@LibUSciences Before FDA began publishing Orange Book in 1980 was there a similar compendium of approved drugs?
It does not appear there was a direct analogue that preceded the publication of the Orange Book in 1980. The FDA certainly maintained lists of prescription drugs that had been approved, but it doesn't appear that they published a comprehensive list that also discussed therapeutic equivalencies between the products of different manufacturers.
The Orange Book came into being because the FDA was being pelted with requests from the various state governments to review lists they were preparing to guide the process of generic substitutions. In the 1970s, the states were relaxing their laws and allowing for greater ability to substitute equivalent drug products at the pharmacy. As a consequence, they were developing lists of allowed substitutions (or non-allowed substitions, depending on the state) and asking for the FDA's assistance.
The Food and Drug Administration decided to publish one unified list of approved prescription drugs and their equivalents and distribute it to all the states at once. A draft of "The List" was published in 1978, followed by a more polished, proposed "Approved Prescription Drug Products List" in 1979. In 1980, the finished version was published in its familiar orange cover and became known as "The Orange Book". You can read a bit more about this process on the FDA's website. Hopefully this information will prove helpful, and please let us know if you have any further questions.