Oxybutynin hydrochloride is primarily used to treat overactive bladder (OAB) by relaxing the bladder muscles. It helps reduce symptoms such as frequent urination, urgency, and incontinence. The medication is also effective in managing urinary leakage in individuals with neurological conditions like spinal cord injuries or multiple sclerosis. Additionally, it is sometimes prescribed for children with nocturnal enuresis (bedwetting) to control bladder activity during sleep. The drug can be administered orally as tablets or liquid, or transdermally through patches or gels for extended relief. Its anticholinergic properties make it useful in minimizing involuntary bladder contractions, improving quality of life for patients with bladder control issues.