Rockwell Medical Inc. has started a private placement to sell 7,556,675 units to The RBI Opportunities Fund LLC, an affiliate of Richmond Brothers Inc., to raise up to $30 million.

The placement has been priced at $3.97 per unit, according to an Oct. 15 press release. Rockwell said the net proceeds will be used to fund working capital needs.

Each unit comprises of one common share and a warrant to purchase 50% of a share of common stock. Warrants can be exercised six months after the closing date to purchase a full share for $4.96 and will expire after five years from the issue date. The Wixom, Mich.-based company will sell the units in two rounds. The first offering of 5,541,562 units worth $22 million is expected to close Oct. 17. Richmond can purchase up to an additional $8 million in units at the offering price until Oct. 26.

Rockwell develops therapies for kidney diseases and for patients undergoing dialysis.