Privatsphäre-Einstellungen

Development of a Rheological Method for the Characterization of Lanolin (Wool Fat)

Kerstin Hilgers^1,2, Andrea V. Kühn²

¹ Fachbereich Lebensmitteltechnik, Fachhochschule Trier, Hochschule für Technik, Wirtschaft und Gestaltung, University of Applied Sciences, Trier (Germany)

² WALA Heilmittel GmbH, Bad Boll/Eckwälden (Germany)

Corresponding author: Dr. Andrea V. Kühn, WALA Heilmittel GmbH, Dorfstr. 3, 73087 Bad Boll/Eckwälden (Germany), Fax +49 (0) 71 64 930 228, e-mail: andrea.kuehn@wala.de

Purpose: Lanolin (wool fat) for the industrial use on the European market comes from several sources. Due to differences in its functionality-related characteristics (e. g. its viscosity) its quality may vary widely. Therefore the application often leads to problems in the manufacturing process of semi-solid formulations and in the performance of the medical or cosmetic products. A rheological evaluation can be useful to characterize wool fat used in water-emulsifying ointments and lipophilic creams. It provides a method of quality control and gives information about the structure of the material. Lanolin itself can not be directly rheologically tested because of its sticky and waxy constitution. The aim was therefore to examine whether a rheological analysis is possible after mixing lanolin with other substances.
Methods: For the characterization of different lanolins, seven lanolin batches of three different suppliers were used to prepare formulations with further ointment bases (white soft paraffin, liquid paraffin). Rotation and oscillation measurements were carried out.
Results: The formulation lanolin/liquid paraffin is best-suited for a rheological classification of lanolin. While many of the tested lanolin batches were very similar, some showed a quite different rheological behaviour.
Conclusion: Due to the different rheological characteristics of the tested lanolins, a rheological classification is possible. Rotation and oscillation measurements show comparable results.
Outlook: Further research is necessary to evaluate the possibility to correlate the rheological results of the excipient (lanolin) with rheological characteristics of the finished product.

Key words Lanolin • Wool fat • Characterization • Rheology • Rotation • Oscillation