Sustained delivery of timolol maleate from liposomal nanocarriers

• Main Author: Ong, Leonard Chin Hui
• Other Authors: School of Materials Science and Engineering
• Format: Final Year Project
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/55781
• Institution: Nanyang Technological University

According to the Glaucoma Research Foundation (2013), glaucoma is the world’s second leading cause of blindness. Current treatment modality includes the use of topical daily eye drops; however this mode of administration has many shortcomings. Less than 5% of the drug actually permeates into the eye due to inherent protective mechanisms of the eye and due to various clearance mechanisms such as tear turnover and blinking of the eye. Treatment by topical eye drops often leads to suboptimal control of intraocular pressure (IOP) and poor patient compliance. To overcome these drawbacks and for better patient compliance, sustained delivery is warranted that could be beneficial for ocular diseases such as glaucoma. In this project loading and release of an anti-­‐glaucoma drug, timolol maleate, will be evaluated in liposomal nanocarriers in-­‐vitro. Liposomes were formulated using 1,2-­‐dipalmitoyl-­‐sn-­‐glycero-­‐3-­‐phosphocholine (DPPC) and with two different concentrations of cholesterol (20 and 40 mol%) as an additive. Liposomes were prepared using thin film hydration and average particle size in the range of around 100 nm was prepared using a bench top extruder and drug was actively loaded by ammonium sulphate gradient loading technique. The liposomes were characterized for size changes during storage and after preparation using zeta sizer. From release studies, it was found that the release of timolol maleate was slow and sustained and was dependent on the amount of cholesterol added. For liposomes that contained 40 mol% cholesterol, drug release was slow and sustained for 50 days, while for 20 mol% drug release was slow and sustained for 21 days, while plain liposomes that lack any cholesterol, completely released the drug within two weeks. In conclusion, we have shown sustained delivery of timolol maleate from liposomal nanocarriers was possible and could be a promising drug delivery system for treatment of glaucoma.