Evaluation of a new high-pressure dispersion unit (HPN) for emulsification

Emulsification plays an important role in the formulation of lipophilic pha rmaceutical agents. These substances are often included in the disperse pha se of an oil-in-water emulsion. To reach a high bioavailability and a good long-term stability, drop sizes much less than 1 micron are required. For t he generation of such emulsions, energy densities of a quality which can on ly be reached in high-pressure systems, are necessary. Actually available a pparatus, such as high-pressure homogenizers fitted with valves, microfluid izer or jet disperser, reach particle sizes of about 0.2 micron in continuo us processes. It is indispensable to produce emulsions with smaller globule s in order to receive a maximum of diversity in application. Therefore, dis persion units with a higher efficiency in drop breakup are needed. Especial ly in the case of parenterally administered medicament formulations an aver age particle size between 0.04 and 0.1 microns is requested which is up to now not reachable by continuous emulsification, In this study the drop brea kup behavior of a new high-pressure nozzle is investigated with the example of oil-in-water emulsions and compared to the breakup behavior of a state- of-the-art nozzle and to available data published.