Common on the Frontier its use is invaluable for Warriors and Hunters who usually make use of it very often. It being a life saving tool the most efficient of the trades make a habit of making sure the stock is kept up usually making a dash for the Pharmacy or local medical center to get fresh supplies.
D's has never had any use, so everything in it has long since expired. He may have discarded it.
Leila Marcus also did not keep up with her supplies which surprised D.
In the movie Bloodlust this was not the case. D had on hand from a medical kit the means to rap and bound Leila's would.