In recent years, antibiotic pollution has become a serious threat to human health. In this study, a gas-liquid discharge plasma is developed to degrade ciprofloxacin hydrochloride in a multiphase mixed system containi...In recent years, antibiotic pollution has become a serious threat to human health. In this study, a gas-liquid discharge plasma is developed to degrade ciprofloxacin hydrochloride in a multiphase mixed system containing inorganic and organic impurities. The discharge characteristics are analyzed by diagnosing the applied voltage and discharge current waveforms, as well as the optical emission spectra. The work investigates how degradation efficiency is affected by applied voltage, gas flow rate, treatment time, initial concentration as well as the addition of γ-Al_(2)O_(3) pellets and peanut straw. After 70 min, the degradation efficiency of ciprofloxacin hydrochloride in the multiphase mixed system reached 99.6%. Its removal efficiency increases as the initial concentration decreases and the applied voltage increases. Besides, there is still a good degradation efficiency of ciprofloxacin hydrochloride with the addition of peanut straw.The degradation mechanism of ciprofloxacin hydrochloride is investigated through the analysis of degraded intermediates and reactive species.展开更多
A general expression for the relationship between induction periodand supersaturation was developed based on polynuclear approach.Different mechanism of primary nucleation in solution can beillustrated by the expressi...A general expression for the relationship between induction periodand supersaturation was developed based on polynuclear approach.Different mechanism of primary nucleation in solution can beillustrated by the expression. The results of induction perioddetermined by laser scattering method shows that the crystallizationof ciprofloxacin hydrochloride monohydrate in water/ethanol oraqueous solution is by the mechanism of primary nucleation followedby one-dimensional diffusion growth, and then on-dimensionalcontinuous or 'birth and spread' growth on crystal face. The growthmechanism on the crystal face is affected by temperature and solvent.展开更多
Interactions of ciprofloxacin hydrochloride(CPFH)with sodium dodecyl sulfate(SDS)were investigated by conductivity measurement in H2O/electrolyte solutions(NaCl,Na2SO4&Na3PO4)over 298.15–318.15 K temperature rang...Interactions of ciprofloxacin hydrochloride(CPFH)with sodium dodecyl sulfate(SDS)were investigated by conductivity measurement in H2O/electrolyte solutions(NaCl,Na2SO4&Na3PO4)over 298.15–318.15 K temperature range(with 5 K interval)considering the human body temperature.In all cases,two critical micelle concentrations(c*)were observed which are increased in the presence of drug and decreased in the presence of salts enunciating the presence of interaction amongst the studied components.For(CPFH+SDS)system in the presence of salt,the c*values at 303.15 K and I=0.50 mmol·kg^-1 followed the order:CNaCl>CNa2SO4>CNa3PO4.TheΔG1,m0 andΔG2,m0values are found to be negative for all systems that show that the micellization process is thermodynamically spontaneous.For(CPFH+SDS)system in water,theΔHm0&ΔSm0 values reveal that the micellization processes is both entropy dominated in almost all cases.In the occurrence of electrolytes,ΔHm0 andΔSm0 values indicate that micellization processes are both entropy&enthalpy restricted at upper temperature but it becomes totally entropy dependent at higher temperature.The higher positiveΔSm0 values indicate the enhanced hydrophobic interaction in presence of salts.The enthalpy-entropy compensation was determined from the linear relationship betweenΔHm0 andΔSm0 values in every state.Different transfer energies as well as compensation temperature and intrinsic enthalpy were also evaluated and the behaviors were comparable to other biological system.展开更多
Ciprofloxacin is an antibiotic generic drug that can treat a number of bacterial infections. It is a second generic fluoroquinolone. This work presents a simple, sensitive and stability indicative method for assay det...Ciprofloxacin is an antibiotic generic drug that can treat a number of bacterial infections. It is a second generic fluoroquinolone. This work presents a simple, sensitive and stability indicative method for assay determination of drug substances ciprofloxacin hydrochloride by high pressure liquid chromatography (HPLC). Separation of impurities from the main drug substances and accurate assay quantification with a simple method is difficult by Spectrophotometry. The separation of co-eluents and impurities from the ciprofloxacin drug substances was archived by HPLC with simple mobile phase 0.15% orthophosphoric acid adjusted pH to 3.0 with triethylamine and acetonitrile using a gradient program, column inertsil C18, 250 mm × 4.0 mm, 5 μm. Flow rate was 0.7 mL/min, the column temperature and injection volume were 35°C and 10.0 μL. Chromato-graphic analysis was carried out at wavelength 278 nm. The developed method was validated according to the international conference on harmonization (ICH) guidelines regarding: Precision, specificity by degradation, linearity, accuracy, range and robustness. The proposed method showed good linearity (correlation coefficient and regression coefficient were not less than 0.999 and 0.998) in the range of 50% to 150% of working concentration. The recovery at 50%, 100% and 150% of working concentration level was within 98.0% to 102.0%. The range of the method is concluded that developed method is from 50% to 150% of target concentration for ciprofloxacin hydrochloride. The applicability of the proposed method was verified through the analysis of the samples and percentage recoveries in the range of 98% to 102% were obtained without any interference detected at the main peak in the chromatogram. The validated method is highly selective, simple, accurate, cost effective, and it is applicable for stability studies and routine quality-control analysis in the pharmaceutical industries.展开更多
Four polyoxometalate complexes, (CPFX·HCl)_3H_4SiW_~12 O_~40 , (CPFX·HCl)_3H_3PW_~12 O_~40 , (CPFX·HCl)_3H_3PMo_~12 O_~40 and (CPFX·HCl)_4H_4SiMo_~12 O_~40 , were prepared from ciprofloxacin hydroc...Four polyoxometalate complexes, (CPFX·HCl)_3H_4SiW_~12 O_~40 , (CPFX·HCl)_3H_3PW_~12 O_~40 , (CPFX·HCl)_3H_3PMo_~12 O_~40 and (CPFX·HCl)_4H_4SiMo_~12 O_~40 , were prepared from ciprofloxacin hydrochloride(CPFX·HCl) reacting with H_nXM_~12 O_~40 ·nH_2O(X=P,Si; M=W,Mo) in an aqueous solution, and characterized by elemental analysis, IR spectrometry and TG-DTA. The IR spectrum confirms the presence of Keggin-type anions of heteropoly acids and the characteristic functional groups of ciprofloxacin. The TG/DTA curves show that their thermal decomposition is a multi-step process including simultaneous collapse of the Keggin-type structure. At first, these compounds had a mass loss of water molecules, then several other mass losses occured due to the decomposition of ciprofloxacin hydrochloride and its fragments with the degradation of Keggin anions. The end product of decomposition is the mixture of WO_3(or MoO_3) and SiO_2(or P_2O_5), identified by X-ray diffraction and IR spectroscopy. The possible thermal decomposition mechanisms of these complexes are proposed. This study exemplified that the thermal stability of the complexes containing tungsten is much better than that of the complexes containing molybdenum.展开更多
A highly sensitive and simple Rayleigh light scattering （RLS） method for the determination of ciprofloxacin hydrochloride has been developed. Ciprofloxacin hydrochloride （CPFH） reacted with tetraphenylboron sodium...A highly sensitive and simple Rayleigh light scattering （RLS） method for the determination of ciprofloxacin hydrochloride has been developed. Ciprofloxacin hydrochloride （CPFH） reacted with tetraphenylboron sodium（TPB） to form an ion-association complex in pH 5.31 aqueous solution, which resulted in a significant enhancement of the RLS intensity, which was linear with the concentration of CPFH in the range of 12.7-419 ng·mL^-1. The limit of detection for CPFH was 6.99 ng·mL^-1. The method is simple, highly sensitive and selective within a wide linear range. Applying this method for the determination of ciprofloxacin hydrochloride in pharmaceutical preparations and biological fluids obtained satisfactory results.展开更多
High-throughput measurements of ciprofloxacin, clomipramine and fexofenadine hydrochlorides were performed by employing an automatic 8-channel electrical titrator. Silver nitrate （AgNO3） and sodium tetraphenylborate...High-throughput measurements of ciprofloxacin, clomipramine and fexofenadine hydrochlorides were performed by employing an automatic 8-channel electrical titrator. Silver nitrate （AgNO3） and sodium tetraphenylborate （NaTPB） were used as titrants. When AgNO3 was used for measuring the drugs in pure form, recoveries were 97.6%-102.0% with RSD values ≤1.0%; for measuring them in pharmaceutical formulations, recoveries were 96.6%-99.1% with RSD values ≤1.0%. Batch samples of eight could be measured simultaneously and maximally 30 measurements per minute could be completed. When NaTPB was used for measuring the drugs in pure form, the recoveries were 96.8%-102.6% with RSD values 〈0.8%; for measuring them in pharmaceutical formulations, the recoveries were 97.5%-102.7% with RSD values ≤0.9%. For all analyses, no auxiliary devices or chemicals were needed and there was no requirement for changing or cleaning working electrodes between measurements. The efficiency, accuracy and precision of the proposed method make it an alternative for routine quality control analyses.展开更多
By employing an electrical micro-titration system, in which a capacitively coupled contactless conductivity detector（C^4D） was used to monitor the reaction process in real time, herein a novel method for determining...By employing an electrical micro-titration system, in which a capacitively coupled contactless conductivity detector（C^4D） was used to monitor the reaction process in real time, herein a novel method for determining ciprofloxacin hydrochloride（CIPHCl） was developed for the first time. Mode 1： Standard CIPHCl solutions at different concentrations were loaded into reaction cells, respectively, and were titrated with standard Ag^＋. Upon the titration, the formation of a precipitate alters the number of ions in the solution, raising the change of conductivity, which was monitored by a special C-4 D to construct a titration curve. The endpoint of the titration was located from the peak of the curve. Between the elapsed time and the initial concentration of titrand, a linear relationship was established over the range of2.0–8.0 mmol/L. Mode 2： Standard Fe^3＋ took the place of Ag^＋, and was used as titrant to recognize ciprofloxacin contributed to the formation of complexation, which also resulting a change of solution conductivity. Under optimized conditions, a working range of 1.0–5.0 mmol/L CIPHCl was found. Because the reaction solutions were isolated from the working electrodes, this pioneer work shows significant simplicity and cost-effectiveness, by eliminating the requirements for detector exchange/renewal between different measurements, and by involving no auxiliary chemicals. Both of the two approaches were applied successfully to determine CIPHCl in tablet samples. And the results were in good agreement with those obtained by reference method.展开更多
基金supported by National Natural Science Foundations of China (Nos. 52307163 and 12305279)the China Postdoctoral Science Foundation (Nos. 2023M740498 and 2022M710590)Postdoctoral Fellowship Program of CPSF (No. GZC20230348)。
文摘In recent years, antibiotic pollution has become a serious threat to human health. In this study, a gas-liquid discharge plasma is developed to degrade ciprofloxacin hydrochloride in a multiphase mixed system containing inorganic and organic impurities. The discharge characteristics are analyzed by diagnosing the applied voltage and discharge current waveforms, as well as the optical emission spectra. The work investigates how degradation efficiency is affected by applied voltage, gas flow rate, treatment time, initial concentration as well as the addition of γ-Al_(2)O_(3) pellets and peanut straw. After 70 min, the degradation efficiency of ciprofloxacin hydrochloride in the multiphase mixed system reached 99.6%. Its removal efficiency increases as the initial concentration decreases and the applied voltage increases. Besides, there is still a good degradation efficiency of ciprofloxacin hydrochloride with the addition of peanut straw.The degradation mechanism of ciprofloxacin hydrochloride is investigated through the analysis of degraded intermediates and reactive species.
文摘A general expression for the relationship between induction periodand supersaturation was developed based on polynuclear approach.Different mechanism of primary nucleation in solution can beillustrated by the expression. The results of induction perioddetermined by laser scattering method shows that the crystallizationof ciprofloxacin hydrochloride monohydrate in water/ethanol oraqueous solution is by the mechanism of primary nucleation followedby one-dimensional diffusion growth, and then on-dimensionalcontinuous or 'birth and spread' growth on crystal face. The growthmechanism on the crystal face is affected by temperature and solvent.
基金funded by the Deanship of Scientific Research(DSR)King Abdulaziz University,Jeddah,under grant No.(D-403-130-1441).
文摘Interactions of ciprofloxacin hydrochloride(CPFH)with sodium dodecyl sulfate(SDS)were investigated by conductivity measurement in H2O/electrolyte solutions(NaCl,Na2SO4&Na3PO4)over 298.15–318.15 K temperature range(with 5 K interval)considering the human body temperature.In all cases,two critical micelle concentrations(c*)were observed which are increased in the presence of drug and decreased in the presence of salts enunciating the presence of interaction amongst the studied components.For(CPFH+SDS)system in the presence of salt,the c*values at 303.15 K and I=0.50 mmol·kg^-1 followed the order:CNaCl>CNa2SO4>CNa3PO4.TheΔG1,m0 andΔG2,m0values are found to be negative for all systems that show that the micellization process is thermodynamically spontaneous.For(CPFH+SDS)system in water,theΔHm0&ΔSm0 values reveal that the micellization processes is both entropy dominated in almost all cases.In the occurrence of electrolytes,ΔHm0 andΔSm0 values indicate that micellization processes are both entropy&enthalpy restricted at upper temperature but it becomes totally entropy dependent at higher temperature.The higher positiveΔSm0 values indicate the enhanced hydrophobic interaction in presence of salts.The enthalpy-entropy compensation was determined from the linear relationship betweenΔHm0 andΔSm0 values in every state.Different transfer energies as well as compensation temperature and intrinsic enthalpy were also evaluated and the behaviors were comparable to other biological system.
文摘Ciprofloxacin is an antibiotic generic drug that can treat a number of bacterial infections. It is a second generic fluoroquinolone. This work presents a simple, sensitive and stability indicative method for assay determination of drug substances ciprofloxacin hydrochloride by high pressure liquid chromatography (HPLC). Separation of impurities from the main drug substances and accurate assay quantification with a simple method is difficult by Spectrophotometry. The separation of co-eluents and impurities from the ciprofloxacin drug substances was archived by HPLC with simple mobile phase 0.15% orthophosphoric acid adjusted pH to 3.0 with triethylamine and acetonitrile using a gradient program, column inertsil C18, 250 mm × 4.0 mm, 5 μm. Flow rate was 0.7 mL/min, the column temperature and injection volume were 35°C and 10.0 μL. Chromato-graphic analysis was carried out at wavelength 278 nm. The developed method was validated according to the international conference on harmonization (ICH) guidelines regarding: Precision, specificity by degradation, linearity, accuracy, range and robustness. The proposed method showed good linearity (correlation coefficient and regression coefficient were not less than 0.999 and 0.998) in the range of 50% to 150% of working concentration. The recovery at 50%, 100% and 150% of working concentration level was within 98.0% to 102.0%. The range of the method is concluded that developed method is from 50% to 150% of target concentration for ciprofloxacin hydrochloride. The applicability of the proposed method was verified through the analysis of the samples and percentage recoveries in the range of 98% to 102% were obtained without any interference detected at the main peak in the chromatogram. The validated method is highly selective, simple, accurate, cost effective, and it is applicable for stability studies and routine quality-control analysis in the pharmaceutical industries.
文摘Four polyoxometalate complexes, (CPFX·HCl)_3H_4SiW_~12 O_~40 , (CPFX·HCl)_3H_3PW_~12 O_~40 , (CPFX·HCl)_3H_3PMo_~12 O_~40 and (CPFX·HCl)_4H_4SiMo_~12 O_~40 , were prepared from ciprofloxacin hydrochloride(CPFX·HCl) reacting with H_nXM_~12 O_~40 ·nH_2O(X=P,Si; M=W,Mo) in an aqueous solution, and characterized by elemental analysis, IR spectrometry and TG-DTA. The IR spectrum confirms the presence of Keggin-type anions of heteropoly acids and the characteristic functional groups of ciprofloxacin. The TG/DTA curves show that their thermal decomposition is a multi-step process including simultaneous collapse of the Keggin-type structure. At first, these compounds had a mass loss of water molecules, then several other mass losses occured due to the decomposition of ciprofloxacin hydrochloride and its fragments with the degradation of Keggin anions. The end product of decomposition is the mixture of WO_3(or MoO_3) and SiO_2(or P_2O_5), identified by X-ray diffraction and IR spectroscopy. The possible thermal decomposition mechanisms of these complexes are proposed. This study exemplified that the thermal stability of the complexes containing tungsten is much better than that of the complexes containing molybdenum.
基金Supported by the National Natural Science Foundation of China(20675059)Research Foundation of Leshan Teachers’ College, China (Z0625)
文摘A highly sensitive and simple Rayleigh light scattering （RLS） method for the determination of ciprofloxacin hydrochloride has been developed. Ciprofloxacin hydrochloride （CPFH） reacted with tetraphenylboron sodium（TPB） to form an ion-association complex in pH 5.31 aqueous solution, which resulted in a significant enhancement of the RLS intensity, which was linear with the concentration of CPFH in the range of 12.7-419 ng·mL^-1. The limit of detection for CPFH was 6.99 ng·mL^-1. The method is simple, highly sensitive and selective within a wide linear range. Applying this method for the determination of ciprofloxacin hydrochloride in pharmaceutical preparations and biological fluids obtained satisfactory results.
基金supported by Special Scientific Research Funds for Central Non-profit Institutes,Yellow Sea Fisheries Research Institute,Chinese Academy of Fishery Sciences(YSFRI-CAFS)(No.20603022016003)Import of International Advanced Agricultural Science and Technology Plan(948 Project)of Chinese Ministry of Agriculture(No.2016-X28)+2 种基金Central Public Interest Scientific Institution Basal Research Fund,CAFS(No.2016RC-BR02)Qingdao National Laboratory for Marine Science and Technology(No.2015ASKJ02-05)Key R&D Program of Shandong Province(No.2016GSF120008)
文摘High-throughput measurements of ciprofloxacin, clomipramine and fexofenadine hydrochlorides were performed by employing an automatic 8-channel electrical titrator. Silver nitrate （AgNO3） and sodium tetraphenylborate （NaTPB） were used as titrants. When AgNO3 was used for measuring the drugs in pure form, recoveries were 97.6%-102.0% with RSD values ≤1.0%; for measuring them in pharmaceutical formulations, recoveries were 96.6%-99.1% with RSD values ≤1.0%. Batch samples of eight could be measured simultaneously and maximally 30 measurements per minute could be completed. When NaTPB was used for measuring the drugs in pure form, the recoveries were 96.8%-102.6% with RSD values 〈0.8%; for measuring them in pharmaceutical formulations, the recoveries were 97.5%-102.7% with RSD values ≤0.9%. For all analyses, no auxiliary devices or chemicals were needed and there was no requirement for changing or cleaning working electrodes between measurements. The efficiency, accuracy and precision of the proposed method make it an alternative for routine quality control analyses.
基金financial support from Key R&D of Shandong Province (No. 2016GSF120008)Qingdao National Laboratory for Marine Science and Technology (No. 2015ASKJ02-05)
文摘By employing an electrical micro-titration system, in which a capacitively coupled contactless conductivity detector（C^4D） was used to monitor the reaction process in real time, herein a novel method for determining ciprofloxacin hydrochloride（CIPHCl） was developed for the first time. Mode 1： Standard CIPHCl solutions at different concentrations were loaded into reaction cells, respectively, and were titrated with standard Ag^＋. Upon the titration, the formation of a precipitate alters the number of ions in the solution, raising the change of conductivity, which was monitored by a special C-4 D to construct a titration curve. The endpoint of the titration was located from the peak of the curve. Between the elapsed time and the initial concentration of titrand, a linear relationship was established over the range of2.0–8.0 mmol/L. Mode 2： Standard Fe^3＋ took the place of Ag^＋, and was used as titrant to recognize ciprofloxacin contributed to the formation of complexation, which also resulting a change of solution conductivity. Under optimized conditions, a working range of 1.0–5.0 mmol/L CIPHCl was found. Because the reaction solutions were isolated from the working electrodes, this pioneer work shows significant simplicity and cost-effectiveness, by eliminating the requirements for detector exchange/renewal between different measurements, and by involving no auxiliary chemicals. Both of the two approaches were applied successfully to determine CIPHCl in tablet samples. And the results were in good agreement with those obtained by reference method.
