Posterior Drug Delivery

 

Posterior Segment Drug Delivery

 

 
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Background 

The main challenge to delivery of drugs in the eye, and the greatest challenge in ocular therapeutics in general, is delivery to the back of the eye. Currently, treatment for wet age related macular degeneration (AMD) is approved involving monthly injections into the back of the eye. As these injections come with a significant risk of complications, including retinal detachment, secondary cataract formation, and endophthalmitis, they are approved only in advanced diseases in the aged. Treatments for other diseases, while potentially available, cannot be delivered in this manner. The ability to deliver drugs to the back of the eye in an efficacious yet relatively non-invasive manner has the potential to revolutionize treatments for posterior segment disease.

Various solid dosage forms have been evaluated, including insertable, and implantable systems with limited success. Building on the acceptability of intraocular injections for the treatment of posterior segment ocular disease, in situ forming injectable systems which take advantage of the properties of the eye have significant potential for the treatment of diseases of the back of the eye. 
 
The use of hydrogels in the context of solving ophthalmic challenges is attractive from several perspectives. In particular, in contrast to most other materials used for ophthalmic drug delivery, the high water content of hydrogels can render them transparent. Hydrogels also have an extensive record of biocompatibility in multiple biological contexts, including the eye, and have been demonstrated to be effective for long-term delivery of bioactive proteins and other therapeutics. To make the gels more appropriate for ocular delivery, significant research efforts have been invested in the design of "injectable" or "in situ gelling" hydrogels that can be delivered in vivo via a minimally invasive injection and then rapidly gel inside the body. 

 

Methodology 

Specifically, we will: 

  1. Applying synthetic strategies to optimize hydrogel compositions for treating specific ocular conditions. 
  2. Examine in vitro release and compatibility of materials 
  3. Develop in vivo toxicity of model systems