Boiled sweet

Boiled sweets were a type of confectionery from Earth used occasionally by the Doctor.

The variant of Nitro-9, Neo-Nitro, resembled boiled sweets and activated using saliva. (PROSE: Shadowmind)

Uses
To counteract the ill effects of time spillage on Jamie McCrimmon, the Second Doctor gave him one of his striped boiled sweets. When Jamie ate it he immediately felt better. (PROSE: Vortex of Fear)

Iris Wildthyme checked to see if she had a boiled sweet in her bag when a taxi servicing Bianca's passed through a wormhole. (AUDIO: The Wormery)

After healing Amy Pond's wounds from a Saturnyn bite, the Eleventh Doctor popped what appeared to be a humbug into her mouth. (TV: The Vampires of Venice)

When Rose Tyler was searching through the Doctor's pockets during one adventure, a packet of boiled sweets was one of the items she found. (PROSE: The Price of Paradise)