| abstract |
Biodegradable polymeric microparticle compositions containing one or more active agents, especially those useful for treating or preventing or one or more diseases or disorders of the eye, and methods of making and using thereof, are described. The microsphere compositions release an effective amount of the one or more active agents for a period greater than 14 days in vivo, preferably greater than 60 days in vivo, more preferably up to 73 days in vivo, more preferably greater than 90 days in vivo, even more preferably over 100 days in vivo, and most preferably greater than 107 days in vivo. In a preferred embodiment, the microparticle compositions contain one or more active agents useful for managing elevated intraocular pressure (IOP) in the eye. In one embodiment, the microspheres are formed from polylactide-co-glycolide ('PLGA'); in another embodiment, the microspheres are formed from a blend PLGA and poly lactic acid ('PLA'). 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. The combination of drug loading and release rate, as well as the minimization of initial burst release, result in prolonged release of a higher amount of drug. |