Stefanía Baldursdottír
Lektor
E-mail: sba(at)farma.ku.dk
Telefon: 35 33 61 05
Rum: 13/716

Stability of protein solutions
Maintaining the physical stability of proteins is crucial in the pharmaceutical formulation and manufacturing, since the biological activity may otherwise be reduced. It is important to investigate the stability of proteins in solutions as proteins are commonly administrated by injection. In addition, many other pharmaceutical formulations involve dissolution of the protein during processing. In this project the aggregation of proteins in aqueous media will be studied, as well as the influence of low molecular weight substances frequently used to stabilize proteins in processing. The methods used for this is mainly rheology with different geometry and methods used for structural characterization of proteins e.g. FTIR, CD and Raman.
Supervisor: Stefania Baldursdottir and Lene Jørgensen

Optimization of thermoresponsive chitosan formulations for controlled release of pharmaceuticals
Chitosan gels have been used in the pharmaceutical industry for many years. Chitosan is mucoadhesive and is therefore considered as a potential polymer for pharmaceutical formulations designed for extended release of drugs in the intestinal tract. Chitosan can also be formulated as thermoresponsive gels that will gel at body temperature and can therefore be considered as subcutaneous depot formulations for drugs. The aim of this project is to optimize a chitosan gel formulation by varying chitosan-crosslinker concentration and ratio, pH and mixing conditions in order to obtain a suitable release of a model compound. The practical methods used will mainly be rheology and erosion testing, but will also contain data processing with Modde computer program.
Supervisor: Stefania Baldursdottir

Effects from excipients on the adsorption of protein at oil-water interfaces
The increase in drug compounds based on macromolecules i.e. proteins are ever increasing but in many drug delivery systems interfaces occur. These interfaces can have a huge effect on the stability of the protein both during production but also in the final product, as proteins are prone to adsorb to these interfaces. This can cause alteration in the protein structure and ultimately loss of the pharmacological effect. The purpose of this project is to focus on the choices of composition of the delivery system and choice of excipients. We will apply some of these analytical techniques: Fourier transform infrared spectroscopy (FTIR), Circular dichroism (CD), fluorescence, surface tension, interface viscosity and many more. In this project you will gain knowledge of basic protein formulation, effect from various excipients and experience with techniques to study adsorption and protein structure.
Supervisor: Lene Jørgensen and Stefania Baldursdottir

Influence of polymeric excipients on the outcome of spray-drying
Spray-drying technology has shown beneficial effects on enhancing the bioavailability of poorly water-soluble drugs as well as stabilizing pharmaceutical protein formulations. During spray-drying the substances undergo a quick drying, and the outcome of the process will be influenced by both formulation composition and process variables. The aim of this project is to study how the chemical and physicochemical properties of the polymeric excipients in combination with process variables influence the particle characteristics, product attributes and stability of the product. The physicochemical properties of the polymeric excipients will be analyzed with rheological and surface analytical tools. The formulation will be processed by using spray-dryer. Methods to be used to characterize particle properties and chemical interactions are SEM, laser diffraction, XRPD, DSC, Raman, and IR.
Supervisors: Stefania Baldursdottir and Mingshi Yang