Molecular encapsulation

Sol-gel microencapsulation in silica particles shares the versatility of the sol-gel molecular encapsulation process, with further unique advantages. Sol-gel controlled release formulations are often more stable, potent and tolerable than currently available formulations. The benefits of microencapsulation can be customized to deliver the maximum set of benefits for each active ingredient. Overall, these new and stable combinations of active pharmaceutical ingredients (APIs) result in improved efficacy and usability. 

Arunkumar E, Forbes CC, Smith BD (2005) Improving the properties of organic dyes by molecular encapsulation. Eur J Org Chem 2005 4051 1059... 

At about the same time that these fundamental studies of molecular encapsulation were beginning to appear, other groups were exploring dendrimer topology broadly. Historically, at this point, there were few examples of metallodendrimers, so many creative example architectures were possible and were shown. Many different architectures and behaviors were being explored, so thematically these examples are diverse. 

Among the most recent and sophisticated flavor encapsulation processes,cyclodextrin complexation represents a special way of encapsulation entrapment of flavors on the lowest possible scale,which is called molecular encapsulation.In this process,every flavor constituent is surrounded by a cyclodextrin ring which offers an almost perfect protection against damaging effects of the environment.The most significant advantages of the application of molecular encapsulation in the food industry and cosmetics are as follows/1/ ... 

Two remarkable and unique properties of molecular encapsulation are protection against atmospheric oxidation and disproportionations between components of flavors. In addition,intermolecular transformations are almost entirely eliminated due to the surrounding cyclodextrin ring. 

The molecular encapsulation of flavors with cyclo-dextrins was found to improve the resistence of light sensitive flavor constituents against daylight and ultraviolet irradiation. The photodecomposition of adsorbed and complexed flavors was tested both in the solid state and in aqueous solutions. The results of the light stability tests are demonstrated in the example of complexed and adsorbed citral,beta-ionone and cinnamaldehyde formulations /Table III./. 

The above flavor formulations were exposed to UV-irrad-iation in aqueous solutions as well. It has been observed that the protective effect of molecular encapsulation against light induced alterations was 15-25 that of the solid state experimental data. 

Long term storage stability tests of flavor beta-cyclodextrin complexes under "non-stress" conditions at room temperature showed that molecular encapsulation in most cases provided an almost perfect preservation of flavors upon ten years storage. The degree of preserving power of cyclodextrin complexation is expressed using a comparison of total flavor content of complexed flavor samples deteimined in 1977 and 1987,respectively./Table IV./... 

Carbenes can be highly reactive but modification of their chemistry through supra-molecular encapsulation by cyclodextrins, hemicarcerands, and zeolites has been discussed in a microreview.10... 

For molecular encapsulation of guest molecules Reinhoudt et al. synthesised a water-insoluble fifth generation POPAM dendrimer containing a total of 62 tertiary amino groups and whose periphery is functionalised with 64 apolar ada-mantyl groups (see Section 4.1). To ensure that this dendrimer (Fig. 8.3a) is sol-... 

Irreversible inclusion of individual isolated molecules can permit their investigation in greater detail, for example in the case of radicals [24]. This principle of molecular encapsulation was used by Cram and Warmuth [25] for the study of molecularly encapsulated cyclobutadiene, arynes, and other guest molecules - which are somewhat unstable in the free form - in macrooligocyclic carcer-ands [26]. Similar applications based on the inclusion of molecules in dendri-mers [27] are to be found in Section 8.7.1. 

Fig. 8.20 Molecular encapsulation of a cytostatic agent in a dendrimer and release at sites with acid pH (according to Haag et a .)...

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