D-Timolol maleate is the (R)-enantiomer of Timolol maleate, a non-selective beta-adrenergic receptor blocker. Unlike the pharmacologically active (S)-enantiomer used in clinical treatments for glaucoma, hypertension, arrhythmias, and migraine prophylaxis, D-Timolol exhibits significantly reduced beta-blocking activity. It is primarily employed as a reference standard and chiral intermediate in pharmaceutical research, drug development, and stereochemistry studies to investigate enantioselective effects and purity assessments.