Final Thesis

Investigation of the stability of casein microparticles for encapsulation of bioactive substances

Key Info

Basic Information

Soft Matter Process Engineering
Masterthesis / Bachelorthesis
Focus/Key Topic:


Pharmaceutical ingredients and dietary supplements are encapsulated in a growing number of applications. This can be used, for example, to prevent unpleasant taste, to accelerate the mode of action of the bioactive substances or to ensure that the active ingredients are only released at the desired point in the body. When taking up active substances orally, encapsulations are often chosen which protect the active substance from the harsh conditions in the stomach and ensure the release in the intestine. This not only places high demands on the active pharmaceutical ingredients and dietary supplements, but also on the encapsulation material.

Casein, for example, as a natural biopolymer, is well suited for encapsulation because it is well tolerated and degradable by the human body. The question as to how stable the casein microparticles are in the vicinity of the stomach or intestine remains unanswered. This requires investigations in aqueous buffer systems at different pH values and ionic strengths as well as in simulated gastrointestinal fluids. The latter are synthetic model solutions that are very similar to the human digestive tract in pH value and salt composition. In addition, they can be mixed with enzymes.

For this purpose, our group has developed a microfluidic particle trap that enables the observation of a single particle during media exchange. From the experiments we want to derive knowledge about the chemical stability of individual particles in different media at discrete points in time.

Within the framework of this work:

  • the particle trap developed by our group will be modified to allow temperature-dependent measurements,
  • microparticles produced by film drying (Zhuang et al. 2015) are examined in the particle traps for their stability against pH value and ionic strength changes, depending on the temperature,
  • the stability of the particles in "simulated gastro intestinal fluids" should be investigated.

The work includes literature research, experimental lab work, as well as the interpretation of the collected data.

Zhuang, Yu; Sterr, Julia; Kulozik, Ulrich; Gebhardt, Ronald (2015): Application of confocal Raman microscopy to investigate casein micro-particles in blend casein/pectin films. In: International journal of biological macromolecules 74, S. 44–48. DOI: 10.1016/j.ijbiomac.2014.11.017.