266
products (cider, apple juice, apple pomace, etc.). Despite their
antioxidant power, their low stability under light or heating conditions restricts the use of this kind of molecules as nutraceuticals.
Encapsulation of polyphenols might be a solution to deal with this
issue. β-CD nanosponges, prepared using hexamethylene diisocyanate (HMDI-NS) and 1,1′-carbonyldiimidazole (CDI-NS) as
cross-linkers and synthesized with different molar ratios
(β-CD:cross-linker), were used for the encapsulation of rutin,
phloridzin, and chlorogenic acid. Physical characterizations of the
solid products obtained confirmed that they were not physical mixtures, but inclusion complexes. The highest encapsulation efficiency for rutin (83.7%) was obtained by using CDI-NS(1:3).
However, HMDI-NS(1:8) showed the best results for the smaller
molecules as phloridzin and chlorogenic acid (87.2% and 77.5%,
respectively). In vitro dissolution studies of encapsulated polyphenols showed that rutin and phloridzin were better dissolved in
ethanol, while chlorogenic acid was better dissolved in water. Thus
polyphenols from apple and its by-products could be encapsulated
to enhance their bioavailability [77].
Resveratrol is a polyphenolic phytoalexin that is found, free
and conjugated, in high concentrations in grape juice, peanuts,
mulberries, and other plant extracts. Resveratrol has been used for
decades in medicine for the treatment of many diseases like inflammation, cardiovascular diseases, skin infections, chemopreventive
activity, gonorrhea, hyperlipidemia, and fever [78]. Hyper-crosslinked NSs of β-CD and CDI (at varying molar ratios, i.e., 1:2, 1:4,
1:8) have been used to increase the solubility, stability, and permeation of resveratrol. In vitro release and stability of NS-resveratrol
complex were increased. Cytotoxicity studies on HCPC-I cell
showed that resveratrol formulations were more cytotoxic than
plain resveratrol. Permeation studies showed good permeation of
the complex in pigskin. Accumulation studies in rabbit mucosa
showed better accumulation of complex than plain resveratrol signifying that resveratrol NS formulation can be used for buccal
delivery and topical application [79].
Norfloxacin (NFX) is a fluoroquinolone antibiotic that has emerged
as one of the preferred agents in the treatment of urinary tract
infections that belongs to biopharmaceutical classification system
BCS class IV drugs [80]. NFX is captured by uptake transporters
but it inhibits them instead of being carried through the enterocyte. NFX is consumed by the uptake transporters, thus reducing
the drug content able to permeate in the gut lumen; thus oral
bioavailability is a crucial factor for NFX. In this context, nanosponges were designed to overcome this biopharmaceutical problem. β-CD was used as building block and diphenyl carbonate as
cross-linker agent; the molar proportion CD:cross-linker 1:2 was
chosen due to its higher encapsulation efficiency (80%). NFX2.7 Cyclodextrin
Nanosponges
for Antibacterial Drug
Maria Tannous et al.
products (cider, apple juice, apple pomace, etc.). Despite their
antioxidant power, their low stability under light or heating conditions restricts the use of this kind of molecules as nutraceuticals.
Encapsulation of polyphenols might be a solution to deal with this
issue. β-CD nanosponges, prepared using hexamethylene diisocyanate (HMDI-NS) and 1,1′-carbonyldiimidazole (CDI-NS) as
cross-linkers and synthesized with different molar ratios
(β-CD:cross-linker), were used for the encapsulation of rutin,
phloridzin, and chlorogenic acid. Physical characterizations of the
solid products obtained confirmed that they were not physical mixtures, but inclusion complexes. The highest encapsulation efficiency for rutin (83.7%) was obtained by using CDI-NS(1:3).
However, HMDI-NS(1:8) showed the best results for the smaller
molecules as phloridzin and chlorogenic acid (87.2% and 77.5%,
respectively). In vitro dissolution studies of encapsulated polyphenols showed that rutin and phloridzin were better dissolved in
ethanol, while chlorogenic acid was better dissolved in water. Thus
polyphenols from apple and its by-products could be encapsulated
to enhance their bioavailability [77].
Resveratrol is a polyphenolic phytoalexin that is found, free
and conjugated, in high concentrations in grape juice, peanuts,
mulberries, and other plant extracts. Resveratrol has been used for
decades in medicine for the treatment of many diseases like inflammation, cardiovascular diseases, skin infections, chemopreventive
activity, gonorrhea, hyperlipidemia, and fever [78]. Hyper-crosslinked NSs of β-CD and CDI (at varying molar ratios, i.e., 1:2, 1:4,
1:8) have been used to increase the solubility, stability, and permeation of resveratrol. In vitro release and stability of NS-resveratrol
complex were increased. Cytotoxicity studies on HCPC-I cell
showed that resveratrol formulations were more cytotoxic than
plain resveratrol. Permeation studies showed good permeation of
the complex in pigskin. Accumulation studies in rabbit mucosa
showed better accumulation of complex than plain resveratrol signifying that resveratrol NS formulation can be used for buccal
delivery and topical application [79].
Norfloxacin (NFX) is a fluoroquinolone antibiotic that has emerged
as one of the preferred agents in the treatment of urinary tract
infections that belongs to biopharmaceutical classification system
BCS class IV drugs [80]. NFX is captured by uptake transporters
but it inhibits them instead of being carried through the enterocyte. NFX is consumed by the uptake transporters, thus reducing
the drug content able to permeate in the gut lumen; thus oral
bioavailability is a crucial factor for NFX. In this context, nanosponges were designed to overcome this biopharmaceutical problem. β-CD was used as building block and diphenyl carbonate as
cross-linker agent; the molar proportion CD:cross-linker 1:2 was
chosen due to its higher encapsulation efficiency (80%). NFX2.7 Cyclodextrin
Nanosponges
for Antibacterial Drug
Maria Tannous et al.