Cyclodextrins in Pharmaceuticals

Szejtli, J.

doi:10.1007/978-94-015-7797-7_3

Cited by 28 publications

(9 citation statements)

References 173 publications

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“…CDs, cyclic oligosaccharides with a hydrophobic central cavity that provides a microenviron- physical, chemical and biological properties of sever-frequency of daily administration [13,14]. The inal drug molecules, due to their characteristic inclu-corporation of a rapid-dissolving fraction together sion ability [1][2][3]. In recent years, various kinds of with a slow-release portion could be advantageous, chemically-derived CDs have been prepared to ex-since the initial release of a certain amount of NC tend the physicochemical and inclusion properties will give more balanced oral bioavailability, reducand also the multi-functional pharmaceutical charac-ing the first-pass metabolism in the liver.…”

Section: Introductionmentioning

confidence: 99%

Hydrophilic and hydrophobic cyclodextrins in a new sustained release oral formulation of nicardipine: in vitro evaluation and bioavailability studies in rabbits

Fernandes

Ramos

Falcão

et al. 2003

Journal of Controlled Release

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The feasibility of using complexes with cyclodextrins (CDs) in nicardipine (NC) controlled delivery has been examined, with a view to extending the pharmaceutical applications spectrum of these carriers. For a fast release fraction, a hydrophilic beta-cyclodextrin derivative (hydroxypropyl-beta-cyclodextrin) was employed to form a water-soluble complex. For the sustained-releasing portion, triacetyl-beta-cyclodextrin (TAbetaCD) was used to provide complexes with appropriate hydrophobicity. An optimal formulation was designed by the combination of each fraction in different mixing ratios. The release behaviour of the complexes, as well as of their mixtures, was examined in simulated gastric (pH 1.2) and intestinal (pH 6.8) fluids. The formulations released the drug rapidly at the initial stage, followed by a slow release. The drug release rate was markedly retarded in the increasing order of the amount of NC/TAbetaCD complex. When NC was administered to rabbits, its absorption was very rapid with a short elimination half-life, while a prolonged maintenance of the plasma levels was obtained for the two selected formulations. The drug bioavailability was considerably improved especially after the administration of the mixture of hydrophilic and hydrophobic complexes, when compared with the NC/TAbetaCD complex. The results suggested that the critical combination of hydrophilic and hydrophobic CDs complexes, in appropriate ratios, could be a promising drug delivery system with a prolonged therapeutic effect coupled with a more balanced bioavailability.

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Section: Introductionmentioning

confidence: 99%

Hydrophilic and hydrophobic cyclodextrins in a new sustained release oral formulation of nicardipine: in vitro evaluation and bioavailability studies in rabbits

Fernandes

Ramos

Falcão

et al. 2003

Journal of Controlled Release

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“…[14][15][16] Cyclodextrins and their derivatives play an important role in the formulation development due to their effect on solubility, dissolution rate, chemical stability, and absorption of a drug. [8][9][10][11][12][13][17][18][19][20] Currently, some of their derivatives, especially 2-hydroxypropyl--cyclodextrin, are being investigated for toxicity for use in parenteral dosage form. 21 The goal of this study was to determine if the aqueous solubility of miconazole can be increased by complexation with various cyclodextrins and their derivatives (R-, -, and 2-hydroxypropyl--cyclodextrins).…”

Section: Introductionmentioning

confidence: 99%

Preparation Characterization Evaluation of Miconazole-Cyclodextrin Complexes for Improved Oral Topical Delivery

Tenjarla

Puranajoti

Kasina

et al. 1998

Journal of Pharmaceutical Sciences

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The solubility of miconazole in water increased in the presence of cyclodextrins (CDs). The apparent K1:1 values calculated from the phase solubility diagrams of gamma-CD, hydroxypropyl-beta-CD, alpha-CD, hydroxyethyl-beta-CD, hydroxypropyl-gamma-CD, and beta-CD were 695 +/- 39.6, 363 +/- 34.1, 333 +/- 18.5, 312 +/- 31.0, 305 +/- 27.6, and 293 +/- 17.6 M(-1), respectively. Solid 1:1 molar complexes were prepared by freeze-drying and kneading and characterized by UV spectroscopy, differential scanning calorimetry, and electron microscopy. The dissolution rate increased to 28-255-fold and the solubility to 9-55-fold. Oral bioavailability in rats increased to 2.3-fold by complexation with hydroxypropyl-beta-CD. Human cadaver skin retained 2.6-fold more drug from the miconazole/alpha-CD complex and hairless mice skin retained 8.4-fold more drug from the HP-beta-CD complex than from miconazole solution alone in 24 h.

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“…From the results, it is known that both inclusion complexes were still soluble within the range of concentrations studied as no plateau was observable in the isotherms. Szejtli reported a similar solubility isotherm with an unlimited linear solubility increase in an aqueous system comprising dimethyl-β-CD and methyltestosterone.…”

Section: Resultsmentioning

confidence: 74%

“…Determination of Stability Constant K′ by Solubility Method. This method was first reported by Higuchi and Connors (19) and later applied by several authors (20)(21)(22) to study the phase solubility of host-guest systems of CDs and various guest molecules. The apparent 1:1 stability constants, K′ (mM -1 ), of 10-undecyn-1-ol/CD derivative systems were calculated using the equation…”

Section: Methodsmentioning

confidence: 99%

“…This method was first reported by Higuchi and Connors and later applied by several authors – to study the phase solubility of host−guest systems of CDs and various guest molecules. The apparent 1:1 stability constants, K ′ (mM −1 ), of 10-undecyn-1-ol/CD derivative systems were calculated using the equation italicK′ = s l o p e C 0 ( 1 − s l o p e ) where K ′ (mM −1 ) denotes the apparent stability constant, slope denotes the inclination of the linear correlation in the phase solubility diagram, and C 0 (mM) denotes the equilibrium solubility of 10-undecyn-1-ol in the absence of CD derivatives, which is obtainable from the phase solubility diagram as the intercept at y -axis.…”

Section: Methodsmentioning

confidence: 99%

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Improvement of Antifungal Activity of 10-Undecyn-1-ol by Inclusion Complexation with Cyclodextrin Derivatives

Neoh

Tanimoto

Ikefuji

et al. 2008

J. Agric. Food Chem.

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The inclusion complexation behavior between 10-undecyn-1-ol and cyclodextrin (CD) derivatives, namely, randomly methylated beta-CD (RM-beta-CD) and hydroxypropyl-beta-CD (HP-beta-CD), was studied in terms of solubility improvement, apparent stability constant, and the inclusion ratios of the resultant inclusion complexes. The aqueous solubility of 10-undecyn-1-ol was greatly improved through complexation with the CD derivatives. RM-beta-CD is comparatively more efficient in solubilizing 10-undecyn-1-ol with an apparent stability constant outstripping that of HP-beta-CD by about an order of magnitude. Comparative in vitro evaluations of the growth inhibition effects of inclusion complex solutions toward Rosellinia necatrix, a phytopathogenic fungus, were performed. In comparison with the positive control, appreciable improvements of the antifungal activity of 10-undecyn-1-ol through the addition of CD derivatives were observed visually. The improvement was evaluated in terms of area covered by the mycelia of Rosellinia necatrix and their growth rate. RM-beta-CD was proven to be more effective compared to HP-beta-CD with regard to the reduction of both fungal mycelium-covered area and growth rate constant, presumably owing to greater solubility enhancement by RM-beta-CD and thus the bioavailability of 10-undecyn-1-ol. Inclusion complexation of 10-undecyn-1-ol with CD derivatives suggests a potential means for production of an environmentally friendly 10-undecyn-1-ol-based fungicide to counteract R. necatrix.

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Cyclodextrins in Pharmaceuticals

Cited by 28 publications

References 173 publications

Hydrophilic and hydrophobic cyclodextrins in a new sustained release oral formulation of nicardipine: in vitro evaluation and bioavailability studies in rabbits

Hydrophilic and hydrophobic cyclodextrins in a new sustained release oral formulation of nicardipine: in vitro evaluation and bioavailability studies in rabbits

Preparation Characterization Evaluation of Miconazole-Cyclodextrin Complexes for Improved Oral Topical Delivery

Improvement of Antifungal Activity of 10-Undecyn-1-ol by Inclusion Complexation with Cyclodextrin Derivatives

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