Performance of a new transdermal nitroglycerin adhesive patch formulation.

This two-period crossover study in 24 healthy men compared the transdermal absorption of nitroglycerin from a new 20-cm2 nitroglycerin adhesive transdermal patch applied for a single 24-hour period (q24hr) with that from one inch of 2% nitroglycerin ointment applied over a 50-cm2 area every eight hours (q8hr) during a single 24-hour period. The observed differences in pharmacokinetic parameters were expected, based on product design (q24hr vs q8hr) and surface area (20 cm2 vs 50 cm2); however, when corrected for surface area, the mean plasma AUC ratios indicated that the patch delivered about 1.5 times more drug than the ointment. The patch delivery of nitroglycerin was confirmed by patch residual results, which indicated nitroglycerin was released at a rate of 0.75 mg/cm2/24 hrs. The patch exhibited good skin adhesion throughout the 24-hour application period.