Updated

A Missouri death-row inmate scheduled for execution this month says the state prison system is improperly storing expired doses of a new lethal injection drug provided by an Oklahoma pharmacy that's not licensed to do business in the neighboring state.

Attorneys for Herbert Smulls filed a complaint with the Oklahoma State Board of Pharmacy on Friday. They want the board to recall an "expired, unsafe" batch of the sedative pentobarbital provided to Missouri by an unidentified Oklahoma compounding pharmacy. The complaint says the pharmacy gave erroneous instructions to store the drug at room temperature.

Missouri switched to its one-drug execution method late last year and has since killed two inmates. The complaint includes Missouri state records showing the pentobarbital given to both inmates had expired eight to 10 days earlier.