An ophthalmic formulation particularly well suited for use as a delivery vehicle in the sustained delivery of ophthalmic active agents to the eye. the formulations comprise an alginate, wherein the guluronic acid content is in a range of about 35 percent to about 45 percent, and an excipient, preferably gellan gum or scleroglucan, with an active agent dissolved or suspended therein that together provide an in situ-gelling system for use in the eye.
