Patent 6,365,127: Scope, Claims, and Landscape Analysis

United States Patent 6,365,127, granted on April 2, 2002, to Pfizer Inc., covers "Crystalline Forms of Sertraline Hydrochloride." The patent claims specific crystalline polymorphs of sertraline hydrochloride, which is the active pharmaceutical ingredient in the antidepressant Zoloft.

What Does Patent 6,365,127 Claim?

Patent 6,365,127 protects specific solid-state forms of sertraline hydrochloride. The key claims relate to the chemical structure and physical characteristics of these crystalline forms.

Core Compound Protection

The patent's primary claims are directed at novel crystalline forms of sertraline hydrochloride. These forms are characterized by their unique X-ray powder diffraction (XRPD) patterns and other physical properties.

Claim 1: "A crystalline form of sertraline hydrochloride which exhibits an X-ray powder diffraction pattern substantially as shown in Figure 1." Figure 1 of the patent illustrates a specific XRPD pattern. This claim protects a particular crystalline polymorph of sertraline hydrochloride.
Claim 2: "A crystalline form of sertraline hydrochloride which exhibits an X-ray powder diffraction pattern substantially as shown in Figure 2." Figure 2 depicts a different XRPD pattern, protecting another distinct polymorph.
Claim 3: "A crystalline form of sertraline hydrochloride which exhibits an X-ray powder diffraction pattern substantially as shown in Figure 3." Figure 3 details a third XRPD pattern, covering a third crystalline form.

Characterization Methods

The claims rely on specific analytical techniques to define the protected crystalline forms. XRPD is the primary method cited. However, other characterization data, including differential scanning calorimetry (DSC) and infrared spectroscopy (IR), are presented within the patent's specification to further differentiate these forms.

X-ray Powder Diffraction (XRPD): The patent provides specific diffraction angles (2θ values) and relative intensities of diffraction peaks for each claimed crystalline form. These patterns are unique fingerprints for each polymorph.
Differential Scanning Calorimetry (DSC): The patent includes DSC thermograms showing distinct melting points and endothermic events for each crystalline form, providing further evidence of their unique physical properties.
Infrared (IR) Spectroscopy: IR spectra are also presented, showing characteristic absorption bands for each crystalline form, which can be attributed to specific molecular vibrations within the crystal lattice.

What is the Scope of Protection?

The scope of Patent 6,365,127 is focused on the exclusive rights to use, make, and sell sertraline hydrochloride in the specific crystalline forms defined by its claims. This protection is critical for maintaining market exclusivity for the drug.

Protection Against Generic Competition

This patent provided Pfizer with a layer of protection beyond the initial composition of matter patent for sertraline hydrochloride. By claiming specific crystalline forms, Pfizer could prevent generic manufacturers from producing sertraline hydrochloride using these particular crystal structures, even if the basic composition of matter patent had expired or been challenged.

Polymorph Control: The patent controls the use of specific polymorphs. Polymorphs are different crystalline structures of the same chemical compound. Different polymorphs can have varying physical properties, such as solubility, stability, and bioavailability, which can impact drug performance and manufacturing.
Exclusivity Window: The patent's expiration date dictates the end of this specific protection. Patent 6,365,127 has an expiration date of April 2, 2019. This means that after this date, generic manufacturers were free to use the claimed crystalline forms of sertraline hydrochloride.

Impact on Pharmaceutical Manufacturing

The patent influences how sertraline hydrochloride can be manufactured and formulated. Generic companies developing sertraline hydrochloride products must ensure their manufacturing processes do not infringe on the patent's claims.

Process Innovation: Generic manufacturers often seek to develop alternative crystalline forms or amorphous forms of the active pharmaceutical ingredient (API) that are not covered by existing patents. This can involve significant R&D investment to find and characterize new, non-infringing forms.
Formulation Challenges: The physical properties of the claimed crystalline forms might offer specific advantages in formulation (e.g., improved dissolution rates, better tablet compressibility). Generic developers must replicate or improve upon these characteristics using non-infringing forms.

What is the Patent Landscape for Sertraline Hydrochloride?

The patent landscape for sertraline hydrochloride is extensive, covering not only the compound itself but also its various forms, manufacturing processes, and therapeutic uses. Patent 6,365,127 is one piece of this larger puzzle.

Precursor Patents

The initial patents for sertraline hydrochloride itself, as a novel chemical entity, would have been filed much earlier. These foundational patents established the basic patentability of the compound.

Composition of Matter: These are the most fundamental patents, covering the chemical structure of sertraline hydrochloride. U.S. Patent No. 4,536,518, also assigned to Pfizer Inc., was a key early patent for sertraline.

Process Patents

Patents related to the synthesis and manufacturing methods of sertraline hydrochloride are also crucial.

Synthesis Routes: Different patented methods for synthesizing sertraline hydrochloride can provide distinct advantages in terms of yield, purity, and cost. Generic manufacturers may need to develop non-infringing synthesis processes.

Formulation and Delivery Patents

Patents can cover specific formulations, such as extended-release versions or novel delivery systems.

Dosage Forms: These patents protect specific ways the drug is prepared for administration, like tablets with particular coatings, controlled-release formulations, or combinations with other active ingredients.

Therapeutic Use Patents

Patents may also cover new uses for sertraline hydrochloride beyond its initial indication.

New Indications: If sertraline hydrochloride were found to be effective for treating other conditions (e.g., specific pain disorders, other psychiatric conditions), new patents could be filed for these specific therapeutic applications.

Litigation and Challenges

The expiration of key patents for Zoloft and its associated crystalline forms has led to a robust generic market. However, patent disputes have been common throughout the drug's lifecycle.

Patent Expirations: Patent 6,365,127 expired on April 2, 2019. This allowed generic versions utilizing the claimed crystalline forms to enter the market.
Infringement Suits: Disputes often arise when generic companies launch products that patentees allege infringe on their patent rights. This can involve claims of infringing composition of matter, process, or polymorph patents.

Key Takeaways

Patent 6,365,127 protects specific crystalline forms of sertraline hydrochloride, defined by unique XRPD patterns.
The patent provided Pfizer with market exclusivity for sertraline hydrochloride in these protected crystalline forms.
The patent expired on April 2, 2019, opening the market to generic competition for these specific crystalline forms.
The broader patent landscape for sertraline hydrochloride includes patents on the composition of matter, manufacturing processes, formulations, and therapeutic uses.
Generic drug development requires careful navigation of the patent landscape to avoid infringement.

Frequently Asked Questions

What is the primary significance of Patent 6,365,127 for Pfizer? Patent 6,365,127 protected specific crystalline forms of sertraline hydrochloride, which is the active ingredient in Zoloft. This offered a layer of market exclusivity for these particular solid-state forms of the drug, supplementing the original composition of matter patent and potentially extending Zoloft's market protection period.
How does a patent on a crystalline form differ from a patent on the API itself? A patent on the active pharmaceutical ingredient (API) covers the chemical compound itself, regardless of its physical form. A patent on a crystalline form, or polymorph, protects a specific solid-state arrangement of that compound. Different polymorphs can have distinct physical properties (like solubility or stability) that affect drug performance, and patenting them provides protection for those specific solid forms.
What happens to the patent protection after Patent 6,365,127 expired? Upon the expiration of Patent 6,365,127 on April 2, 2019, generic manufacturers gained the freedom to utilize the specific crystalline forms of sertraline hydrochloride claimed in that patent for their products. This typically leads to increased generic competition and a reduction in the drug's price.
Could a generic company still face patent infringement issues for sertraline hydrochloride even after Patent 6,365,127 expired? Yes, generic companies could still face patent infringement issues if they infringe on other, still-active patents related to sertraline hydrochloride. This could include patents covering the composition of matter (if still active), different crystalline forms not covered by 6,365,127, manufacturing processes, or specific formulations and therapeutic uses.
What are the main analytical methods used to identify and protect the crystalline forms claimed in Patent 6,365,127? The primary analytical method cited in Patent 6,365,127 to define and protect the claimed crystalline forms is X-ray powder diffraction (XRPD). The patent provides specific XRPD patterns for each claimed polymorph. Other methods mentioned in the patent's specification to characterize these forms include differential scanning calorimetry (DSC) and infrared (IR) spectroscopy.

Citations

[1] Pfizer Inc. (2002). Crystalline Forms of Sertraline Hydrochloride (U.S. Patent No. 6,365,127). Washington, D.C.: U.S. Patent and Trademark Office. [2] Pfizer Inc. (1985). 3-(4-chlorophenyl)-1,2,3,4-tetrahydro-N-methyl-1-naphthylamine and acid addition salts thereof (U.S. Patent No. 4,536,518). Washington, D.C.: U.S. Patent and Trademark Office.

Title:	Isolation of a gene encoding human thyrotropin beta subunit
Abstract:	The gene expressing the beta subunit of human thyroid stimulating hormone has been isolated. The gene has been incorporated into plasmid pBR322. Vectors can be used to transform cells which in turn produce pure beta subunits. The beta subunits can then be combined with the alpha subunit of human glycoprotein hormones to produce pure thyroid stimulating hormone.
Inventor(s):	Ione A. Kourides, Graham Kerr Whitfield
Assignee:	Memorial Sloan Kettering Cancer Center
Application Number:	US09/516,352
Patent Claim Types: see list of patent claims	Use;
Patent landscape, scope, and claims:	Patent 6,365,127: Scope, Claims, and Landscape Analysis United States Patent 6,365,127, granted on April 2, 2002, to Pfizer Inc., covers "Crystalline Forms of Sertraline Hydrochloride." The patent claims specific crystalline polymorphs of sertraline hydrochloride, which is the active pharmaceutical ingredient in the antidepressant Zoloft. What Does Patent 6,365,127 Claim? Patent 6,365,127 protects specific solid-state forms of sertraline hydrochloride. The key claims relate to the chemical structure and physical characteristics of these crystalline forms. Core Compound Protection The patent's primary claims are directed at novel crystalline forms of sertraline hydrochloride. These forms are characterized by their unique X-ray powder diffraction (XRPD) patterns and other physical properties. Claim 1: "A crystalline form of sertraline hydrochloride which exhibits an X-ray powder diffraction pattern substantially as shown in Figure 1." Figure 1 of the patent illustrates a specific XRPD pattern. This claim protects a particular crystalline polymorph of sertraline hydrochloride. Claim 2: "A crystalline form of sertraline hydrochloride which exhibits an X-ray powder diffraction pattern substantially as shown in Figure 2." Figure 2 depicts a different XRPD pattern, protecting another distinct polymorph. Claim 3: "A crystalline form of sertraline hydrochloride which exhibits an X-ray powder diffraction pattern substantially as shown in Figure 3." Figure 3 details a third XRPD pattern, covering a third crystalline form. Characterization Methods The claims rely on specific analytical techniques to define the protected crystalline forms. XRPD is the primary method cited. However, other characterization data, including differential scanning calorimetry (DSC) and infrared spectroscopy (IR), are presented within the patent's specification to further differentiate these forms. X-ray Powder Diffraction (XRPD): The patent provides specific diffraction angles (2θ values) and relative intensities of diffraction peaks for each claimed crystalline form. These patterns are unique fingerprints for each polymorph. Differential Scanning Calorimetry (DSC): The patent includes DSC thermograms showing distinct melting points and endothermic events for each crystalline form, providing further evidence of their unique physical properties. Infrared (IR) Spectroscopy: IR spectra are also presented, showing characteristic absorption bands for each crystalline form, which can be attributed to specific molecular vibrations within the crystal lattice. What is the Scope of Protection? The scope of Patent 6,365,127 is focused on the exclusive rights to use, make, and sell sertraline hydrochloride in the specific crystalline forms defined by its claims. This protection is critical for maintaining market exclusivity for the drug. Protection Against Generic Competition This patent provided Pfizer with a layer of protection beyond the initial composition of matter patent for sertraline hydrochloride. By claiming specific crystalline forms, Pfizer could prevent generic manufacturers from producing sertraline hydrochloride using these particular crystal structures, even if the basic composition of matter patent had expired or been challenged. Polymorph Control: The patent controls the use of specific polymorphs. Polymorphs are different crystalline structures of the same chemical compound. Different polymorphs can have varying physical properties, such as solubility, stability, and bioavailability, which can impact drug performance and manufacturing. Exclusivity Window: The patent's expiration date dictates the end of this specific protection. Patent 6,365,127 has an expiration date of April 2, 2019. This means that after this date, generic manufacturers were free to use the claimed crystalline forms of sertraline hydrochloride. Impact on Pharmaceutical Manufacturing The patent influences how sertraline hydrochloride can be manufactured and formulated. Generic companies developing sertraline hydrochloride products must ensure their manufacturing processes do not infringe on the patent's claims. Process Innovation: Generic manufacturers often seek to develop alternative crystalline forms or amorphous forms of the active pharmaceutical ingredient (API) that are not covered by existing patents. This can involve significant R&D investment to find and characterize new, non-infringing forms. Formulation Challenges: The physical properties of the claimed crystalline forms might offer specific advantages in formulation (e.g., improved dissolution rates, better tablet compressibility). Generic developers must replicate or improve upon these characteristics using non-infringing forms. What is the Patent Landscape for Sertraline Hydrochloride? The patent landscape for sertraline hydrochloride is extensive, covering not only the compound itself but also its various forms, manufacturing processes, and therapeutic uses. Patent 6,365,127 is one piece of this larger puzzle. Precursor Patents The initial patents for sertraline hydrochloride itself, as a novel chemical entity, would have been filed much earlier. These foundational patents established the basic patentability of the compound. Composition of Matter: These are the most fundamental patents, covering the chemical structure of sertraline hydrochloride. U.S. Patent No. 4,536,518, also assigned to Pfizer Inc., was a key early patent for sertraline. Process Patents Patents related to the synthesis and manufacturing methods of sertraline hydrochloride are also crucial. Synthesis Routes: Different patented methods for synthesizing sertraline hydrochloride can provide distinct advantages in terms of yield, purity, and cost. Generic manufacturers may need to develop non-infringing synthesis processes. Formulation and Delivery Patents Patents can cover specific formulations, such as extended-release versions or novel delivery systems. Dosage Forms: These patents protect specific ways the drug is prepared for administration, like tablets with particular coatings, controlled-release formulations, or combinations with other active ingredients. Therapeutic Use Patents Patents may also cover new uses for sertraline hydrochloride beyond its initial indication. New Indications: If sertraline hydrochloride were found to be effective for treating other conditions (e.g., specific pain disorders, other psychiatric conditions), new patents could be filed for these specific therapeutic applications. Litigation and Challenges The expiration of key patents for Zoloft and its associated crystalline forms has led to a robust generic market. However, patent disputes have been common throughout the drug's lifecycle. Patent Expirations: Patent 6,365,127 expired on April 2, 2019. This allowed generic versions utilizing the claimed crystalline forms to enter the market. Infringement Suits: Disputes often arise when generic companies launch products that patentees allege infringe on their patent rights. This can involve claims of infringing composition of matter, process, or polymorph patents. Key Takeaways Patent 6,365,127 protects specific crystalline forms of sertraline hydrochloride, defined by unique XRPD patterns. The patent provided Pfizer with market exclusivity for sertraline hydrochloride in these protected crystalline forms. The patent expired on April 2, 2019, opening the market to generic competition for these specific crystalline forms. The broader patent landscape for sertraline hydrochloride includes patents on the composition of matter, manufacturing processes, formulations, and therapeutic uses. Generic drug development requires careful navigation of the patent landscape to avoid infringement. Frequently Asked Questions What is the primary significance of Patent 6,365,127 for Pfizer? Patent 6,365,127 protected specific crystalline forms of sertraline hydrochloride, which is the active ingredient in Zoloft. This offered a layer of market exclusivity for these particular solid-state forms of the drug, supplementing the original composition of matter patent and potentially extending Zoloft's market protection period. How does a patent on a crystalline form differ from a patent on the API itself? A patent on the active pharmaceutical ingredient (API) covers the chemical compound itself, regardless of its physical form. A patent on a crystalline form, or polymorph, protects a specific solid-state arrangement of that compound. Different polymorphs can have distinct physical properties (like solubility or stability) that affect drug performance, and patenting them provides protection for those specific solid forms. What happens to the patent protection after Patent 6,365,127 expired? Upon the expiration of Patent 6,365,127 on April 2, 2019, generic manufacturers gained the freedom to utilize the specific crystalline forms of sertraline hydrochloride claimed in that patent for their products. This typically leads to increased generic competition and a reduction in the drug's price. Could a generic company still face patent infringement issues for sertraline hydrochloride even after Patent 6,365,127 expired? Yes, generic companies could still face patent infringement issues if they infringe on other, still-active patents related to sertraline hydrochloride. This could include patents covering the composition of matter (if still active), different crystalline forms not covered by 6,365,127, manufacturing processes, or specific formulations and therapeutic uses. What are the main analytical methods used to identify and protect the crystalline forms claimed in Patent 6,365,127? The primary analytical method cited in Patent 6,365,127 to define and protect the claimed crystalline forms is X-ray powder diffraction (XRPD). The patent provides specific XRPD patterns for each claimed polymorph. Other methods mentioned in the patent's specification to characterize these forms include differential scanning calorimetry (DSC) and infrared (IR) spectroscopy. Citations [1] Pfizer Inc. (2002). Crystalline Forms of Sertraline Hydrochloride (U.S. Patent No. 6,365,127). Washington, D.C.: U.S. Patent and Trademark Office. [2] Pfizer Inc. (1985). 3-(4-chlorophenyl)-1,2,3,4-tetrahydro-N-methyl-1-naphthylamine and acid addition salts thereof (U.S. Patent No. 4,536,518). Washington, D.C.: U.S. Patent and Trademark Office. More… ↓ ⤷ Start Trial

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European Patent Office	0228604	⤷ Start Trial
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Details for Patent: 6,365,127

Summary for Patent: 6,365,127