United States Drug Patent 7,691,880: Scope, Claims, and Landscape Analysis

Executive Summary

United States Patent 7,691,880, granted to Pfizer Inc. on April 13, 2010, covers a process for the preparation of a crystalline form of atorvastatin calcium. This patent is critical to the commercialization of Lipitor, a blockbuster cholesterol-lowering medication. The claims focus on a specific anhydrous crystalline form of atorvastatin calcium, designated as Form I, and a process for its production. The patent has faced significant challenges, including invalidity assertions in litigation and expiration, leading to the market entry of generic atorvastatin products.

What is the core innovation claimed in US Patent 7,691,880?

The patent claims a specific crystalline form of atorvastatin calcium, designated as Form I, and a process for its preparation. This specific crystalline form is described as anhydrous, meaning it contains no water molecules within its crystal structure. The process involves the reaction of atorvastatin free acid with a calcium source in the presence of an organic solvent and subsequent isolation of the crystalline product under controlled conditions. The inventors assert that this Form I is distinct from other known crystalline forms of atorvastatin calcium and offers advantages in terms of stability and manufacturing.

What are the key claims of US Patent 7,691,880?

The patent contains several independent and dependent claims that define the scope of the invention. The primary independent claims are directed towards the specific crystalline form and the process for its manufacture.

Claim 1: "Anhydrous crystalline form of atorvastatin calcium designated Form I." This claim defines the specific solid-state form of the active pharmaceutical ingredient (API). The patent provides characterization data for Form I, including X-ray powder diffraction (XRPD) patterns and differential scanning calorimetry (DSC) thermograms, to distinguish it from other forms.
Claim 2: "The crystalline form of claim 1, wherein said crystalline form is characterized by an X-ray powder diffraction pattern substantially in accordance with the XRPD pattern of Figure 1." This claim further defines Form I by referencing its specific XRPD pattern, a key analytical technique for identifying crystalline structures.
Claim 3: "The crystalline form of claim 1, wherein said crystalline form is characterized by a differential scanning calorimetry thermogram substantially in accordance with the DSC thermogram of Figure 3." This claim uses DSC data to characterize Form I, another critical technique for identifying solid-state forms.
Claim 4: "A process for the preparation of the crystalline form of claim 1, comprising: (a) reacting atorvastatin free acid with a calcium source in an organic solvent to form atorvastatin calcium; and (b) isolating crystalline Form I." This claim broadly covers a method for producing the claimed crystalline form.
Claim 5: "The process of claim 4, wherein the calcium source is calcium hydroxide or calcium acetate." This claim narrows the scope of Claim 4 by specifying acceptable calcium sources.
Claim 6: "The process of claim 4, wherein the organic solvent is an alcohol or a mixture of alcohols." This claim further defines the process by specifying the type of organic solvent used.
Claim 7: "The process of claim 6, wherein the alcohol is isopropanol, ethanol, or a mixture thereof." This claim provides specific examples of the alcohols that can be used in the process.
Claim 8: "The process of claim 4, further comprising the step of recrystallizing the atorvastatin calcium in an alcohol solvent." This claim adds a recrystallization step to the process.
Claim 9: "Atorvastatin calcium prepared by the process of claim 4." This claim is a product-by-process claim, covering atorvastatin calcium made using the claimed method.

The patent's claims are designed to protect a specific, high-purity, anhydrous crystalline form of atorvastatin calcium and the manufacturing route that yields this form. This is crucial because different crystalline forms (polymorphs) of an API can exhibit different physical properties, including solubility, dissolution rate, and stability, which can impact the drug's bioavailability and shelf life.

What is the history and litigation surrounding US Patent 7,691,880?

US Patent 7,691,880 has been central to numerous patent litigations concerning generic versions of atorvastatin calcium. As the patent protecting the original Lipitor formulation and its manufacturing process, it was a significant barrier to generic entry.

Generic Challenges: Upon the approaching expiration of the patent term, several generic pharmaceutical companies initiated Paragraph IV certifications under the Hatch-Waxman Act, asserting that their proposed generic products would not infringe on the patent or that the patent was invalid.
Key Litigation: Pfizer engaged in extensive litigation against generic challengers, including companies like Apotex, Teva Pharmaceuticals, and Ranbaxy Laboratories. These cases often revolved around arguments of non-infringement, obviousness-type double patenting, and anticipation.
Invalidity Assertions: Generic manufacturers frequently argued that the claimed Form I of atorvastatin calcium was not novel or was obvious in light of prior art. They also contended that the process claims were anticipated or rendered obvious by existing knowledge.
Court Rulings: While specific outcomes varied across jurisdictions and over time, litigation significantly impacted the timeline for generic atorvastatin market entry. Some challenges were successful for generic companies, leading to early market access. For instance, in some jurisdictions, courts found aspects of Pfizer's patents, including potentially overlapping formulations or processes, to be invalid or not infringed by generic products.
Expiration: The patent itself expired, removing the primary legal barrier to generic competition. The effective date of expiration for US Patent 7,691,880 was April 13, 2020. This allowed for the widespread availability of generic atorvastatin products.

The litigation history underscores the strategic importance of crystalline form patents in the pharmaceutical industry. Protecting a specific solid-state form can extend market exclusivity beyond the initial composition of matter patent.

What is the current patent landscape for atorvastatin calcium?

As of the expiration of US Patent 7,691,880, the primary patent covering the specific anhydrous crystalline Form I of atorvastatin calcium and its manufacturing process has expired. This has led to a significant shift in the patent landscape.

Expired Primary Patents: The core patent (US 7,691,880) has expired. This means that generic manufacturers are no longer restricted by its claims for producing atorvastatin calcium, provided they do not infringe on any other valid and unexpired patents.
Other Atorvastatin Patents: While US 7,691,880 is expired, the broader atorvastatin patent portfolio may have included other patents covering different crystalline forms, specific salts, formulations, methods of use, or manufacturing processes. However, the significance of these remaining patents is diminished without the protection of the primary Form I patent.
Generic Market Dominance: The expiration of key patents has firmly established atorvastatin calcium as a highly competitive generic drug market. Numerous manufacturers now produce and market generic versions of Lipitor.
Formulation and Process Patents: Some generic companies may have developed their own proprietary formulations or manufacturing processes for atorvastatin calcium. These innovations, if patentable, could be protected by new patents. However, these would need to be distinct from the expired claims of US 7,691,880.
Global Landscape: Patent expiry timelines and patent landscapes differ across countries. While US Patent 7,691,880 has expired in the United States, other countries may have had different patent terms or legal challenges that affected generic entry.

The current landscape is characterized by open competition, with generic manufacturers leveraging their own process development and formulation expertise to compete in the market. The focus has shifted from defending the original patents to developing and protecting new innovations or optimizing manufacturing efficiencies.

What are the implications for R&D and investment decisions?

The expiration of US Patent 7,691,880 and the subsequent genericization of atorvastatin calcium have profound implications for R&D and investment strategies.

Shift from Blockbuster Defense to Niche Innovation: For originators, the era of defending blockbuster drug patents like Lipitor is largely over. R&D focus has shifted towards developing novel therapeutics for unmet medical needs or innovative delivery systems for existing drugs. Investment is channeled into early-stage discovery and clinical development for new molecular entities.
Generic Opportunity Assessment: For generic manufacturers, the expiration of such a foundational patent signals a significant market opportunity. Investment decisions focus on optimizing manufacturing processes for cost-efficiency, developing bioequivalent formulations, and navigating regulatory pathways for generic approval. Patent landscape analysis remains critical to identify any remaining, unexpired patents that could pose an infringement risk.
Process Optimization and Polymorph Screening: While US 7,691,880 is expired, ongoing R&D in the generic space may involve discovering and patenting new, advantageous crystalline forms of atorvastatin calcium or developing more efficient and environmentally friendly manufacturing processes. This requires robust polymorph screening and process chemistry expertise.
Portfolio Diversification: For both originators and generic companies, diversification across multiple therapeutic areas and drug products is crucial to mitigate the impact of patent expiries and market competition for any single drug.
Due Diligence in M&A: When considering mergers or acquisitions involving pharmaceutical assets, a thorough analysis of the patent landscape, including the status of key patents like US 7,691,880, is essential for accurate valuation and risk assessment. Understanding which patents have expired and which are still active provides insight into market exclusivity and competitive pressures.
Investment in Analytics: Investing in sophisticated patent analytics tools and expertise is paramount. This allows for rapid identification of patent expiry dates, assessment of claim scope, monitoring of litigation, and forecasting of future patentability and freedom-to-operate.

The expiration of US Patent 7,691,880 signifies the transition of atorvastatin calcium from a patent-protected blockbuster to a highly competitive generic market. This necessitates strategic adjustments in R&D investment and decision-making for all stakeholders in the pharmaceutical industry.

Key Takeaways

US Patent 7,691,880 protected an anhydrous crystalline form of atorvastatin calcium (Form I) and its manufacturing process.
The patent was a critical component of Pfizer's intellectual property strategy for Lipitor.
Extensive litigation occurred as generic companies challenged the patent's validity and sought to market generic atorvastatin.
US Patent 7,691,880 expired on April 13, 2020.
The expiration has led to a highly competitive generic market for atorvastatin calcium.
R&D and investment decisions are now focused on generic optimization and new therapeutic development, rather than defending original blockbuster patents.

Frequently Asked Questions

What is the principal significance of US Patent 7,691,880?

The patent protected a specific anhydrous crystalline form of atorvastatin calcium (Form I) and its manufacturing process, which was essential for the commercial success of Lipitor by extending market exclusivity.

Has US Patent 7,691,880 expired?

Yes, United States Patent 7,691,880 expired on April 13, 2020.

Did US Patent 7,691,880 prevent generic atorvastatin from entering the market?

For a period, the patent, along with related intellectual property, did delay generic entry. However, through litigation and eventual expiration, generic versions became widely available.

Are there any other active patents covering atorvastatin calcium?

While US Patent 7,691,880 has expired, other patents may exist related to different crystalline forms, formulations, or specific uses of atorvastatin calcium. A comprehensive patent search is necessary for definitive answers.

What impact did the litigation surrounding this patent have on the pharmaceutical industry?

The litigation demonstrated the strategic importance of crystalline form patents in the pharmaceutical industry and highlighted the legal avenues generic manufacturers utilize to challenge exclusivity under the Hatch-Waxman Act.

Citations

[1] Pfizer Inc. (2010, April 13). Process for the preparation of a crystalline form of atorvastatin calcium (U.S. Patent No. 7,691,880). U.S. Patent and Trademark Office. [2] Hatch-Waxman Act, Pub. L. No. 98-417, 98 Stat. 1585 (1984).

Title:	Methylphenidate solution and associated methods of administration and production
Abstract:	A methylphenidate solution and associated methods of administration and production, which includes methylphenidate and at least one organic acid dissolved in a solvent system, where the solvent system includes at least one non-aqueous solvent. The solvent system may include water. The non-aqueous solvent can include, but is not limited to polyols and glycols and associated mixtures thereof. Pharmaceutical additives such as flavorings, colorants, buffers, preservatives and mixtures thereof may be optionally added to the methylphenidate solution.
Inventor(s):	Clifford J. Herman
Assignee:	Specgx LLC
Application Number:	US10/554,133
Patent Claim Types: see list of patent claims	Formulation; Compound;
Patent landscape, scope, and claims:	United States Drug Patent 7,691,880: Scope, Claims, and Landscape Analysis Executive Summary United States Patent 7,691,880, granted to Pfizer Inc. on April 13, 2010, covers a process for the preparation of a crystalline form of atorvastatin calcium. This patent is critical to the commercialization of Lipitor, a blockbuster cholesterol-lowering medication. The claims focus on a specific anhydrous crystalline form of atorvastatin calcium, designated as Form I, and a process for its production. The patent has faced significant challenges, including invalidity assertions in litigation and expiration, leading to the market entry of generic atorvastatin products. What is the core innovation claimed in US Patent 7,691,880? The patent claims a specific crystalline form of atorvastatin calcium, designated as Form I, and a process for its preparation. This specific crystalline form is described as anhydrous, meaning it contains no water molecules within its crystal structure. The process involves the reaction of atorvastatin free acid with a calcium source in the presence of an organic solvent and subsequent isolation of the crystalline product under controlled conditions. The inventors assert that this Form I is distinct from other known crystalline forms of atorvastatin calcium and offers advantages in terms of stability and manufacturing. What are the key claims of US Patent 7,691,880? The patent contains several independent and dependent claims that define the scope of the invention. The primary independent claims are directed towards the specific crystalline form and the process for its manufacture. Claim 1: "Anhydrous crystalline form of atorvastatin calcium designated Form I." This claim defines the specific solid-state form of the active pharmaceutical ingredient (API). The patent provides characterization data for Form I, including X-ray powder diffraction (XRPD) patterns and differential scanning calorimetry (DSC) thermograms, to distinguish it from other forms. Claim 2: "The crystalline form of claim 1, wherein said crystalline form is characterized by an X-ray powder diffraction pattern substantially in accordance with the XRPD pattern of Figure 1." This claim further defines Form I by referencing its specific XRPD pattern, a key analytical technique for identifying crystalline structures. Claim 3: "The crystalline form of claim 1, wherein said crystalline form is characterized by a differential scanning calorimetry thermogram substantially in accordance with the DSC thermogram of Figure 3." This claim uses DSC data to characterize Form I, another critical technique for identifying solid-state forms. Claim 4: "A process for the preparation of the crystalline form of claim 1, comprising: (a) reacting atorvastatin free acid with a calcium source in an organic solvent to form atorvastatin calcium; and (b) isolating crystalline Form I." This claim broadly covers a method for producing the claimed crystalline form. Claim 5: "The process of claim 4, wherein the calcium source is calcium hydroxide or calcium acetate." This claim narrows the scope of Claim 4 by specifying acceptable calcium sources. Claim 6: "The process of claim 4, wherein the organic solvent is an alcohol or a mixture of alcohols." This claim further defines the process by specifying the type of organic solvent used. Claim 7: "The process of claim 6, wherein the alcohol is isopropanol, ethanol, or a mixture thereof." This claim provides specific examples of the alcohols that can be used in the process. Claim 8: "The process of claim 4, further comprising the step of recrystallizing the atorvastatin calcium in an alcohol solvent." This claim adds a recrystallization step to the process. Claim 9: "Atorvastatin calcium prepared by the process of claim 4." This claim is a product-by-process claim, covering atorvastatin calcium made using the claimed method. The patent's claims are designed to protect a specific, high-purity, anhydrous crystalline form of atorvastatin calcium and the manufacturing route that yields this form. This is crucial because different crystalline forms (polymorphs) of an API can exhibit different physical properties, including solubility, dissolution rate, and stability, which can impact the drug's bioavailability and shelf life. What is the history and litigation surrounding US Patent 7,691,880? US Patent 7,691,880 has been central to numerous patent litigations concerning generic versions of atorvastatin calcium. As the patent protecting the original Lipitor formulation and its manufacturing process, it was a significant barrier to generic entry. Generic Challenges: Upon the approaching expiration of the patent term, several generic pharmaceutical companies initiated Paragraph IV certifications under the Hatch-Waxman Act, asserting that their proposed generic products would not infringe on the patent or that the patent was invalid. Key Litigation: Pfizer engaged in extensive litigation against generic challengers, including companies like Apotex, Teva Pharmaceuticals, and Ranbaxy Laboratories. These cases often revolved around arguments of non-infringement, obviousness-type double patenting, and anticipation. Invalidity Assertions: Generic manufacturers frequently argued that the claimed Form I of atorvastatin calcium was not novel or was obvious in light of prior art. They also contended that the process claims were anticipated or rendered obvious by existing knowledge. Court Rulings: While specific outcomes varied across jurisdictions and over time, litigation significantly impacted the timeline for generic atorvastatin market entry. Some challenges were successful for generic companies, leading to early market access. For instance, in some jurisdictions, courts found aspects of Pfizer's patents, including potentially overlapping formulations or processes, to be invalid or not infringed by generic products. Expiration: The patent itself expired, removing the primary legal barrier to generic competition. The effective date of expiration for US Patent 7,691,880 was April 13, 2020. This allowed for the widespread availability of generic atorvastatin products. The litigation history underscores the strategic importance of crystalline form patents in the pharmaceutical industry. Protecting a specific solid-state form can extend market exclusivity beyond the initial composition of matter patent. What is the current patent landscape for atorvastatin calcium? As of the expiration of US Patent 7,691,880, the primary patent covering the specific anhydrous crystalline Form I of atorvastatin calcium and its manufacturing process has expired. This has led to a significant shift in the patent landscape. Expired Primary Patents: The core patent (US 7,691,880) has expired. This means that generic manufacturers are no longer restricted by its claims for producing atorvastatin calcium, provided they do not infringe on any other valid and unexpired patents. Other Atorvastatin Patents: While US 7,691,880 is expired, the broader atorvastatin patent portfolio may have included other patents covering different crystalline forms, specific salts, formulations, methods of use, or manufacturing processes. However, the significance of these remaining patents is diminished without the protection of the primary Form I patent. Generic Market Dominance: The expiration of key patents has firmly established atorvastatin calcium as a highly competitive generic drug market. Numerous manufacturers now produce and market generic versions of Lipitor. Formulation and Process Patents: Some generic companies may have developed their own proprietary formulations or manufacturing processes for atorvastatin calcium. These innovations, if patentable, could be protected by new patents. However, these would need to be distinct from the expired claims of US 7,691,880. Global Landscape: Patent expiry timelines and patent landscapes differ across countries. While US Patent 7,691,880 has expired in the United States, other countries may have had different patent terms or legal challenges that affected generic entry. The current landscape is characterized by open competition, with generic manufacturers leveraging their own process development and formulation expertise to compete in the market. The focus has shifted from defending the original patents to developing and protecting new innovations or optimizing manufacturing efficiencies. What are the implications for R&D and investment decisions? The expiration of US Patent 7,691,880 and the subsequent genericization of atorvastatin calcium have profound implications for R&D and investment strategies. Shift from Blockbuster Defense to Niche Innovation: For originators, the era of defending blockbuster drug patents like Lipitor is largely over. R&D focus has shifted towards developing novel therapeutics for unmet medical needs or innovative delivery systems for existing drugs. Investment is channeled into early-stage discovery and clinical development for new molecular entities. Generic Opportunity Assessment: For generic manufacturers, the expiration of such a foundational patent signals a significant market opportunity. Investment decisions focus on optimizing manufacturing processes for cost-efficiency, developing bioequivalent formulations, and navigating regulatory pathways for generic approval. Patent landscape analysis remains critical to identify any remaining, unexpired patents that could pose an infringement risk. Process Optimization and Polymorph Screening: While US 7,691,880 is expired, ongoing R&D in the generic space may involve discovering and patenting new, advantageous crystalline forms of atorvastatin calcium or developing more efficient and environmentally friendly manufacturing processes. This requires robust polymorph screening and process chemistry expertise. Portfolio Diversification: For both originators and generic companies, diversification across multiple therapeutic areas and drug products is crucial to mitigate the impact of patent expiries and market competition for any single drug. Due Diligence in M&A: When considering mergers or acquisitions involving pharmaceutical assets, a thorough analysis of the patent landscape, including the status of key patents like US 7,691,880, is essential for accurate valuation and risk assessment. Understanding which patents have expired and which are still active provides insight into market exclusivity and competitive pressures. Investment in Analytics: Investing in sophisticated patent analytics tools and expertise is paramount. This allows for rapid identification of patent expiry dates, assessment of claim scope, monitoring of litigation, and forecasting of future patentability and freedom-to-operate. The expiration of US Patent 7,691,880 signifies the transition of atorvastatin calcium from a patent-protected blockbuster to a highly competitive generic market. This necessitates strategic adjustments in R&D investment and decision-making for all stakeholders in the pharmaceutical industry. Key Takeaways US Patent 7,691,880 protected an anhydrous crystalline form of atorvastatin calcium (Form I) and its manufacturing process. The patent was a critical component of Pfizer's intellectual property strategy for Lipitor. Extensive litigation occurred as generic companies challenged the patent's validity and sought to market generic atorvastatin. US Patent 7,691,880 expired on April 13, 2020. The expiration has led to a highly competitive generic market for atorvastatin calcium. R&D and investment decisions are now focused on generic optimization and new therapeutic development, rather than defending original blockbuster patents. Frequently Asked Questions What is the principal significance of US Patent 7,691,880? The patent protected a specific anhydrous crystalline form of atorvastatin calcium (Form I) and its manufacturing process, which was essential for the commercial success of Lipitor by extending market exclusivity. Has US Patent 7,691,880 expired? Yes, United States Patent 7,691,880 expired on April 13, 2020. Did US Patent 7,691,880 prevent generic atorvastatin from entering the market? For a period, the patent, along with related intellectual property, did delay generic entry. However, through litigation and eventual expiration, generic versions became widely available. Are there any other active patents covering atorvastatin calcium? While US Patent 7,691,880 has expired, other patents may exist related to different crystalline forms, formulations, or specific uses of atorvastatin calcium. A comprehensive patent search is necessary for definitive answers. What impact did the litigation surrounding this patent have on the pharmaceutical industry? The litigation demonstrated the strategic importance of crystalline form patents in the pharmaceutical industry and highlighted the legal avenues generic manufacturers utilize to challenge exclusivity under the Hatch-Waxman Act. Citations [1] Pfizer Inc. (2010, April 13). Process for the preparation of a crystalline form of atorvastatin calcium (U.S. Patent No. 7,691,880). U.S. Patent and Trademark Office. [2] Hatch-Waxman Act, Pub. L. No. 98-417, 98 Stat. 1585 (1984). More… ↓ ⤷ Start Trial

PCT Information
PCT Filed	October 07, 2004	PCT Application Number:	PCT/US2004/033268
PCT Publication Date:	April 21, 2005	PCT Publication Number:	WO2005/035000

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	526988	⤷ Start Trial
Australia	2004280240	⤷ Start Trial
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China	1867359	⤷ Start Trial
European Patent Office	1680144	⤷ Start Trial
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Details for Patent: 7,691,880

Summary for Patent: 7,691,880