High-Pressure Homogenization for the Production of Emulsions

Heike P. Schuchmann, Nee Karbstein, Lena L Hecht, Marion Cedrat, and Karsten Kohler 

Motivation Why High-Pressure Homogenization for Emulsification Processes  

Indi trUd High Pressure Applicatiom Proc s, Equipment mid Si ety, First Edition. Edited by Rudolf E ers. 2012 Wiley-VCH Verlag GmbH Co. KGaA. Published 2012 by Wiley-VCH Verlag GmbH Co. KGaA. 

---

Differences can be found not only in mean droplet sizes or specific energies required, but also in the width of droplet size distributions (Figure 20.16). High-pressure homogenization allows for the production of emulsions in the sub-micron range however, the droplet size distributions are rather broad. In contrast, membrane emulsification results in droplet size distributions that are extremely narrow. Hence products with well-defined characteristics (e.g. release kinetics) can be produced, as required in, e.g., pharmaceutical applications. 

Many types of emulsification equipment are widely appUed in industry, such as high pressure homogenizers and rotor-stator systems. In these machines the premix droplets are deformed and disrupted in the flow field of the emulsification device [1]. In addition to these techniques, alternative methods for the production of emulsions using microporous devices have been developed since the early 1990s. 

To get a better idea of how to formulate the nanosized emulsion delivery systems suitable for parenteral, ocular, percutaneous, and nasal uses, the reader is referred to more detailed descriptions of methods of nanosized emulsion preparation [6, 116], A hot-stage high-pressure homogenization technique or combined emulsification technique (de novo production) is frequently employed in order to prepare nanosized emulsions with desired stability even after subjection to autoclave sterilization. Therefore, the steps involved in this technique in making blank anionic and cationic emulsions were arranged in the following order ... 

High-pressure melt homogenization is most frequently used for the preparation of SLN dispersions. As the whole production is carried out at a temperature above the melting point of the lipid, the process can be regarded as homogenization of an emulsion. 

For emulsion production, the components were first mixed using an agitator and then passed through a high pressure homogenizer (Microfluidizer, Microfluidcs Corp. USA) at 500 bar of pressure. All the concentrations are given in % by mass. 

---