Recombination of vesicles during freeze-drying

Bernard Cabane (1) , Sylvène Blanchon (2) , Carole Neves (2)

1 PMMH - Physique et mécanique des milieux hétérogenes (UMR 7636)
2 Sanofi-Aventis, Department of Pharmaceutical Sciences, Paris Research Center

Concentrated dispersions of nanometric lipid vesicles (mean diameter 20 nm) in water/maltose solutions have been freeze-dried, and then redispersed in water, yielding again dispersions of lipid vesicles. At each stage of the freeze-drying process, the organization of the vesicles in the dispersion and their size distribution were examined through Small Angle Neutron Scattering and Gel Permeation Chromatography. It was found that the osmotic deswelling of the vesicles caused them to recombine into larger vesicles. A single burst of recombination events occurred when the maltose concentration in the aqueous phase rose above 100 g/L. The final vesicle population was monopopulated, with a central diameter about twice as large as that of the original dispersion.

Domaines: Chimie thérapeutique

Bernard Cabane, Sylvène Blanchon, Carole Neves. Recombination of vesicles during freeze-drying. Langmuir, 2006, 22, pp.1982. ⟨hal-00160010⟩