A parent in Ohio reportedly leveled a class-action lawsuit against EpiPen maker Mylan (NSDQ:MYL) over the nearly 500% increase in the cost of the epinephrine injector since Mylan acquired the device in 2007.

The suit, filed yesterday in Hamilton County Common Pleas Court, seeks an unspecified amount of damages for its 25 plaintiffs, according to Cincinnati.com. Plaintiffs’ attorney Carl Lewis said the roster of plaintiffs could increase significantly, according to the website.

Lead plaintiff Linda Bates is a Connecticut resident whose 15-year-old son carries an EpiPen in case of a peanut allergy attack. The lawsuit alleges that the price for a pair of EpiPens surged from $50 a year to $600.

Mylan violated Ohio’s Consumer Sales Practices Act, which prohibits a supplier from committing “an unconscionable act or practice in connection with a consumer transaction,” the suit alleges, according to the site.

“I filed the lawsuit to right an injustice,” Lewis told Cincinnati.com. “The fact is, Mylan Pharmaceuticals – or any company – will not stop unconscionable practices if we as individuals … don’t strike. And I’m striking because I think it’s outrageous.”

The lawsuit calls the company’s actions “immoral” and “nothing more than price-gouging.”

The company defended the price hikes, with CEO Heather Bresch calling the costs justified because of improvements Mylan made to the device. Bresch cited the “complexity and opaqueness of today’s branded pharmaceutical supply chain” as a motivation for companies that raise their prices.

In response to calls from politicians for federal investigations into Mylan’s cost analysis, the company said in late August that it would expand existing patient support programs and develop a cheaper generic that would cost around $300 for a pair of injectors.

When the initial bout of criticism began August 22, MYL shares dropped 10%; the stock was trading at $40.45 per share today in early trading, up 0.12%.