Discoidal niosome based controlled ocular delivery of timolol maleate

Non-ionic surface active agents based discoidal vesicles (discomes) bearing timolol maleate were prepared. Niosomes were incorporated with Solulan C24 in order to effect vesicle to discome transition. The discomes were relatively large in size, 12-60 mu m. They were found to entrap a relatively high quantity of timolol maleate. The prepared system were characterized for size, shape and drug release profile in vitro. They were found to release the contents following a biphasic profile particularly in the case where the drug was loaded using a pH gradient technique. The prepared system could produce or sustain a suitable activity profile upon administration into the ocular cavity; however, systemic absorption was minimized to a negliable level. The discomes were found to be promising and of potential for controlled ocular administration of water soluble drugs.