Sol-gel microencapsulation

Several patent applications have been granted to SGT covering its sol gel microencapsulation process and its implementation for... 

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. 

The sol-gel microencapsulation in silica-based materials is an emerging and powerful nanochem-istry technology in which the active ingredients are protected (stabilized) in silica-based particles. ... 

FIGURE 18.5 In certain cases, application requires porous particles (a) to ensure controlled release of the encapsulated active. In other cases, encapsulation in closed, totally leach-proof particles (b) is required. The sol-gel microencapsulation technology allows to meet both requirements by making different capsules. (Image courtesy of Prof. D. Avnir.)... 

In 2010, Wang s and Fang s teams in China independently showed that PCM with enhanced thermal conductivity and phase-change performance can be successfully fabricated by sol-gel microencapsulation of wax such as n-octadecane and paraffin in silica microspheres obtained from TEOS polycondensation. The thermal conductivity of the microencapsulated n-octadecane is also significantly enhanced due to the presence of the high thermally conductive silica shell. However, the silica microcapsules prepared from TEOS only have poor mechanical properties, with the brittle shell of the microencapsulated PCM easily cracking. 

Further progress can be easily envisaged. For example, attempts to create perfumes based on suspended capsules go back to the early 1970s. Now formulation in water of sol-gel-entrapped perfumes of tunable scent to avoid skin irritation becomes possible. Stabilized natural fragrances replacing toxic synthetic musks are also forecasted herein. In particular, sol-gel microencapsulated essential oils will replace nonbiodegradable musks as a consequence of the chemical and physical stabilization of nice fragrances that thus far could not be widely commercialized due to weU-known poor chemical stability. 

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