Drug delivery through hydrogel plugs

A process for making a punctal plug for blocking or reducing tear flow through a punctum or canaliculus of an eye and delivering a drug to the eye comprising:

• forming a covalently crosslinked hydrogel that is free of polysaccharides, the forming comprising reacting, in a presence of a drug, a first synthetic water soluble polymer that comprises first functional groups and a second synthetic water soluble polymer that comprises second functional groups, with the first and second functional groups reacting with each other to form covalent bonds, wherein the drug is dispersed within the hydrogel,
• cutting or breaking the hydrogel into lengths, with the hydrogel being prepared in a dehydrated form, and
• with the dehydrated hydrogel absorbing physiological water to swell and directly contact a tissue of the canaliculus in an expanded state and having a proximal face in fluid communication with a tear film of the eye,
• with the hydrogel having a water content of at least about 50% by weight or volume when allowed to fully hydrate in vitro in physiological saline.