Which of the following is the FDA guide on interchangeable biological products (biosimilars)?

The correct answer is the Purple Book, which serves as the FDA guide on interchangeable biological products, including biosimilars. The Purple Book lists biological products that have been deemed biosimilar to an FDA-licensed reference product, and it provides information about their interchangeability. This is particularly important in the context of healthcare, as it helps ensure that pharmacists and healthcare providers have access to critical information regarding the appropriateness of these products for patient use.

The other options do not pertain to interchangeable biological products. The Pink Book is specifically a guide on vaccines, detailing vaccine-preventable diseases and immunization schedules. The Orange Book deals with approved drug products with therapeutic equivalence evaluations, primarily for small molecule drugs, rather than biologics. The Black Book is not an official FDA publication and does not relate specifically to the regulation of drug products or biologicals. Understanding these distinctions is essential for navigating pharmaceutical regulations and ensuring compliance with federal law.