Prof. Farrugia’s research interests are primarily in the field of the physical chemistry of gelatin, gelatin-surfactant interactions and gelatin nanoparticle production. He is also active in the field of applied chemistry in the pharmaceutical industry, particularly the stability and analysis of medicinal products and their ingredients, powder surface properties and flow behaviour, and hydrophobic dispersions of pharmaceutical powders. Moreover, through collaboration with other researchers at the University of Malta, he has an ongoing research interest in the analysis of natural products.

Physical chemistry of gelatin and gelatin nanoparticles Gelatin, the denaturation product of the protein collagen, has been found to be a suitable candidate for the production of nanoparticles for drug delivery systems. Gelatin nanoparticles are biocompatible and biodegradable, they can be targeted towards fibronectin-containing tissues, and they can allow for the loading and release of a pharmacologically active agent. The production of these nanoparticles involves the coacervation of the protein by various methods, such as the addition of a nonsolvent, ethanol, to aqueous solutions of the polymer. The reproducible production of nanoparticles by this method requires a systematic characterization of the effects of temperature, pH, desolvating agent, and ionic strength, amongst others, on the desolvation process.

Interfacial properties of powders and liquids Interfacial properties of powders and liquids are key to understanding both the flow properties of powders, that are important in the manufacturing sector, as well as their dispersion and wetting behaviour. Studies on the flow behaviour of excipients and powder formulations and the influence of humidity on these properties are important in ensuring consistent behaviour in a manufacturing environment. The wetting behaviour of excipients and active ingredients by various hydrophilic and hydrophobic liquids is important both to achieve stable dispersions for characterisation of the powders, as well as to investigate their wettability when administered as medicinal products.

Analysis of natural products Natural products have applications in both food science and as herbal medicinal products. However, their characterisation is an arduous process, due to their heterogeneity. Many studies are ongoing both to identify the key components of natural products, their regional variation, and hence to develop reliable analytical methods for their analysis. The group has worked on propolis, emodin and, more recently, olive oil and honey. The development of analytical techniques that can be used to reliably characterise the products in a regulated environment is important for the quality control of both medicinal products and food products alike.