Solifenacin is a selective muscarinic M3 receptor antagonist used as an active pharmaceutical ingredient (API) in medications for overactive bladder (OAB). It treats symptoms including urinary urgency, frequency, and incontinence by relaxing bladder detrusor muscle, reducing involuntary contractions, and increasing bladder capacity. This high-purity (≥97.5%) white to off-white powder, confirmed by IR spectrum, is intended for pharmaceutical manufacturing, research, and development.