Written By: Arbaz Saiyyad, DPharm, BSc, BPharm
Reviewed By: Pharmacally Editorial Team
The United States has seen a key development in rare disease therapeutics with the launch of both authorized and generic versions of Ravicti (glycerol phenylbutyrate) Oral Liquid, 1.1 g/mL, following recent FDA approvals. The products, introduced by Endo Pharmaceuticals and Lupin Limited in October 2025, mark an important milestone for complex generics and long-term management of Urea Cycle Disorders (UCDs) a group of rare genetic conditions that impair nitrogen metabolism and can cause toxic ammonia buildup.
These launches expand treatment options for patients who cannot be managed solely through dietary interventions and protein restriction, improving therapeutic flexibility and affordability for affected families.
About Ravicti and Its Generics
Ravicti (Glycerol Phenylbutyrate) Oral Liquid is a nitrogen-binding agent approved for chronic management of UCDs in both adult and pediatric patients unable to achieve control with dietary measures alone. It helps prevent ammonia accumulation, reducing neurological risks and hospitalizations.
The new generic and authorized generic formulations contain the same active ingredient, dosage form, strength, and route of administration as the reference product, ensuring equivalent clinical efficacy and safety.
Endo Pharmaceuticals launched the first FDA-approved generic version of Ravicti after receiving ANDA approval on October 20, 2025, as confirmed by the company’s press release.
Lupin Limited announced the launch of an authorized generic version on October 24, 2025, developed and marketed under agreement with the brand holder.
Both companies highlight adherence to stringent quality and manufacturing standards, with a shared goal of broadening access to essential rare-disease treatments.
Regulatory Path, Prescribing Information, and Patient Impact
The FDA’s Abbreviated New Drug Application (ANDA) approval for Endo’s generic confirms full equivalence to the branded Ravicti in quality, safety, and efficacy. Lupin’s authorized generic was launched under the originator’s authorization, maintaining identical formulation and supply chain to the brand product.
While pricing details have not been publicly disclosed, both companies note that generic availability is expected to reduce financial burden, improve medication continuity, and support payer coverage for families managing lifelong UCD therapy. Actual savings may vary depending on insurance and distribution channels.
Healthcare providers can now prescribe either the FDA-approved generic or the authorized generic Glycerol Phenylbutyrate Oral Liquid, depending on patient preference and formulary availability.
Industry Impact and Future Directions
The dual entry of Endo and Lupin into the U.S. UCD market underscores growing industry focus on complex generics and rare-disease affordability. These launches reflect ongoing collaboration with the FDA’s Office of Generic Drugs to expand treatment access in high-investment, low-prevalence conditions.
Industry analysts expect these approvals to drive:
- Broader insurance coverage for nitrogen-scavenging agents
- Competitive pricing within specialty pharmacy channels
- Continued innovation in inherited metabolic disorder therapeutics
This expansion also signals greater competition in the rare disease segment previously dominated by branded Ravicti, which remains a vital therapy for ammonia control.
Significance of Lupin’s Authorized Generic Launch
Portfolio Expansion: The launch strengthens Lupin’s position in the U.S. rare disease and specialty segment, leveraging its growing complex generic portfolio.
Improved Access: As an authorized generic manufactured under the brand holder’s consent, Lupin’s version maintains brand-level quality while potentially lowering cost barriers for long-term therapy.
Market Differentiation: Authorized generics often face fewer competitors and carry higher provider confidence due to shared manufacturing standards with the originator.
Summary
With Endo’s first FDA-approved generic and Lupin’s authorized generic now available, U.S. patients living with Urea Cycle Disorders gain new options for safer, more affordable, and continuous access to therapy. These launches represent a coordinated step toward improving care equity in rare diseases and advancing complex generic development for metabolic conditions.
Understanding Authorized Generic vs. First Generic
An Authorized Generic (AG) is produced by the brand manufacturer or its licensee using the same formulation, process, and facility as the branded drug but marketed under a generic label usually with the originator’s consent. It does not require a separate FDA approval process under an ANDA.
A First Generic, by contrast, is the first product approved by the FDA through an Abbreviated New Drug Application (ANDA) after the brand’s exclusivity expires. It must independently demonstrate bioequivalence, safety, and quality compared to the reference product.
Ravicti (glycerol phenylbutyrate) was developed and commercialized by Horizon Therapeutics for long-term management of Urea Cycle Disorders (UCDs). After Amgen’s acquisition, the rights and marketing of Ravicti were transferred under Amgen Rare Disease portfolio.
Lupin’s authorized generic version was launched under agreement with the brand holder, Amgen (previously Horizon Therapeutics), the original developer and marketer of Ravicti in the United States.
References
Lupin Launches Authorized Generic Version of Ravicti® in the United States, 24 October 2025, Lupin, https://www.lupin.com/lupin-launches-authorized-generic-version-of-ravicti-in-the-united-states/
Lupin Expands U.S. Portfolio with Authorized Generic of Ravicti Oral Liquid, 24 October 2025, scanx, https://scanx.trade/stock-market-news/orders-deals/lupin-expands-u-s-portfolio-with-authorized-generic-of-ravicti-oral-liquid/22824537
Endo Launches First and Only Generic Version of RAVICTI® (glycerol phenylbutyrate) Oral Liquid in the United States, 20 October 2025, PRNewswire, https://www.prnewswire.com/news-releases/endo-launches-first-and-only-generic-version-of-ravicti-glycerol-phenylbutyrate-oral-liquid-in-the-united-states-302588244.html
RAVICTI is a UCD treatment option with long-term data that delivers 24-hour ammonia control for patients with UCDs, https://www.ravicti.com/about-ravicti/results-with-ravicti