Effects of ions and detergents in drug partition chromatography on liposomes

Lipid Bilayer Fragments and Disks in Drug Delivery

“…Sterically stabilized liposomes prepared from phospholipids with covalently attached poly(ethylene glycol) (PEG lipids) are commonly used for the preparation of long based methods for the determination of drug partitioning such as potentiometric [55][56][57], chromatographic [58][59][60][61][62][63][64], electrophoretic [65][66][67] and calorimetric methods [68,69]. From Lundhal and coworkers technique [58,59] liposomes and disks were immobilized in chromatographic gel beads so that the partition of a large set of drugs was quickly and conveniently assessed [54].…”

Determination of partitioning of drug molecules using immobilized liposome chromatography and chemometrics methods

“…Liposomes possess an orderly molecular structure and are able to exert electrostatic interactions 36, 37. Generally, the membrane partitioning of drugs decreased in the order neutral 〉 positively charged 〉 negatively charged drugs.…”

“…The drug partitioning was assessed from the retention volume, which was expressed as a capacity factor, K s , normalized with respect to the amount of immobilized phospholipids, and can be used for semi‐quantitative analysis of solute–membrane interaction 3, 4. For normalization of the results obtained on gel beds with different amounts of phospholipids, and for elimination of the dead volume of the system, a logarithm of the normalized retention values, K s , for a drug was calculated by using Eqn 1: where V r is the retention volume of the drug, V o is the retention volume of a small and hydrophilic reference ion (whereby the dead volume of the system is eliminated) and A is the amount of immobilized phospholipids 7. Using chemometric tools to predict drug and chemical tissue distribution, membrane permeability or biphasic system partition is of major importance in physicochemical, environmental, and life sciences 8.…”

Bilayer disk capillary electrophoresis: A novel method to study drug partitioning into membranes

“…2 and 3). The solute partitioning into disks stabilized with PEG-DSPE(5000) was generally more pronounced than the partitioning into disks stabilized with PEG-Cer(5000), which indicates the importance of electrostatic interactions [3,6,8] in addition to the hydrophobic interactions [2,28]. Furthermore, the variation in the partitioning between different disk systems appeared to depend on the position and orientation of the charged/polar groups of the drugs (Table 1).…”

“…They are commonly used as model membranes in studies of substance-membrane interactions [1][2][3] and as carriers of drugs to be released at specific targets in the body [4]. The partitioning of solutes into liposomes has been studied by several analytical techniques such as immobilized liposome chromatography (ILC) [5][6][7][8], isothermal titration calorimetry [9,10], and CE with liposomes as a pseudostationary phase (liposome EKC) [1,11] or as a stationary phase [12,13]. Another technique used for partitioning studies is immobilized artificial membrane (IAM) chromatography [14].…”