fosphenytoin sodium - Profile

What are the generic drug sources for fosphenytoin sodium and what is the scope of patent protection?

Fosphenytoin sodium is the generic ingredient in three branded drugs marketed by Parke Davis, Am Regent, Amneal, Apotex Inc, Dr Reddys, Fresenius Kabi Usa, Gland, Hikma, Hikma Farmaceutica, Hospira, Pharmobedient, Sun Pharm, Wockhardt Bio Ag, and Lupin, and is included in sixteen NDAs. There are five patents protecting this compound. Additional information is available in the individual branded drug profile pages.

Fosphenytoin sodium has fifty-four patent family members in fourteen countries.

Summary for fosphenytoin sodium

International Patents:	54
US Patents:	5
Tradenames:	3
Applicants:	14
NDAs:	16
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for fosphenytoin sodium

US Patents and Regulatory Information for fosphenytoin sodium

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Parke Davis	CEREBYX	fosphenytoin sodium	INJECTABLE;INJECTION	020450-001	Aug 5, 1996	AP	RX	Yes	Yes
Am Regent	FOSPHENYTOIN SODIUM	fosphenytoin sodium	INJECTABLE;INJECTION	078277-001	Aug 6, 2007		DISCN	No	No
Am Regent	FOSPHENYTOIN SODIUM	fosphenytoin sodium	INJECTABLE;INJECTION	090099-001	May 13, 2010		DISCN	No	No
Amneal	FOSPHENYTOIN SODIUM	fosphenytoin sodium	INJECTABLE;INJECTION	078476-001	Mar 18, 2008		DISCN	No	No
Apotex Inc	FOSPHENYTOIN SODIUM	fosphenytoin sodium	INJECTABLE;INJECTION	078126-001	Aug 6, 2007		DISCN	No	No

Expired US Patents for fosphenytoin sodium

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Parke Davis	CEREBYX	fosphenytoin sodium	INJECTABLE;INJECTION	020450-001	Aug 5, 1996	4,260,769
Parke Davis	CEREBYX	fosphenytoin sodium	INJECTABLE;INJECTION	020450-001	Aug 5, 1996	4,925,860

International Patents for fosphenytoin sodium

Country	Patent Number	Title	Estimated Expiration
Japan	4923144
Mexico	352459	COMPOSICIONES DE ETER-SULFOALQUILICO-CICLODEXTRINA. (SULFOALKYL ETHER CYCLODEXTRIN COMPOSITIONS.)
Canada	2865950
Russian Federation	2014136206	КОМПОЗИЦИИ АЛКИЛИРОВАННОГО ЦИКЛОДЕКСТРИНА И СПОСОБЫ ИХ ПОЛУЧЕНИЯ И ПРИМЕНЕНИЯ
South Korea	101314803

Supplementary Protection Certificates for fosphenytoin sodium

Patent Number	Supplementary Protection Certificate	SPC Country	SPC Expiration	SPC Description
0145340	99C0005	Belgium		PRODUCT NAME: FOSPHENYTOIN DISODIUM; NAT. REGISTRATION NO/DATE: NL 23 613 19980806; FIRST REGISTRATION: GB - PL 000 19/0157 19980204
0473687	99C0008	Belgium		PRODUCT NAME: FOSPHENYTOINUM DINATRICUM; REGISTRATION NO/DATE: 19 IS 102 F12 19980901; FIRST REGISTRATION: GB PL00019/1057 19980204
0473687	C980045	Netherlands		PRODUCT NAME: FOSPHENYTOINUM-DI-NATRICUM; NATL REGISTRATION NO/DATE: RVG 22758 19980702; FIRST REGISTRATION: GB PL 00019/0157 19980204
0473687	3/1999	Austria		PRODUCT NAME: FOSPHENYTOIN-NATRIUM; NAT. REGISTRATION NO/DATE: 1-22664 19980728; FIRST REGISTRATION: GB 00019/0157 19980204
0473687	SPC/GB98/030	United Kingdom		PRODUCT NAME: FOSPHENYTOIN SODIUM (3-HYDROXYMETHYL)-5,5-DIPHENYLHYDANTOIN DISODIUM PHOSPHATE ESTER); REGISTERED: UK 0019/0157 19980204

Overview
Fosphenytoin sodium is a prodrug of phenytoin, used to treat seizures, including status epilepticus and prophylaxis following neurosurgery. It has gained market share in hospitals due to its improved safety profile over phenytoin, notably less injection site reactions and greater infusion rate flexibility. The drug's growth trajectory depends on regional prescribing trends, patent status, and competitive landscape.

Market Size and Growth
The global anti-epileptic drug market reached approximately $5.9 billion in 2022, with injections accounting for a growing segment due to emergency and perioperative indications. Fosphenytoin holds an estimated 20% share within intravenous anti-epileptic therapies, valued roughly at $1.2 billion (2022 figures). Projected compound annual growth rate (CAGR) is 4-6% over the next five years, driven by emergency seizure management needs, with growth potential in emerging markets where hospital infrastructure expands.

Key Players and Competitive Dynamics

• Pfizer: Market leader with branded product Cerebyx, patent expired in 2014 but retains market dominance through brand recognition and clinical familiarity.
• Other competitors: Generic formulations by multiple manufacturers, increasing price competition.
• Emerging options: Newer anti-seizure drugs and formulations, including levetiracetam IV, are impacting the market share dynamics.

Regulatory and Patent Status

• The original patent for Cerebyx expired in 2014, leading to a wave of generics.
• Pfizer is pursuing patent extensions and line extensions to fortify market position.
• Regulatory hurdles are moderate; approvals primarily concern new indications or formulations.

R&D and Pipeline Dynamics

• Limited pipeline activity specific to fosphenytoin; focus shifts towards next-generation seizure therapies.
• Innovation in infusion technology and drug delivery could influence future adoption.

Financial and Investment Considerations

• Revenue stability is challenged by generic competition post-patent expiration.
• Market share is maintained through clinical preference and hospital formularies.
• ROI prospects depend on successful patent litigation, line extension strategies, and regional market expansion.
• Recent global supply chain issues may impact production costs and pricing strategies.

Risks

• Patent cliff and increased generic competition.
• Emergence of new anti-epileptic drugs with better safety profiles.
• Regulatory changes affecting hospital formulary preferences.
• Pricing pressures in healthcare systems globally.

Opportunities

• Focus on hospital penetration in emerging markets.
• Development of new formulations or delivery methods.
• Possible expansion into additional seizure indications or periprocedural applications.

Fundamentals Summary
Fosphenytoin sodium provides a targeted treatment option for seizure management, with a mature but competitive market landscape. Growth is primarily driven by hospital-based demand, with regional variation. Patent expirations have introduced robust generic competition, constraining margins. Long-term investment hinges on reformulation efforts, regional expansion, and advances in seizure therapy.

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Key Takeaways

• The drug’s market is stabilizing amid generic competition but benefits from hospital and emergency care demand.
• Growth prospects depend on regional expansion, patent strategies, and innovative formulations.
• Market risks include patent cliffs and competition from newer agents; opportunities exist in emerging markets and delivery technology.
• Financial stability relies heavily on hospital formulary positioning, regulatory environment, and supply chain reliability.
• Limited pipeline activity suggests near-term opportunities are primarily in strategic positioning rather than new drug development.

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FAQs

Last updated: February 3, 2026

1. How does fosphenytoin sodium compare economically to phenytoin?
Fosphenytoin generally costs more per dose than generic phenytoin but offers safety and administration advantages, which can reduce hospital costs related to adverse reactions or infusion complications. Its premium pricing is justified by clinical benefits in acute care settings, though this advantage diminishes with increasing generic competition.

2. What regional markets have the highest growth potential for fosphenytoin?
Emerging markets with expanding hospital infrastructure, such as China, India, and parts of Southeast Asia, exhibit strong growth potential. These regions are increasingly adopting injectable anti-epileptic medications due to rising seizure incidence and outpatient hospitalizations.

3. What strategic actions can pharmaceutical companies take to prolong the market life of fosphenytoin?
Strategies include securing patent extensions, developing new formulations (e.g., intranasal or subcutaneous), expanding indications, and pursuing market expansion through regional regulatory approvals.

4. How might recent healthcare policies impact fosphenytoin sales?
Healthcare systems emphasizing cost containment and generic drug utilization may pressure prices and reduce brand loyalty. Conversely, policies promoting the adoption of safer injectable options could favor fosphenytoin if safety profiles are prioritized.

5. Will new anti-seizure drugs supplant fosphenytoin in the long term?
Potentially. Drugs like levetiracetam IV, brivaracetam, and others with favorable safety profiles could replace fosphenytoin in some applications, particularly where safety and tolerability are prioritized over traditional anticonvulsant mechanisms.

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Sources
[1] MarketWatch. "Anti-epileptic drugs market size and forecast." 2023. [2] MarketsandMarkets. "Anti-Epileptic Drugs Market," 2022. [3] Pfizer. "Cerebyx product information," 2023. [4] FDA. "Drug approvals and patent expirations," 2022. [5] IQVIA. "Global hospital drug utilization report," 2022.