Disperse composition stability, definition

The core material defined as the specific material to be coated can be liquid or solid in nature. The composition of the core material is varied, as the liquid core can include dispersed and/or dissolved material. The solid core can be a mixture of active constituents, stabilizers, diluents, recipients, and release-rate retardants or accelerators. The ability to vary the core material composition provides definite flexibility, and utilization of this characteristic often allows effectual design and development of the desired microcapsule properties. 

The making of finely dispersed suspension with sufficient stability for the definite composition. 

Amorphous solid dispersions are leveraged at varying stages in development for a number of reasons. For extruded dispersions, a limited number of polymer systems summarized in Table 6.3 form the backbone of the compositional definition. In early development, they are most commonly used to support elevated exposures necessary for preclinical assessment and/or assure phase stability when a crystalline form is not readily isolated. At this stage of development, the amount of material available for development will be restricted. As discussed previously, this constraint can challenge the utility of extruded systems where minimum batch sizes are significantly larger than for development of spray-dried dispersions or coprecipitated material. 

The approach outlined in this chapter should be applicable to other poly-mer-nanotube systems provided that the molecular models used in the calculations are modified to reflect their chemical natures. Although the results may not offer a definitive answer to the question of whether or not it is possible to obtain a well-dispersed nanocomposite fi om a given set of components, they do provide a quantitative basis for assessment of the relative stability of various compositions. We hope to be able to demonstrate this in the future by using this approach to examine the effects of the nature and degree of functionalization of SWCNTs on the thermodynamic stability of nanocomposites. 

There can be two definitions of the term compatibilization . The first is the process of reinforcement of the interfacial border in an immiscible polymer blend. The physical essence consists of increasing the interaction between two phases by introduction of substances like diblock polymers, when dissimilar blocks of copolymer will locate at the phase interface. Such com-patibilizers do not change the thermodynamic stability of the system and at the same time vary the morphology of the composition, leading to a more fine dispersion of components in the course of blending. 

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