It is unlawful for any person to distribute in commerce any food, drug, device, or cosmetic, if its packaging or labeling does not conform to the provisions of this article or to regulations adopted pursuant to this article. This section does not apply to persons engaged in business as wholesale or retail distributors of foods, drugs, devices, or cosmetics, except to the extent that they are engaged in the packaging or labeling of the commodities or they prescribe or specify the manner in which the commodities are packaged or labeled. This section shall not be
construed to repeal, invalidate, or supersede any other section of this part.