Clarissa Harman

In 2016, Clarissa graduated from the University of Sheffield having completed a Master's degree in Chemistry, achieving a upper second-class degree. As part of her Master's project Clarissa investigated the reactivity of rhodium-complexes with acetyl chloride. Clarissa also studied for a year at the University of Adelaide, Australia. Since completing her undergraduate studies, Clarissa worked as a laboratory technician for the food company Apetito, ensuring the food produced was safe to consume with the correct nutritional value advertised. Following this, Clarissa volunteered for three months in Bangladesh as volunteer for VSO/ICS, working on improving the livelihood of vulnerable people.

In September 2017 she joined the Centre for Doctoral Training in Advanced Therapeutics and Nanomedicienes at UCL School of Pharmacy. She started her doctoral research with a short project investigating layered terbium nanoparticles potential for drug delivery, under the supervision of Dr Gareth Williams. Afterwards Clarissa did an industrial placement at AstraZeneca investigating the stability of amorphous materials, under the supervision of Dr James McCabe and Martin Kearns.

PhD Project Title: Nanoparticle-based micro-assemblies for encapsulation and precision release of target compounds

Supervisor: Dr Stefan Guldin

Project description: Clarissa's research will investigate nanoparticle-based micro-assemblies for encapsulation and precision release of target compounds.  Currently it is estimated that 40 % of existing and 90% of developing active pharmaceutical ingredients (APIs) are poorly soluble, often exhibiting low bioavailability. These APIs require tricky or cumbersome formulations to improve solubility, thus a demand for simpler and easier formulations is needed – encapsulation of the API at the nano-scale could provide a creative and promising solutio

Pickering emulsions are emulsions stabilised with solid particles at the droplet interface, preventing coalescence and phase separation, forming incredibly stable emulsions. These emulsions are capable of encapsulating molecules within the internal cavity of the droplet, and can be used for the encapsulation of poorly soluble APIs. These emulsions can be modified with stimuli responsive functional groups, that can be sensitive to light, external magnetic field, pH, temperature, or external chemicals, to name a few. When exposed to the external stimulus a disruption in the stability of the emulsion occurs, resulting in demulsification and release of the target compound.

The aim of this project is to develop novel nanoparticle-based micro-assemblies as stimuli-responsive drug delivery systems. These systems will be capable encapsulating APIs efficiently and triggering their release on demand. The formulation of Pickering emulsions with a range of different emulsifiers will be explored, such as silica, iron oxide (Fe₃O₄), or gold. These nanoparticles will be modified with a stimuli responsive group to initiate demulsification of the Pickering emulsions. The responsiveness and collapse of the Pickering emulsion will be tested. Once complete the drug encapsulation within the optimised emulsions system will be investigated, using model drugs such as terbinafine HCl, amorolfine HCl, and amphotericin B. The drug activity after encapsulation and triggered release will also be explored.

Harman CLG, Patel MA, Guldin S, Davies GL (2019) Recent developments in Pickering emulsions for biomedical applications, Current Opinion in Colloid & Interface Science; 3: 173-189 https://doi.org/10.1016/j.cocis.2019.01.017