Recent Advances in the Excipients Used for Modified Ocular Drug Delivery

Authors: Melitini Koutsoviti Scientific coordinator: Marilena Vlachou, Associate Professor, Department of Pharmaceutical Technology Institution: National and Kapodistrian University of Athens

INTRODUCTION: In ocular drug delivery, maintaining an efficient concentration of the drug in the target area for a sufficient period of time is a challenging task. There is a pressing need for the development of effective strategies for drug delivery to the eye using recent advances in material sciences and novel approaches to drug delivery.

AIM: This review summarizes the important aspects of ocular drug delivery and the factors affecting drug absorption in the eye including encapsulating excipients (chitosan, hyaluronic acid, poloxamer, PLGA, PVCL-PVA-PEG, cetalkonium chloride, and gelatin) for modified drug delivery.

MATERIAL AND METHODS: Information was gathered in March and April of 2021 from google scholars. We used in our review the most recent published papers, starting from 2018, and the keywords used were eye, drug delivery, anatomy, physiology, Chitosan, Hyaluronic acid, Poloxamer, PLGA, PVCL–PVA–PEG, Cetalkonium Chloride and Gelatin.

RESULTS: The most important advantage of the excipients studied was the fact that they are biocompatible and biodegradable, while they can be used in nanotechnology. In specific, chitosan can deliver the API to the mucosa and hyaluronic acid improves tissue hydration and resistance. Poloxamer is thermo-activate while PLGA encapsulates molecules of virtually any size and PVCL – PVA – PEG increases the solubility of poorly soluble drugs. However, there are also disadvantages, including the non-stability of poloxamer in 20-25°C and the marginal effects of hyaluronic acid. CONCLUSION: Ocular drug delivery is a truly challenging field. However, great strides have been made in this field to improve available treatments. Future research should focus on improving the stability and the availability of the API, improving the sterilization methods, and decreasing the toxicity.

Questions & answers

Please, tell us a little bit more about yourself. I am a pharmacy student very passionate about Drug Development with a strong intrinsic motivation to play an active role in delivering quality and innovative healthcare to patients all around the world. This goal drives me to always want more from myself and strive to become the best pharmacist - scientist I can be.

Tell us a bit more about your research and its significance. My research focuses on finding new multifunctional excipients for ocular drug delivery. In ocular drug delivery, maintaining an efficient concentration of the drug in the target area for a sufficient period of time is a challenging task. There is a pressing need for the development of effective strategies for drug delivery to the eye using recent advances in material sciences and novel approaches to drug delivery. This review summarises the important aspects of ocular drug delivery and the factors affecting drug absorption in the eye including encapsulating excipients (chitosan, hyaluronic acid, poloxamer, PLGA, PVCL-PVA-PEG, cetalkonium chloride, and gelatin) for modified drug delivery. In your opinion, what is the benefit of joining ESSP and what advice do you have for students undertaking research in the future? Joining ESSP will give the opportunity to pharmacy students to read my work on ocular drug delivery and trigger their interest in this field. Also, scientists who are interested in this field and already pursue research on ocular delivery, might get in touch with me and collaborate for further research.

What was the biggest challenge while carrying out the research and how did you overcome that? The main challenge was to collect the data for the review (source of data, which articles to collect). This challenge was overcome by reading articles on the topic of data collection and the selection of our resources.