What law prohibited the shipment of adulterated or misbranded drugs in interstate commerce?

The Pure Food and Drug Act of 1906 was significant in establishing federal regulations around the safety and labeling of drugs and food in the United States. This law aimed to protect consumers by prohibiting the shipment of adulterated (substandard or contaminated) or misbranded (misleadingly labeled) drugs across state lines.

Prior to this act, there was little regulation to ensure that medications were safe or accurately labeled, which led to widespread issues with effectiveness and safety. The 1906 act was a response to public health concerns, and it initiated the federal government's role in overseeing drug safety and labeling, laying the groundwork for future legislations and the establishment of the Food and Drug Administration (FDA).

The other laws mentioned had different focuses or addressed various issues related to drugs but did not specifically initiate the prohibition of adulterated or misbranded drugs in the same way the Pure Food and Drug Act did. The Controlled Substances Act, for example, primarily regulates the manufacture and distribution of narcotics and other drugs that could be abused, while the Drug Quality and Security Act focuses on enhancing drug safety and preventing counterfeit medications. Thus, the Pure Food and Drug Act of 1906 is the correct answer because it specifically addresses the issue of misbranding