22 research outputs found
Charge Determines Guest Orientation:A Combined NMR and Molecular Dynamics Study of β-Cyclodextrins and Adamantane Derivatives
Complexation Kinetics of Cyclodextrins with Bile Salt Anions:Energy Barriers for the Threading of Ionic Groups
Structure and thermodynamics of inclusion complexes between cyclodextrins and bile salts in aqueous solution:Enthalpy-entropy compensation, convergence temperatures and other features of hydrophobic dehydration
Exploring the Origins of Enthalpy–Entropy Compensation by Calorimetric Studies of Cyclodextrin Complexes
Drug Solubilization by Mixtures of Cyclodextrins:Additive and Synergistic Effects
Cyclodextrins are
popular drug solubilizers, but the use of the
natural cyclodextrins is hampered by their tendency to coprecipitate
with the drug. To understand and overcome such problems, we have studied
the solubility of dexamethasone in the presence of natural β-cyclodextrin
and Îł-cyclodextrin, individually and in various combinations.
Equilibrium models of the phase-solubility diagrams with individual
cyclodextrins revealed that dexamethasone was solubilized as 1:1 complexes,
but formation of insoluble higher-order complexes set an upper limit
to the concentration of solubilized dexamethasone. This limit could
be raised from 8 to 17 mM by using combinations of the two cyclodextrins,
as their solubilizing properties were additive in some regions of
the phase-solubility diagram and synergistic in other regions. The
additive effects arise from the additivity of solubilitiesî—¸the
same phenomenon contributes to the good solubilizing properties of
many modified cyclodextrins. The synergistic effects, however, could
not be explained. The results open up for an increased use of the
natural cyclodextrins as an improved alternative to modified cyclodextrins