Buy from Plenum Biotech. It's useful in treating and preventing heart related chest pain (angina). Plinit 6.4 Tablet is a brand name of Nitroglycerin controlled release tablet 6.4 mg is useful in treating and preventing heart related chest pain (angina). Angina occurs when the heart muscle is not getting enough blood. Nitroglycerin relaxes and widens blood vessels so that blood can flow more easily to the heart. It is a medicine that belongs to a class of medicines known as nitrates and helps in improving blood flow to the heart muscle.