title: Monolayer kinetic model of formation of β-cyclodextrin-β-carotene inclusion complex.
abstract: The carotenoids are sensitive molecules and their chemical integrity must be preserved from pro-oxidant elements which could affect and decrease their physiological benefits. The encapsulation based on the inclusion of the carotenoids into cage molecules is a promising approach for preserving over time of the intrinsic properties of the carotenoids. It is well known that cyclic oligosaccharide β-cyclodextrin (CD) as a cage molecule possesses strong inclusion ability to β-carotene (C) and as a result of the hydrophobic interactions forms an inclusion complex. In the present paper a monolayer kinetic model was established with the notion to extract more information about the influence of the molecular structure and organization to the interfacial interactions between the interacting species as well as about the role of the specific areas, which are often underestimated in previously studied dispersed systems. We developed the monolayer kinetic model for the formation of the inclusion CD-C complex by applying an experimental approach for following the kinetics by means of measuring the decrease of the surface area (ΔA) versus time (t) at constant surface pressure (π) and the decrease of surface pressure (π) versus time (t) at constant surface area (A). We also visualized by AFM the state of the monolayers at the initial and end points of the kinetic process. The values for the degree (d) and constant (Ka) of the association were estimated and compared with those from the studies of dispersed systems.
authors: Biophysical Chemistry Laboratory, Department of Physical Chemistry, Faculty of Chemistry and Pharmacy, University of Sofia, James Bourchier Street 1, 1164 Sofia, Bulgaria. Electronic address: tzivanova@chem.uni-sofia.bg.
authors: Tz
authors: T
authors: Ivanova
authors: Biophysical Chemistry Laboratory, Department of Physical Chemistry, Faculty of Chemistry and Pharmacy, University of Sofia, James Bourchier Street 1, 1164 Sofia, Bulgaria.
authors: K
authors: K
authors: Mircheva
authors: Biophysical Chemistry Laboratory, Department of Physical Chemistry, Faculty of Chemistry and Pharmacy, University of Sofia, James Bourchier Street 1, 1164 Sofia, Bulgaria.
authors: K
authors: K
authors: Balashev
authors: Biophysical Chemistry Laboratory, Department of Physical Chemistry, Faculty of Chemistry and Pharmacy, University of Sofia, James Bourchier Street 1, 1164 Sofia, Bulgaria.
authors: I
authors: I
authors: Panaiotov
authors: INSERM U1066, MINT "Micro et Nanomédecines Biomimétiques", 49033 Angers, France.
authors: F
authors: F
authors: Boury
mesh_terms: D004339:Drug Compounding; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D018625:Microscopy, Atomic Force; D008956:Models, Chemical; D013499:Surface Properties; D019207:beta Carotene / Q000737:chemistry*; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D047392:beta-Cyclodextrins; D019207:beta Carotene
keywords: Inclusion complex; Langmuir monolayer; β-Carotene; β-Cyclodextrin