Non-ionic detergent

It has been demonstrated that intact influenza virus membranes can be solubilized by octaethylene glycol monododecyl ether (C12E8). The accumulation of C12E8 molecules outside the membrane until micelle formation, which allows for the extraction of membrane contents, provides the basis for the mechanism of viral membrane solubilization[1].

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Micellization of di-n-decyldimethylammonium chloride, [DiC10][Cl], and octaethylene glycol monododecyl ether, C12E8, mixtures have been investigated by surface tension and conductivity measurements. From these results, various physicochemical and thermodynamic key parameters (e.g. micellar mole fraction of [DiC10][Cl], interaction parameter, free energy of micellization, etc.) have been evaluated and discussed in detail. The results prove high synergistic effect between the two surfactants. Based on these results, the virucidal activity of an equimolar mixture of [DiC10][Cl] and C12E8 has been investigated. A marked synergism was observed on lipid-containing deoxyribonucleic and ribonucleic acid viruses, such as herpes virus, respiratory syncytial virus, and vaccinia viruses. In contrast, Coxsackievirus (non-enveloped virus) was not inactivated. These results support that the mechanism is based on the extraction of lipids and/or proteins from the envelope inside the mixed micelles. This extraction creates "holes" the size of which increases with concentration up to a specific value which triggers the virus inactivation. Such a mixture could be used to extend the spectrum of virucidal activity of the amphiphiles virucides commonly employed in numerous disinfectant solutions. [1]

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Mixed micelles of n-octyl-β-D-thioglucoside (OTG) and octaethylene-glycol monododecyl ether (C12E8), two non-ionic surfactants belonging to the alkyl glucosides and polyoxyethylene alkyl ether families, respectively, were investigated by using light scattering and fluorescence probe techniques. From the determination of the critical micelle concentration (cmc), by the well-established pyrene 1:3 ratio method, it was found that the mixed system behaves ideally, the micellization process being clearly controlled by the ethoxylated surfactant. The micellar hydrodynamic radius as a function of temperature, composition and concentration was obtained by dynamic light scattering measurements. It was observed that the micellar size increases with temperature, this growth being more pronounced as the relative proportion of the ethoxylated surfactant was increased. The behavior of the micellar size with the total surfactant concentration was also found to be dependent on temperature and composition. The clouding temperature, characteristic of the ethoxylated surfactants, was increased with the addition of the sugar surfactant. Lastly, possible structural changes in the micellar palisade layer were examined by steady-state fluorescence anisotropy in conjunction with time-resolved fluorescence studies with the hydrophobic probe coumarin 6 (C6). The obtained results indicate that the participation of the ethoxylated surfactant induces a slightly more polar palisade layer, whereas the probe carries out a faster rotational reorientation as a result of a less compact environment. All these observations were attributed to the different structure of the head groups of both surfactants and, as a consequence, to their different hydration [2].

Virus inactivation [1]
200 μL of the viral stock solution was added to 200 μL of pure surfactant (C12E8 or [DiC10][Cl]) or 200 μL of the aqueous binary mixtures of C12E8 and [DiC10][Cl] (in equimolar proportions) After incubation for 15 min at room temperature, the mixtures were immediately filtered on MicroSpin S-400 HR columns to separate viruses from the other components of the mixtures. Residual viruses were then titrated as described above. Each experiment was performed at least three times.

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The samples of surfactants used in this investigation were the same that we employed in earlier studies. The fluorescence probes pyrene, and coumarin 6 (C6) (laser grade, Exciton) were of high purity grade and, therefore, were used as received. Different aqueous stock solutions containing OTG and C12E8 at several proportions were prepared. The bulk composition of the solutions was expressed in mole fraction of the ethoxylated surfactant, α2, defined as, where [C12E8] and [OTG] are the molar concentration of the C12E8 and OTG, respectively. Stock solutions of the fluorescence probes were prepared in absolute ethanol and stored at 4 °C. Working solutions of lower concentration were daily prepared and used immediately after preparation. Ultra pure water (resistivity ∼18 MΩ cm) used for the preparation of all the solutions was obtained by passing deinoized water through an ultra high quality purification system (UHQ-PS, ELGA) [2].

Viruses and cells [1]
HSV-1 (Strain Kos) and VACV (Strain Elstree) were propagated in Vero cells (ATCC® CCL-81⿢) in Minimum essential Medium supplemented with 2 mM l-glutamine, 1% non-essential amino-acids and 2% inactivated fetal calf serum. Cell-free viral suspensions of the viruses were obtained by freezing-thawing cycles followed by a low speed centrifugation to remove cell debris. The very resistant non-enveloped CVB4 (Strain JVB) were propagated in BGM cells in the same medium. RSV (local laboratory strain) was propagated in Hep-2 cells (ATCC® CCL-23⿢) in the same medium. Viruses titers were assayed by the cytopathic effect of serial dilutions (1:10) of virus-containing samples on Vero, Hep-2 or BGM cells. A sample (100 μL) for each dilution was used to infect four replicate wells in 96-well microtiter plates. Virus-induced cytopathic effects were scored after 5 days of incubation at 37 °C ± 0.1 °C in a humidified 5% CO2 atmosphere. Titers were expressed as the quantity of viruses infecting 50% of the tissue culture wells (Tissue Culture Infectious Doses, TCID50) according to Spearman and Kärber (Spearman, 1908, Kärber, 1931). The detection limit was 5.62 TCID50/mL. Virus stocks were 2 ÿ 107 TCID50 mL⿿1 for HSV-1, 2 ÿ 106 TCID50 mL⿿1 for VACV, 3 ÿ 106 TCID50 mL⿿1 for RSV and, 6 ÿ 106 TCID50 mL⿿1 for CVB4.

[1]. Aqueous solutions of didecyldimethylammonium chloride and octaethylene glycol monododecyl ether: Toward synergistic formulations against enveloped viruses. Int J Pharm. 2016 Sep 10;511(1):550-559.

[2]. Characterization of mixed non-ionic surfactants n-octyl-β-D-thioglucoside and octaethylene-glycol monododecyl ether: micellization and microstructure. J Colloid Interface Sci. 2011 Sep 1;361(1):178-85.

Octaethyleneglycol monododecyl ether is the hydroxypolyether that is octaethylene glycol in which one of the hydroxy groups is substituted by dodecyloxy. It is functionally related to an octaethylene glycol.

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In the present study, micellization of [DiC10][Cl] and C12E8 mixtures have been investigated by surface tension and conductivity measurements. The surface tension data have been treated from Clint, Rubingh and Maeda models in order to access to various physicochemical and thermodynamic key parameters (e.g. micellar mole fraction of [DiC10][Cl], interaction parameter, free energy of micellization, etc.). The results highlight a high synergistic effect between the two surfactants in term of micellization especially for an equimolar mixture of [DiC10][Cl] and C12E8. This mixture also shows a wide spectrum of virucidal activity with a marked synergism against deoxyribonucleic and ribonucleic acid viruses which contain lipids in their outercoat (HSV-1, RSV, and VACV). In contrast, non-enveloped virus (CVB4) was not inactivated. Those supports that the virucidal mechanism is based on the solubilization of lipid and/or protein envelope inside mixed micelles. This solubilization creates ⿿holes⿿ whose size increases with the concentration until to a specific concentration (named minimum virucidal concentration that corresponds to end point of activity) which leads to virus inactivation. In view of our new findings that an enhancement of virucidal activity occurs with [DiC10][Cl]/C12E8 mixtures, it becomes clearly evident that the physicochemical data and the competition with biological processes must be rationalized in order to explain the additivity, synergism or antagonism behaviors observed in the simultaneous activity of two biocidal agents in vitro. Moreover, such mixtures could be used to boost the virucidal activity of other amphiphilic virucides commonly employed in various disinfectant formulations. Indeed, synergism is particularly interesting both for the formulator and the user in the fight against viruses and other nosocomial infections.[1]

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The results obtained here for the system formed by a sugar-based surfactant (OTG) and a conventional ethylene oxide one (C12E8) indicate an ideal behavior of the mixed system, which is mainly controlled by the ethoxylated surfactant. We have also found that the micellar size increases with temperature for systems rich in C12E8, but the extension of this growth strongly depends on the system composition. It was found that the addition of the sugar-based surfactant increased the cloud temperature, the cloudy being inhibited in mixtures with a high content of this surfactant. The observed growth of micelles with concentration was also dependent on temperature and system composition. These results were explained on the basis of the higher conformational flexibility of the POE segments of C12E8, allowing not only a greater amount of water penetration, but also a favorable packing with the more rigid head groups of the sugar surfactant. The photophysical and dynamic behavior of a neutral probe, C6, residing in the micellar palisade layer, corroborates that the participation of the ethoxylated surfactant induces the formation of less compact and hydrophobic micelles.
All these observations are important for two reasons. On the one hand, our results support recent findings in related mixed systems, which indicate that the observed properties can be explained on the basis of different hydration and flexibilities of the head groups and the higher surface activity of the ethoxylated surfactant. On the other, we have demonstrated how the physicochemical properties of the system can be modulated, which is important in practice, because by adjusting the proportions of both surfactants we can obtain suitable systems to cover a wide range of process requirements. [2]

C28H58O9

538.75

538.408

3055-98-9

123921

Colorless to light yellow liquid

1.0±0.1 g/cm3

585.5±45.0 °C at 760 mmHg

30ºC

307.9±28.7 °C

0.0±3.7 mmHg at 25°C

1.459

2.54

1

9

34

37

389

0

CCCCCCCCCCCCOCCOCCOCCOCCOCCOCCOCCOCCO

YYELLDKEOUKVIQ-UHFFFAOYSA-N

InChI=1S/C28H58O9/c1-2-3-4-5-6-7-8-9-10-11-13-30-15-17-32-19-21-34-23-25-36-27-28-37-26-24-35-22-20-33-18-16-31-14-12-29/h29H,2-28H2,1H3

2-[2-[2-[2-[2-[2-[2-(2-dodecoxyethoxy)ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethanol

3055-98-9; Octaethyleneglycol monododecyl ether; C12E8; 3,6,9,12,15,18,21,24-Octaoxahexatriacontan-1-ol; dodecyloctaethyleneglycol monoether; O-DODECANYL OCTAETHYLENE GLYCOL; Octaethyleneglycol-dodecylmonoether; n-Dodecyl octaethylene glycol monoether;

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

H2O : ~100 mg/mL (~186 mM)
DMSO : ~100 mg/mL (~186 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (4.64 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (4.64 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (4.64 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)