solution B contains a mixture of acetonitrile and water in the ratio of (90:10 v/v). The flow rate was 0.22 ml/min and the detection wavelength was 210 nm. In the developed UPLC method, the resolution between Finasteride and its potential impurities, namely Imp-1, Imp-2, Imp-3 and Imp-4 was found to be greater than 2.0. The drug was subjected to stress conditions of hydrolysis, oxidation, photolysis and thermal degradation. Considerable degradation was found to occur in alkaline medium and oxidative stress conditions. Degradation product formed during oxidative hydrolysis was found to be Imp-1. The stress samples were assayed against a qualified reference standard and the mass balance was found close to 99.5%. The developed RP-UPLC method was validated with respect to linearity, accuracy, precision and robustness. The limit of quantification of Imp-1, Imp-2, Imp-3 and Imp-4 were 0.06, 0.06, 0.05 and 0.036% (of analyte concentration, i.e. 0.5 mg/ml) with 1μl injection volume. The developed method was found to be linear in the range of 2.5 - 15 μg/mL with correlation coefficient of 0.999 for assay procedures and found to be linear in the range of 0.05 - 3 μg/mL with correlation coefficient of 0.999 for related impurities.
文摘A selective and rapid high-performance liquid chromatography–tandem mass spectrometry method was developed and validated for the quantification of raltegravir using raltegravir-d3 as an internal standard（IS）. The analyte and IS were extracted with methylene chloride and n-hexane solvent mixture from 100 mL human plasma. The chromatographic separation was achieved on a Chromolith RP-18 e endcapped C18（100 mm 4.6 mm） column in a run time of 2.0 min. Quantitation was performed in the negative ionization mode using the transitions of m/z 443.1-316.1 for raltegravir and m/z 446.1-319.0 for IS. The linearity of the method was established in the concentration range of 2.0–6000 ng/m L.The mean extraction recovery for raltegravir and IS was 92.6% and 91.8%, respectively, and the IS-normalized matrix factors for raltegravir ranged from 0.992 to 0.999. The application of this method was demonstrated by a bioequivalence study on 18 healthy subjects.
基金the support and necessary facilities provided by Accutest Research Lab,Ahmedabad
文摘A highly sensitive and selective high performance liquid chromatography–tandem mass spectrometry method was developed and validated for the quantification of alverine（ALV） and its active metabolite, para hydroxy alverine（PHA）, in human plasma. For sample preparation, solid phase extraction of analytes was performed on Phenomenex Strata-X cartridges using alverine-d5 as the internal standard. The analytes were separated on Symmetry Shield RP18（150 mm×3.9 mm, 5 μm） column with a mobile phase consisting of acetonitrile and10 mM ammonium formate（65：35, v/v）. Detection and quantitation was done by electrospray ionization mass spectrometry in the positive mode using multiple reaction monitoring. The assay method was fully validated over the concentration range of 15.0–15,000 pg/mL for ALV and 30.0–15,000 pg/mL for PHA. The intra-day and inter-day accuracy and precision（% CV） ranged from 94.00% to 96.00% and 0.48% to 4.15% for both the analytes. The mean recovery obtained for ALV and PHA was 80.59% and 81.26%, respectively. Matrix effect,expressed as IS-normalized matrix factor ranged from 0.982 to 1.009 for both the analytes. The application of the method was demonstrated for the specific analysis of ALV and PHA for a bioequivalence study in 52 healthy subjects using 120 mg ALV capsules. The assay reproducibility was also verified by reanalysis of 175 incurred subject samples.
文摘A rapid and sensitive ultra-performance liquid chromatography–tandem mass spectrometry（UPLC–MS/MS） method was developed and validated for the estimation of 17-desacetyl norgestimate in human plasma using solid-phase extraction technique. 17-desacetyl norgestimate D6 was used as the internal standard. Simple gradient chromatographic conditions and mass spectrometric detection enabled accurate and precise measurement of 17-desacetyl norgestimate at sub-picogram levels. The proposed method was validated for a linear range of 20–5000 pg/m L with a correlation coefficient Z 0.9988. The intra-run and inter-run precision and accuracy were within 10%. The overall recoveries for 17-desacetyl norgestimate and 17-desacetyl norgestimate D6 were 96.30% and 93.90%, respectively. The total run time was 4.5 min. The developed method was applied for the determination of the pharmacokinetic parameters of 17-desacetyl norgestimate following a single oral administration of a norgestimate and ethinyl estradiol0.250 mg/0.035 mg tablets in 35 healthy female volunteers.
