Challenges in Simultaneous Determination of Hydrochlorothiazide and Ramipril in Human Plasma: Application to a Bioequivalence Study.

An isotope dilution selective and sensitive high-performance liquid chromatography-tandem mass spectrometry (LC-ESI-MS/MS) method has been developed for the simultaneous determination of hydrochlorothiazide (HCTZ) and ramipril in human plasma through a new concept of periodical polarity switching. Extraction of HCTZ, ramipril and their deuterated analogs as internal standards (ISs) was carried out from 150 μL of human plasma by solid-phase extraction method. Chromatographic separation of analytes was performed on Hypurity C18 (150 mm × 4.

Novel bio analytical method development, validation and application for simultaneous determination of nebivolol and S-amlodipine in human plasma using ultra performance liquid chromatography-tandem mass spectrometry.

A sensitive and specific ultra-performance liquid chromatography tandem mass spectrometric (UPLC-MS/MS) method has been developed, validated and applied for the assay of Nebivolol and S-amlodipine in human plasma. Sample extraction was carried out through hybrid extraction method from 250 μL of human plasma sample. Linearity of the method was (r ≥ 0.

An improved LC-MS/MS method for the quantification of alverine and para hydroxy alverine in human plasma for a bioequivalence study.

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 RP (150 mm×3.

Simultaneous analysis of allopurinol and oxypurinol using a validated liquid chromatography-tandem mass spectrometry method in human plasma.

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) of 100 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.

The simultaneous UPLC-MS/MS determination of emerging drug combination; candesartan and chlorthalidone in human plasma and its application.

A novel, precise, sensitive and accurate ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method has been developed for the simultaneous determination of a novel drug combination, candesartan (CAN) and chlorthalidone (CHL), in human plasma. Chromatographic separation was achieved on Waters Acquity UPLC BEH C (50 × 2.1 mm, 1.

Liquid chromatography--tandem mass spectrometry method for simultaneous determination of albendazole and albendazole sulfoxide in human plasma for bioequivalence studies.

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) from 100 µL human plasma. The chromatography was carried out on Hypurity C column using acetonitrile-2.

Application of an LC-MS/MS method for reliable determination of amodiaquine, N-desethylamodiaquine, artesunate and dihydroartemisinin in human plasma for a bioequivalence study in healthy Indian subjects.

A sensitive and high throughput bioanalytical method has been developed for reliable determination of amodiaquine (AQ), N-desethylamodiaquine (DEAQ), artesunate (AS) and dihydroartemisinin (DHA) in human plasma by LC-MS/MS. The method employs a solid phase extraction procedure without an evaporation step and with optimum use of organic solvents to circumvent degradation of artemisinin derivatives. The analytes and their deuterated internal standards (ISs) were analyzed on Hypersil Gold (100 mm × 4.

Systematic evaluation of matrix effect and cross-talk-free method for simultaneous determination of zolmitriptan and N-desmethyl zolmitriptan in human plasma: a sensitive LC-MS/MS method validation and its application to a clinical pharmacokinetic study.

The objective of the present work was to carry out systematic evaluation to eliminate matrix effect owing to plasma phospholipids as observed during sample preparation and to develop a cross-talk-free sensitive, selective and rapid bioanalytical method for the simultaneous determination of zolmitriptan (ZT) and N-desmethyl zolmitriptan (DZT) in human plasma by liquid chromatography-tandem mass spectrometry using naratriptan as internal standard (IS). The analytes and IS were quantitatively extracted from 200 μL human plasma by solid phase extraction. No cross-talk was found between ZT and DZT having identical product ions.

Application of UPLC-MS/MS for separation and quantification of 3α-Hydroxy Tibolone and comparative bioavailability of two Tibolone formulations in healthy volunteers.

A novel, fast, sensitive and robust method based on ultra-performance liquid chromatography coupled to atmospheric pressure electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) has been developed to separate two Tibolone stereoisomers i.e., 3α-Hydroxy Tibolone and 3β-Hydroxy Tibolone and to quantify 3α-Hydroxy Tibolone using p-toulenesulfonyl isocyanate (PTSI) as a derivatizing reagent in human plasma.

A single, selective and simple validated method for simultaneous estimation of amiloride and hydrochlorothiazide in human plasma by liquid chromatography-tandem mass spectrometry.

A single, simple and selective method for simultaneous estimation of amiloride and hydrochlorothiazide in human plasma was validated using triamterine and hydrochlorothiazide (13)C,d2 as internal standard. The compounds were separated on a reverse-phase column with an isocratic mobile phase consisting of 2 mm ammonium acetate pH 3.0 and acetonitrile (30:70, v/v) and detected by tandem mass spectrometry with positive/negative ion mode.

A simple, selective and rapid validated method for estimation of anastrazole in human plasma by liquid chromatography-tandem mass spectrometry and its application to bioequivalence study.

A rapid, simple and specific method for estimation of anastrazole in human plasma was validated using letrozole as internal standard. The analyte and internal standard were extracted from plasma using simple solid-phase extraction. The compound were separated on a reverse-phase column with an isocratic mobile phase consisting of 0.

Highly sensitive and rapid LC-ESI-MS/MS method for the simultaneous quantification of uroselective alpha1-blocker, alfuzosin and an antimuscarinic agent, solifenacin in human plasma.

An accurate, selective and sensitive bioanalytical method has been developed and validated for the simultaneous quantification of alfuzosin and solifenacin in human plasma using propranolol as internal standard (IS). The analytes and IS were extracted in methyl tert-butyl ether, separated on Hypurity C8 column and detected by tandem mass spectrometry with a turbo ion spray interface. The method had a chromatographic run time of 3.

Sensitive and rapid method to determine trimetazidine in human plasma by liquid chromatography/tandem mass spectrometry.

A simple, sensitive, and rapid liquid chromatographic/tandem mass spectrometric (LC/MS/MS) method, using electrospray ionization, was developed and validated to quantify trimetazidine in human plasma using propranolol hydrochloride as an internal standard (IS). Samples were prepared by solid-phase extraction and analyzed without drying and reconstitution. The analyte and IS were chromatographed on a C18 reversed-phase column under isocratic conditions using 2 mM ammonium acetate (pH 3.

HPLC-ESI-MS/MS validated method for simultaneous quantification of zopiclone and its metabolites, N-desmethyl zopiclone and zopiclone-N-oxide in human plasma.

A simple, selective and sensitive isocratic HPLC method with triple quadrupole mass spectrometry detection has been developed and validated for simultaneous quantification of zopiclone and its metabolites in human plasma. The analytes were extracted using solid phase extraction, separated on Symmetry shield RP8 column (150 mm x 4.6 mm i.

Liquid chromatography tandem mass spectrometry method for simultaneous determination of antidiabetic drugs metformin and glyburide in human plasma.

A simple and rapid liquid chromatography/tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the simultaneous quantitation of antidiabetic drugs metformin and glyburide in human plasma using glimepiride as internal standard (IS). After acidic acetonitrile-induced protein precipitation of the plasma samples, metformin, glyburide and IS were chromatographed on reverse phase C18 (50 mm x 4.6 mm i.

High throughput LC-MS/MS method for simultaneous quantification of lamivudine, stavudine and nevirapine in human plasma.

A selective and high throughput liquid chromatography/tandem mass spectrometry (LC-MS/MS) method has been developed and validated to separate, detect and simultaneously quantify lamivudine (3TC), stavudine (d4T) and nevirapine (NVP) in human plasma using metaxalone as internal standard (IS). After solid phase extraction (SPE), the analytes and the IS were chromatographed on a Symmetry C18 (150 mmx3.9 mm i.

Electrospray ionization LC-MS/MS validated method to quantify griseofulvin in human plasma and its application to bioequivalence study.

A simple, sensitive and rapid liquid chromatography/tandem mass spectrometry (LC-MS/MS) method has been developed and validated to quantify griseofulvin in human plasma using propranolol hydrochloride as internal standard (IS). Samples were prepared using solid phase extraction and analysed without drying and reconstitution. The analytes were chromatographed on Hypersil, hypurity C18 reverse phase column under isocratic conditions using 0.

Rapid and sensitive liquid chromatography-tandem mass spectrometry method for the estimation of nicorandil in human plasma.

A rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the estimation of nicorandil in human plasma. Nicorandil was extracted from human plasma using solid-phase extraction technique. Imipramine was used as the internal standard.

Rapid and sensitive liquid chromatography-mass spectrometry method for determination of ropinirole in human plasma.

A rapid and robust liquid chromatography-mass spectrometry (LC-MS/MS) method was developed for non-ergoline dopamine D(2)-receptor agonist, ropinirole in human plasma using Es-citalopram oxalate as an internal standard. The method involves solid phase extraction from plasma, reversed-phase simple isocratic chromatographic conditions and mass spectrometric detection that enables a detection limit at picogram levels. The proposed method was validated with linear range of 20-1,200 pg/ml.

Liquid chromatography-tandem mass spectrometry (LC-MS-MS) method for simultaneous determination of venlafaxine and its active metabolite O-desmethyl venlafaxine in human plasma.

A rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS-MS) method has been developed and validated for simultaneous quantification of venlafaxine (VEN) and O-desmethyl venlafaxine (ODV) in human plasma. The analytes were extracted from human plasma by using solid-phase extraction (SPE) technique. Escitalopram (ESC) was used as the internal standard.

Quantification of zolpidem in human plasma by liquid chromatography-electrospray ionization tandem mass spectrometry.

A simple and robust method for quantification of zolpidem in human plasma has been established using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI MS/MS). Es-citalopram was used as an internal standard. Zolpidem and internal standard in plasma sample were extracted using solid-phase extraction cartridges (Oasis HLB, 1 cm3/30 mg).