The U.S. Food and Drug Administration has approved a new topical gel to help treat symptoms of overactive bladder. Gelnique is a once-daily topical dose of oxybutynin chloride gel that is applied to the thigh, abdomen, upper arm, or shoulder. Researchers say that because the gel is delivered through the skin it is not metabolized in the liver, which means patients may see fewer side effects such as dry mouth and constipation. The drug’s maker says the gel will be available in spring 2009.