Risperidone long-acting injection.

Risperidone long-acting is the first atypical antipsychotic medication available in an injectable sustained-action formulation, potentially conferring the advantages of an atypical antipsychotic together with assured medication delivery. In addition, unlike depots of conventional antipsychotics composed of a prodrug in a viscous oil vehicle, this formulation uses microsphere technology to encapsulate risperidone in a biodegradable polymer. Progressive hydrolysis of the microspheres results in gradual release of risperidone leading to predictable and sustained plasma levels with repeated injections.