Submission & ApprovalLast reviewed April 2026

Orange Book(Orange Book)

FDA's publication identifying drug products approved on the basis of safety and effectiveness with associated therapeutic equivalence evaluations.

Usage Examples

The ANDA cited the Orange Book RLD and included Paragraph IV certification against the listed patents.
The generic was rated AB-equivalent in the Orange Book, enabling automatic pharmacy substitution.
Patent delisting from the Orange Book opened the door to generic competition.

What is Orange Book?

The Orange Book — officially titled Approved Drug Products with Therapeutic Equivalence Evaluations — is FDA's official list of FDA-approved drug products with therapeutic equivalence ratings and patent and exclusivity information. It is the primary reference for generic drug (ANDA) sponsors to identify Reference Listed Drugs (RLDs) and for state pharmacy boards governing drug substitution decisions.

Orange Book entries include the drug name, dosage form, strength, applicant, approval date, application number, therapeutic equivalence code (AB, BP, etc.), and associated patent and exclusivity periods. Only drugs approved under the Federal Food, Drug, and Cosmetic Act appear in the Orange Book; biologics licensed under the Public Health Service Act appear in the Purple Book.

Generic sponsors filing an ANDA must reference an Orange Book-listed drug as the RLD. Patent listings in the Orange Book trigger Paragraph IV certifications and potential patent litigation under the Hatch-Waxman Act framework. The Orange Book is updated daily and available both as a searchable database and downloadable file.

Regulatory Context

This term appears most often in submission & approval workflows where submission quality, regulatory evidence, and audit readiness depend on consistent language. It is commonly referenced alongside FDCA SECTION 505J, HATCH WAXMAN ACT.

FDAICHEMA

When This Matters

The ANDA cited the Orange Book RLD and included Paragraph IV certification against the listed patents.
The generic was rated AB-equivalent in the Orange Book, enabling automatic pharmacy substitution.
Patent delisting from the Orange Book opened the door to generic competition.

Common Mistakes

Treating submission readiness as a formatting-only check without lifecycle validation.
Using outdated guidance references across modules and summaries.
Missing cross-functional review between RA, CMC, and quality before submission.

Related Regulations

FDCA SECTION 505JHATCH WAXMAN ACT

Frequently Asked Questions

The Orange Book lists drugs approved under the FDCA (small molecules, some biologics approved before the BPCIA transition). The Purple Book lists biologics licensed under the Public Health Service Act, including originator biologics and biosimilars.

An AB rating indicates FDA considers the generic drug therapeutically equivalent to the reference drug for the listed dosage form — same active ingredient, strength, dosage form, route of administration, and proven bioequivalence. AB-rated generics can be substituted for the RLD at the pharmacy level in most US states.

An ANDA applicant must certify the status of each Orange Book-listed patent. A Paragraph IV certification asserts the patent is invalid, unenforceable, or will not be infringed by the generic — triggering a 45-day notice to the patent holder and potentially initiating Hatch-Waxman litigation.