Tolterodine is a selective muscarinic receptor antagonist used as an active pharmaceutical ingredient (API) in the treatment of overactive bladder symptoms, including urinary frequency, urgency, and incontinence. Chemically, it is supplied as a colorless to light yellow oil with a purity of 98%, conforming to the infrared spectrum structure. This specialty chemical intermediate is primarily utilized in pharmaceutical research, development, and manufacturing processes to produce formulations for managing bladder overactivity, often due to neurological or idiopathic causes. It enables tailored dosing in immediate-release or extended-release forms. Common clinical side effects when formulated include dry mouth, constipation, and blurred vision, but as a raw material, it requires proper handling in controlled environments.