High performance liquid chromatography mass spectrometric method for the simultaneous quantification of pravastatin and aspirin in human plasma: Pharmacokinetic application

AbstractA rapid and sensitive liquid chromatography–tandem mass spectrometric (LC–MS/MS) assay method has been developed and fully validated for the simultaneous quantification of pravastatin and aspirin in human plasma. Furosemide was used as an internal standard. Analytes and the internal standard were extracted from human plasma by liquid–liquid extraction technique using methyl tertiary butyl ether. The reconstituted samples were chromatographed on a Zorbax SB-C18 column by using a mixture of 5mM ammonium acetate buffer and acetonitrile (20:80, v/v) as the mobile phase at a flow rate of 0.8mL/min. The calibration curve obtained was linear (r≥0.99) over the concentration range of 0.50–600.29ng/mL for pravastatin and 20.07–2012.00ng/mL for aspirin. Method validation was performed as per FDA guidelines and the results met the acceptance criteria. A run time of 2.0min for each sample made it possible to analyze more than 400 human plasma samples per day. The proposed method was found to be applicable to clinical studies

Mixed-Ligand Complexes of Co(II), Ni(II) And Cu(II) with Mercaptosuccinic Acid And 1, 10-Phenanthroline in Dimethylformamide Media

The ternary systems of Co(II), Ni(II) and Cu(II) complexes with Mercaptosuccinic acid as Primary Ligand and 1, 10-Phenanthroline as Secondary Ligand are investigated. The stability constants of the complexes were determined pH metrically in Dimethylformamide medium at 303K and I = 0.16 mol/L NaCl. The predominant species detected are MLX, ML2X, MLXH and MLX2H. Models containing different numbers of species were refined by using the computer program MINIQUAD75. The best-fit chemical models were arrived at based on statistical parameters. The relative stabilities of the ternary complexes and species distributions of all complexes in solution were evaluated

LC-MS/MS ASSAY FOR IRBESARTAN IN HUMAN PLASMA USING SOLID PHASE EXTRACTION TECHNIQUE: A PHARMACOKINETIC STUDY

Objective: The objective of this research was to develop a novel liquid chromatography/tandem mass spectrometry (LC-MS/MS) method for the determination of irbesartan in human plasma.Methods: An analytical method based on liquid chromatography/tandem mass spectrometry (LC-MS/MS) has been developed and validated for the quantitative determination of irbesartan in human plasma. The method utilizes irbesartan d4 as internal standard (IS). After solid phase extraction (SPE), analyte and the IS were chromato graphed on a C18 columns using a isocratic mobile phase composed of methanol–0.2% formic acid (85:15, v/v) pumped at a flow rate of 0.70 mL/min.Results: Precision and accuracy of the method was determined using five analytical batches in the concentration range of 50.0–9982 ng/ml. All the validation experiments were carried out as per the US FDA guidelines and results met the acceptance criteria.Conclusion: The proposed LC–MS/MS assay method is simple, rapid and enough sensitive for the determination of irbesartan in human plasma. A chromatographic run time set at 2.0 min, thus can analyze more than 300 samples in a day. Also, the proposed method was found to be applicable to clinical studies.Â

SIMULTANEOUS DETERMINATION OF ARTESUNATE AND AMODIAQUINE IN HUMAN PLASMA USING LC-MS/MS AND ITS APPLICATION TO A PHARMACOKINETIC STUDY

Objective: The objective of this research was to develop a simple, rapid and sensitive liquid chromatography/tandem mass spectrometry (LC-MS/MS) method for the simultaneous quantification of artesunate and amodiaquine in human plasma.Methods: An analytical method based on LC-MS/MS has been developed and validated for the simultaneous determination of artesunate and amodiaquine in human plasma. Isotope-labeled compounds are used as internal standards for the quantification of these drugs. Analytes were extracted from the plasma using solid phase extraction (SPE) technique and chromatographed on a C8 column using an isocratic mobile phase composed of 0.1% ammonia solution and methanol (10:90, v/v). The mobile phase was pumped at a flow rate of 1.00 ml/min. A total of five analytical batches were generated for the calculation of intra-day and inter-day precision and accuracy during the entire course of validation.Results: The assay exhibits excellent linearity in the concentration range of 3.07–305.29 ng/ml for artesunate and 0.30–30.01 ng/ml for amodiaquine. Intra-day and inter-day precision and accuracy results are well within the acceptance limits. All the stability experiments were conducted in plasma samples and in neat samples are complying with the recent US FDA and EMEA guidelines.Conclusion: The proposed LC–MS/MS assay method is simple, rapid and sensitive enough for the simultaneous determination of artesunate and amodiaquine in human plasma. This method was successfully used to quantitate the in-vivo plasma concentrations obtained from a pharmacokinetic study and the results were validated by conducting incurred samples reanalysis (ISR).Â

Simultaneous determination of atorvastatin, metformin and glimepiride in human plasma by LCâMS/MS and its application to a human pharmacokinetic study

A simple, rapid and sensitive liquid chromatography-tandem mass spectrometric (LCâMS/MS) assay method has been developed and fully validated for the simultaneous quantification of atorvastatin, metformin and glimepiride in human plasma. Carbamazepine was used as internal standard (IS). The analytes were extracted from 200 μL aliquots of human plasma via protein precipitation using acetonitrile. The reconstituted samples were chromatographed on a Alltima HP C18 column by using a 60:40 (v/v) mixture of acetonitrile and 10 mM ammonium acetate (pH 3.0) as the mobile phase at a flow rate of 1.1 mL/min. The calibration curves obtained were linear (r2â¥0.99) over the concentration range of 0.50â150.03 ng/mL for atorvastatin, 12.14â1207.50 ng/mL for metformin and 4.98â494.29 ng/mL for glimepiride. The API-4000 LCâMS/MS in multiple reaction monitoring (MRM) mode was used for detection. The results of the intra- and inter-day precision and accuracy studies were well within the acceptable limits. All the analytes were found to be stable in a battery of stability studies. The method is precise and sensitive enough for its intended purpose. A run time of 2.5 min for each sample made it possible to analyze more than 300 plasma samples per day. The developed assay method was successfully applied to a pharmacokinetic study in human male volunteers. Keywords: Atorvastatin, Metformin, Glimepiride, LCâMS/MS, Human plasma, Pharmacokinetic

Highly sensitive assay for the determination of therapeutic peptide desmopressin in human plasma by UPLC–MS/MS

An analytical method based on ultra-performance liquid chromatography with positive ion electrospray ionization (ESI) coupled with tandem mass spectrometry detection (UPLC–MS/MS) was developed and validated for the determination of therapeutic peptide desmopressin in human plasma. A desmopressin stable labeled isotope (desmopressin d8) was used as an internal standard. Analyte and the internal standard were extracted from 200 µL of human plasma via solid-phase extraction technique using Oasis WCX cartridges. The chromatographic separation was achieved on an Aquity UPLC HSS T3 column by using a gradient mixture of methanol and 1 mM ammonium formate buffer as the mobile phase. The calibration curve obtained was linear (r2≥0.99) over the concentration range of 1.01–200 pg/mL. Method validation was performed as per FDA guidelines and the results met the acceptance criteria. The results of the intra- and inter-day precision and accuracy studies were well within the acceptable limits. The proposed method was successfully applied to pharmacokinetic studies in humans

Synthesis and Cytotoxic Activity of Some New 2,6-Substituted Purines

A seriesof twenty four acyclic unsaturated 2,6-substututed purines 5a-20b were synthesized. These compounds were evaluated for cytotoxic activity against NCI-60 DTP human tumor cell line screen at 10µMconcentration. N9-[(Z)-4'-chloro-2'-butenyl-1'-yl]-2,6-dichloropurine(5a), N9-[4'-chloro-2'-butynyl-1'-yl]-2,6-dichloropurine(10a), N9-[(E)-2',3'-dibromo-4'-chloro-2'-butenyl-1'-yl]-6-methoxypurine(14)and N9-[4'-chloro-2'-butynyl-1'-yl]-6-(4-methoxyphenyl)-purine(19)exhibited highly potent cytotoxic activity with GI50 values in the 1–5 µM range for most human tumor cell lines. Other compounds exhibited moderate activity

Simultaneous determination of pioglitazone and candesartan in human plasma by LC-MS/MS and its application to a human pharmacokinetic study

A simple and rapid liquid chromatography-tandem mass spectrometric (LC-MS/MS) assay method has been developed and fully validated for simultaneous quantification of pioglitazone and candesartan in human plasma. Irbesartan was used as an internal standard. The analytes were extracted from human plasma samples by solid-phase extraction technique using a Strata-X 33 μm polymeric sorbent. The reconstituted samples were chromatographed on a C18 column by using a 80:20 (v/v) mixture of acetonitrile and 0.1% formic acid as the mobile phase at a flow rate of 0.8 mL/min. The calibration curves obtained were linear (râ¥0.99) over the concentration range of 15â3000 ng/mL for pioglitazone and 5â608 ng/mL for candesartan. The results of the intra- and inter-day precision and accuracy studies were well within the acceptable limits. A run time of 2.7 min for each sample made it possible to analyze more than 300 plasma samples per day. The proposed method was found to be applicable to clinical studies. Keywords: Pioglitazone, Candesartan, Human plasma, Solid-phase extraction, LC-MS/MS, Pharmacokinetic

Simultaneous determination of telmisartan and amlodipine in human plasma by LCâMS/MS and its application in a human pharmacokinetic study

A rapid and sensitive liquid chromatographyâtandem mass spectrometric (LCâMS/MS) assay method has been developed and fully validated for the simultaneous quantification of telmisartan and amlodipine in human plasma. Carbamazepine was used as an internal standard. Analytes and the internal standard were extracted from human plasma by solid-phase extraction technique using Waters Oasis® HLB 1 cm3 (30 mg) extraction cartridge. The reconstituted samples were chromatographed on a Hypurity advance C18 column (50 mmÃ4.6 mm, 5 μm) using a mixture of acetonitrileâ5 mM ammonium acetate buffer (pH-4.0) (50:50, v/v) as the mobile phase at a flow rate of 0.8 mL/min. The calibration curve obtained was linear (râ¥0.99) over the concentration range of 2.01â400.06 ng/mL for telmisartan and 0.05â10.01 ng/mL for amlodipine. Method validation was performed as per FDA guidelines and the results met the acceptance criteria. A run time of 2.5 min for each sample made it possible to analyze more than 400 human plasma samples per day. The proposed method was found to be applicable to clinical studies. Keywords: Telmisartan, Amlodipine, Human plasma, Solid-phase extraction, LCâMS/MS, Pharmacokinetic

A rapid and sensitive liquid chromatographyâtandem mass spectrometric assay for duloxetine in human plasma: Its pharmacokinetic application

This paper describes a simple, rapid and sensitive liquid chromatographyâtandem mass spectrometry assay for the determination of duloxetine in human plasma. A duloxetine stable labeled isotope (duloxetine d5) was used as an internal standard. Analyte and the internal standard were extracted from 100 μL of human plasma via solid phase extraction technique using Oasis HLB cartridges. The chromatographic separation was achieved on a C18 column by using a mixture of acetonitrileâ5 mM ammonium acetate buffer (83:17, v/v) as the mobile phase at a flow rate of 0.9 mL/min. The calibration curve obtained was linear (r2â¥0.99) over the concentration range of 0.05â101 ng/mL. Multiple-reaction monitoring mode (MRM) was used for quantification of ion transitions at m/z 298.3/154.1 and 303.3/159.1 for the drug and the internal standard, respectively. Method validation was performed as per FDA guidelines and the results met the acceptance criteria. A run time of 2.5 min for each sample made it possible to analyze more than 300 plasma samples per day. The proposed method was found to be applicable to clinical studies. Keywords: Duloxetine in human plasma, Solid-phase extraction (SPE), Liquid chromatographyâtandem mass spectrometry, Method validation, Pharmacokinetic studie