Thermo-Gels for Drug Delivery

About

Eye drops are the most common and easily administered form of ophthalmic drug delivery, but they produce considerable waste and must be frequently reapplied. Replacing conventional eyedrops with a hydrogel-based system can improve bioavailability and provide sustained drug release, however, the mechanical loading from blinking causes rapid deterioration of the applied gel. Application to the inferior fornix (the pocket below the lower eyelid) has been investigated such that the hydrogels do not deteriorate as quickly while blinking or obstruct vision. However, these developed systems are often non-degradable, uncomfortable, and difficult to place accurately. Therefore, there is a need for degradable eye drops that offer prolonged drug release and simple application. Researchers at McMaster have developed a gel formula consisting of a thermo-sensitive synthetic polymer that forms a gel when introduced to ocular heat, and the natural polymer chitosan to improve ophthalmic drug delivery. The gel degrades over a period of days, during which therapeutic can be steadily released into the eye. By administering the gel to the inferior fornix non-transparent interventions can be administered without causing visual impairment.