THE EFFECT OF DEVICE CHARACTERISTICS ON NITROGLYCERIN RELEASE FROM A TRANSDERMAL PATCH

The effects of device characteristics on the release of nitroglycerin from a silicone disc were evaluated. A series of silicone discs containing nitroglycerin was prepared at varying levels of drug concentration, surface area, and firmness. A modification of the U.S.P. Dissolution Method I was used to evaluate the effects of these parameters on the in-vitro release of nitroglycerin from the discs. Reverse-phase HPLC was used for the quantitative analysis. The in-vitro dissolution method appeared reliable and reproducible in that there was good correlation (r=0.920) of dissolution profiles in both commercial transdermal products and test systems. The experimental data indicate that drug concentration and surface area have the greatest effect on the rate and extent of release of nitroglycerin over a 24 hour period. Firmness of the matrix appeared to have no significant effect on the rate or total amount of drug released from the systems