Sustained intraocular delivery of drugs from biodegradable polymeric microparticles

Biodegradable polymeric microparticle compositions containing one or more active agents, especially those useful for treating or preventing one or more diseases or disorders of the eye, and methods of making and using thereof, are described. In a preferred embodiment, the microparticle compositions contain one or more active agents useful for managing elevated intraocular pressure (IOP) in the eye. Relatively hydrophilic, and preferably carboxylated, polymeric materials such as PLGA are used for a drug such as timolol maleate, which is relatively water soluble, to increase drug loading. Higher molecular weight polymers, as well as the ratio of LA (which has a longer degradation time, up to one to two years) to GA (which has a short degradation time, as short as a few days to a week), are used to provide release over a longer period of time.