Hydrophobic pharmaceutical cyclodextrins

There are three main types of CDs a-cyclodextrin (a-CD), -cyclodexlrin (p-CD), and y-cyclodextrin (y-CD), which are macrocycles formed by six, seven, and eight sugar ring molecules, respectively. The spatial structure of p-CD is shown on Fig. 3. Review [19] generalizes data on the synthesis, modification, physicochemical and theoretical investigations of CDs, and certain applications particularly for enantio-separation and pharmaceutical applications. CDs are able to form host-guest complexes (pseudorotaxanes) with hydrophobic molecules such as aza-dyes... 

Synthetic methods in dendrimer chemistry have developed in recent year to such an extent that one can obtain dendrimers with hydrophilic surface and hydrophobic inside. In such a way dendrimers can exhibit solubilizing effect analogous to that shown by micelles. Similarly to cyclodextrins 278 in the pharmaceutical industry discussed in Sect. 6.3.3, dendrimers can be used as drug... 

Cyclodextrins (CDs) have a wide range of application in the pharmaceutical field due to their unique structure, which allows them to include hydrophobic molecules in their apolar cavity and to mask the physicochemical properties of the included molecule. This results in the enhancement of drug bioavailability by improving aqueous solubility and the physical and chemical stability of the drug, masking undesired side effects such as irritation, taste, or odor, and overcoming compatibility problems or interactions between drugs and excipients. 

With the advent of hydrophobic cyclodextrin derivatives, many chiral constituents of essential oils became the subject of a detailed investigation of their enantiomeric composition. Several essential oils are used as additives in pharmaceutical formulations, for example, pine needle oil or peppermint oil. They are not only used for their pleasant flavor or fragrance, monoterpene hydrocarbons like a-pinene 18], p-pinene [9], and... 

It is also well known that sweet and bitter tastes interact. It is the case for the inhibition of sucrose sweet taste by inhibitors like lactisol or methyl-4, 6-dichloro-4,6-dideoxy-galactopyranoside which was attributed to their hydrophobic character and their bitterness (Mathlouthi et al., 1993). Bitter taste was foimd to be suppressed by sweeteners such as sucrose (Bartoshuk, 1975). The masking of unpleasant taste by pleasant (sweet) stimuli is greatly sought after in pharmaceuticals. For example, cyclodextrins were described to have the ability of masking the bitterness of drugs like propantheline... 

Fagui AE, Amiel C (2012) PLA nanoparticles coated with a p-cyclodextrin polymer shell preparation, characterization and release kinetics of a hydrophobic compound. Int J Pharmaceut 436 644-651. doi 10.1016/j.ijpharm.2012.07.052... 

A wide area of supramolecular chemistry focuses on host-guest interactions between two or more molecules that are not covalently bonded (1). A special part of this chemistry deals with cyclodextrins and their derivatives (2). It is well known that cyclodextrins tend to include several types of hydrophobic guest molecules into their cavity. Accordingly, a large number of applications have been found in many areas, eg, in food chemistry as well as in the pharmaceutical (3) and cosmetic industries. Furthermore, cyclodextrins may be used in organic chemistry and also in polymer chemistry. 

A/-ISOpropyl Acrylamid6. Homopolymers from A(-isopropyl acrylamide (NlPAAm) are well known and have been of great interest because of their low critical solution temperature (LOST) behavior in water-solution. The polymer is soluble at low temperatures in water and precipitates above the LOST upon heating. Those kinds of polymers are potentially useful in the pharmaceutical or medical area. The homo- and copolymerization with water-soluble comonomers such as 2-hydroxyethyl methacrylate and characterization of the corresponding polymers of NlPAAm are described in some papers. In the case of copolymerization with hydrophobic comonomers, the use of an organic solvent is necessary, otherwise the polymerization has to be carried out in emulsion. But the different solubilities of the monomers in water often make the copol3unerization of water-soluble and water-insoluble monomers by classical emulsion polymerization difficult. Because of the above discussed property of cyclodextrin derivatives, these problems can be avoided if the copolymerization reactions are performed in the presence of cyclodextrin derivatives. 

Topics covered range from cyclodextrin complexes and their use as media for selective chemical reagents and their applications in chromatography and in the pharmaceutical and agricultural areas the synthesis of new hosts, particularly those containing hydrophobic cavities the characterisation of inclusion compounds using crystallographic and spectroscopic techniques the use of inclusion compounds as enzyme models macrocyclic complexes and ionophores to intercalates and zeolites. 

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