Coordination Chemistry in Proton-containing Donor Solvents

Gutmann, V.

doi:10.1007/978-3-7091-8194-2_3

Cited by 4 publications

(5 citation statements)

References 109 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, the solutions of alcohols are better conductors than water, and the conductivities of alcohols are also greatly increased by the presence of water. 32 The appropriate electrical conductivity values for the conductivity study were obtained with formulations without water and DS, primarily enabled by the presence of alcohols; then the electrical conductivity values of microemulsions with and without DS were compared. DS-loaded microemulsions clearly showed higher conductivity values than unloaded formulations.…”

Section: Resultsmentioning

confidence: 99%

Comparison of different water/oil microemulsions containing diclofenac sodium: Preparation, characterization, release rate, and skin irritation studies

Kantarcı¹,

Özgüney²,

Karasulu³

et al. 2007

AAPS PharmSciTech

View full text Add to dashboard Cite

The aim of the present study was to make a comparison of the in vitro release rate of diclofenac sodium (DS) from microemulsion (M) vehicles containing soybean oil, nonionic surfactants (Brij 58 and Span 80), and different alcohols (ethanol [E], isopropyl alcohol [I], and propanol [P]) as cosurfactant. The optimum surfactant:cosurfactant (S:CoS) weight ratios and microemulsion areas were detected by the aid of phase diagrams. Three microemulsion formulations were selected, and their physicochemical properties were examined for the pH, viscosity, and conductivity. According to the release rate of DS, M prepared with P showed the significantly highest flux value (0.059 ± 0.018 mg/cm 2 /h) among all formulations (P G .05). The conductivity results showed that DS-loaded microemulsions have higher conductivity values (18.8-20.2 microsiemens/cm) than unloaded formulations (16.9-17.9 microsiemens/cm), and loading DS into the formulation had no negative effect on system stability. Moreover, viscosity measurements were examined as a function of shear rate, and Newtonian fluid characterization was observed for each microemulsion system. All formulations had appropriate observed pH values varying from 6.70 to 6.85 for topical application. A skin irritation study was performed with microemulsions on human volunteers, and no visible reaction was observed with any of the formulations. In conclusion, M prepared with P may be a more appropriate formulation than the other 2 formulations studied as drug carrier for topical application.

show abstract

Section: Resultsmentioning

confidence: 99%

Comparison of different water/oil microemulsions containing diclofenac sodium: Preparation, characterization, release rate, and skin irritation studies

Kantarcı¹,

Özgüney²,

Karasulu³

et al. 2007

AAPS PharmSciTech

View full text Add to dashboard Cite

show abstract

“…Reagent grade solvents were used throughout as they were received from the distributor without 404 Donor numbers are taken from v. Gutmann (1968) except for water which is taken from Ehrlich et al (1970).…”

Section: Solventsmentioning

confidence: 99%

“…These include surface charge density, nature of the interlayer cations, and the bulk dielectric constants, dipole moments and surface tensions of the added solvent. The Gutmann donor number is the negative molar enthalpy of the reaction between a particular solvent and SbC1 s in 1,2-dichloroethane (Gutmann, 1968). Since ion solvation is an important phenomenon in smectite swelling (Norrish, 1954), this parameter might be of use in describing clay solvent interactions.…”

Section: Introductionmentioning

confidence: 99%

Variability in Exchange Ion Position in Smectite: Dependence on Interlayer Solvent

Berkheiser

1975

Clays and clay miner.

View full text Add to dashboard Cite

Abstract--Full and reduced charge smectite saturated with Na(I), Ca(II), Cu(II), or tetralkylammonium ions were s&ollen by a series of solvents of various bulk physical properties. In the full charge smectites, swelling occurred in all solvents regardless of the exchange ion or the initial water content. Charge differences did not usually result in differential swelling of the smectite. Little correlation was found between the degree of swelling and the Gutmann donor numbers, bulk dielectric constants, bulk surface tensions, or dipole moments of the solvents. The intensities of the high field Fe(III) resonance (9 = 3.6) in the esr spectra of full charge smectite swollen in various solvents reflected variability in exchange ion positions and depended upon the Gutmann donor number of the solvent. Considerable variety in the stereochemistry of Cu(II)-solvent complexes was revealed by esr spectra of the swollen systems.

show abstract

“…The results were generally Solvation by HMPA It is generally considered that HMPA is an especially strong complexing species and, in fact, it has the highest donor number (38.8) in the original Gutmann listing of solvent donicities (7). This position has recently been substantiated with respect to Nat (8).…”

Section: Discussionmentioning

confidence: 86%

The two liquid phase system NaAl(ethyl)4 – benzene–HMPA

Medley¹,

Ahmad²,

Day³

1985

Can. J. Chem.

View full text Add to dashboard Cite

A detailed study of complexation of the sodium ion by HMPA2 has been made using the system[Formula: see text]where HMPA is observed to be a strong donor towards Na+ but does not complex AlEt4−. This system forms two liquid phases at low HMPA:Na+ molar ratios with the salt and the HMPA, up to a 4:1 HMPA:Na+ ratio, occurring only in the lower phase. Based on a variety of experimental techniques, reasonable proposals of the solute species in the lower phase as a function of HMPA:Na+ ratio are presented. A 2.5:1 ratio of HMPA:Na+ is observed to be particularly significant. This ratio is rationalized in terms of a bridging HMPA molecule resulting in a cationic species with the stoichiometry [2Na•5HMPA]2+. It is found that the 27Al and 1H nmr spectra are determined primarily by quadrupole relaxation of the 27Al nucleus rather than by exchange.

show abstract

Coordination Chemistry in Proton-containing Donor Solvents

Cited by 4 publications

References 109 publications

Comparison of different water/oil microemulsions containing diclofenac sodium: Preparation, characterization, release rate, and skin irritation studies

Comparison of different water/oil microemulsions containing diclofenac sodium: Preparation, characterization, release rate, and skin irritation studies

Variability in Exchange Ion Position in Smectite: Dependence on Interlayer Solvent

The two liquid phase system NaAl(ethyl)4 – benzene–HMPA

Contact Info

Product

Resources

About