Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Cetrimonium Compounds”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1983

Effect of nutrient depletion on the sensitivity of Pseudomonas cepacia to antimicrobial agents.

Pseudomonas cepacia depleted of various nutrients showed marked variation in sensitivity to cetrimide, chlorhexidine, and benzalkonium chloride. In all cases cells depleted of magnesium were the most resistant. It is proposed that these observations may be due to alterations of the envelope of P. cepacia in response to changes in the growth environment. This may have profound implications for investigations of the resistance of this organism both in vivo and in vitro.

Anti-Infective Agents, Local↗
PubMed1981

Shape and volume changes in rat erythrocytes induced by surface-active alkyltrimethylammonium salts and sodium dodecyl sulphate.

Surface-active alkyltrimethylammonium salts (C12, C14 and C16) and sodium dodecyl sulphate (SDS) caused shape alterations and a volume increase in rat erythrocytes. The alkyltrimethylammonium salts caused echinocytic shapes at both prelytic and lytic concentrations during the first minutes of incubation at 37 degrees C but as the incubation proceeded some of the echinocytes were transformed into stomatocytes. This transformation developed through the normal discocyte shape and it occurred only above certain concentrations. With C14 and C16 the concentration at which stomatocytic shapes appeared coincided with those at which the volume increase began. With the C12 homologue stomatocytic shapes did not appear until lytic concentrations were reached, whereas the volume increase began at prelytic concentrations. SDS caused only echinocytic shapes at 37 degrees C and these appeared at prelytic concentrations, whereas the volume increase was associated with lytic concentrations. When erythrocytes crenated by SDS were cooled to room temperature they were transformed into stomatocytes and discocytes. Our results indicate that (a) even though ionic surfactants induce both swelling and shape alterations in erythrocytes these two changes are not necessarily connected, and that (b) the different shapes induced by cationic and anionic surfactants cannot be due to differences in the distribution of the surfactant molecules within the lipid bilayer of the erythrocyte membrane alone.

Absorption↗
PubMed1994

Quantitative analysis of quaternary ammonium antiseptics using thin-layer densitometry.

A thin-layer chromatography method for quantitative analysis of quaternary ammonium antiseptics is described. Silanized silica gel was used as the stationary phase. The mobile phase consisted of methanol-25% (m/v) sodium acetate solution-acetone (65:35:20). The method is able to separate the chain homologues of benzalkonium chloride, cetylpyridinium chloride and cetrimide. Detection was performed using a colour reaction with potassium triiodide solution. The different homologues were quantified using UV densitometry at 400 nm. A number of commercial samples was analysed using this method. From the results it appears that it is worthwhile to have a limit test for the composition of quaternary ammonium antiseptics in pharmacopoeial monographs, the more so as the antibacterial activity depends on it.

Acetates↗
PubMed1987

Comparative susceptibility of hospital isolates of gram-negative bacteria to antiseptics and disinfectants.

The sensitivity of hospital isolates of Gram-negative bacteria to cationic antiseptics, mercuric chloride and two organomercury compounds has been measured. A comparison was made with laboratory strains of known sensitivity which acted as standards. All strains of Escherichia coli showed a uniformly high sensitivity to chlorhexidine diacetate; other organisms tended to be less sensitive to the biguanide. Quaternary ammonium compounds were less effective than chlorhexidine. Resistance to mercuric chloride was observed frequently, but there was little evidence of organomercurial resistance except in Pseudomonas aeruginosa isolates.

Anti-Infective Agents, Local↗
PubMed1985

Effects of surfactants on the permeability of canine oral mucosa in vitro.

The effect of 3 cationic, 1 anionic, and 1 non-ionic surfactant on the permeability of oral frenulum removed from anesthetized dogs was determined in vitro. Permeability to 12 organic compounds was measured in the presence and absence of surfactant. Cetylpyridinium chloride, cetyltrimethylammonium bromide, benzalkonium chloride and sodium lauryl sulfate, at concentrations from 0.025-1.0% caused dose-related increases in permeability to each of the solutes tested, whereas polysorbate 80 caused an increase in permeability to only 3 solutes, and this occurred only at the highest surfactant concentration employed.

Animals↗
PubMed2006

Removal of arsenic from groundwater by micellar-enhanced ultrafiltration (MEUF).

The removal characteristics of arsenate using micellar-enhanced ultrafiltration (MEUF) were investigated. Among four different cationic surfactants used, hexadecylpyridinium chloride (CPC) showed the highest removal efficiency of arsenic (96%), and the removal efficiency with hexadecyltrimethylammonium bromide (CTAB) was 94%. But the removal efficiency with benzalkonium chloride (BC) was the lowest (57%) due to higher critical micelle concentration (CMC) of BC than those of other surfactants. Over 80% of arsenic was removed with octadecylamine acetate (ODA). On the effect of solution pH on the arsenic removal, since the valance of arsenate decreases from trivalent to monovalent as pH decreases, the removal was reduced at lower pH. The presence of 0.45mM of nitrate and 0.01mM of phosphate reduced the removal efficiency by 5-8%. This decrease was because of the competition between the arsenate, nitrate and phosphate for the binding sites of the surfactant micelle. Similar decrease in the removal of arsenate was observed with CPC, CTAB and ODA in the presence of these anions. In cross-flow filtration, the removal efficiency of arsenic was similar to that in the dead-end system. However, the decline in flux was less than that in dead-end filtration. In order to lower the concentration of the surfactant in the effluent, the effluent was treated with powdered activated carbon (PAC) before discharging to the environment. Over 98% surfactant was removed with 1gl(-1) of PAC. In conclusions, the MEUF is considered as a feasible process using CPC or CTAB to remove the arsenate from groundwater compared with the other solid based adsorbent processes.

Arsenic↗
PubMed2006

Block ionomer complexes as prospective nanocontainers for drug delivery.

Nanosized environmentally responsive materials are of special interest for various applications, including drug delivery. Block ionomer complexes (BIC) composed of graft-comb copolymers of Pluronic and poly(acrylic acid) (Pluronic-PAA) and a model cationic surfactant, hexadecyltrimethylammonium bromide (HTAB), were synthesized by mixing the polymer and surfactant in aqueous media. According to TEM, the resulting BIC represented spherical particles of nanoscale size (50 to 100 nm). The stability of the BIC in the aqueous dispersion depended on the lengths of the hydrophilic poly(ethylene oxide) and hydrophobic poly(propylene oxide) chains in Pluronic molecules as well as on the surface charge of the resulting complexes. The latter was controlled by changing the ratio of the Pluronic-PAA and HTAB in the BIC and by changing the pH due to reversible ionization of the PAA chains. The acidification of the media below pH 6.0 resulted in the appearance of a strong positive charge on the BIC, which in the intracellular environment can trigger interaction of such BIC with the cell membranes. An efficient solubilization of a model hydrophobic molecule, Sudan III, and a drug, Etoposide, in such BIC was demonstrated with the loading capacities of about 6 to 15% by weight of the dispersed complex. Overall, these BIC wield a promise as environmentally responsive nanocarriers for pharmaceuticals.

Acrylic Resins↗
PubMed2006

Removal of phenol and 4-chlorophenol by surfactant-modified natural zeolite.

In this study the adsorption characteristics of phenol and 4-chlorophenol by surfactant-modified zeolite was investigated. Batch studies were performed to evaluate the effects of various experimental parameters such as contact time, adsorbent dose, initial concentration, and temperature on the removal of phenol and 4-chlorophenol. The sorption kinetics was tested for intraparticle diffusion, Elovich, and pseudo-second order reaction and rate constants of kinetic models were calculated. Equilibrium isotherms for the adsorption of phenol were analyzed by Freundlich, Langmuir, and Tempkin isotherm models. Freundlich isotherm was found to best represent the data for phenol and 4-chlorophenol adsorption.

Adsorption↗
PubMed2006

Anomalous association and fluorophore influence on the position of dimethylaniline in micelles: fluorescence quenching of 1,8-acridinedione.

Fluorescence quenching of 9,10-dimethyl-3, 4,6,7,9,10-hexahydro-1,8(2H,5H) acridinedione (ADD) dye by N,N-dimethylaniline (DMA) in SDS and CTAB were studied by steady state fluorescence and time resolved techniques. The Stern-Volmer plots for the quenching of ADD by DMA is found to be linear and the Stern-Volmer constant K(SV) depends on the micellar concentration. The fluorescence quenching analysis reveals the binding of DMA with the micelles. The perturbation of the probe on the position of DMA molecule in micelle is inferred in the present investigation. The ADD fluorophore drives the DMA molecule into the non-polar region (core) of the micelle whereas other fluorophores like pyrene and rhodamine6G do not affect the position of DMA. In this report, the importance of the nature of fluorophores in determining the position and association of the quencher molecules in the aggregated systems is being discussed.

Acridines↗
PubMed1998

The action of three antiseptics/disinfectants against enveloped and non-enveloped viruses.

The antiviral action of chloroxylenol, benzalkonium chloride and cetrimide/chlorhexidine was assessed against a range of enveloped and non-enveloped human viruses using a suspension test method. Viral suspensions of 10(6)-10(7) pfu/TCID50 or sfu were prepared in each of the antiseptic/disinfectant solutions in the presence of a bovine serum/yeast extract mixture to simulate 'dirty conditions'. During incubation, aliquots were removed at predetermined timepoints up to 10 min to assess the kinetics of inactivation. Results indicate that all products were effective in inactivating the enveloped viruses herpes simplex virus type 1 and human immunodeficiency virus type 1, whilst being ineffective in inactivating human coronavirus, also enveloped, and the non-enveloped viruses. The exception to this was the benzalkonium chloride-based product (Dettol Hospital Concentrate) which was active against the non-enveloped human coxsackie virus. Four antiseptic/disinfectant solutions with chloroxylenol, benzalkonium chloride, cetrimide/chlorhexidine and povidone-iodine were also assessed for antiviral effect against human immunodeficiency virus in the presence of whole human blood. All four solutions proved to be effective within 1 min despite the cytotoxic nature of the compounds to the detection system.

Anti-Infective Agents, Local↗
PubMed2000

Fractional inhibitory concentration index of combinations of antibacterial agents against cariogenic organisms.

OBJECTIVES: To examine the inhibitory effects between paired combinations of four antibacterial agents that have been investigated in dentistry against six bacteria associated with dentinal caries. METHODS: The antibacterial agents tested were: chlorhexidine dihydrochloride, benzalkonium chloride, cetrimide and cetylpyridinium chloride. Two organisms each belonging to Streptococcus, Lactobacillus and Actinomyces species were evaluated against these agents. A checkerboard microtitration method was used to determine the minimum inhibitory concentration and fractionary inhibitory concentration (FIC) and summation operator FIC index of the paired combinations of antibacterial agents against the six species of bacteria. Appropriate controls were included. The summation operator FIC index was then used to determine if synergy, antagonism, or indifference occurred as a result of interactions between the antibacterial agents and the test organisms. RESULTS: The data from a total of 295 test results were evaluated. Using summation operator FIC values for synergy as < or = 0.5 and antagonism as > 4.0 as recommended by The American Society for Microbiology, no significant synergistic or antagonistic interactions were observed between the paired antibacterial agents when tested against selected organisms. However, a tendency for an additive antibacterial effect was observed with approximately a third of the test results. Nonetheless, no combination of antibacterial agents appeared to be superior to any other. CONCLUSIONS: According to these in vitro results, there appears to be no beneficial effect of combining the antibacterial agents against the individual cariogenic micro-organisms selected. However, it may be beneficial to use combined antibacterial agents that have a broader range of activity against an ecosystem of bacteria than using individual agents.

Actinomyces↗
PubMed2005

Single-walled carbon nanotube-based coaxial nanowires: synthesis, characterization, and electrical properties.

We report herein the template-directed synthesis, characterization, and electric properties of single-walled carbon nanotube- (SWNT-) based coaxial nanowires, that is, core (SWNT)-shell (conducting polypyrrole and polyaniline) nanowires. The SWNTs were first dispersed in aqueous solutions containing cationic surfactant cetyltrimethylammonium bromide (CTAB) or nonionic surfactant poly(ethylene glycol) mono-p-nonyl phenyl ether (O pi-10). Each individual nanotube (or small bundle) was then encased in its own micellelike envelope with hydrophobic surfactant groups orientated toward the nanotube and hydrophilic groups orientated toward the solution. And thus a hydrophobic region within the micelle/SWNT (called a micelle/SWNT hybrid template) was formed. Insertion and growth of pyrrole or aniline monomers in this hybrid template, upon removal of the surfactant, produce coaxial structures with a SWNT center and conducting polypyrrole or polyaniline coating. Raman and Fourier transform infrared (FTIR) spectroscopy and scanning (SEM) and transmission (TEM) electron microscopy were used to characterize the composition and the structures of these coaxial nanowires. The results revealed that the micellar molecules used could affect the surface morphologies of the resulting coaxial nanowires but not the molecular structures of the corresponding conducting polymers. Electric properties testing indicated that the SWNTs played the key roles in the conducting polymer/SWNT composites during electron transfer in the temperature range 77 K to room temperature. Compared with the SWNT network embedded in the conducting polymers, the composites within which SWNTs were coated perfectly by the identical conducting polymers exhibited higher barrier heights during electron transfer.

Aniline Compounds↗
PubMed2005

DNA-network-templated self-assembly of silver nanoparticles and their application in surface-enhanced Raman scattering.

A large-scale lambda-DNA network on a mica surface was successfully fabricated with a simple method. Silver nanoparticles capped with the cationic surfactant cetyltrimethylammonium bromide (CTAB) were self-assembled onto a two-dimensional DNA network template by electrostatic interaction and formed nanoporous silver films, which can be used as active surface-enhanced raman scattering (SERS) substrates. Two probe molecules, Rhodamine 6G (R6G) and 4-aminothiophenol (4-ATP), were studied on these substrates with very low concentrations, and great enhancement factors for R6G (0.21 x 10(10)-4.09 x 10(11)) and 4-ATP (approximately 1.70 x 10(5)) were observed. It was found that the enhancement ability was affected by the DNA concentration and the electrostatic absorption time of the CTAB-stabilized silver nanoparticles on the DNA strands. These SERS substrates formed by the self-assembly of silver nanoparticles on DNA network also show good stability and reproducibility in our experiments.

Aniline Compounds↗
PubMed2006

Self-motion of a camphanic acid disk on water with different types of surfactants.

Control of the self-motion of a camphanic acid disk on water was investigated upon the addition of different kinds of surfactants (Triton X-100 and Brij58 as neutral surfactants, cetyltrimethylammonium bromide (CTAB) as a cationic surfactant, and sodium dodecyl sulfate (SDS) as an anionic surfactant) to the water phase. With an increase in the concentration of surfactant, continuous motion changed to no motion via intermittent motion (repetition between motion and rest), and the concentration regions of these motions were different among these surfactants. Although the concentration regions of these motions were determined by the surface tension for neutral surfactants, they were different than those for CTAB and SDS. These characteristics of self-motion are discussed in relation to the surface tension, depending on the concentration of individual surfactants, and the hydrophilic effect of the surfactants.

Bridged-Ring Compounds↗
PubMed2004

Interfacial tension of a nematic liquid crystal/water interface with homeotropic surface alignment.

Pendant drop experimental results are presented for the temperature dependence of the interfacial tension between water and the immiscible nematic liquid crystal 4'-pentyl-4-biphenylcarbonitrile (5CB) in the presence of the adsorbed surfactant cetyltrimethylammonium bromide (CTAB). Adsorption of the surfactant lowers the interfacial tension value and is also known from earlier work to induce a transition in liquid crystal surface alignment from planar to homeotropic [Brake et al. Langmuir 2003, 19, 6436.]. Discrepancies exist in the literature regarding the density of 5CB, and the density difference between 5CB and water in any case is very small. However, from the ability to form pendant 5CB drops, one may infer that the density of 5CB exceeds that of water over the entire temperature range studied (28-41 degrees C), in disagreement with the predictions of one earlier report on 5CB. The interfacial tension is shown to exhibit a relative maximum near the bulk 5CB nematic-isotropic transition temperature T(NI), regardless of which published data set of 5CB density values is used to analyze the measurements, with a possible discontinuity in tension occurring at T(NI). The anomalous shape of the interfacial tension curve, depending on the choice of the 5CB density data set, may be quite similar to that recently reported for the interface between 5CB and a hydrophobic, isotropic molten polymer (Rai et al. Langmuir 2003, 19, 7370).

Adsorption↗
PubMed1998

Comparison of the efficacy and safety of two eye gels in the treatment of dry eyes: Lacrinorm and Viscotears.

PURPOSE: To compare the efficacy and safety of two carbomer 940 eye gels in the treatment of dry eyes: Lacrinorm (also called GelTears), a recently introduced eye gel, and Viscotears (also called Vidisic or Lacrigel), used as a reference gel. The main difference between the two gels is in the preservative, respectively benzalkonium chloride and cetrimide. METHODS: A double-masked, randomised, parallel-group study was conducted in 16 centres in four European countries. A total of 179 patients suffering from aqueous-deficient dry eye were enrolled, of whom 92 were randomised to treatment with Lacrinorm and 87 to the reference gel. Gel was instilled four times a day for a period of 30 days. RESULTS: After 30 days of treatment, subjective symptoms (the combined scores of foreign body sensation, ocular dryness, burning or pain, and photophobia) had improved by 50% in the Lacrinorm group and by 45% in the reference gel group, and objective test results (break-up time, fluorescein test, Schirmer test, Lissamine Green test) by 35-36% in the Lacrinorm group and 25-45% in the reference group. The improvements were significant in both treatment groups (p < 0.001), with no significant differences between the treatment groups. Subjective local tolerability upon instillation on day 30 was rated 'good' or 'very good' by 91% of patients in both treatment groups. Adverse events were reported for 21 patients in the Lacrinorm group and 17 in the reference group, the most frequent being discomfort, blurred vision, hyperaemia, burning and itching. The frequency and descriptions of adverse events did not differ significantly between the two treatment groups. No serious adverse events were reported. CONCLUSIONS: Over the period of study, Lacrinorm eye gel was as effective and safe as Viscotears/Lacrigel in the treatment of dry eye.

Acrylic Resins↗
PubMed2006

Reaction route control by microperoxidase-9/CTAB micelle ratios.

Microperoxidases (MP) as water-soluble models attract interest to studying the reaction mechanism of peroxidases because these heme peptides are able to form the same enzyme intermediates during the reaction with peroxides. In this work we have demonstrated that the association of Fe(III)MP-9 and Fe(III)MP-11 with CTAB micelles (MP-9/CTAB and MP11/CTAB) provides a microenvironment with an alkaline interface and a hydrophobic core that exhibits peroxidase behavior. This microenvironment shifts positively the redox potential of microperoxidases by approximately 100 mV. tert-Butylhydroperoxide (t-BuOOH) when added to the medium, converted Fe(III)MP-9/CTAB to MP-9/CTAB Compound II, a high valence oxidized intermediate of the heme peptide. Subsequent addition of diphenylacetaldehyde (DPAA) to MP-9/CTAB Compound II regenerated the native form of the enzyme, Fe(III)MP-9/CTAB, what characterizes the occurrence of a peroxidase cycle. Fe(III)MP-9/CTAB regenerated during the peroxidase cycle reacted with residual DPAA in the medium to form Fe(II)MP-9/CTAB, which indicates that both Fe(III)MP-9/CTAB and its oxyferryl form can use aldehydes as reducing agents. According to the determined reduction potential, Fe(III)MP-9 and Fe(III)MP-9/CTAB should be able to oxidize DPAA (reduction potential -630 mV). The reaction of MP-9/CTAB with DPAA produced benzophenone as final product, detected by infrared spectroscopy and mass spectrometry. Interestingly, a significant difference was observed in the benzophenone yield according to the micelle/MP-9 molar ratio.

Aldehydes↗
PubMed2004

Uptake of aniline and nitrobenzene from aqueous solution by organo-zeolite.

Adsorption mechanisms of toxic non-ionic organic contaminants (NOCs), aniline and nitrobenzene, with natural-zeolite and organo-zeolite (OZ) were investigated in both batch and continuous systems. In batch tests, the adsorption capacity of aniline and nitrobenzene onto natural zeolite surface is very low or almost nil but becomes significant upon modifying the zeolite surface by hexadecyltrimethylammonium (HDTMA). A partitioning mechanism is proposed to be responsible for the adsorption of NOCs onto OZ. The effectiveness of the partitioning mechanism is directly connected with hydrophobic properties of the NOCs. The column tests were carried out as an indicator for continuous system. The breakthrough curves were constructed for OZ/NOC system and the adsorption capacity of NOCs onto OZ under the present conditions were determined as 2.36 and 3.25 mg per gram of OZ, for aniline and nitrobenzene, respectively. A schematic model is proposed to account for the adsorption of NOCs onto OZ.

Adsorption↗