Simultaneous determination of atenolol,chlorthalidone and amiloride in pharmaceutical preparations by capillary zone electrophoresis with ultraviolet detection

Capillary zone electrophoresis methods for the simultaneous determination of the β‐blocker drugs, atenolol, chlorthalidone and amiloride, in pharmaceutical formulations have been developed. The influences of several factors (buffer pH, concentration, applied voltage, capillary temperature and injection time) were studied. Using phenobarbital as internal standard, the analytes were all separated in less than 4 min. The separation was carried out in normal polarity mode at 25°C, 25 kV and using hydrodynamic injection (10 s). The separation was effected in an uncoated fused‐silica capillary (75 μm i.d. × 52 cm) and a background electrolyte of 25 mm H₃PO₄ adjusted with 1 m NaOH solution (pH 9.0) and detection at 198 nm. The method was validated with respect to linearity, limit of detection and quantification, accuracy, precision and selectivity. Calibration curves were linear over the range 1–250 μg/mL for atenolol and chlorthalidone and from 2.5–250 μg/mL for amiloride. The relative standard deviations of intra‐ and inter‐day migration times and corrected peak areas were less than 6.0%. The method showed good precision and accuracy and was successfully applied to the simultaneous determination of atenolol, chlorthalidone and amiloride in various pharmaceutical tablets formulations. Copyright © 2010 John Wiley & Sons, Ltd.     

Optimization,Validation and Application of a Capillary Zone Electrophoresis Method for the Assay of Sparfloxacin in Pharmaceutical Formulation

Abstract

A capillary zone electrophoresis (CZE) method has been developed for the determination of the antibiotic sparfloxacin in tablets. The CZE separation was performed using 75 µm×35 cm fused-silica capillary under the following conditions: 25°C; applied voltage, 12 kV; 25 mM H₃PO₄-NaOH running buffer (pH 8.5). The detection wavelength was 254 nm. Flumequine was used as internal standard (IS). The method was suitably validated with respect to linearity, limit of detection and quantification, accuracy, precision, specificity, and robustness. The calibration was linear from 10 to 60 µg mL^?1 and the limit of detection and quantification were 5.38 and 9.46 µg mL^?1, respectively. Recoveries ranging from 95.68%–102.4% were obtained in the determination of sparfloxacin that were spiked to placebos. Excipients in the commercial tablets and degraded products from different stress conditions did not interfere in the assay. The method was successfully applied to the determination of sparfloxacin in pharmaceutical tablets.     

Validated Assay for the Determination of Mitoxantrone in Pharmaceuticals Using Capillary Zone Electrophoresis

Abstract

The first capillary zone electrophoretic (CZE) method for the determination of mitoxantrone (MTX) in pharmaceutical formulations was developed. The influence of background electrolyte (BGE) species, pH, concentration (c _BGE), organic modifier, capillary temperature, applied voltage, and injection time was investigated. Optimum results were achieved with 25 mM ammonium acetate at an apparent pH value of 5.0 in 50% v/v acetonitrile, applied voltage of +30 kV, and capillary temperature of 25°C. The samples were introduced into the capillary hydrodynamically for 2 s at 33.5 mbar. Mitoxantrone was detected at a wavelength of 242 nm. Mitoxantrone and doxorubicin (DOX) (used as internal standard, ISTD) were completely separated in less than 7 min. The method was suitably validated with respect to linearity, limits of detection (LOD) and quantification (LOQ), accuracy, precision, selectivity, and robustness. The proposed method was applied successfully for the determination of MTX in its injectable pharmaceutical formulation.     

Simultaneous quantification of atenolol and chlorthalidone in human plasma by ultra‐performance liquid chromatography–tandem mass spectrometry

A simple, sensitive and reproducible ultra‐performance liquid chromatography–tandem mass spectrometry method has been developed for the simultaneous determination of atenolol, a β‐adrenergic receptor‐blocker and chlorthalidone, a monosulfonamyl diuretic in human plasma, using atenolol‐d7 and chlorthalidone‐d4 as the internal standards (ISs). Following solid‐phase extraction on Phenomenex Strata‐X cartridges using 100 μL human plasma sample, the analytes and ISs were separated on an Acquity UPLC BEH C₁₈ (50 mm × 2.1 mm, 1.7 µm) column using a mobile phase consisting of 0.1% formic acid–acetonitrile (25:75, v/v). A tandem mass spectrometer equipped with electrospray ionization was used as a detector in the positive ionization mode for both analytes. The linear concentration range was established as 0.50–500 ng/mL for atenolol and 0.25–150 ng/mL for chlorthalidone. Extraction recoveries were within 95–103% and ion suppression/enhancement, expressed as IS‐normalized matrix factors, ranged from 0.95 to 1.06 for both the analytes. Intra‐batch and inter‐batch precision (CV) and accuracy values were 2.37–5.91 and 96.1–103.2%, respectively. Stability of analytes in plasma was evaluated under different conditions, such as bench‐top, freeze–thaw, dry and wet extract and long‐term. The developed method was superior to the existing methods for the simultaneous determination of atenolol and chlorthalidone in human plasma with respect to the sensitivity, chromatographic analysis time and plasma volume for processing. Further, it was successfully applied to support a bioequivalence study of 50 mg atenolol + 12.5 mg chlorthalidone in 28 healthy Indian subjects. Copyright © 2015 John Wiley & Sons, Ltd.     

Simultaneous determination of atenolol and amiloride in pharmaceutical preparations by capillary zone electrophoresis with capacitively coupled contactless conductivity detection

Capillary zone electrophoresis coupled with a capacitively coupled contactless conductivity detector (CE‐C⁴D) has been employed for the determination of atenolol and amiloride in pharmaceutical formulations. Acetic acid (150 mm ) was used as background electrolyte. The influence of several factors (detector excitation voltage and frequency, buffer concentration, applied voltage, capillary temperature and injection time) was studied. Non‐UV‐absorbing L‐valine was used as internal standard; the analytes were all separated in less than 7 min. The separation was carried out in normal polarity mode at 28°C, 25 kV and using hydrodynamic injection (25 s). The separation was effected in an uncoated fused‐silica capillary (75 μm, i.d. × 52 cm). The CE‐C⁴D method was validated with respect to linearity, limit of detection and quantification, accuracy, precision and selectivity. Calibration curves were linear over the range 5–250 μg/mL for the studied analytes. The relative standard deviations of intra‐ and inter‐day migration times and corrected peak areas were less than 6.0%. The method showed good precision and accuracy and was successfully applied to the simultaneous determination of atenolol and amiloride in different pharmaceutical tablet formulations. Copyright © 2010 John Wiley & Sons, Ltd.     

CZE Determination of Mismatched Double-Stranded Oligonucleotides (poly I:poly C12U) in Beagle Serum

A capillary zone electrophoretic (CZE) method with diode-array detection has been established for analysis of mismatched double-stranded oligonucleotides, poly I:poly C₁₂U, in beagle serum. The effects of sample pretreatment, buffer pH, buffer concentration, and applied voltage on the separation of inosine were optimized. Baseline separation was obtained for inosine within 11 min by use of 0.05 mol L^?1 borate running buffer, pH 9.60, and an applied voltage of 25 kV at 25 °C; the detection wavelength was 254 nm. To evaluate the performance of the method and demonstrate the utility of the approach, an experiment was designed in which poly I:poly C₁₂U were added to serum at different concentrations, artificially creating groups of samples. The proposed CZE method seemed a powerful technique for kinetic study of poly I:poly C₁₂U in serum.     

CZE Determination of Mismatched Double-Stranded Oligonucleotides (poly I:poly C12U) in Beagle Serum

A capillary zone electrophoretic (CZE) method with diode-array detection has been established for analysis of mismatched double-stranded oligonucleotides, poly I:poly C₁₂U, in beagle serum. The effects of sample pretreatment, buffer pH, buffer concentration, and applied voltage on the separation of inosine were optimized. Baseline separation was obtained for inosine within 11 min by use of 0.05 mol L⁻¹ borate running buffer, pH 9.60, and an applied voltage of 25 kV at 25 °C; the detection wavelength was 254 nm. To evaluate the performance of the method and demonstrate the utility of the approach, an experiment was designed in which poly I:poly C₁₂U were added to serum at different concentrations, artificially creating groups of samples. The proposed CZE method seemed a powerful technique for kinetic study of poly I:poly C₁₂U in serum.

     

High‐Performance Liquid Chromatographic Determination of Parecoxib in Human Plasma and Pharmaceutical Formulations

Abstract

A simple and sensitive RP‐HPLC method for the determination of parecoxib (PXB) in human plasma and pharmaceutical formulations has been developed and validated. The separation of PXB and the internal standard, ibuprofen (IBF) was achieved on a CLC C₁₈ (5 μ, 25 cm×4.6 mm i.d.) column using UV detector at 200 nm. The mobile phase consisted of acetonitrile‐water (92:8 v/v). The linear range of detection was found to be 0.9–18.4 µg/ml (r=0.9985). Intra‐ and inter‐day assay relative standard deviations were observed to be less than 0.3%. The method has been applied successfully for the determination of PXB in spiked human plasma and pharmaceutical preparations. Analytical parameters were calculated and complete statistical evaluation is incorporated.     

RP‐HPLC Method for the Determination of Tenofovir in Pharmaceutical Formulations and Spiked Human Plasma

Abstract

A simple reverse‐phase high‐performance liquid chromatographic method for the determination of tenofovir disoproxil fumarate (TDF) in pharmaceutical formulations and human plasma samples has been developed and validated. Piroxicam (PRX) was used as an internal standard. The assay of the drug was performed on a CLC C₁₈ (5 μ, 25 cm×4.6 mm i.d.) with UV detection at 259 nm. The mobile phase consisted of acetonitrile–water mixture in the ratio of 75∶25, and a flow rate of 1 ml/min was maintained. The standard curve was linear over the range of 0.2–10 µg/ml (r ²=0.9966). Analytic parameters have been evaluated. Within‐day and between‐day precision as expressed by relative standard deviation was found to be less than 2%. The method has been applied successfully for the determination of TDF in spiked human plasma samples and pharmaceutical formulations.     

Trace analysis of acetylcholinesterase inhibitors with antipsychotic drugs for Alzheimer’s disease by capillary electrophoresis with on column field-amplified sample injection

A simple and sensitive capillary zone electrophoresis (CZE) with UV detection (214 nm) was developed and validated for the simultaneous determination of the acetylcholinesterase inhibitors (AChEI), donepezil, and rivastigmine, with antipsychotic drugs in plasma. A sample pretreatment by liquid–liquid extraction and subsequent quantification by CZE with field-amplified sample injection (FASI) was used. The optimum separation for these analytes was achieved in <20 min at 25 °C with a fused-silica capillary column of 60.2 cm?×?50 μm I.D. (effective length 50 cm) and a run buffer containing 120 mM phosphate (pH 4.0) with 0.1 % γ-cyclodextrin, 40 % methanol (MeOH), and 0.02 % polyvinyl alcohol as a dynamic coating to reduce analytes’ interaction with the capillary wall. Using phenformin as an internal standard (40.0 ng/mL), the linear ranges of the proposed method for the simultaneous determination of donepezil, rivastigmine, aripiprazole, quetiapine, risperidone, clozapine, ziprasidone, and trazodone were over the range 4.0–80.0 ng/mL, and olanzapine was over the range 1.0–20.0 ng/mL. The method was applied for concentrations monitoring of AChEIs and antipsychotic drugs in ten Alzheimer’s disease patients with behavioral and psychological symptoms of dementia after oral administration of the commercial products.

Simultaneous Determination of Losartan Potassium, Atenolol and Hydrochlorothiazide in Pharmaceutical Preparations by Stability-Indicating UPLC

A stability-indicating UPLC method was developed for the simultaneous quantitative determination of losartan potassium, atenolol, and hydrochlorothiazide in pharmaceutical dosage forms in the presence of degradation products. The separation was achieved on a simple isocratic method (water: acetonitrile: triethyl amine: ortho phosphoric acid (60:40:0.1:0.1, v/v) at 0.7 mL min^?1, a detection wavelength of 225 nm). The retention times of losartan potassium, atenolol, and hydrochlorothiazide were 2.3, 0.6 and 0.9 min. The total runtime was 3 min. Losartan potassium, atenolol, and hydrochlorothiazide were subjected to different ICH prescribed stress conditions. The method was validated with respect to linearity, accuracy, precision, robustness and ruggedness.     

Simultaneous Determination of Senecionine,Senlciphylline, and Senecionine N-Oxide in Gynura segetum by RP-HPLC

Abstract

A rapid reversed-phase high-performance liquid chromatographic (RP-HPLC) method was established for simultaneous determination of senecionine, senlciphylline, and senecionine N-oxide in a famous traditional Chinese medicine, Gynura segetum, which has been commonly used for hemostasis. The HPLC assay was performed on a Kromasil KR100-5 C₁₈ column (25 cm × 4.6 mm, 5 µm) with mobile phase composed of acetonitrile and 0.2% phosphoric acid–triethylamine within 40 min. The detection wavelength was 220 nm. All the compounds showed good linearity (r² > 0.9997). The method was reproducible with intra- and interday variation less than 2.82%. The recovery of the assay was in the range of 96.55–103.88%. The method was successfully applied to the quantification of three constituents in 15 Gynura segetum samples collected from different metropolis. The results indicated that the developed assay could be considered as a suitable quality-control method for Gynura segetum.     

Determination of Rosuvastatin in Pharmaceutical Formulations by Capillary Zone Electrophoresis

A capillary zone electrophoretic method with diode array detection was developed and validated for the determination of rosuvastatin calcium in pharmaceutical formulations. Using fused-silica capillary (i.d. 50.0 μm, total length 48.5 cm and effective length 40.0 cm), the influence of the buffer composition, buffer pH and buffer concentration, as well as organic modifier, applied voltage, capillary temperature and injection time were investigated to optimize the method. Optimum results were obtained with 50.0 mM borate buffer at pH 9.5, capillary temperature 30 °C and applied voltage 25 kV. The samples were injected hydrodynamically for 5 s at 50 mbar. Detection wavelength was set at 243 nm. Diflunisal was used as internal standard. The migration times of rosuvastatin calcium and diflunisal were 3.20 ± 0.01 and 4.20 ± 0.02. The total time of analysis was <6 min. The method was validated for rosuvastatin calcium determination in pharmaceutical formulations through following performance parameters: stability, linearity, sensitivity, precision, accuracy, recovery, selectivity, robustness and ruggedness. The linear calibration range was 3.00–200.00 μg mL^?1 and the limits of detection and quantification were 1.00 and 3.00 μg mL^?1 with RSD of 4.38 and 3.09%. The proposed method was applied for the determination of rosuvastatin calcium in its pharmaceutical formulation.     

Derivative Spectrophotometric Determination of Copper and Palladium Simultaneously by Using MDTC as a Reagent

Abstract

A selective, sensitive, and economical derivative spectrophotometric method has been developed for the determination of trace amount of Cu(II) and Pd(II) with MDTC as a reagent in the presence of CTAB, a solubilizing agent. The molar absorption coefficient and analytical sensitivities of the 1:2 Cu(MDTC)₂ and Pd(MDTC)₂ complexes are 2.467×10⁴ and 2.989×10⁴ l mol^?1, respectively. The developed derivative procedure, is applied for the rapid and selective simultaneous determination of Cu(II) and Pd(II) in the range of 0.2–15 and 0.1–10 µg/ml, respectively. Complex matrices, including alloys, biological samples, pharmaceutical samples and synthetic mixtures have been successfully analyzed for trace amounts of two metal ions.     

Determination of Abacavir, Lamivudine and Zidovudine in Pharmaceutical Tablets, Human Serum and in Drug Dissolution Studies by HPLC

A simple, accurate, precise and fully automated method for the simultaneous determination of abacavir, lamivudine and zidovudine in pharmaceutical tablets, human serum samples and drug dissolution studies has been developed. Separation was performed on a 5 μm Zorbax^® C₁₈ column (150 × 4.6 mm ID) with methanol:water:phosphate buffer at pH 5.65 (80:10:10; v/v/v) isocratic elution in less than 7 min with a flow rate of 0.6 mL min^?1.Good sensitivity for all analytes was observed with UV detection at 275 nm. The method allowed quantitation over the 500–3,000 ng mL^?1 range for abacavir and 500–5,000 ng mL^?1 range for lamivudine and zidovudine. The method has been applied, without any interference from excipients or endogenous substances, for the simultaneous determination of these three compounds in tablets. Human serum and drug dissolution studies.     

Simultaneous Determination of Atenolol and Chlorthalidone by LC–MS–MS in Human Plasma

A simple, sensitive, selective and rapid liquid chromatography–tandem mass spectrometry method was developed and validated for the simultaneous separation and quantitation of atenolol and chlorthalidone in human plasma using metoprolol and hydrochlorothiazide as internal standard. Following solid phase extraction, the analytes were separated by an isocratic mobile phase on a reversed-phase C₁₈ column and analyzed by MS in the multiple reaction-monitoring mode (atenolol in positive and chlorthalidone in the negative ion mode). The limit of quantitation for this method was 10 and 15 ng mL^?1 and the linear dynamic range was generally 10–2,050 ng mL^?1 and 15–3,035 ng mL^?1 for atenolol and chlorthalidone, respectively.     

Enantioselective determination of modafinil in pharmaceutical formulations by capillary electrophoresis, and computational calculation of their inclusion complexes

A fast capillary electrophoretic method is described for the separation and determination of the enantiomers of the novel wake-promoting agent, modafinil. Several parameters affecting the separation were studied, including the type and concentration of chiral selector, buffer pH, buffer concentration, voltage and temperature. Good chiral separation of the racemic mixture was achieved in less than 5 min with resolution factor Rs?=?2.51, using a bare fused-silica capillary and a background electrolyte (BGE) of 25 mM H₃PO₄?1 M tris solution; pH 8.0; containing 30 mg mL^?1 of sulfated-β-cyclodextrin (S-β-CD). The separation was carried out in normal polarity mode at 25 ^?C, 18 kV and using hydrostatic injection. Acceptable validation criteria for selectivity, linearity, precision, and accuracy were included. The developed method was successfully applied to the assay of enantiomers of modafinil in pharmaceutical formulations. The computational calculations for the enantiomeric inclusion complexes rationalized the reasons for the different migration times between the modafinil enantiomers.     

Spectrofluorometric Determination of Drotaverine Hydrochloride in Pharmaceutical Preparations

Abstract

A highly sensitive, spectrofluorometric method was developed for the determination of drotaverine HCl in pharmaceutical preparations. The proposed method is based on the measurement of the native fluorescence of the drug in 0.1 M H₂SO₄ at emission 465 nm after excitation at 295 nm. The relative fluorescence intensity-concentration plot was rectilinear over the range of 0.16–4 µg·ml^?1, with good correlation (r = 0.9999) and a lower limit of detection (LOD) of 0.032 µg·ml?1. The proposed method was successfully applied for the determination of drotaverine HCl in tablets and ampoules with a recovery percentage of 100.42 ± 0.601,99.83 ± 0.82 and 99.43 ± 1.08, respectively, which were in accordance with those obtained by a compendial method.     

Development of a CZE Method for the Determination of Olmesartan Medoxomil in Tablets

A CZE method was developed and validated for the analysis of Olmesartan medoxomil (OLMD) in tablets. The influences of pH, buffer concentration, applied voltage and capillary temperature on the migration time of OLMD were investigated. About 50 mM pH 6.5 phosphate buffer were used as background electrolyte. The optimum instrument parameters were found to be 30 °C temperature with 30 kV applied voltage and diode array detection was carried out at 210 nm. OLMD was hydrodynamically injected (P _inj  = 50 mbar, t _inj  = 3 s) and an internal standard, diflunisal (IS), was used to improve the precision and repeatability. Under these conditions, the migration time of OLMD was 2.32 min and the total analysis time was shorter than 5 min. Linearity range for the developed method was found to be 2.0–50.0 μg mL⁻¹ and the limit of detection was 0.5 μg mL⁻¹. The developed method was applied for the analysis of OLMD in pharmaceutical tablet formulations.

     

Electrochemical Determination of Citalopram by Adsorptive Stripping Voltammetry–Determination in Pharmaceutical Products

Abstract

The electrochemical behavior of citalopram was studied by square‐wave and square‐wave adsorptive‐stripping voltammetry (SWAdSV). Citalopram can be reduced and accumulated at a mercury drop electrode, with a maximum peak current intensity being obtained at a potential of approximately ?1.25 V vs. AgCl/Ag, in an aqueous electrolyte solution of pH 12. A SWAdSV method has been developed for the determination of citalopram in pharmaceutical preparations. The method shows a linear range between 1.0×10^?7 and 2.0×10^?6 mol L^?1 with a limit of detection of 5×10^?8 mol L^?1 for an accumulation time of 30 s. The precision of the method was evaluated by assessing the repeatability and intermediate precision, achieving good relative standard deviations in all cases (≤2.3%). The proposed method was applied to the determination of citalopram in five pharmaceutical products and the results obtained are in good agreement with the labeled values.