title: β-Cyclodextrin-dextran polymers for the solubilization of poorly soluble drugs.
abstract: The aim of this study was to assess the potential of novel β-cyclodextrin (βCD)-dextran polymers for drug delivery. The size distribution of βCD-dextrans (for eventual parenteral administration), the influence of the dextran backbones on the stability of the βCD/drug complex, the solubilization efficiency of poorly soluble drugs and drug release properties were investigated. Size analysis of different βCD-dextrans was measured by size exclusion chromatography (SEC) and asymmetrical flow field-flow fractionation (AF4). Stability of drug/βCD-dextrans was assessed by isothermal titration calorimetry (ITC) and molar enthalpies of complexation and equilibrium constants compared to some commercially available βCD derivatives. For evaluation of the solubilization efficiency, phase-solubility diagrams were made employing hydrocortisone (HC) as a model of poorly soluble drugs, whereas reverse dialysis was used to detect potential drug supersaturation (increased molecularly dissolved drug concentration) as well as controlled release effects. Results indicate that all investigated βCD-polymers are of appropriate sizes for parenteral administration. Thermodynamic results demonstrate that the presence of the dextran backbone structure does not affect the stability of the βCD/drug complex, compared to native βCD and commercially available derivatives. Solubility studies evidence higher solubilizing abilities of these new polymers in comparison to commercially available βCDs, but no supersaturation states were induced. Moreover, drug release studies evidenced that diffusion of HC was influenced by the solubilization induced by the βCD-derivatives.
authors.affiliation: Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, Odense M 5230, Denmark. Electronic address: mdc@sdu.dk.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: di Cagno
authors.affiliation: Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 57, Aalborg 9000, Denmark. Electronic address: ttn@bio.aau.dk.
authors.forename: Thorbjørn
authors.initials: T
authors.lastname: Terndrup Nielsen
authors.affiliation: Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 57, Aalborg 9000, Denmark. Electronic address: kll@bio.aau.dk.
authors.forename: Kim
authors.initials: K
authors.lastname: Lambertsen Larsen
authors.affiliation: Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, Odense M 5230, Denmark. Electronic address: kuntsche@sdu.dk.
authors.forename: Judith
authors.initials: J
authors.lastname: Kuntsche
authors.affiliation: Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, Odense M 5230, Denmark. Electronic address: annette.bauer@sdu.dk.
authors.forename: Annette
authors.initials: A
authors.lastname: Bauer-Brandl
mesh_terms: D000073738:2-Hydroxypropyl-beta-cyclodextrin; D002151:Calorimetry; D002626:Chemistry, Pharmaceutical; D002850:Chromatography, Gel; D003692:Delayed-Action Preparations; D003911:Dextrans / Q000737:chemistry*; D003956:Dialysis; D004058:Diffusion; D004337:Drug Carriers; D004355:Drug Stability; D006854:Hydrocortisone / Q000737:chemistry*; D007700:Kinetics; D008970:Molecular Weight; D010316:Particle Size; D012995:Solubility; D013678:Technology, Pharmaceutical / Q000379:methods; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D003692:Delayed-Action Preparations; D003911:Dextrans; D004337:Drug Carriers; D047392:beta-Cyclodextrins; C108732:methyl-beta-cyclodextrin; D000073738:2-Hydroxypropyl-beta-cyclodextrin; D006854:Hydrocortisone
keywords: Calorimetry (ITC); Cyclodextrins; Poorly soluble drugs; Solubilization; βCD-dextran polymers