(S)-Timolol-d 9 (maleate) is deuterium labeled (S)-Timolol (Maleate). (S)-Timolol Maleate (L-714,465 Maleate) is a non-cardioselective hydrophilic β-adrenoceptor blocker. (S)-Timolol Maleate is widely used as standard medication for intraocular pressure (glaucoma) by preventing the production of aqueous humor. (S)-Timolol Maleate can be used for hypertension, angina pectoris and myocardial infarction.