Dual asymmetric centrifugation as an alternative preparation method for parenteral fat emulsions in preformulation development.

Nanoscaled fat emulsions are well established as a drug delivery system for lipophilic drugs and for the use in parenteral nutrition. Typically, the production of nanoscaled fat emulsions requires several formulation steps, including high pressure homogenization and filtration. The applicability of dual asymmetric centrifugation as an alternative technique to produce submicron fat emulsions in a short and easy way was investigated. The emulsions could be prepared without substance loss in a closed system within 30 min. Formulations with 10% soybean oil and up to 5% emulsifier-mixture were produced. The droplet size distribution was determined by static light scattering. Stability over six months was shown by regular static light scattering measurements and determination of the zeta potential. Furthermore, hemolytic activity of the samples was investigated. With the dual asymmetric centrifugation physiological tolerable emulsions with droplets in the lower micron and submicron range could be prepared. This method could be used as a model for screening active pharmaceutical ingredients.