Captopril In Plasma Research Articles

LC-MS/MS bioanalytical method for the quantitative analysis of nifedipine, bisoprolol, and captopril in human plasma: Application to pharmacokinetic studies.

In this study, the development and validation of an accurate and highly sensitive LC-MS/MS method were performed for the estimation of nifedipine, bisoprolol and captopril in real human plasma. Liquid-liquid extraction using tert-butyl methyl ether was efficiently applied for extraction of the analytes from plasma samples. The chromatographic separation was carried out using an isocratic elution mode on the X-terra MS C18 column (4.6 × 50 mm, 3.5μm). The mobile phase consisted of methanol-0.1% formic acid (95:5, v/v) for determination of nifedipine and bisoprolol and acetonitrile-0.1% formic acid (70:30, v/v) for determination of captopril with a flow rate of 0.5ml/min. Acceptable results regarding the different validation characteristics of the analytes were obtained in accordance with US Food and Drug Administration recommendations for bioanalytical methods. The developed approach was linear over concentration ranges of 0.5-130.0, 50.0-4,500.0 and 0.3-30.0ng/ml for nifedipine, captopril and bisoprolol, respectively. The method revealed a sufficient lower limit of quantification in the range of 0.3-50.0ng/ml, as well as high recovery percentages, indicating high bioanalytical applicability. The proposed method was efficiently applied to a pharmacokinetic evaluation of a fixed-dose combination of the analytes in healthy male volunteers.

Magnetic molecularly imprinted polymer based on dynamically established metal-mediated binding sites for the determination of trace captopril in rat plasma.

Therapeutic drug monitoring of captopril, which is a commonly used antihypertensive agent in clinical practice, is necessary. However, matrix effect-induced pretreatment is the bottleneck for determination. Metal-mediated molecularly imprinted polymers, an essential branch of molecularly imprinted polymers with better specificity and selectivity, have been used to separate/enrich analytes from complex matrices. In this work, Cu2+ was introduced to dynamically establish the binding sites of metal-mediated molecularly imprinted polymer towards captopril. All evidence demonstrated that the metal-mediated molecularly imprinted polymer based on Cu2+ coordination obtained a higher adsorption capacity (81.23mg/g), faster adsorption rate (adsorption equilibrium within 50min), and better selectivity (with the unrecognized analog). Subsequently, the Cu2+ -mediated molecularly imprinted polymer was used as dispersive molecularly imprinted solid-phase extraction to successfully establish an analytical platform for the determination of trace captopril in rat plasma. The enrichment factor was up to 20, the detection limit was as low as 0.16μg/ml, and the average recovery was in the range of 87.51%-98.28% with a relative standard deviation of less than 3.29%. This study provides a promising reference for the preparation of selective adsorbents to improve pretreatment.

Development and validation of reversed phase high performance liquid chromatography (RP-HPLC) for quantification of captopril in rabbit plasma

AbstractTh accurate rapid, simple and selective reversed phase high performance liquid chromatography (RP-HPLC) has been established and validated for the determination of captopril (CAP). Chromatographic separation was accomplished using prepacked ODSI C18 column (250 mm × 4.6 mm with 5 μm particle size) in isocratic mode, with mobile phase consisting of water: acetonitrile (60:40 v/v), pH adjusted to 2.5 by using 85% orthophosphoric acid at a flow rate of 1 mL/min and UV detection was performed at 203 nm. RP-HPLC method used for the analysis of CAP in mobile phase and rabbit plasma was established and validated as per ICH-guidelines. It was carried out on a well-defined chromatographic peak of CAP was established with a retention time of 4.9 min and tailing factor of 1.871. The liquid–liquid extraction method was used for extraction of CAP from the plasma. Excellent linearity (R2 = 0.999) was shown over range 3.125–100 µg/mL with mean percentage recoveries ranges from 97 to 100.6%. Parameters of precision and accuracy of the developed method meet the established criteria. Intra and inter-day precision (% relative standard deviation) study was also performed which was less than 2% which indicate good reproducibility of the method. The limit of detection (LOD) and quantification for the CAP in plasma were 3.10 and 9.13 ng/mL respectively. The method was suitably validated and successfully applied to the determination of CAP in rabbit plasma samples.

Determination of Captopril in Rat Plasma by LC-MS/MS in Presence of Apigenin

Determination of Captopril in Rat Plasma by LC-MS/MS in Presence of Apigenin

Development and validation of a simple and sensitive HPLC–UV method for the determination of captopril in human plasma using a new derivatizing reagent 2-naphthyl propiolate

In this study, a simple, sensitive and reliable HPLC-UV method applying rapid sample preparation technique for the determination of captopril in human plasma was developed and validated. The method is based on pre-column derivatization of captopril and 2-propene-1-thiol (internal standard) with a new reagent 2-naphthyl propiolate. Sample clean-up, derivatization and extraction were carried out in two steps, totally less than 30min. The extracts were chromatographed on a C18 column (5μm, 150mm×4.6mmi.d.). The mobile phase consisted of methanol (75%, v/v) and phosphate buffer (25%, pH=8, 0.01M). UV detection was performed at 290nm. To obtain the best reaction yield, the factors that could influence the derivatization process, including the concentration of derivatization reagent, pH of sample solution and temperature were investigated in detail and optimized using Box-Behnken response surface methodology. Under optimized conditions the average extraction recovery of captopril and internal standard were >86%. The achieved lower limit of quantification (LLOQ) was 3ng/mL; the assay exhibited a linear dynamic range of 3-2000ng/mL with correlation coefficient (r(2)) of ≥0.99. The precision was satisfactory in the whole calibration range with RSD of 5.9-12.4% (accuracy: from 97.5% to 93.6%) and of 6.4-12.8% (accuracy: from 97.3% to 95.2%) for intra- and inter-assay, respectively. The method stability was confirmed in a series of experiments including: freeze-thaw, short- and long-term stability testing. Lastly, the developed method was successfully applied to the bioequivalence study of captopril administrated as a single oral dose (50mg) to 12 healthy male volunteers.

Direct Determination of Four ACE-Inhibitors Lisinopril, Enalapril, Captopril and Fosinopril in Pharmaceuticals and Serum by HPLC

The high performance liquid chromatography (HPLC)-UV method for the simultaneous determination of lisinopril, enalapril, captopril and fosinopril in human plasma is proposed. Good separation of the analytes was achieved by gradient RP-HPLC with the mobile phase composed as acetonitrile: water (60:40 v/v) adjusted to pH 3.0 by orthophosphoric acid. Lisinopril, enalapril, captopril and fosinopril were eluted from a Purospher STAR RP-and Hypersil ODS column in 1.8, 2.9, 3.2 and 5.4 min respectively. Good linear relationships were observed for all of the analytes (R2 higher than 0.995). Intra and inter-day precision and accuracy results were 98.0 to 102%. Application of the suggested procedure was successfully applied to the determination of theses compounds in active pharmaceutical preparations, dosage formulations and human serum with high percentage of recovery, good accuracy and precision (no interference of excepients) and this method can be applied to routine clinical analysis

Highly sensitive turn-on fluorescent detection of captopril based on energy transfer between fluorescein isothiocyanate and gold nanoparticles

A novel approach for highly sensitive detection of captopril was developed based on the fluorescence resonance energy transfer (FRET) between gold nanoparticles (Au NPs) and fluorescein isothiocyanate (FITC), in which FITC acts as the donor and Au NPs as the acceptor. The fluorescence intensity of fluorescein isothiocyanate (FITC) was strictly quenched as a result of noncovalently adsorbed on Au NPs. Upon the addition of captopril, the fluorescence intensity of FITC “turn-on” due to the competition between captopril and FITC towards the surface of Au NPs. Under the optimum conditions, the fluorescence intensity of the released FITC displays a linear relationship in the range of 20μgL−1 to 500μgL−1 of captopril. Lower limit of detection for captopril, at the signal-to-noise ratio of 3 (3σ), was 2.6μgL−1. The developed methodology was successfully applied for the determination of captopril in human plasma.

Preparation and Characterization of Polymer Solid-phase Microextraction Monolith Modified with Gold Nanoparticles

In this experiment, a novel polymer monolithic capillary column functionalized with gold nanoparticles (AuNPs) that enables selective capture of thiol-containing compounds was prepared for solid-phase microextraction. The column was prepared from a poly (glycidyl methacrylate-co-ethylenedimethacrylate) monolith and was modified chemically with cysteamine, followed by immobilization of AuNPs on the surface of the pores of the monolith. Thiol-containing compounds as model compounds were tested to evaluate the performance of this solid-phase microextraction monolith. The results indicated that the polymer monolith could selectively capture thiol-containing compounds from analytes, because AuNPs have a strong affinity for thiol-containing ligands. The loading capacity of the polymer monolith modified with AuNPs and the regenerated column determined for glutathione were 0.718 and 0.603 μmol, respectively. The extraction and enrichment of thiol-containing drugs on the polymer monolith modified with AuNPs was also investigated. It was found that the enrichment was 30-fold for captopril and this monolith can be used for the extraction and enrichment of trace captopril in plasma.

Analysis of Captopril in Human Plasma Using Gas Chromatography-Mass Spectrometry (GCMS) with Solid-Phase Extraction (SPE)

A sensitive and simple Gas Chromatographic-Mass Spectrometric method was developed and validated for the determination of captopril in human plasma. Thiosalicylic acid was used as an internal standard, and plasma extraction was performed by solid phase extraction. The limit of quantification was 0.5 ng/mL with signal to noise ratio greater than 5. The calibration curve was linear from 1 to 160 ng/mL with r2 greater than 0.99. The coefficient of variation for within and between assay imprecision of the standards and for the limit of quantification were ≤ 10 % and ≤ 7 %, respectively. The percentage of inaccuracy for within- and between-assay including lower and upper limits of quantitation were ≤ 8 % and ≤ 6 %, respectively. The absolute recovery of captopril and thiosalicylic acid in plasma were greater than 98 % and 99 %, respectively. The high sensitivity and accuracy of this method allowed us to measure low concentrations of captopril in plasma for bioequivalence studies in healthy subjects. Keywords: Captopril, Gas chromatography-mass spectrometry, Solid phase extraction (SPE).

Assay of free captopril in human plasma as monobromobimane derivative, using RPLC/(+)ESI/MS/MS: validation aspects and bioequivalence evaluation

A sensitive method for determination of free captopril as monobromobimane derivative in plasma samples is discussed. The internal standard (IS) was 5-methoxy-1H-benzimidazole-2-thiol. Derivatization with monobromobimane immediately after blood collection and plasma preparation prevents oxidation of captopril to the corresponding disulfide compound and enhances the ionization yield. Consequently, derivatization enhances sample stability and detection sensitivity. Addition of the internal standard was made immediately after plasma preparation. The internal standard was also derivatized by monobromobimane, as it contains a thiol functional group. Preparation of plasma samples containing captopril and IS derivatives was based upon protein precipitation through addition of acetonitrile, in a volumetric ratio 1:2. The reversed-phase liquid chromatographic separation was achieved on a rapid resolution cartridge Zorbax SB-C(18), monitored through positive electrospray ionization and tandem MS detection using the multiple-reaction monitoring mode. Transitions were 408-362 amu for the captopril derivative and 371-260 amu for the internal standard derivative. The kinetics of captopril oxidation to the corresponding disulfide compound in plasma matrix was also studied using the proposed method. A linear log-log calibration was obtained over the concentration interval 2.5-750 ng/mL. A low limit of quantitation in the 2.5 ng/mL range was obtained. The analytical method was fully validated and successfully applied in a three-way, three-period, single-dose (50 mg), block-randomized bioequivalence study for two pharmaceutical formulations (captopril LPH 25 and 50 mg) against the comparator Capoten 50 mg.

Rapid analysis of captopril in human plasma and pharmaceutical preparations by headspace solid phase microextraction based on polypyrrole film coupled to ion mobility spectrometry

A rapid, simple, and sensitive headspace solid phase microextraction coupled to ion mobility spectrometry (HS-SPME-IMS) method is presented for analysis of the highly specific angiotensin-converting enzyme (ACE) inhibitor, captopril (CAP). Positive ion mobility spectra of CAP were acquired with an ion mobility spectrometer equipped with a corona discharge ionization source. Mass-to-mobility correlation equation was used to identify product ions. A dodecylsulfate-doped polypyrrole (PPy-DS) coating was used as a fiber for SPME. The results showed that PPy-DS based SPME fiber was suitable for successfully extracting CAP from human blood plasma and pharmaceutical samples. The HS-SPME-IMS method provided good repeatability (R.S.D.s < 4%) for aqueous and spiked plasma samples. The calibration graphs were linear in the range of 10–300 ng mL −1 ( R 2 > 0.99) and detection limits were 7.5 ng mL −1 for aqueous and 6.3 ng mL −1 for plasma blank samples. Finally, a standard addition calibration method was applied to HS-SPME-IMS technique for the analysis of blood plasma samples and tablets. Purpose method seemed to be suitable for the analysis of CAP in plasma samples as it is not time consuming (state total time from sample preparation to analysis), it required only small quantities of the sample, and no derivatization was required.

Determination of free captopril in human plasma by liquid chromatography with mass spectrometry detection

A new simple, sensitive and selective liquid chromatography coupled with mass spectrometry (LC/MS) method for quantification of captopril after precolumn derivatization with p-bromo-phenacyl-bromide in human plasma was validated. Plasma samples were analysed on a monolithic column (Cromolith Performance-RP 18e, 100 mm × 4.6 mm I.D., 3 μm) under isocratic conditions using a mobile phase of a 40:60 (v/v) mixture of acetonitrile and 0.1% (v/v) formic acid in water. The flow rate was 1 mL/min at the column temperature of 30 °C. In these chromatographic conditions, the retention time was 4.4 min for captopril derivative. The detection of the analyte was in MRM mode using an ion trap mass spectrometer with electrospray positive ionisation. The monitored ions were 216, 253, 255, 268, 270 m/ z derived from 415 m/ z for derivatized captopril. The sample preparation was very simple and consisted in plasma protein precipitation from 0.2 mL plasma using 0.3 mL methanol after the derivatization reaction was completed. Calibration curves were generated over the range of 10–3000 ng/mL with values for coefficient of correlation greater than 0.993 and by using a weighted (1/ y 2) quadratic regression. The values for precision (CV %) and accuracy (relative error %) at quantification limit were less than 9.9% and 3.9%, for within- and between-run, respectively. The mean recovery of the analyte was 99%. Derivatized samples demonstrated good short-term, long-term, post-preparative and freeze–thaw stability. This is the first reported LC–MS/MS method for analysis of captopril in human plasma that uses protein precipitation as sample processing procedure. The method is very simple and allows obtaining a very good recovery of the analyte. The validated LC–MS/MS method has been applied to a pharmacokinetic study of 50 mg captopril tablets on healthy volunteers.

Simultaneous CE Determination of Captopril and Indapamide in Pharmaceuticals and Human Plasma

Capillary electrophoresis with UV photo diode-array detection was utilized to adopt a new method for the assay of captopril and indapamide in pharmaceuticals and human plasma. Electrophoretic conditions controlling the analysis were optimized to develop separation, sensitivity and rapidity. The optimum conditions obtained were 100 mM borate at pH 9.0, injection time 10.0 s, voltage 25 kV and column temperature 25 °C with detection at 220 nm. Relatively, wide dynamic ranges for captopril (1–100 mg L−1) and indapamide (0.1–40 mg L−1) were obtained. Also, the method recorded acceptable intra- and inter-day accuracy (89.8–97.9%) and precision (0.77–3.50%) in pharmaceutical formulations and human plasma. The sensitivity of the method was developed by the optimization and the preconcentration conducted for human plasma sample using liquid–liquid extraction. The limit of detection gained (0.075 and 0.045 mg L−1 for captopril and indapamide, respectively) reached the level of both drugs possibly found in human plasma. The method is suitable to be applied in pharmaceutical industries for quality control and in clinical laboratories for therapeutic drug monitoring purposes.

Determination of captopril in human plasma with precolumn derivatization using solid phase extraction and HPLC

A rapid, accurate and sensitive method for the determination of captopril in human plasma was developed by solid phase extraction and high performance liquid chromatography (HPLC), using precolumn derivatization of captopril with chromophore label o-phethaldialdehyde (OPA). The extraction of captopril from human plasma was carried out by an amino propyl cartridge. A 0.01 M solution of HCl in methanol showed the best recovery and was chosen for elution of captopril in cartridge. This methanolic solution was applied to react with aqueous solution of OPA and glycine as a coderivatization reagent. The process of derivatization was completed within 2 min at room temperature. The derivatized captopril was injected into a reverse phase HPLC system. Mobile phase was consisted of water:acetonitrile:trifluoroacetic acid (85:15:0.1 v/v/v) with a flow rate of 1 ml min−1 and detector was used at 345 nm. Linear dynamic range and limit of detection were found as 0.1–6 ppm and 0.1 ppm, respectively.

Determination of Captopril in Human Plasma by Liquid Chromatography/Tandem Mass Spectrometry

In this study, a fast and sensitive liquid chromatography/tandem mass spectrometry method for the determination of captopril in human plasma was developed and validated. The analyte and enalaprilat, used as the internal standard, were extracted from plasma using methanol directly precipitate protein. Analysis was performed on a Lichrospher CN column with water (containing 0.1% formic acid) and methanol (60∶40, v/v) as the mobile phase. Linearity was assessed from 6.25 to 800 ng/ml in plasma. The analytical method proved to be applicable in a pharmacokinetic study of captopril after oral administration of 20 mg captopril tablet to 20 healthy volunteers.

Phenotypical peculiarities of captopril pharmacokinetics

Individual pharmacokinetic profiles of captopril and capoten depend on adaptation reactions of the organism and variants of autonomic regulations of functions. Maximum bioavailability and peak concentrations of captopril in blood plasma were observed during phenotypically determined physiological adaptation reactions of the general adaptation syndrome (“training” and “zone of mild activation”) and decreased during reactions of “enhanced activation” and “hyperactivation” The observed relationships can be explained by the existing gradient of sympathetic influences in the regulation of variants of adaptation reactions.

Determination of captopril in human plasma, using solid phase extraction and high-performance liquid chromatography, coupled to mass spectrometry: Application to bioequivalence study

A specific high performance liquid chromatography–mass spectrometric (LC–MS/MS) assay was developed for the determination of captopryl in plasma. The retention time was 1.45 and 1.37 min for captopril and enalapril, respectively. The overall mean recovery, using SPE extraction with OASIS ® HLB cartridges, was found to be 107.2 ± 9.5 and 100.04 ± 2%, respectively. Calibration curves were linear in the concentration range of 10.00–2000.00 ng/ml, and the lower limit of quantification (LLOQ) was 10.00 ng/ml. The LLOQ was sensitive enough for detecting terminal phase concentrations of the drug. Inter-batch precision of the method ranged from 0.88 to 1.95%. Intra-batch accuracy ranged from 97.15 to 105.77%, while intra-batch precision ranged from 2.49 to 5.66% at concentrations of 30.00, 760.00 and 1500.00 ng/ml. The developed method was applied to study bioequivalence of captopril in a group of 25 human subjects at a single oral dose of a 50 mg tablet.

Simultaneous determination of captopril and hydrochlorothiazide in human plasma by reverse-phase HPLC from linear gradient elution

A simple, rapid and sensitive high-performance liquid chromatographic method for the simultaneous determination of captopril and hydrochlorothiazide in human plasma samples was developed. Captopril was derivatized with 2,4′-dibromoacetophenone (pBPB) to form a captopril-pBPB adduct. From acidified serum plasma samples, the hydrochlorothiazide and derivatized captopril was extracted with 5 ml ether, then with 5 ml dichloromethane. Effective chromatographic separation was achieved using a C 18 column (DIAMONSIL 150 mm × 4 mm i.d., 5 μm) based on an acetonitrile–trifluoroacetic acid–water gradient elution at a flow rate of 1.2 ml/min. The internal standard (IS), derivatized captopril and hydrochlorothiazide were detected at 263 nm and were eluted at 4.2, 6.8 and 16.9 min, respectively. No endogenous substances were found to interfere. The limit of quantification for hydrochlorothiazide and derivatized captopril in plasma were 3.3 and 7 ng/ml. The calibration curve for derivatized captopril showed linearity in the range 20–4000 ng/ml, with a regression coefficient corresponding to 0.9993 and the coefficient of the variation of the points of the calibration curve being lower than 10%. The calibration curve for hydrochlorothiazide showed linearity in the range 10–1200 ng/ml, with a regression coefficient corresponding to 0.9999 and the coefficient of the variation of the points of the calibration curve being lower than 10%. The method was suitably validated and successfully applied to the determination of captopril and hydrochlorothiazide in human plasma samples.

A selective and rapid method for the quantification of captopril in human plasma using liquid chromatography/selected reaction monitoring mass spectrometry

A specific hyphenated high performance liquid chromatography–mass spectrometric (LC–MS/MS) assay was developed for the determination of captopril in plasma. The drug was extracted from plasma using liquid–liquid extraction with a mixture of diethylether:dichloromethane. After the addition of the internal standard, samples were applied to a prepacked C 8 Waters Symmetry column. The ion trap MS/MS detector was equipped with electrospray ionization (ESI) source operating in the positive ion mode. Drug determination was accomplished monitoring captopril at molecular ion m/ z 218 and MS/MS (daughter) at m/ z 171.6. The method was applied to captopril determination in human plasma after the administration of captopril 50 mg tablets to healthy volunteers who have participated in a pharmacokinetic study. The method was proved to be specific and precise by testing six different plasma batches. Linearity was established for the range of concentrations 25–3000 ng/ml with a regression factor of 0.9995. Intra-day accuracy ranged from 90.16 to 96.18%, while the intra-day precision ranged from 2.60 to 9.66% at the concentrations of 75, 1440 and 2500 ng/ml. Inter-day precision of the method ranged from 5.04 to 10.10%. This validated method of analysis was successfully applied to human plasma analyses after the administration of a single dose of 50 mg captopril tablets to healthy volunteers.

Validation of a LC-fluorescence method for determination of free captopril in human plasma, using a pre-column derivatization reaction with monobromobimane

Both derivatization of free captopril in human plasma samples using monobromobimane as fluorescent label and the corresponding HPLC-fluorescence detection (FLD) method were validated. Calibration curve for the fluorescent captopril derivative in plasma samples is linear in the ppb–ppm range with a detection limit of 4 ppb and an identification limit of 10 ppb ( P%: 90; ν≥5). These methods were successfully applied on bioequivalence studies carried out on some marketed pharmaceutical formulations.