atropine sulfate; difenoxin hydrochloride - Profile

What are the generic sources for atropine sulfate; difenoxin hydrochloride and what is the scope of patent protection?

Atropine sulfate; difenoxin hydrochloride is the generic ingredient in two branded drugs marketed by Legacy Pharma and is included in one NDA. Additional information is available in the individual branded drug profile pages.

Summary for atropine sulfate; difenoxin hydrochloride

US Patents:	0
Tradenames:	2
Applicants:	1
NDAs:	1

US Patents and Regulatory Information for atropine sulfate; difenoxin hydrochloride

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Legacy Pharma	MOTOFEN	atropine sulfate; difenoxin hydrochloride	TABLET;ORAL	017744-002	Approved Prior to Jan 1, 1982		RX	Yes	Yes
Legacy Pharma	MOTOFEN HALF-STRENGTH	atropine sulfate; difenoxin hydrochloride	TABLET;ORAL	017744-001	Approved Prior to Jan 1, 1982		DISCN	No	No

Expired US Patents for atropine sulfate; difenoxin hydrochloride

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Legacy Pharma	MOTOFEN	atropine sulfate; difenoxin hydrochloride	TABLET;ORAL	017744-002	Approved Prior to Jan 1, 1982
Legacy Pharma	MOTOFEN HALF-STRENGTH	atropine sulfate; difenoxin hydrochloride	TABLET;ORAL	017744-001	Approved Prior to Jan 1, 1982

Atropine Sulfate and Difenoxin Hydrochloride: Investment Fundamentals Analysis

Last updated: February 19, 2026

Atropine sulfate and difenoxin hydrochloride represent established pharmaceutical assets with distinct market positions and patent landscapes. Atropine sulfate, a anticholinergic agent, has a long history of therapeutic use across various indications. Difenoxin hydrochloride, an opioid antidiarrheal, operates within a more specialized therapeutic niche, subject to differing regulatory and market dynamics. This analysis examines their current patent status, market relevance, and potential for future value.

Atropine Sulfate: Established Therapeutic, Evolving Patent Landscape

What is the current patent status for atropine sulfate?

The primary patent landscape for atropine sulfate is largely expired. As a well-established compound, its original composition of matter patents have long lapsed. However, new patent filings often focus on specific formulations, manufacturing processes, novel delivery systems, or new indications.

• Original Compound Patents: Expired.
• Formulation Patents: Patents may exist for specific sustained-release formulations, ophthalmic solutions, or injectable preparations. The lifespan of these patents varies based on the filing date and the specific innovation claimed. For example, a patent granted in 2005 for a novel ophthalmic formulation might expire in 2025 if it received the full patent term extension.
• Process Patents: Innovations in the synthesis or purification of atropine sulfate could be patented. These patents typically last 20 years from the filing date. Identifying specific active process patents requires detailed database searches.
• New Indication Patents: While atropine sulfate is approved for multiple uses, new patent applications can be filed for novel therapeutic applications discovered through research. These patents offer a 20-year term from the filing date. For instance, research into atropine's potential for myopia control has led to specific patent filings for such uses.

Table 1: Atropine Sulfate Patent Considerations

Patent Type	Typical Expiry Consideration	Current Relevance
Composition of Matter	Expired (Original synthesis)	Low. Generic competition is standard for the basic compound.
Formulation	20 years from filing date + potential extensions	High for specialized delivery mechanisms (e.g., sustained release, targeted delivery) which can provide a competitive advantage.
Manufacturing Process	20 years from filing date	Moderate. Efficiency improvements or novel synthesis routes can impact cost of goods.
New Indications	20 years from filing date + potential extensions	High. Discovery of new therapeutic uses can redefine the market for the established compound.

What are the key therapeutic applications and market dynamics of atropine sulfate?

Atropine sulfate's utility spans a broad range of medical applications due to its anticholinergic properties, blocking the action of acetylcholine at muscarinic receptors.

• Ophthalmology: Used to dilate pupils (mydriasis) for eye examinations and to relax the ciliary muscle (cycloplegia) for refractive error assessment. It also treats certain eye inflammations like uveitis.
• Cardiology: Administered to treat symptomatic bradycardia (slow heart rate).
• Anesthesiology: Used as a pre-anesthetic medication to reduce secretions (salivary and bronchial) and to counteract the effects of certain anesthetic agents.
• Poisoning Treatment: Crucial antidote for organophosphate and carbamate poisoning (e.g., insecticides) and muscarinic mushroom poisoning.
• Gastroenterology: Historically used, though less common now, for treating peptic ulcers and irritable bowel syndrome due to its ability to reduce gastrointestinal motility and secretions.
• Respiratory Medicine: Can be used to reduce respiratory secretions in palliative care or certain respiratory conditions.

Market Dynamics:

The market for atropine sulfate is mature, characterized by a significant number of generic manufacturers. Pricing is largely driven by cost-effectiveness and availability. Competition is intense among generic suppliers. The primary drivers for market growth are its established therapeutic uses, particularly in emergency medicine (antidote) and ophthalmology. The development of novel drug delivery systems, such as extended-release formulations for specific conditions, represents a potential area for market differentiation and value creation. Demand is relatively stable, influenced by healthcare utilization patterns and prevalence of conditions requiring its use.

Table 2: Atropine Sulfate Key Market Indicators

Metric	Description	Data Point Example
Therapeutic Areas	Primary medical fields where atropine sulfate is utilized.	Ophthalmology, Cardiology, Emergency Medicine (Antidote), Anesthesiology.
Market Maturity	Stage of development and competition within the atropine sulfate market.	Mature market with extensive generic penetration.
Key Growth Drivers	Factors contributing to increased demand or market expansion.	Emergency preparedness (antidote), routine ophthalmological procedures, advancements in specialized formulations.
Competitive Landscape	Nature of competition among manufacturers.	High competition from numerous generic manufacturers. Price is a significant factor.
Pricing Trends	General direction of pricing for the drug.	Stable to declining prices for standard formulations due to generic competition. Potential for premium pricing on novel delivery systems or new indications.
Regulatory Environment	Key regulatory bodies and their influence.	FDA, EMA, and other national health authorities. Approval for new indications or formulations is required. Manufacturing must adhere to Good Manufacturing Practices (GMP).
Recent Innovation Focus	Areas where current research and development are concentrated.	Novel drug delivery systems (e.g., long-acting injections, specialized ophthalmic devices), new therapeutic indications (e.g., myopia control), improved synthesis efficiency.

Difenoxin Hydrochloride: Specialized Niche, Evolving Regulatory Scrutiny

What is the current patent status for difenoxin hydrochloride?

Difenoxin hydrochloride, an opioid agonist used for the symptomatic treatment of diarrhea, has a more limited and specialized patent history compared to atropine sulfate. As a controlled substance in many jurisdictions, its development and commercialization are subject to stringent regulatory oversight.

• Original Compound Patents: The original composition of matter patents for difenoxin have expired.
• Formulation Patents: Patents may exist for specific fixed-dose combinations, such as difenoxin hydrochloride with atropine sulfate. The combination of difenoxin with atropine is a common strategy to deter abuse, as the atropine component can cause unpleasant anticholinergic side effects if the drug is taken in excessive doses. These combination patents, or patents related to specific ratios or delivery methods of the combination, have a defined expiry. For example, a patent for a specific tablet formulation of difenoxin/atropine might have been filed in the early 2000s and could expire in the early 2020s.
• Process Patents: As with atropine sulfate, novel or improved manufacturing processes for difenoxin hydrochloride could be patented.
• New Indication Patents: While primarily used for diarrhea, research into other potential applications is less common given its opioid classification and risk of abuse.

Table 3: Difenoxin Hydrochloride Patent Considerations

Patent Type	Typical Expiry Consideration	Current Relevance
Composition of Matter	Expired	Low. Generic competition for the active pharmaceutical ingredient (API) itself is possible if regulatory hurdles are met.
Formulation	20 years from filing date + potential extensions	Moderate to High, particularly for patented fixed-dose combinations (e.g., with atropine) designed to mitigate abuse. Specific ratios and excipients can be patentable.
Manufacturing Process	20 years from filing date	Moderate. Cost of production and API purity are key factors in a competitive generic market.
New Indications	20 years from filing date + potential extensions	Low. Limited potential for new indications due to its opioid nature and associated risks.

What are the key therapeutic applications and market dynamics of difenoxin hydrochloride?

Difenoxin hydrochloride's therapeutic use is concentrated and carefully managed.

• Symptomatic Treatment of Diarrhea: Its primary indication is to reduce the frequency and severity of diarrhea. It acts by slowing intestinal motility.
• Combination Therapy: It is almost always formulated with atropine sulfate in a fixed-dose combination. This combination is known commercially under various brand names (e.g., Lotomil, Motofen). The atropine is present in sub-therapeutic doses for its anticholinergic effects but is intended to discourage intentional overdose and abuse of the difenoxin component.

Market Dynamics:

The market for difenoxin hydrochloride is significantly influenced by its classification as a Schedule IV controlled substance in the United States by the Drug Enforcement Administration (DEA). This classification imposes strict regulations on manufacturing quotas, distribution, prescribing, and record-keeping.

• Controlled Substance Status: The Schedule IV status necessitates significant compliance infrastructure for manufacturers and distributors. This regulatory burden limits the number of market participants.
• Competition: While generic versions of difenoxin/atropine combinations exist, the controlled substance status creates barriers to entry for new generic manufacturers. The primary competition comes from other antidiarrheal agents, including over-the-counter (OTC) options like loperamide (Imodium A-D) and bismuth subsalicylate (Pepto-Bismol), as well as other prescription medications.
• Prescriber Preference: Prescribing patterns for difenoxin hydrochloride are influenced by physician familiarity, patient response, and the need for a prescription for opioid-based antidiarrheals. Its use is generally reserved for cases where OTC options are insufficient.
• Abuse Deterrence: The inclusion of atropine is a key market feature, aimed at reducing the potential for abuse. This has implications for prescribing guidelines and physician confidence in the product.
• Market Size: The market for prescription antidiarrheals, including difenoxin hydrochloride, is smaller than the OTC market. Growth is generally modest, influenced by changes in gastrointestinal disease prevalence and the availability of alternative treatments. The focus is on maintaining market share within its specialized niche rather than rapid expansion.

Table 4: Difenoxin Hydrochloride Key Market Indicators

Metric	Description	Data Point Example
Therapeutic Areas	Primary medical field where difenoxin hydrochloride is utilized.	Symptomatic treatment of diarrhea.
Market Maturity	Stage of development and competition within the difenoxin hydrochloride market.	Mature market.
Key Market Drivers	Factors contributing to demand.	Physician prescription for persistent or severe diarrhea not managed by OTC alternatives.
Competitive Landscape	Nature of competition.	Competition from other prescription antidiarrheals and a large OTC market (loperamide, bismuth subsalicylate). Barriers to entry exist due to controlled substance status.
Pricing Trends	General direction of pricing.	Stable to moderate pricing, influenced by manufacturing costs, regulatory compliance, and competition from generics and OTC products. Potential for premium on the combination formulation's abuse-deterrent properties.
Regulatory Environment	Key regulatory bodies and their influence.	DEA (controlled substance scheduling), FDA (drug approval, manufacturing standards). Strict quotas and oversight are in place.
Key Differentiator	Unique characteristic contributing to its market position.	Fixed-dose combination with atropine sulfate designed to deter abuse.
Risk Factors	Potential challenges or threats to the market.	Increased regulatory scrutiny, potential for stricter controls on opioid-related medications, development of more effective or safer alternatives, diversion and abuse potential.

Investment Outlook and Strategy

What are the investment considerations for atropine sulfate?

Investment in atropine sulfate is primarily centered on companies that hold patents for novel formulations, delivery systems, or new indications. The generic market itself offers low margins and high competition.

• Focus on Innovation: The key to investment value lies in identifying entities with patent protection on differentiated products. This could include:
  • Ophthalmic solutions with improved compliance: Extended-release formulations reducing the need for frequent dosing.
  • Advanced antidote delivery: Devices or formulations for faster, more effective administration in emergency settings.
  • Myopia control: If clinical trials are successful and patent protection is robust, this could open a significant new market segment.
• Manufacturing Efficiency: Companies with highly efficient, cost-effective manufacturing processes for atropine sulfate API or finished products could maintain a competitive edge in the generic space, though this is typically a lower-margin play.
• Partnerships and Licensing: Investment may also come from partnerships or licensing agreements where a company licenses a patented atropine sulfate technology from an innovator.

Strategic Insight: For atropine sulfate, consider investments in companies that are actively pursuing innovation in delivery or indication, moving beyond the basic compound. Valuations will be tied to the strength and breadth of their intellectual property portfolio and the potential market size of their innovations.

What are the investment considerations for difenoxin hydrochloride?

Investment in difenoxin hydrochloride is more complex due to its controlled substance status and specialized market. Opportunities are likely to be found in:

• Established Generic Manufacturers: Companies with established manufacturing capabilities and regulatory compliance expertise for Schedule IV substances can maintain a steady, albeit modest, revenue stream. Profitability is dependent on efficient production and secure supply chains.
• Abuse-Deterrent Formulations: While the current combination with atropine is a form of abuse deterrence, any novel, patent-protected formulation that further enhances abuse resistance or improves patient compliance could be valuable, provided it navigates regulatory approval.
• Supply Chain Security: Companies that can reliably and compliantly produce and distribute difenoxin hydrochloride API and finished products are strategically positioned. This includes robust security measures and adherence to DEA quotas.

Strategic Insight: For difenoxin hydrochloride, investment is best suited for entities with deep experience in regulated and controlled substance markets. Growth potential is limited by the therapeutic niche and regulatory ceiling. Focus on companies with strong operational controls and a stable market position within the prescription antidiarrheal segment. Diversification beyond difenoxin hydrochloride is likely advisable for a broader portfolio.

Key Takeaways

Atropine sulfate, an established anticholinergic, offers investment potential primarily through patented innovations in drug delivery and new therapeutic indications. Its generic market is mature and highly competitive. Difenoxin hydrochloride, a controlled substance used for diarrhea, operates in a niche market where investment is driven by regulatory compliance expertise, efficient manufacturing of its fixed-dose combination with atropine, and the inherent barriers to entry.

Frequently Asked Questions

1. What is the primary risk associated with investing in atropine sulfate? The primary risk is the highly saturated generic market, leading to price erosion and low profit margins for standard formulations, with innovation being the key differentiator.
2. How does the controlled substance status of difenoxin hydrochloride impact its investment potential? It creates significant barriers to entry, limiting competition but also increasing operational complexity and compliance costs, which can cap profit potential.
3. Are there opportunities for new patent filings for atropine sulfate? Yes, particularly for novel drug delivery systems, specific pharmaceutical formulations, and the discovery of new therapeutic uses.
4. What is the role of atropine in the difenoxin hydrochloride formulation? Atropine is included in sub-therapeutic doses primarily to deter abuse of the difenoxin component by inducing unpleasant anticholinergic side effects at higher doses.
5. Which therapeutic area presents the greatest untapped patent potential for atropine sulfate? The potential for myopia control in ophthalmology represents a significant, albeit still developing, area for new patent applications and market expansion.

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Citations

[1] Drug Enforcement Administration. (n.d.). Schedules of Controlled Substances. Retrieved from [DEA Website - Specific URL not provided as it varies by schedule and update] [2] U.S. Food and Drug Administration. (n.d.). Patent Term Restoration. Retrieved from [FDA Website - Specific URL not provided as it varies] [3] World Health Organization. (n.d.). International Classification of Diseases (ICD). Retrieved from [WHO Website - Specific URL not provided as it varies] [4] General Pharmaceutical Patent Databases (e.g., USPTO, Espacenet, Google Patents). (Ongoing searches). [5] Pharmaceutical Market Research Reports (Various industry-specific reports). (Ongoing analysis).