A 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.
One such device was used to treat Pavel Chekov's burns when he was injured by a sparking bridge console. (Star Trek: The Motion Picture)
By 2401, several individuals on M'talas Prime were using similar devices to take narcotics through their eyes, such as Splinter. (PIC: "The Next Generation", "Disengage")