Lewis & Short

pustŭlātus, a, um, v. pusulatus.

pūsŭlātus and pustŭlātus, a, um, adj. [pusula and pustula], blistered, i. e. refined, purified: argentum pusulatum, Dig. 19, 2, 31; also, argentum pustulatum, Suet. Ner. 44; Mart. 7, 86, 7.