Solubility and bioavailability enhancement of ciprofloxacin by induced oval-shaped mono-6-deoxy-6-aminoethylamino-ß-cyclodextrin.

Ciprofloxacin is a broad-spectrum fluoroquinolone antibiotic used to treat bacterial infections; however, its limited aqueous solubility inhibits its broader clinical uses. This study investigated the complexation effect of mono-6-deoxy-6-aminoethylamino-ß-cyclodextrin on the aqueous solubility and bioavailability of ciprofloxacin. During complexation, the oval-shaped cavity induced by mono-aminoethylamine substitution on the primary rim of ß-cyclodextrin, was considered to be a key factor according to NMR spectroscopy and molecular modeling studies. The ciprofloxacin with mono-6-deoxy-6-aminoethylamino-ß-cyclodextrin complex was characterized using FE-SEM, DSC, FT-IR, T1 relaxation, 2D NOESY, and DOSY NMR spectroscopy and molecular modeling studies. The solubility property of ciprofloxacin complexed with mono-6-deoxy-6-aminoethylamino-ß-cyclodextrin was enhanced by seven-fold compared to that of pure ciprofloxacin. Furthermore antibacterial activity of that complex against methicillin-resistant Staphylococcus aureus was enhanced and it clearly showed the growth inhibition. The mono-6-deoxy-6-aminoethylamino-ß-cyclodextrin has the potential to be utilized for other oblong guest molecules besides ciprofloxacin based on the novel induced elliptical cavity.

Enhancing bio-availability of ß-naphthoflavone by supramolecular complexation with 6,6'-thiobis(methylene)-ß-cyclodextrin dimer.

The aryl hydrocarbon receptor (AhR) is a ligand activated transcriptional regulator, which governs key biological processes including detoxification of carcinogens. ß-Naphthoflavone (ß-NF) is a non-toxic flavonoid, and a potent AhR agonist. Thus, ß-NF can induce the representative detoxifying enzyme cytochrome P4501A1, thereby enhancing the detoxification potential. However, its low water solubility hampers the use. We found that supramolecular complexation of ß-NF with the synthetic 6,6'-thiobis(methylene)-ß-cyclodextrin (ß-CD-S) dimer significantly enhanced ß-NF's role as an AhR agonist. The water solubility of ß-NF was increased to 469 fold by effective supramolecular complexation with the ß-CD-S dimer, and caused significant induction of cytochrome P4501A1. Stable formation of the supramolecular complex of ß-NF with ß-CD-S-dimer was verified by various analyses. In summary, supramolecular complexation of ß-NF with ß-CD-S dimer greatly enhanced bio-availability of ß-NF as an AhR agonist. Our findings provide an easy, non-destructive, and alternative approach to enhance the bio-availability of therapeutics.