e., nuclei). Subsequent growth requires diffusion to and along the surface, followed by a specific integration process that incorporates these molecules into the crystal matrix of a particular polymorph. The observed crystallization rate is, therefore, highly dependent on length scales and the local degree of supersaturation. The polymorph that is obtained is dependent Inhibitors,research,lifescience,medical on thermodynamic considerations, such as component activity coefficients (solvent/antisolvent/solute species interactions, composition/concentrations, and temperature)

and entropy generated due to the spontaneous nature of the process, that is, rates influenced by supersaturation ratios. To generate the high energy dissipation rates used to produce nanoparticles, many processing techniques utilize high shear fields. Jet impingement, on a solid surface or with another jet, has been shown Inhibitors,research,lifescience,medical to be a highly efficient method [11, 12, 27, 28]. Systems that incorporate high velocity Docetaxel linear fluid jets that collide can rapidly reduce the scale of segregation between the streams. High-energy dissipation is observed because the kinetic Inhibitors,research,lifescience,medical energy of each stream is converted into a turbulent-like motion as the result of the collision and redirection of the flow within a very small volume. More thorough discussions on the

phenomenological events, equipment design criteria, and characterization studies are given elsewhere [11–15, 18–26]. 2.1.6. Energy Dissipation Surface tension and various molecular forces between the species present Inhibitors,research,lifescience,medical are key variables associated with the crystal size distribution. Thus, surface active agents can play a significant role whether as a contributor to growth mechanisms or as a size stabilizer. For example, they are involved in self-assembly mechanisms, and can act as barrier components that restrict transport, as possible chaperones that target specific sites during drug delivery, as sequestering agents to facilitate contact efficacy, as promoters of interfacial phenomena, and Inhibitors,research,lifescience,medical as inhibitors to agglomeration. The fraction of the input energy

available for formation of surfaces is instrumental in establishing system efficacy. CYTH4 Performing an energy audit to determine overall requirements is an essential task for this systems analysis approach. This entails determining the amount of input energy transformed into kinetic energy of the jets, identifying all forms of dissipation (whether desired or not), and ascertaining the amount stored as internal energy. Although the system energy requirements are not readily identified a priori, the total energy input and the amount dissipated and stored are measurable. Estimates of the various losses occurring can be made, and the energy utilization for the desired processes can also be estimated. This permits energy considerations to be used in predicting performance from the estimated length and time scales obtained.