Paralysing lip gloss

Paralyzing lip gloss was owned by Captain John Hart. He used it against Gwen Cooper. The function was when a person with the gloss on, kissed another person, the person who received the kiss, began to experience paralysis and eventually died. (TW: Kiss Kiss, Bang Bang)

The same lip gloss, or perhaps a similar item, was used by River Song. (DW: The Time of Angels)