nitroglicerin

Nitroglycerin, also known as glyceryl trinitrate, is a nitrate ester of glycerol with the chemical formula C3H5N3O9. It is a volatile, oily liquid that ranges from colorless to pale yellow. It is highly explosive when subjected to shock, heat, or friction, and it also serves as a potent vasodilator in medicine. It was first prepared by Italian chemist Ascanio Sobrero in 1847, who noted its powerful explosive properties.

Industrial production involves nitration of glycerol with a mixture of nitric and sulfuric acids at controlled low temperatures. Due to its instability, nitroglycerin has long been handled with care; Alfred Nobel developed dynamite by absorbing nitroglycerin into an inert absorbent, kieselguhr (diatomaceous earth), around 1867, which made handling safer.

As an explosive, nitroglycerin is extremely sensitive to shock and temperature fluctuations. It is typically stabilized through absorption in porous materials and formulated with stabilizers; pure nitroglycerin is rarely used alone in blasting except in specialized applications.

Medically, nitroglycerin acts as a donor of nitric oxide, triggering relaxation of vascular smooth muscle via the guanylate cyclase–cGMP pathway. It is used to treat angina pectoris and other ischemic heart conditions. Common forms include sublingual tablets or sprays for rapid relief, transdermal patches for longer effects, and intravenous infusions in hospital settings. Onset with sublingual dosing is usually within 1–5 minutes, with relief lasting 30–60 minutes. Side effects include headache, flushing, and hypotension; caution is advised with concurrent use of phosphodiesterase-5 inhibitors.

Safety and handling: Nitroglycerin is flammable and sensitive to heat and shock; store in tightly closed, light-protected containers in a cool, dry place away from ignition sources. Medical formulations are regulated and supplied in sealed units.