Hemodynamic and coronary vasodilative action of two nitroglycerin oral spray formulations

This study compared glycerol trinitrate (NTG) oral spray in a new hydrophilic formulation with a reference aerosol in a lipophilic base with respect to the time to onset of action on hemodynamics and on the coronary vasomotor tone. Differences in the profile of action between the two spray formulations were assessed in two groups of ten patients each. In each of the two groups the patients were randomly assigned to receive 0.8 mg of aerosolized NTG in either the hydrophilic or lipophilic base in double-blind fashion. The patients of group A had stable, exercise-induced angina pectoris, in whom responses to the sprays were evaluated under resting conditions. The patients of group B were suspicious of vasospastic or mixed form of angina pectoris, in whom the effects of the sprays were studied under diagnostic ergonovine provocation. The onset and extent of action of the sprays were assessed by serial measurements of hemodynamic parameters and repeat quantitative coronary angiography. The two formulations of NTG oral spray had a comparably potent coronary vasodilator effect in patients under resting conditions and under ergonovine provocation. As far as hemodynamic action is concerned, the new hydrophilic spray exerted its hemodynamic effect more rapidly than the lipophilic spray. Thus, the new NTG oral spray promises to afford therapeutic advantages for the relief of anginal attacks as well as hemodynamic unloading in congestive heart failure and acute pulmonary hypertension.