Sublingual drug delivery traditionally" involves systemic administration via mucosal membrane of floor of mouth or the ventral surface of tongue. The sublingual mucosa is relatively permeable due to the lipoidal nature of mucous membrane with a rich vasculature, which allows rapid absorption and has acceptable bioavailability. It is convenient, facilitates ease of administration and its ability to bypass hepatic first pass.This research elaborate about development Sublingual" tablets of ISBD NT(Isosorbide dinitrate). Compared to all "formulations ISDN4 showed high" % "drug release i.e., 97.15 % "in 8 min so it is considered as best formulation which contains Pullulan as super disintegrate in the concentration of 10 mg".