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The creation and use of chaperone systems in drug delivery and diagnostic imaging has greatly broadened the applications, and thus needs, for polymer nanosuspensions. The enhancement of surface to volume ratios obtained when these nanosuspensions are created provides unique capabilities for functionalization of the surface required for specificity. Encapsulation of APIs and contrast agents within these biocompatible polymers is readily accomplished using versatile Microfluidizer based technologies for processes that are reproducible and scalable. Furthermore, the probability of physical property changes due to processing is reduced. Especially when compared to sonication, the most commonly used laboratory scale technique, where cavitation and sono-chemistry issues may arise.

Two techniques are reported here that can create nanosuspensions of many different polymers types with varying particle sizes by controlling the formulation and process variables. Microfluidics Reaction Technology (MRT) was used with the solvent/anti-solvent precipitation method. Particle size distribution can be controlled by varying parameters such as processing pressure, degree of supersaturation and the ratio of solvent and anti-solvent streams. This process has the advantage of producing nanosuspensions in a single step which is ideal for process intensification. The emulsion evaporation method was implemented using a Microfluidizer Processor; i.e., dissolving a polymer in a solvent, creating a nanoemulsion with an immiscible continuous phase, then removal of the solvent to produce the nanosuspension. Particle size distributions can be controlled by varying process parameters and/or formulation.

Both systems control the amount and form of energy dissipation that occurs at specific locations in the system, i.e., directed toward maximizing the useful work in forming surfaces and interfaces. Narrow flow channels convert the energy input to high fluid velocities. These jet streams impinge upon each other in precision fabricated micro-liter sized interaction chambers. Various degrees of mixing intensity (i.e., macro-, meso-, or micro-mixing) and associated level of turbulence intensity (i.e., eddy sizes) are obtained depending upon the energy dissipation rate. The size of the smallest eddies formed, and thus the Kolmogorov scale for the desired diffusion and reaction coordinates, are in the 50-200 nanometer range. This platform can achieve processing pressures of up to 276 MPa (40,000 psi), generate fluid velocities of over 400 m/s and achieve energy dissipation values exceeding 107 W/kg.