A carbon paste electrode (CPE) modified with ferrocene carboxylic acid (FcCA) and TiO2 nanoparticles was constructed by incorporating TiO2 nanoparticles and ferrocene carboxylic acid into the carbon paste matrix. The ...A carbon paste electrode (CPE) modified with ferrocene carboxylic acid (FcCA) and TiO2 nanoparticles was constructed by incorporating TiO2 nanoparticles and ferrocene carboxylic acid into the carbon paste matrix. The electrochemical behavior of captopril (CAP) at the surface of the modified electrode was investigated using electroanalytical methods. The modified electrode showed excellent electrocatalytic activity for the oxidation of CAP in aqueous solutions at physiological pH values. Cyclic voltammetric curves showed that the oxidation of CAP at the surface of the modified electrode reduced its overpotential by more than 290 mV. The modified electrode was used for detecting captopril using cyclic voltammetry and square wave voltammetry techniques. A calibration curve in the range of 0.03 to 2400 μmol/L was obtained that had a detection limit of 0.0096 μmol/L (3?) under the optimized conditions. The modified electrode was successfully used for the determination of captopril in pharmaceutical and biological samples.展开更多
The combined use of chemometrics and chemiluminescence(CL)measurements,with the aid of the stopped-flow mixing technique,developed a simple time-resolved CL method for the simultaneous determination of captopril(CP...The combined use of chemometrics and chemiluminescence(CL)measurements,with the aid of the stopped-flow mixing technique,developed a simple time-resolved CL method for the simultaneous determination of captopril(CPL)and hydrochlorothiazide(HCT).The stopped-flow technique in a continuous-flow system was employed in this work in order to emphasize the kinetic differences between the two analytes in cerium(IV)-rhodamine 6G CL system.After the flow was stopped,an initial rise of CL signal was observed for HCT standards,while a direct decay of CL signal was obtained for CPL standards.The mixed CL signal was monitored and recorded on the whole process of continuous-flow/stopped-flow,and the obtained data were processed by the chemometric approach of artificial neural network.The relative prediction error(RPE)of CPL and HCT was 5.9% and 8.7%,respectively.The recoveries of CPL and HCT in tablets were found to fall in the range between 95% and 106%.The proposed method was successfully applied to the simultaneous determination of CPL and HCT in a compound pharmaceutical formulation.展开更多
A novel method for the determination of captopril by spectrophotometer is described in this paper. The experiment is based on the fact that Fe(Ⅲ) is reduced to Fe(Ⅱ) by captopril, then the in sire formed Fe(Ⅱ...A novel method for the determination of captopril by spectrophotometer is described in this paper. The experiment is based on the fact that Fe(Ⅲ) is reduced to Fe(Ⅱ) by captopril, then the in sire formed Fe(Ⅱ) reacts with potassium ferricyanide to give the soluble prussian blue at pH 4.00, and its maximal adsorption wavelength (λmax) is 735 nm. Good linear relationship is obtained between the absorbance and the concentration of captopril in the wide range of 0.05-20 μg/mL. The linear regression equation is A = -0.04314 + 0.11423C (μg/mL) with a correlation coefficient R = 0.9998. The detection limit (3σ/k) is 0.04 μg/mL, the molar absorption coefficient is 2.5×10^4 L/mol cm. By mensurating the absorbance of soluble prussian blue, the indirect determination of captopril can be obtained. This method has been successfully applied to determination of captopril in pharmaceutical samples. Analytical results obtained are satisfactory.展开更多
Objective:To observe the effect of captopril on the tumor necrosis factor-α(TNF- α) level and arterial blood gases in acute lung injury(All) induced by HCL in rats,and to analyze its protective mechanism.Methods:Fif...Objective:To observe the effect of captopril on the tumor necrosis factor-α(TNF- α) level and arterial blood gases in acute lung injury(All) induced by HCL in rats,and to analyze its protective mechanism.Methods:Fifty Wistar rats were selected and randomly divided into three groups,with 20 rats in Group Ⅰ and Ⅱ,respectively and 10 animals in Group Ⅲ.ALI model was constructed by intratracheal injection of diluted hydrochloric acid(pH=1.25.1.2 mL/kg).Group Ⅰrats received not any treatment after construction of AM model.Group Ⅱ rats were treated with captopril(5 mg/kg,i.p.) 5 min after induction of ALI.Group Ⅲ served as normal control without any treatment.Ninety minutes after construction of ALI model,all the rats were sacrificed.Blood was withdrawn for detection of TNF- α level and arterial blood gases index.And lung tissue slices of the three groups were prepared for observation of pathologic histology changes.Results:TNF- α level in serum of Group Ⅰ and Ⅱ rats was significantly higher than that in Group Ⅲ(P<0.05),while TNF- α level in serum of Group Ⅱ was significantly lower in Group Ⅰ(P<0.05).PaCO_2 level was significantly higher(P<0.05),while PaO_2 was significantly lower(P<0.05) in Group Ⅰ and Ⅱ rats than those in Group Ⅲ.PaCO_2 was significantly lower(P<0.05) and PaO_2 was significantly higher(P<0.05) in Group Ⅱ than those in Group Ⅰ.Histological observation showed diffuse congestion and severe edema of luug tissue,obvious thickening and structure damage of alveolar walls and a large amount of neutrophil infiltration in Group Ⅰ rats.Group Ⅱ rats showed mild edema of lung tissue;only a small portion of alveolar walls showed thickening and only a few of neutrophil infiltration could be observed.The degree of injury was remarkably slighter than that of Group Ⅰ rats.Group Ⅲ rats showed clear lung tissue structure and normal morphology:alveolar walls were uniform and the margin was smooth and few neutrophil could be observed.Conclusions:Captopril can significantly reduce serum TNF- α level,elevate PaO_2 and reduce PaCO_2 in rats with ALI.It has a protective effect on ALI rats.展开更多
In this work,we describe a new strategy for the electrochemical determination of captopril(CA) using ferrocenemonocarboxylic acid as a mediator and multiwall carbon nanotubes as sensors in aqueous solution at pH 7.0...In this work,we describe a new strategy for the electrochemical determination of captopril(CA) using ferrocenemonocarboxylic acid as a mediator and multiwall carbon nanotubes as sensors in aqueous solution at pH 7.0.The diffusion coefficient(D),and the kinetic parameters such as electron transfer coefficient(α).and heterogeneous rate constant(kh),for CA were also determined using electrochemical approaches.Under the optimized conditions,the electrocatalytic oxidation peak current of captopril showed two linear dynamic ranges with a detection limit of 0.3×10^-6 mol L^-1 captopril.The linear calibration range was 0.8×10^(-6) to 65×10^-6 mol L^-1 using cyclic voltammetry.Finally,this modified electrode was also examined as a selective,simple and precise new electrochemical sensor for the determination of captopril in real samples such as drug and patient human urine.展开更多
Objective:To investigate the therapeutic effect of the intervention treatment with different doses of Captopril on TNF-α contents in serum of rheumatoid arthritis(RA) rats,and to provide the theoretical proofs for cl...Objective:To investigate the therapeutic effect of the intervention treatment with different doses of Captopril on TNF-α contents in serum of rheumatoid arthritis(RA) rats,and to provide the theoretical proofs for clinical application of Captopril in treatments ol rheumatoid diseases.Methods:Fifty Wistar rats were randomly divided into 5 groups,namely.Group A,Group 13.Group C.Group D,Group E with 10 rats in each group.Injection of Freund's complete adjuvant was employed to establish adjuvant-induced arthritis model in rats.Group A was model group;after model establishment,rats were treated with 20 mL normal saline as placebo(ip.).Rats in Group B were treated with 8 mg/kg cyclophosphamide(ip.).Rats in Group C.D and E were intraperitoneally injected with 30 mg/kg.100 mg/kg and 300 mg/kg Captopril respectively.Rats in each group were subjected to continuous treatment for 3 weeks,and then sacrificed.Eyeballs of rats were excised and blood was collected.TNF- α content in serum were detected using ELISA:each group rats were compared for the hind legs arthrocele.Right ankle tissues of rats were collected to prepare section,and microscopic observation of pathological changes was performed.Results:TNF- α content in serum of Group A rats was significantly higher than that of rats in other 4 groups(P<0.05).TNF- α content in serum of Group B rats was significantly lower compared with that of rats in Groups C.D and E.The highest TNF- α content in serum of rats treated with Captopril was found in Group C,followed by Groups D and E(P<0.05).Right ankle arthrocele of rats in Groups B.C.D and E in early stage showed no statistical difference compared with that of Group A rats(P>0.05).From Day 8,ankle arthrocele of rats in Groups B.C.D and E was obviously relieved compared with that of Group A rats:the anti-inflammatory effects were gradually enhanced with the extension of medication time.Treatments of Groups C.D and E showed significant activities against tardive aithrocele:the degree of ankle arthrocele in rats of these three groups was lower than that of Group A rats(P<0.01).Histological observation showed that large amount of inflammatory cells and plasmocyte infiltration was found in ankle synovial tissues of Group A rats.Relief of hyperaemia and edema of right ankle synovial tissues as well as significant decrease in synoviocyte layer hyperplasia,intra—articular inflammatory cells infiltration and cartilage articularis damage degree etc.were observed in Groups B.C.D and E.Conclusions:Intervention treatment with Captopril can effectively reduce the TNF- α content in serum of rheumatoid arthritis rats and inhibit the generation of inflammatory factors,so as to achieve the therapeutic effect.展开更多
The captopril/ Chitosan-gelatin net-polymer microspheres ( Gap/ CGNPMs ) were prepared using Chitosan ( CS ) and gelatin ( Gel ) by the methods of emulsification. A cross linked reagent alone or in combination ...The captopril/ Chitosan-gelatin net-polymer microspheres ( Gap/ CGNPMs ) were prepared using Chitosan ( CS ) and gelatin ( Gel ) by the methods of emulsification. A cross linked reagent alone or in combination with microcrystalline cellulose ( MCC ) was added in the process of preparation of microspheres to eliminate dose dumping and burst phenomenon of microspheres for the improvemeat of the therapeutic efficiency and the decrease of the side effects of captopril ( Cap ). The results indicate that Cap/ CGNPMs have a spherical shape , smooth surface roorphology and integral inside structure and no adhesive phenomena and good roobility , and the size distribution is mairdy from 220 to 280 μm. Researches on the Cap release test in vitro demonstrate that Cap/ CGNPMs are of the role of retarding release of Cap compared with Cap ordinary tablets (COT), embedding ratio (ER) , drug loading ( DL ), and swelling ratio ( SR ), and release behaviors of CGNPMS are influenced by process conditions of preparation such as experimental material ratio (EMR) , composition of cross linking reagents. Among these factors , the EMR(1/4), CLR ( FOR + TPP) and 0.75% microcrystulline cellulose (MCC) added to the microspheres are the optimal scheme to the preparation of Cap/CGNPMs. The Cap/CGNPMs have a good characteristic of sustained release of drug, and the process of emulsifieation and crossinking process is simple and stable. The CGNPMs is probable to be one of an ideal sustained release system for water-soluble drugs.展开更多
Spectrophotometric method has been developed for the direct quantitative determination of captopril in pharmaceutical preparation and biological fluids (human plasma and urine) samples. The method was accomplished b...Spectrophotometric method has been developed for the direct quantitative determination of captopril in pharmaceutical preparation and biological fluids (human plasma and urine) samples. The method was accomplished based on parallel factor analysis (PARAFAC) and partial least squares (PLS). The study was carried out in the pH range from 2.0 to 12.8 and with a concentration from 0.70 to 61.50μg mL^-1 of captopril. Multivariate calibration models such as PLS at various pH and PARAFAC were elaborated from ultraviolet spectra deconvolution and captopril determination. The best models for this system were obtained with PARAFAC and PLS at pH 2.0. The applications of the method for determination of real samples were evaluated by analysis of captopril in pharmaceutical preparations and biological fluids with satisfactory results. The accuracy of the method, evaluated through the RMSEE was 0.5801 for captopril with best calibration curve by PARAFAC and 0.6168 for captopril with PLS at pH 2.0 model.展开更多
文摘A carbon paste electrode (CPE) modified with ferrocene carboxylic acid (FcCA) and TiO2 nanoparticles was constructed by incorporating TiO2 nanoparticles and ferrocene carboxylic acid into the carbon paste matrix. The electrochemical behavior of captopril (CAP) at the surface of the modified electrode was investigated using electroanalytical methods. The modified electrode showed excellent electrocatalytic activity for the oxidation of CAP in aqueous solutions at physiological pH values. Cyclic voltammetric curves showed that the oxidation of CAP at the surface of the modified electrode reduced its overpotential by more than 290 mV. The modified electrode was used for detecting captopril using cyclic voltammetry and square wave voltammetry techniques. A calibration curve in the range of 0.03 to 2400 μmol/L was obtained that had a detection limit of 0.0096 μmol/L (3?) under the optimized conditions. The modified electrode was successfully used for the determination of captopril in pharmaceutical and biological samples.
基金supported by the National Natural Science Foundation of China(No.20675063)
文摘The combined use of chemometrics and chemiluminescence(CL)measurements,with the aid of the stopped-flow mixing technique,developed a simple time-resolved CL method for the simultaneous determination of captopril(CPL)and hydrochlorothiazide(HCT).The stopped-flow technique in a continuous-flow system was employed in this work in order to emphasize the kinetic differences between the two analytes in cerium(IV)-rhodamine 6G CL system.After the flow was stopped,an initial rise of CL signal was observed for HCT standards,while a direct decay of CL signal was obtained for CPL standards.The mixed CL signal was monitored and recorded on the whole process of continuous-flow/stopped-flow,and the obtained data were processed by the chemometric approach of artificial neural network.The relative prediction error(RPE)of CPL and HCT was 5.9% and 8.7%,respectively.The recoveries of CPL and HCT in tablets were found to fall in the range between 95% and 106%.The proposed method was successfully applied to the simultaneous determination of CPL and HCT in a compound pharmaceutical formulation.
文摘A novel method for the determination of captopril by spectrophotometer is described in this paper. The experiment is based on the fact that Fe(Ⅲ) is reduced to Fe(Ⅱ) by captopril, then the in sire formed Fe(Ⅱ) reacts with potassium ferricyanide to give the soluble prussian blue at pH 4.00, and its maximal adsorption wavelength (λmax) is 735 nm. Good linear relationship is obtained between the absorbance and the concentration of captopril in the wide range of 0.05-20 μg/mL. The linear regression equation is A = -0.04314 + 0.11423C (μg/mL) with a correlation coefficient R = 0.9998. The detection limit (3σ/k) is 0.04 μg/mL, the molar absorption coefficient is 2.5×10^4 L/mol cm. By mensurating the absorbance of soluble prussian blue, the indirect determination of captopril can be obtained. This method has been successfully applied to determination of captopril in pharmaceutical samples. Analytical results obtained are satisfactory.
基金supported by Science and Technology Research and Development Program of Tangshan City,Reference No.07130233d
文摘Objective:To observe the effect of captopril on the tumor necrosis factor-α(TNF- α) level and arterial blood gases in acute lung injury(All) induced by HCL in rats,and to analyze its protective mechanism.Methods:Fifty Wistar rats were selected and randomly divided into three groups,with 20 rats in Group Ⅰ and Ⅱ,respectively and 10 animals in Group Ⅲ.ALI model was constructed by intratracheal injection of diluted hydrochloric acid(pH=1.25.1.2 mL/kg).Group Ⅰrats received not any treatment after construction of AM model.Group Ⅱ rats were treated with captopril(5 mg/kg,i.p.) 5 min after induction of ALI.Group Ⅲ served as normal control without any treatment.Ninety minutes after construction of ALI model,all the rats were sacrificed.Blood was withdrawn for detection of TNF- α level and arterial blood gases index.And lung tissue slices of the three groups were prepared for observation of pathologic histology changes.Results:TNF- α level in serum of Group Ⅰ and Ⅱ rats was significantly higher than that in Group Ⅲ(P<0.05),while TNF- α level in serum of Group Ⅱ was significantly lower in Group Ⅰ(P<0.05).PaCO_2 level was significantly higher(P<0.05),while PaO_2 was significantly lower(P<0.05) in Group Ⅰ and Ⅱ rats than those in Group Ⅲ.PaCO_2 was significantly lower(P<0.05) and PaO_2 was significantly higher(P<0.05) in Group Ⅱ than those in Group Ⅰ.Histological observation showed diffuse congestion and severe edema of luug tissue,obvious thickening and structure damage of alveolar walls and a large amount of neutrophil infiltration in Group Ⅰ rats.Group Ⅱ rats showed mild edema of lung tissue;only a small portion of alveolar walls showed thickening and only a few of neutrophil infiltration could be observed.The degree of injury was remarkably slighter than that of Group Ⅰ rats.Group Ⅲ rats showed clear lung tissue structure and normal morphology:alveolar walls were uniform and the margin was smooth and few neutrophil could be observed.Conclusions:Captopril can significantly reduce serum TNF- α level,elevate PaO_2 and reduce PaCO_2 in rats with ALI.It has a protective effect on ALI rats.
文摘In this work,we describe a new strategy for the electrochemical determination of captopril(CA) using ferrocenemonocarboxylic acid as a mediator and multiwall carbon nanotubes as sensors in aqueous solution at pH 7.0.The diffusion coefficient(D),and the kinetic parameters such as electron transfer coefficient(α).and heterogeneous rate constant(kh),for CA were also determined using electrochemical approaches.Under the optimized conditions,the electrocatalytic oxidation peak current of captopril showed two linear dynamic ranges with a detection limit of 0.3×10^-6 mol L^-1 captopril.The linear calibration range was 0.8×10^(-6) to 65×10^-6 mol L^-1 using cyclic voltammetry.Finally,this modified electrode was also examined as a selective,simple and precise new electrochemical sensor for the determination of captopril in real samples such as drug and patient human urine.
基金supported by Science and Technology Research and Development Program of Tangshan City.Grant Number:07130233d
文摘Objective:To investigate the therapeutic effect of the intervention treatment with different doses of Captopril on TNF-α contents in serum of rheumatoid arthritis(RA) rats,and to provide the theoretical proofs for clinical application of Captopril in treatments ol rheumatoid diseases.Methods:Fifty Wistar rats were randomly divided into 5 groups,namely.Group A,Group 13.Group C.Group D,Group E with 10 rats in each group.Injection of Freund's complete adjuvant was employed to establish adjuvant-induced arthritis model in rats.Group A was model group;after model establishment,rats were treated with 20 mL normal saline as placebo(ip.).Rats in Group B were treated with 8 mg/kg cyclophosphamide(ip.).Rats in Group C.D and E were intraperitoneally injected with 30 mg/kg.100 mg/kg and 300 mg/kg Captopril respectively.Rats in each group were subjected to continuous treatment for 3 weeks,and then sacrificed.Eyeballs of rats were excised and blood was collected.TNF- α content in serum were detected using ELISA:each group rats were compared for the hind legs arthrocele.Right ankle tissues of rats were collected to prepare section,and microscopic observation of pathological changes was performed.Results:TNF- α content in serum of Group A rats was significantly higher than that of rats in other 4 groups(P<0.05).TNF- α content in serum of Group B rats was significantly lower compared with that of rats in Groups C.D and E.The highest TNF- α content in serum of rats treated with Captopril was found in Group C,followed by Groups D and E(P<0.05).Right ankle arthrocele of rats in Groups B.C.D and E in early stage showed no statistical difference compared with that of Group A rats(P>0.05).From Day 8,ankle arthrocele of rats in Groups B.C.D and E was obviously relieved compared with that of Group A rats:the anti-inflammatory effects were gradually enhanced with the extension of medication time.Treatments of Groups C.D and E showed significant activities against tardive aithrocele:the degree of ankle arthrocele in rats of these three groups was lower than that of Group A rats(P<0.01).Histological observation showed that large amount of inflammatory cells and plasmocyte infiltration was found in ankle synovial tissues of Group A rats.Relief of hyperaemia and edema of right ankle synovial tissues as well as significant decrease in synoviocyte layer hyperplasia,intra—articular inflammatory cells infiltration and cartilage articularis damage degree etc.were observed in Groups B.C.D and E.Conclusions:Intervention treatment with Captopril can effectively reduce the TNF- α content in serum of rheumatoid arthritis rats and inhibit the generation of inflammatory factors,so as to achieve the therapeutic effect.
基金Funded by the National Natural Science Foundation of China(No.30370344)
文摘The captopril/ Chitosan-gelatin net-polymer microspheres ( Gap/ CGNPMs ) were prepared using Chitosan ( CS ) and gelatin ( Gel ) by the methods of emulsification. A cross linked reagent alone or in combination with microcrystalline cellulose ( MCC ) was added in the process of preparation of microspheres to eliminate dose dumping and burst phenomenon of microspheres for the improvemeat of the therapeutic efficiency and the decrease of the side effects of captopril ( Cap ). The results indicate that Cap/ CGNPMs have a spherical shape , smooth surface roorphology and integral inside structure and no adhesive phenomena and good roobility , and the size distribution is mairdy from 220 to 280 μm. Researches on the Cap release test in vitro demonstrate that Cap/ CGNPMs are of the role of retarding release of Cap compared with Cap ordinary tablets (COT), embedding ratio (ER) , drug loading ( DL ), and swelling ratio ( SR ), and release behaviors of CGNPMS are influenced by process conditions of preparation such as experimental material ratio (EMR) , composition of cross linking reagents. Among these factors , the EMR(1/4), CLR ( FOR + TPP) and 0.75% microcrystulline cellulose (MCC) added to the microspheres are the optimal scheme to the preparation of Cap/CGNPMs. The Cap/CGNPMs have a good characteristic of sustained release of drug, and the process of emulsifieation and crossinking process is simple and stable. The CGNPMs is probable to be one of an ideal sustained release system for water-soluble drugs.
文摘Spectrophotometric method has been developed for the direct quantitative determination of captopril in pharmaceutical preparation and biological fluids (human plasma and urine) samples. The method was accomplished based on parallel factor analysis (PARAFAC) and partial least squares (PLS). The study was carried out in the pH range from 2.0 to 12.8 and with a concentration from 0.70 to 61.50μg mL^-1 of captopril. Multivariate calibration models such as PLS at various pH and PARAFAC were elaborated from ultraviolet spectra deconvolution and captopril determination. The best models for this system were obtained with PARAFAC and PLS at pH 2.0. The applications of the method for determination of real samples were evaluated by analysis of captopril in pharmaceutical preparations and biological fluids with satisfactory results. The accuracy of the method, evaluated through the RMSEE was 0.5801 for captopril with best calibration curve by PARAFAC and 0.6168 for captopril with PLS at pH 2.0 model.