Fesoterodine Impurity A with CAS No: 200801-70-3 is an impurity standard of Fesoterodine. Fesoterodine is a medication used for the treatment of overactive bladder (OAB) and its associated symptoms, such as urinary urgency, frequency, and urge incontinence (involuntary leakage of urine).Fesoterodine is belongs to a class of drugs known as antimuscarinic agents, which work by blocking certain receptors in the bladder muscles, leading to relaxation and a decrease in bladder contractions. Buy high quality Fesoterodine Impurity A from Molsyns Research. Molsyns Research is one of the leading manufacturer and exporter of Fesoterodine Impurity A