Oculus Innovative Sciences, a Petaluma company that is developing a treatment against viruses and other products to help with wound recovery, has already filed for an initial public offering.

But it is also raising private money at the same time, which is significant because it can give insiders and other investors a nice stake in the company before the company goes public at a higher price.

According to VentureWire (sub required), the company has raised $2.4 million recently, a toward a $10 million total third round, according to a filing with the Securities and Exchange Commission.

Oculus raised $8 million in 2004 from 198 accredited investors in Series A financing and $47.4 million in 2005 from 361 accredited investors in Series B financing, according to its IPO filing. Brookstreet Securities Corp., the placement agent on all three of Oculus’ fundraising rounds, has received warrants for stock each time.