The doctoral dissertation in the field of Pharmacy will be examined at the Faculty of Health Sciences at Kuopio campus. The public examination will be streamed online.
What is the topic of your doctoral research? Why is it important to study the topic?
The treatment of chronic ocular diseases is difficult due to the barriers that protect the eye from foreign material. These barriers hinder the drug’s ability to reach the target site. Eye drops can be used in the treatment of the front part of the eye. However, eye drops must typically be administered multiple times daily, which is a hindrance to patients. The back of the eye is treated with injections directly into the vitreous inside the eye. Depending on the drug molecule, these treatments must be readministered monthly. Repeated administration of these injections requires visits to the healthcare, and it causes significant costs.
My doctoral thesis focused on the development of long-acting ocular drug delivery systems. The studies focused on hydrogels in the treatment of the front part of the eye utilising either eye drops or a subconjunctival injection. For the back of the eye, a new laboratory model was developed, and biodegradable implants were studied using the model.
What are the key findings or observations of your doctoral research?
The developed hydrogel formulation was a tunable platform for drug delivery. It seemed to lower the intraocular pressure in rabbits for 48 hours in comparison to a commercial eye drop. After subconjunctival administration, the hydrogel affected the intraocular pressure for around 20 days. The laboratory model demonstrated a good predictive capability in comparison to published in vivo results. It was also useful in the development of the biodegradable implants. The solid-state of the drug had a significant effect on the implant structure and its drug release rate. The amorphous state without an organised crystalline structure demonstrated more controlled drug release over the crystalline state.
The research demonstrated that chemically unmodified components could extend the intraocular pressure-lowering effect compared with a commercial product. For the intravitreal implants, new insights into the effect of solid-state were gained.
How can the results of your doctoral research be utilised in practice?
The results can be used in the development of new long-acting ocular drugs. Most of all, the results expand the toolbox for the development of intraocular injections. However, a model drug was used and clinical application would require significant research effort. The developed laboratory model could reduce the number of animals required for the first animal studies in drug development. Insights into the development of biodegradable implants could accelerate research on generic versions of already approved implants. Long-acting ocular drug delivery systems are important as they could increase patient compliance to the treatment of chronic diseases.
What are the key research methods and materials used in your doctoral research?
Multiple hydrogel formulations were developed during the studies and the most promising ones were evaluated in vitro and in vivo. Development of the laboratory model was an iterative process, which eventually resulted in the final model. The model was subsequently used in the development of biodegradable implants. The dissertation was done in collaboration with the University of Eastern Finland Ocular Drug Delivery group, Johnson & Johnson, and the University of Southern Denmark.
The doctoral dissertation of Teemu Sorsa, MSc (Pharm), entitled Long-acting ocular drug delivery systems – from in vitro method to in vivo investigation, will be examined at the Faculty of Health Sciences. The Opponent in the public examination will be Tenured Professor Vanessa Andrés Guerrero of the Complutense University of Madrid, and the Custos will be Docent Astrid Subrizi of the University of Eastern Finland. The public examination will be held in English.
For further information, please contact:
Teemu Sorsa, MSc, [email protected]
