2‐Naphthol‐containing β‐cyclodextrin–epichlorohydrin copolymers: synthesis, characterization and fluorescence studies

Abstract

Fluorescent 2‐naphthol (NOH)‐containing β‐cyclodextrin (β‐CD)–epichlorohydrin (EP) copolymers were synthesized. Polymerization was confirmed through viscosity and FT‐IR spectroscopic measurements. Under certain conditions, the copolymers were water‐soluble (molar ratio of EP/β‐CD <22:1), while under other conditions water‐insoluble gels were formed (EP/β‐CD ≥ 22:1). Increase of the EP content to EP/β‐CD ≤ 39:1 increased the fluorescence intensity of the copolymer and shifted the emission maximum from 422 nm toward 352 nm (measured at pH ≥ 12). Further increases in the EP content resulted in a slight decrease in the fluorescence intensity. The fluorescence properties of our system at EP/β‐CD < 22 were sensitive to pH variation, while at EP/β‐CD ≥ 22 no pH effect was observed. These variations can be explained in terms of the exposure of the fluorophore to solvent in soluble versus insoluble polymers, as well as changes in the mode of association (host–guest complexation, trapping within the polymer network, covalent bonding, etc) of NOH with the polymers. Crystallographic studies on a single crystal grown in the absence of EP, but under basic conditions, suggest that host–guest complexation is not an important mode for NOH incorporation. Copyright © 2005 Society of Chemical Industry

Cyclodextrins in Drug Delivery Systems and Their Effects on Biological Barriers

“…NS offers possibility to increase the solubility of insoluble drugs, the permeability of the drugs and controlled drug release (Figure 4). [64][65][66][67][68][69][70], 2nd generation [71][72][73][74][75], 3rd generation [76][77][78][79], and 4th generation [80,81]).…”

Cyclodextrin‐Based Supramolecular Assemblies and Hydrogels: Recent Advances and Future Perspectives

“…The use of these systems was further extended to high‐performance capillary electrophoresis, whereby β‐CD was covalently embedded into dextran polymer gel networks and consequently applied to the chiral separation of peptides and small ions . This ideology was further extrapolated for use within the pharmaceutical industry as drug deposits, whereby networks were fabricated through the cross‐linking of CDs with epichlorohydrin . Aside from epichlorohydrin, other functional linkers that have been used include diisocyanates, anhydrides, and functional polymers …”

“…[ 58 ] This ideology was further extrapolated for use within the pharmaceutical industry as drug deposits, whereby networks were fabricated through the cross-linking of CDs with epichlorohydrin. [ 1,[59][60][61] Aside from epichlorohydrin, other functional linkers that have been used include diisocyanates, [ 1,44 ] anhydrides, [ 62,63 ] and functional polymers. [ 44,47,64 ] Recently, covalent CD-based polymeric networks synthesized via the cross-linking of diisocyanate-terminated PEG with β-CDs were shown to entrap metal ions for the fabrication of hybrid organic/inorganic materials displaying both soft and hard characteristics.…”

Preparation and enantiomer separation characteristics of chitosan/β-cyclodextrin composite membranes

“…The ␤-CDP was synthesized by cross-linking hydroxyl groups of ␤-cyclodextrin via EP by the following procedure. Water-insoluble ␤-cyclodextrin polymer (␤-CDP) for the preparation of the membrane was synthesized similar to the procedures from some previous reports [21,22]: 10.0 g of ␤-CD was dissolved in 20.0 ml of deionized water containing 6.67 g of NaOH. After total dissolution of ␤-CD, 7.0 ml of EP was added dropwise to cross-link ␤-CD molecules (EP:CD = 10:1, molar ratio).…”