title: In line monitoring of the preparation of water-in-oil-in-water (W/O/W) type multiple emulsions via dielectric spectroscopy.
abstract: Multiple emulsions offer various applications in a wide range of fields such as pharmaceutical, cosmetics and food technology. Two features are known to yield a great influence on multiple emulsion quality and utility as encapsulation efficiency and prolonged stability. To achieve a prolonged stability, the production of the emulsions has to be observed and controlled, preferably in line. In line measurements provide available parameters in a short time frame without the need for the sample to be removed from the process stream, thereby enabling continuous process control. In this study, information about the physical state of multiple emulsions obtained from dielectric spectroscopy (DS) is evaluated for this purpose. Results from dielectric measurements performed in line during the production cycle are compared to theoretically expected results and to well established off line measurements. Thus, a first step to include the production of multiple emulsions into the process analytical technology (PAT) guidelines of the Food and Drug Administration (FDA) is achieved. DS proved to be beneficial in determining the crucial stopping criterion, which is essential in the production of multiple emulsions. The stopping of the process at a less-than-ideal point can severely lower the encapsulation efficiency and the stability, thereby lowering the quality of the emulsion. DS is also expected to provide further information about the multiple emulsion like encapsulation efficiency.
authors.affiliation: Institute of Medical Physics and Radiation Protection, Technische Hochschule Mittelhessen, Wiesenstrasse 14, 35390 Giessen, Germany. Sebastian.Beer@kmub.thm.de
authors.forename: Sebastian
authors.initials: S
authors.lastname: Beer
authors.forename: Dorota
authors.initials: D
authors.lastname: Dobler
authors.forename: Alexander
authors.initials: A
authors.lastname: Gross
authors.forename: Martin
authors.initials: M
authors.lastname: Ost
authors.forename: Christiane
authors.initials: C
authors.lastname: Elseberg
authors.forename: Ulf
authors.initials: U
authors.lastname: Maeder
authors.forename: Thomas Michael
authors.initials: TM
authors.lastname: Schmidts
authors.forename: Michael
authors.initials: M
authors.lastname: Keusgen
authors.forename: Martin
authors.initials: M
authors.lastname: Fiebich
authors.forename: Frank
authors.initials: F
authors.lastname: Runkel
mesh_terms: D058266:Dielectric Spectroscopy / Q000379:methods*; D004339:Drug Compounding / Q000379:methods*; D004355:Drug Stability; D004655:Emulsions / Q000737:chemistry* / Q000592:standards; D017408:Guidelines as Topic; D009821:Oils / Q000737:chemistry; D013678:Technology, Pharmaceutical / Q000379:methods; D014481:United States; D014486:United States Food and Drug Administration; D014867:Water / Q000737:chemistry
chemical_list: D004655:Emulsions; D009821:Oils; D014867:Water