Interaction of some anticancer drugs with carboxymethyl-β-cyclodextrin

Supramolecular Complexation of Carbohydrates for the Bioavailability Enhancement of Poorly Soluble Drugs

In this review, a comprehensive overview of advances in the supramolecular complexes of carbohydrates and poorly soluble drugs is presented. Through the complexation process, poorly soluble drugs could be efficiently delivered to their desired destinations. Carbohydrates, the most abundant biomolecules, have diverse physicochemical properties owing to their inherent three-dimensional structures, hydrogen bonding, and molecular recognition abilities. In this regard, oligosaccharides and their derivatives have been utilized for the bioavailability enhancement of hydrophobic drugs via increasing the solubility or stability. By extension, polysaccharides and their derivatives can form self-assembled architectures with poorly soluble drugs and have shown increased bioavailability in terms of the sustained or controlled drug release. These supramolecular systems using carbohydrate will be developed consistently in the field of pharmaceutical and medical application.

Pattern recognition methods as supplementary techniques for identification of salicylamide — cyclodextrins inclusion complexes

The objective of this study was to learn whether or not the pattern recognition methods, such as agglomerative cluster analysis (CA) and principal component analysis (PCA), can be used as supplementary techniques for identification of salicylamide (SAA) inclusion complexes with β-cyclodextrin (β-CD) and 2-hydroxypropyl-β-cyclodextrin (HP-β-CD). To do this, phase-solubility of SAA in the presence of the cyclodextrins was studied by the Higuchi-Connors method, which showed that the cyclodextrins enhanced the solubility of SAA in water as compared to that of the drug. Next, the solid phase complexes of the drug with β-CD and HP-β-CD were prepared by using the coprecipitation, precipitation-evaporation, and kneading methods. Identification of the inclusion complexes was performed by using thermal analysis, infrared spectroscopy, and wide angle X-ray scattering. Two multivariate statistical methods, CA and PCA, were used as the supplementary techniques for identification of the inclusion complexes. The results of the statistical analysis have shown that CA and PCA are helpful for interpretation of the thermoanalytical and spectral data. Moreover, these methods enabled proper classification of the products in all doubtful cases. They can be used as supplementary techniques to verify the conclusions of the above-mentioned standard methods.

Sulfobutylether-β-cyclodextrin/chitosan nanoparticles enhance the oral permeability and bioavailability of docetaxel

The aim of this research is to develop novel chitosan nanoparticles including cyclodextrins complexes for docetaxel (DTX), evaluate the performance of nanoparticles which could enhance the oral permeability and bioavailability of DTX in vitro and in vivo. DTX/sulfobutylether-β-cyclodextrin inclusion complexes were made and it was the main ingredient to prepare the DTX/sulfobutylether-β-cyclodextrin/chitosan nanoparticles due to their promising physicochemical properties. DTX/sulfobutylether-β-cyclodextrin/chitosan nanoparticles were prepared by the ionic gelation of chitosan with tripolyphosphate in the presence of cyclodextrins. Results indicated that DTX/sulfobutylether-β-cyclodextrin inclusion complexes and docetaxel/sulfobutylether-β-cyclodextrin/chitosan nanoparticles both had good performances in the studies of release and the rat small intestinal absorption in vitro. DTX/sulfobutylether-β-cyclodextrin/chitosan nanoparticles showed preferable capability in improving the small intestinal absorption and inhibiting the efflux of DTX. In pharmacokinetics study, the DTX/sulfobutylether-β-cyclodextrin/chitosan nanoparticles increased the AUC0→t and decreased the clearance significantly, and the oral relative bioavailability of the DTX/sulfobutylether-β-cyclodextrin/chitosan nanoparticles was as high as 1447.53% compared to the pure DTX formulation. The DTX/sulfobutylether-β-cyclodextrin/chitosan nanoparticles prepared in this study have a good prospect for oral administration as an alternative of current DTX formulations.

Modification of the apparent lipophilicity of steroidal drugs with gamma-cyclodextrin

The interaction between 17 steroidal drugs and gamma-cyclo-dextrin (gamma-CD) was determined by charge-transfer chromatography and the relative strength of interaction was calculated. The relationship between the strength of interaction and the physico-chemical parameters of steroidal drugs was elucidated with principal component analysis. Gamma-CD interacted with each steroidal drug decreasing the apparent hydrophobicity of the guest molecules. Calculations indicated that the interaction between the drugs and gamma-CD is of mixed character: steric, hydrophobic and electronic forces are involved in the complex formation. The marked influence of gamma-CD on the apparent hydrophobicity of drugs suggests that this interaction may modify the biological properties (absorption, uptake, half-life etc.) of drug-gamma-CD complexes resulting in modified efficacy.

Pharmaceutical applications of cyclodextrins. 1. Drug solubilization and stabilization

Cyclodextrins are cyclic oligosaccharides which have recently been recognized as useful pharmaceutical excipients. The molecular structure of these glucose derivatives, which approximates a truncated cone or torus, generates a hydrophilic exterior surface and a nonpolar cavity interior. As such, cyclodextrins can interact with appropriately sized molecules to result in the formation of inclusion complexes. These noncovalent complexes offer a variety of physicochemical advantages over the unmanipulated drugs including the possibility for increased water solubility and solution stability. Further, chemical modification to the parent cyclodextrin can result in an increase in the extent of drug complexation and interaction. In this short review, the effects of substitution on various cyclodextrin properties and the forces involved in the drug-cyclodextrin complex formation are discussed. Some general observations are made predicting drug solubilization by cyclodextrins. In addition, methods which are useful in the optimization of complexation efficacy are reviewed. Finally, the stabilizing/destabilizing effects of cyclodextrins on chemically labile drugs are evaluated.