No action to revoke or suspend the license of any pharmacist or the permit to operate any pharmacy in this state shall be taken until the licensee or holder of such permit has been furnished a statement in writing of the charges against him or her together with a notice of the time and place of hearing. The statement of charges and notice shall be served upon such a person at least 30 days before the date fixed for the hearing, either personally or by registered or certified mail sent to his or her last known post-office address. The burden of proof shall be on the board.