CPL - Chalmers Publication Library
| Utbildning | Forskning | Styrkeområden | Om Chalmers | In English In English Ej inloggad.

Structure and dynamics of a sponge phase in the methyl delta-aminolevulinate/monoolein/water/propylene glycol system

Johanna Bender (Institutionen för kemi- och bioteknik, Teknisk ytkemi) ; Patrik Jarvoll (Institutionen för kemi- och bioteknik) ; Magnus Nydén (Institutionen för kemi- och bioteknik, Teknisk ytkemi ; SuMo Biomaterials) ; Sven Engström (Institutionen för kemi- och bioteknik, Teknisk ytkemi)
Journal of Colloid and Interface Science (0021-9797). Vol. 17 (2008), 2, p. 577-584.
[Artikel, refereegranskad vetenskaplig]

The structural effect caused by the addition of up to 16% (w/w) of the hydrochloride salt of delta-aminolevulinic acid (ALA, HOOC-CH(2)-CH(2)-CO-CH(2)-NH(2)HCl) or its methyl ester (m-ALA) to the sponge phase formed of monoolein/water/propylene glycol was investigated by means of crossed polarizers, small angle X-ray diffraction (SAXD) and nuclear magnetic resonance diffusometry (NMRD). Inspection with crossed polarizers revealed that additions of 4-16% (w/w) m-ALA transformed the isotropic bicontinuous sponge phase partly (4-10%) or completely (13 and 16%) into an anisotropic lamellar phase, indicating that m-ALA has a flattening effect on the bilayer curvature. The addition of 16% (w/w) ALA did not show any effect on the sponge phase. By addition of water to the anisotropic m-ALA samples, isotropic liquids were re-formed. The SAXD data for the isotropic liquids showed a diffuse Bragg peak and the NMRD self-diffusion coefficients for the drug (m-ALA) and the components of the original sponge phase (monoolein, water and propylene glycol) were shown to be essentially constant for 0-16% (w/w) added m-ALA. These results confirmed the hypothesis that the re-formed isotropic phases were indeed sponge phases. Water, for example, showed a diffusion coefficient of 3.1-3.9x10(-10)m(2)s(-1) in the sponge phase, compared to 5.3-5.7x10(-10)m(2)s(-1) in relevant water/propylene glycol solutions or 2.3x10(-9)m(2)s(-1) in pure water. The reduction can be explained as a consequence of the microstructure (congruent monoolein bilayer) of the sponge phase and of the viscosity effect caused by propylene glycol and m-ALA.

Nyckelord: ALA; m-ALA; Monoolein; NMRD; Propylene glycol; SAXD; Self-diffusion; Sponge phase

Denna post skapades 2008-01-03. Senast ändrad 2016-07-07.
CPL Pubid: 64279


Läs direkt!

Länk till annan sajt (kan kräva inloggning)

Institutioner (Chalmers)

Institutionen för kemi- och bioteknik, Teknisk ytkemi (2005-2014)
Institutionen för kemi- och bioteknik (2005-2014)
SuMo Biomaterials


Galenisk farmaci

Chalmers infrastruktur

Relaterade publikationer

Denna publikation ingår i:

Mass Transport Properties in Supramolecular Systems Studied by Diffusion and Relaxation NMR