Human pharmacological studies of a new transdermal system containing nitroglycerin

A new transdermal therapeutic system (TTS) for the administration of nitroglycerin (NTG) was tested in human pharmacological studies in 26 healthy volunteers. Plasma concentrations and haemodynamic responses were determined after the application of the system in different dosages. The concentrations of NTG reached in the plasma were uniform and dose-related, i.e. dependent on the drug-release area, and showed only minor inter-individual variation. They remained almost constant as long as the system was in contact with the skin. Renewal of the system caused no appreciable change in the plasma concentration. The haemodynamic effects, like those of all nitrates, were not clearly related to the dose administered, and were not always dependent on the plasma concentration. Upon repeated application, NTG-TTS was well tolerated locally and systemically and led to no alteration in blood chemistry or haematological parameters. The typical nitrate headaches disappeared after a few days. The presence of the system on the skin caused no discomfort or inconvenience.