The present invention is directed to a closure system for an oral active agent delivery device. The device comprises an elongate tubular member having first and second ends. The closure system includes a deformable closure means adapted to allow delivery of the active agent upon deformation. The closure system prevents spillage and maintains the integrity of the dose within the device. In use, the closure system is deformed and separated from the second end of the tubular member, liquid is drawn up into the first end of the member, and the liquid and active agent are drawn out of the second end of the member and into the patient's mouth.