[The evaluation of the effect of venodilatation in 2 different systems of transdermal nitroglycerin release]

The aim of our study was to compare the activity of two different nitroglycerin controlled release systems (active matrix versus polyptychial matrix) on venous lower limbs circulation evaluated with strain-gauge plethysmography. Ten patients with stable coronary heart disease (M 5, F 5, mean age 65.1 +/- 4.6) were recruited and randomized to receive transdermal placebo and 5 or 10 mg of nitroglycerin carried by polyptychial or active matrix in a sequential and variable order. Five transdermal delivery systems were used with different content: placebo, nitroglycerin 5 or 10 mg on two different matrices (active matrix or polyptychial matrix). Venous strain-gauge plethysmography was performed in basal conditions and after 30, 60, 90, 120, 180, 240, 480, 1440 minutes, to evaluate the following parameters: maximal venous incremental volume at 40 and 60 mmHg (MVIV40 and MVIV60); time of maximal venous incremental volume at 60 mmHg (tMVIV60); maximal volume of outflow (MVO); time of maximal volume of outflow (tMVO); index of venous distensibility (dV/dP); index of venous tone (dP/dP); venous pressure (PV). Statistical data analysis was performed by one-way A.NO.VA and two-tailed Student's t test. The results of our study have shown that both transdermal systems, active and polyptychial matrix, are able to induce a venodilatation, but venodilatation induced by active matrix carried transdermal nitroglycerin along 24 hours is more stable and higher than that induced by polyptychial matrix carried transdermal nitroglycerin.