Spray applicator
The spray applicator or spray healer was a medical device standard in medkits from the 2260s to 2270s. It was capable of dispensing a wide variety of topical liquids, foams and gels. The spray applicator was routinely preloaded with a flesh-colored suspension of a coagulant, numbing anesthetic, and antibiotic. 

It was used to treat Pavel Chekov's burns when he was injured by a sparking bridge console. ()

Medical equipment

it:Applicatore spray