Journal ArticleDOI
Structural effects on the binding of amine drugs with the diphenylmethyl functionality to cyclodextrins. I. A microcalorimetric study.
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The results suggest that one of the phenyl groups of the diphenylmethyl functionality resides in the CD cavity and is in van der Waals contact with the inside wall of theCD cavity, suggesting that hydrogen bonding to the carbonyl oxygen by the hydroxyl group on the rim of the CD ring can influence the strength of the binding interaction.Abstract:
Solution calorimetry has been employed to evaluate the stability constants and enthalpy changes associated with complex formation between α-, β, or -γ-cyclodextrin (CD) and a group of amine compounds having the diphenylmethyl functionality. Data from thermal titrations of the compounds were analyzed using nonlinear least squares. The standard free energy decrease accompanying the formation of inclusion complexes is generally due to a negative standard enthalpy change (ΔH°). The standard entropy change (ΔS°) was negative, except in the case of complexes formed with γ-CD. Of the 13 compounds studied, only 2 formed complexes with 1:2 (compound: (β-CD) stoichiometry, terfenadine · HC1 and cinnarizine · 2HC1. All the others formed 1:1 complexes. The structural effect on the stability constants, thermodynamics, and inclusion geometry was explored by relating the calorimetric results to the chemical structures of the guest molecules and the cavity sizes of the CD molecules. The results suggest that one of the phenyl groups of the diphenylmethyl functionality resides in the CD cavity and is in van der Waals contact with the inside wall of the CD cavity. In the case of α- and β-CDs, van der Waals interaction dominates in the stabilization. On the other hand, the interaction between these compounds and γ-CD is largely entropically driven. Adiphenine · HC1 forms a more stable complex with β-CD than proadifen · HC1, suggesting that hydrogen bonding to the carbonyl oxygen by the hydroxyl group on the rim of the CD ring can influence the strength of the binding interaction.read more
Citations
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Journal ArticleDOI
Pharmaceutical Applications of Cyclodextrins. 1. Drug Solubilization and Stabilization
TL;DR: The effects of substitution on various cyclodextrins properties and the forces involved in the drug-cyclodextrin complex formation are discussed, and methods which are useful in the optimization of complexation efficacy are reviewed.
Journal ArticleDOI
Strategies to Address Low Drug Solubility in Discovery and Development
Hywel David Williams,Natalie L. Trevaskis,Susan A. Charman,Ravi Mysore Shanker,William N. Charman,Colin W. Pouton,Christopher J.H. Porter +6 more
TL;DR: The article provides an integrated and contemporary discussion of current approaches to solubility and dissolution enhancement but has been deliberately structured as a series of stand-alone sections to allow also directed access to a specific technology where required.
Journal ArticleDOI
Drug/Cyclodextrin/Hydroxy Acid Multicomponent Systems. Properties and Pharmaceutical Applications
TL;DR: The objective of this mini-review is to summarize the findings concerning the properties and the pharmaceutical applications of multicomponent complexes made of a sparingly water-soluble amino-type drug, a cyclodextrin, and a hydroxy carboxylic acid.
Journal ArticleDOI
Protein stabilization by cyclodextrins in the liquid and dried state.
TL;DR: A comprehensive overview of the available research work on the beneficial use of cyclodextrins and their derivatives in protein formulations, liquid as well as dried, is provided and the mechanisms of stabilization against different kinds of stress conditions, such as thermal or surface-induced, are discussed.
Journal ArticleDOI
Capillary zone electrophoresis for separation of drug enantiomers using cyclodextrins as chiral selectors: Influence of experimental parameters on separation
TL;DR: In this article, enantiomeric separations in cyclodextrin-modified capillary zone electrophoresis (CZE) can be tuned by many experimental conditions, such as the cyclodexxtrin type, concentration and degree of substitution, pH and separation voltage.
References
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Journal Article
Cyclodextrins in drug carrier systems.
TL;DR: The works published thus far apparently indicate that the inclusion phenomena of cyclodextrin analogs may allow the rational design of drug formulation and that the combination of molecular encapsulation with other carrier systems will become a very effective and valuable method for the development of a new drug delivery system in the near future.
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Cyclodextrin-adamantanecarboxylate inclusion complexes: studies of the variation in cavity size
Journal ArticleDOI
Approach to the aspects of driving force of inclusion by .alpha.-cyclodextrin
Book ChapterDOI
Inclusion Complexes of the Cyclomalto-Oligosaccharides (Cyclodextrins)
TL;DR: This chapter provides an overview of the inclusion complexes of cyclomalto-oligosaccharides (cyclodextrins) and provides details about formation of inclusion complexes, detection of complex formation, and thermodynamics ofcomplex formation.
Journal ArticleDOI
Inclusion compounds of non-steroidal antiinflammatory and other slightly water soluble drugs with alpha- and beta-cyclodextrins in powdered form.
TL;DR: The result showed that the coprecipitation method might be originally inferior to the freeze-drying method in obtaining the inclusion compounds of drugs in powdered form, and it was shown by X-ray diffractometry that the inclusion compound obtained by the Freeze-Drying method were amorphous.