The nitroglycerin tablets taken to relieve angina pain (mentioned in the previous posting) were 2% nitroglycerin adsorbed on mannitol, a mildly sweet-tasting sugar alcohol powder commonly used as a base in medicinal tablets. In this form, nitroglycerin is nonexplosive in normal handling. Our company also sold a dilute nitroglycerin solution used as an IV drip in open-heart surgery, that was also nonexplosive.
The tablet form was much cheaper and easier to store, so some hospital pharmacies would prepare their own IV solutions by dissolving the tablets in water. This would work if they used the full amount of water at the start, but they would often attempt to first dissolve the tablets in a little water, then dilute it to specification. This smaller amount of water dissolved away the highly soluble mannitol, leaving the much less soluble, and highly explosive, pure nitroglycerin behind.
Perhaps about once a month, I would get a call that began like this: “We are X Hospital. We were preparing a nitroglycerin solution and we noticed a few drops of an oily, yellow liquid at the bottom of the flask. Should we be concerned?”
“Well, does your local police department have a bomb squad?”
“Ahh . . . I don’t know.”
“Now would be a good time to find out.”
This was just to get their attention, and it always worked. I then continued with more specific instructions.
A less frequent problem was when a pharmacy tried to incinerate substantial amounts of expired nitroglycerin tablets, despite clear warnings on the label. I could never resist throwing a barb: “So let me get this straight. You actually thought incineration would be a good way to destroy nitroglycerin tablets?”