USP Quality Review

No. 16, Issued 3/91

NITROGLYCERIN: Handle With Care

Reports questioning the potency and/or stability of Nitroglycerin products have been received through the USP Drug Product Problem Reporting Program (DPPR). Because Nitroglycerin is an inherently volatile substance, potency can be lost through volatilization, through the walls and/or closure of permeable plastics, or when the Nitroglycerin is exposed to air. Moisture can also accelerate the degradation of Nitroglycerin products. To avoid loss of potency, it is crucial for Nitroglycerin products to be properly packaged and stored. Appropriate storage and handling conditions must be maintained by the manufacturer, the distributor, the dispensing pharmacist, as well as the patient.

Questions arise as to whether Nitroglycerin must be packaged in a glass container, or whether plastic is a suitable packaging material. Should Nitroglycerin tablets be kept in the original manufacturer's container? Why do patients feel that they are not getting the same effect from their Nitroglycerin as they have in the past when they are certain they have kept the medication properly stored? We may be able to answer a few of these questions.