Supernus (NASDAQ: SUPN) were down 20% Friday after raising a little over $51 million through a dilutive share offering. The company is hoping to use the funds to commercialize its extended-release epilepsy drugs in 2013, but the offering price of $8 per share compared with yesterday's close of $9.83 sent the stock plunging. Shares have sold off by a third since the start of the week.

The epilepsy space has been typically dominated by big pharma, but several of the drugs have gone off patent, leading to generic competition. However, extended-release formulas may leave Supernus with an avenue to sales. Here, Motley Fool health care analyst David Williamson tells investors whether the diluted price is the right entry point or if it's time to sit back and wait.