Aim Ciprofloxacin polylactic acid microspheres (CFX-PLA-MS) were preparedusing solvent evaporation method from a solid-in-oil-in-water emulsion system. Methods Orthogonalexperiment was used to optimize the method of C...Aim Ciprofloxacin polylactic acid microspheres (CFX-PLA-MS) were preparedusing solvent evaporation method from a solid-in-oil-in-water emulsion system. Methods Orthogonalexperiment was used to optimize the method of CFX-PLA-MS preparation. Microspheres werecharacterized in terms of morphology, size, encapsulation efficiency, drug loading and in vitro drugrelease. Results The physical state of CFX-PLA-MS was determined by scanning electron microscopy(SEM) and differential scanning calorimetry (DSC) . Microspheres formed were spherical with smoothsurfaces. Drug was enveloped in microspheres without mixing physically with PLA. The averageparticle size was 280.80 ± 0.15 μm, with over 90% of microspheres falling in the range of 250 -390 μm. The encapsulation efficiency was 65.8% ± 0.58% and the drug loading was 34.1% ± 0.51% .In vitro release study revealed a profile of sustained release of Ciprofloxacin from CFX-PLA-MS. Theaccumulated release percentage and half-life (T_(1/2) of Ciprofloxacin microspheres were 84.0% in53.2 h, and 31.9 h, respectively. Higuchi equation was Q= -0.0043 + 0.003 9 t^(1/2), r = 0.9941.Conclusion Ciprofloxacin microspheres have been successfully prepared and sustained release of CFXfrom microspheres is achieved.展开更多
This paper describes an effective method for determining ciprofloxacin lactate. An excess of sodium tetraphenylboron was added to precipitate ciprofloxacin lactate in HAc-NaAc buffer solution (pH=4.0). After filtering...This paper describes an effective method for determining ciprofloxacin lactate. An excess of sodium tetraphenylboron was added to precipitate ciprofloxacin lactate in HAc-NaAc buffer solution (pH=4.0). After filtering off the precipitate, the excessive sodium tetraphenylboron in the filtrate was titrated with cetyltrimethylammonium bromide standard solution, with bromophenol blue as indicator. The method is simple and rapid, it has been applied to the determination of ciprofloxacin lactate raw material with satisfactory results. The recovery was between 99.66% and 100.2%, the relative error was less than ±0.40%. Experiments showed that the method gave the same results as the approach using nonaqueous titration (ChP).展开更多
Objective: To investigate the possible presence ofan active efflux system in resistance tofluoroquinolones in Mycoplasma hominis. Methods: The resistant strains of M. hominis wereselected from one hundred and three cl...Objective: To investigate the possible presence ofan active efflux system in resistance tofluoroquinolones in Mycoplasma hominis. Methods: The resistant strains of M. hominis wereselected from one hundred and three clinical strainsof M. hominis by broth microdilution method. The ac-cumulation of ciprofloxacin in M. hominis and the in-fluence of carbonyl cyanide m-chlorophenyl-hydrazone(CCCP) and reserpine were measured by a fluores-cence method. Results: Two resistant strains and two susceptiblestrains of M. hominis were selected in vitro. The accu-mulation of ciprofloxacin for resistant strains is lowerthan that of susceptible strains. CCCP and reserpinehad different influence on clinical strains of M.hominis. Reserpine could dramatically increase theaccumulation of ciprofloxacin, however CCCP had alittle effect on it. Conclusion: These results suggest that the pres-ence of an active efflux system implicated in thefluoroquinolones-resistant in M. hominis.展开更多
The inhibiting effect of ciprofloxacin,norfloxacin and ofloxacin on the corrosion of mild steel in 1 mol·L-1 HCl and the mechanism were studied at different temperatures using mass loss measurement,electrochemica...The inhibiting effect of ciprofloxacin,norfloxacin and ofloxacin on the corrosion of mild steel in 1 mol·L-1 HCl and the mechanism were studied at different temperatures using mass loss measurement,electrochemical method,and X-ray photoelectron spectroscopy(XPS) .Effective inhibition was shown by mass loss,potentiodynamic polarization and impedance spectroscopy measurement.The corrosion rate of the metal in the mass loss measurement,and the corrosion reaction on cathode and anode in the electrochemical measurement were accelerated when temperature was increased.XPS results showed that the inhibitors adsorbed effectively on the metal surface.展开更多
基金National Natural Science Foundation of Guangdong Province (020885,980504).
文摘Aim Ciprofloxacin polylactic acid microspheres (CFX-PLA-MS) were preparedusing solvent evaporation method from a solid-in-oil-in-water emulsion system. Methods Orthogonalexperiment was used to optimize the method of CFX-PLA-MS preparation. Microspheres werecharacterized in terms of morphology, size, encapsulation efficiency, drug loading and in vitro drugrelease. Results The physical state of CFX-PLA-MS was determined by scanning electron microscopy(SEM) and differential scanning calorimetry (DSC) . Microspheres formed were spherical with smoothsurfaces. Drug was enveloped in microspheres without mixing physically with PLA. The averageparticle size was 280.80 ± 0.15 μm, with over 90% of microspheres falling in the range of 250 -390 μm. The encapsulation efficiency was 65.8% ± 0.58% and the drug loading was 34.1% ± 0.51% .In vitro release study revealed a profile of sustained release of Ciprofloxacin from CFX-PLA-MS. Theaccumulated release percentage and half-life (T_(1/2) of Ciprofloxacin microspheres were 84.0% in53.2 h, and 31.9 h, respectively. Higuchi equation was Q= -0.0043 + 0.003 9 t^(1/2), r = 0.9941.Conclusion Ciprofloxacin microspheres have been successfully prepared and sustained release of CFXfrom microspheres is achieved.
文摘This paper describes an effective method for determining ciprofloxacin lactate. An excess of sodium tetraphenylboron was added to precipitate ciprofloxacin lactate in HAc-NaAc buffer solution (pH=4.0). After filtering off the precipitate, the excessive sodium tetraphenylboron in the filtrate was titrated with cetyltrimethylammonium bromide standard solution, with bromophenol blue as indicator. The method is simple and rapid, it has been applied to the determination of ciprofloxacin lactate raw material with satisfactory results. The recovery was between 99.66% and 100.2%, the relative error was less than ±0.40%. Experiments showed that the method gave the same results as the approach using nonaqueous titration (ChP).
基金Financially supported by a grant from the Education Committee of Hunan Province(No.00A009)
文摘Objective: To investigate the possible presence ofan active efflux system in resistance tofluoroquinolones in Mycoplasma hominis. Methods: The resistant strains of M. hominis wereselected from one hundred and three clinical strainsof M. hominis by broth microdilution method. The ac-cumulation of ciprofloxacin in M. hominis and the in-fluence of carbonyl cyanide m-chlorophenyl-hydrazone(CCCP) and reserpine were measured by a fluores-cence method. Results: Two resistant strains and two susceptiblestrains of M. hominis were selected in vitro. The accu-mulation of ciprofloxacin for resistant strains is lowerthan that of susceptible strains. CCCP and reserpinehad different influence on clinical strains of M.hominis. Reserpine could dramatically increase theaccumulation of ciprofloxacin, however CCCP had alittle effect on it. Conclusion: These results suggest that the pres-ence of an active efflux system implicated in thefluoroquinolones-resistant in M. hominis.
基金Supported by the National Science ＆ Technology Pillar Program（082603101c） China Postdoctoral Science Foundation （O92623101H）+2 种基金 Shandong Postdoctoral Foundation（200902040） Open Project Program of Marine Corrosion and Protection Research Center of Institute of Oceanology Chinese Academy of Science（200901005） Doctor Foundation of University of Jinan（XBS0899）
文摘The inhibiting effect of ciprofloxacin,norfloxacin and ofloxacin on the corrosion of mild steel in 1 mol·L-1 HCl and the mechanism were studied at different temperatures using mass loss measurement,electrochemical method,and X-ray photoelectron spectroscopy(XPS) .Effective inhibition was shown by mass loss,potentiodynamic polarization and impedance spectroscopy measurement.The corrosion rate of the metal in the mass loss measurement,and the corrosion reaction on cathode and anode in the electrochemical measurement were accelerated when temperature was increased.XPS results showed that the inhibitors adsorbed effectively on the metal surface.
