Magnus Erickson

Experimental modelling of drug membrane permeability by capillary electrophoresis using liposomes, micelles and microemulsions

Capillary electrophoresis (CE) was evaluated as an in‐vitro format for experimental modelling of membrane permeability using only nanogram quantities of drug compounds. The rationale for the CE technique emanates from emulation of a lipid‐like pseudo‐stationary phase that governs separations mainly as a result of differences in molecular size, lipophilicity, hydrogen bonding and charge, all of which also have a strong influence on in‐vivo drug absorption. By means of micellar, microemulsion and liposome electrolytes, the migration behaviour was studied at 37°C for 22 model drug compounds. The generated CE retention factor data were then compared with membrane permeability reference data. Both simple log D and more common Caco‐2 cell parameters were evaluated. In addition, permeation through intestinal segments of rat ileum and rat colon was included. An improved correlation was obtained in the order: micellar

Effect of polymerization conditions on morphology and chromatographic characteristics of polyacrylamide‐based beds (monoliths) for capillary electrochromatography and capillary liquid chromatography

Pioneering research work on continuous or monolithic beds for LC was published in 1989. However, till date there is a lack of complex investigation of various factors affecting the morphology of the beds polymerized from water-soluble co-monomers. In this article the effect of buffer, used as polymerization medium, concentration and pH, and total monomer concentration on the morphology of the resultant continuous beds are discussed. Evaluation of the continuous beds was performed by means of capillary LC, CEC, and inverse size-exclusion chromatography.