Removal of chlorhexidine digluconate from aqueous solution by heterogenous photocatalysis using sunlight-driven Ni-doped TiO2 material

Nitrogen-doped TiO2 has been prepared by calcining technical grade guanidine hydrochloride and commercial anatase TiO2 powders. XRD patterns indicate that the prepared powders are composed of anatase. XPS results show that N atoms have been incorporated into the lattice of anatase. UV-Vis reflectance spectra show that the light absorption of the synthesized N-doped anatase powders has red-shifted well into visible-light region. Degradation of methylene blue (MB) aqueous solution by N-doped anatase has been investigated by UV-Vis light spectrophotometer. The 400-mL 10 mg/L aqueous solution of MB could be degraded with 4 g N-doped TiO2 within 4.5 hrs of visible light irradiation. Photocatalytic paint was prepared by adding the synthesized N-doped nanocrystalline anatase TiO2 powders into self-engineered oxidation resistance latex paint system. The effects of the amount and types of the TiO2 in the paints on the sterilization were systematically investigated. The colony counting method was used to study its sterilization performance under visible light irradiation. The sterilization experiments show that the rate of sterilizing E. coli by the N-doped TiO2 modified paint can exceed more than 99% after irradiation by the visible light for 2 to 4 hours.

Download Full-text

Development and validation of a microbiological assay for determination of chlorhexidine digluconate in aqueous solution

Brazilian Journal of Pharmaceutical Sciences ◽

10.1590/s1984-82502013000200017 ◽

2013 ◽

Vol 49 (2) ◽

pp. 351-358 ◽

Cited By ~ 3

Author(s):

Flávia Angélica Másquio Fiorentino ◽

Marcos Antonio Corrêa ◽

Hérida Regina Nunes Salgado

Keyword(s):

Aqueous Solution ◽

Pharmaceutical Formulations ◽

Parallel Line ◽

Inhibitory Effect ◽

Microbiological Assay ◽

Diffusion Method ◽

Chlorhexidine Digluconate ◽

Relative Standard ◽

Pharmaceutical Industries ◽

Development And Validation

Chlorhexidine (CHX) is a broad-spectrum antiseptic that is used in many topical pharmaceutical formulations. Because there is no official microbiological assay reported in the literature that is used to quantify CHX, this paper reports the development and validation of a simple, sensitive, accurate and reproducible agar diffusion method for the dosage of chlorhexidine digluconate (CHX-D) in an aqueous solution. The assay is based on the inhibitory effect of CHX-D upon the strain of Staphylococcus aureus ATCC 25923, which is used as the test microorganism. The design 3x3 parallel-line model was used. The results were treated statistically by analysis of variance (ANOVA), and they were excellent in terms of linearity (r = 0.9999), presenting a significant regression between the zone diameter of growth inhibition and the logarithm of the concentration within the range of 0.5 to 4.5%. The results obtained were precise, having relative standard deviations (RSD) for intra-day and inter-day precision of 2.03% and 2.94%, respectively. The accuracy was 99.03%. The method proved to be very useful and appropriate for the microbiological dosage of CHX-D in pharmaceutical formulations; it might also be used for routine drug analysis during quality control in pharmaceutical industries.

Download Full-text

Synthesis, Characterization and Photocatalytic Activity of Nb-Doped TiO2 Nanoparticles

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.455-456.110 ◽

2012 ◽

Vol 455-456 ◽

pp. 110-114 ◽

Cited By ~ 1

Author(s):

Xuan Dong Li ◽

Xi Jiang Han ◽

Wen Ying Wang ◽

Xiao Hong Liu ◽

Yan Wang ◽

...

Keyword(s):

Aqueous Solution ◽

Photocatalytic Activity ◽

Methyl Orange ◽

Photoelectron Spectroscopy ◽

Sol Gel ◽

Molar Ratio ◽

X Ray Diffraction ◽

Doped Tio2 ◽

X Ray ◽

Vis Spectroscopy

Nb-doped TiO2 powders with different concentrations of Nb have been synthesized by a sol-gel method and characterized by a series of technologies including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-vis spectroscopy. The photocatalytic activity of Nb-doped TiO2 is evaluated by degradation efficiency of methyl orange in aqueous solution. The results indicate that the photocatalytic activity of Nb-doped TiO2 synthesized with a Nb/Ti molar ratio of 5% is higher than that of TiO2 under the visible light.

Download Full-text