Inspire Pharmaceuticals (Nasdaq: ISPH) has filed with the SEC to periodically sell up to $140 million in common stock.

The Durham-based drug developer said it plans to use the proceeds from the shelf offering for clinical development of its product candidates and commercialization, working capital and general corporate purposes.

Under a shelf registration, a company may sell securities in one or more separate offerings with the size, price and terms to be determined at the time of sale.

In late morning trading on the Nasdaq, shares of ISPH were down 18 cents to $13.29 from its previous close of $13.47. Volume was lighter than average.