It shall be a violation, punishable by a fine not to exceed two hundred fifty dollars, for a manufacturer, distributor, or seller of drugs or an employee or agent thereof to distribute a free sample of any drug, other than a cosmetic not intended for ingestion, to any residential dwelling unless the sample is given directly to a person who is, or reasonably appears to be, over the age of eighteen. This section shall not be construed to permit distribution where otherwise prohibited by this chapter or any other law.