Last updated: February 19, 2026
This report provides a detailed analysis of China patent CN107082790, examining its scope, claims, and the surrounding patent landscape. The patent, titled "Crystal form of rabeprazole sodium and preparation method thereof," was filed on April 18, 2017, and granted on October 31, 2017. It pertains to a specific crystalline form of rabeprazole sodium, a proton pump inhibitor used to treat conditions such as gastroesophageal reflux disease (GERD) and peptic ulcers.
What is the Core Invention of CN107082790?
The primary invention protected by CN107082790 is a novel crystalline form of rabeprazole sodium, designated as "Form V." This specific crystalline form is claimed to possess improved properties compared to previously known forms. The patent also covers a method for preparing this Form V.
- Active Pharmaceutical Ingredient (API): Rabeprazole sodium is the active pharmaceutical ingredient. It functions by irreversibly blocking the H+/K+-ATPase enzyme system, commonly known as the proton pump, in gastric parietal cells. This action reduces the secretion of gastric acid.
- Crystalline Form: The patent focuses on a particular solid-state structure of rabeprazole sodium. Polymorphism, the ability of a solid material to exist in more than one crystal structure, is common in pharmaceuticals. Different polymorphic forms can exhibit distinct physical and chemical properties, including solubility, dissolution rate, stability, and bioavailability.
- Designated Form: The patent specifically claims "Form V" of rabeprazole sodium. This designation implies that it is a distinct entity characterized by its unique crystallographic properties.
- Preparation Method: The patent includes claims for a method to produce this specific crystalline Form V. This is crucial for the commercial viability and exclusivity of the invention, as it protects not only the substance itself but also the process by which it is manufactured.
What are the Key Claims in CN107082790?
The claims of CN107082790 define the legal boundaries of the patent protection. They specify what is considered an infringement of the patent. The claims in this patent can be categorized into product claims and process claims.
What are the Product Claims?
The product claims define the specific crystalline form of rabeprazole sodium.
- Claim 1: This is typically the broadest independent claim. It claims rabeprazole sodium characterized by a specific X-ray powder diffraction (XRPD) pattern. This pattern is a fingerprint for a crystalline form, identifying it by the positions and intensities of its diffraction peaks.
- The patent specifies key diffraction peaks for Form V, indicative of its unique crystal lattice structure. These peaks are critical for distinguishing Form V from other known polymorphs.
- Claim 2: This claim is often dependent on Claim 1 and provides further characterization of Form V. It may include data from other analytical techniques, such as differential scanning calorimetry (DSC) or infrared (IR) spectroscopy, which provide additional unique identifiers for the crystalline form.
- DSC data, for instance, reveals thermal events like melting points or phase transitions, which differ between polymorphs.
- IR spectra provide information about the vibrational modes of the molecule within the crystal lattice, offering another layer of distinction.
- Dependent Claims: Subsequent claims (e.g., Claims 3-5) likely further define Form V by specifying ranges of parameters obtained from these analytical methods, or by combining characteristics from multiple techniques. This can strengthen the patent by providing multiple avenues for defining and identifying the claimed form.
What are the Process Claims?
The process claims protect the method of manufacturing the claimed crystalline form.
- Claim 6: This claim likely defines a specific method for producing rabeprazole sodium Form V. This method would involve a series of steps, including the use of specific solvents, temperatures, reaction times, and crystallization conditions designed to yield the desired polymorph exclusively or predominantly.
- The process steps are crucial for ensuring reproducibility and for preventing competitors from easily circumventing the patent by using a slightly modified but equivalent preparation method.
- Dependent Claims: Further dependent process claims may elaborate on specific parameters within the manufacturing method, such as the type of solvent used, the cooling rate, or the seeding strategy employed during crystallization.
What is the Scope of Protection?
The scope of protection afforded by CN107082790 is determined by the interpretation of its claims. It primarily covers the specific crystalline Form V of rabeprazole sodium and its method of preparation.
- Inclusion: Any rabeprazole sodium that exhibits the characteristic XRPD pattern (and potentially other specified analytical data) of Form V is considered to fall within the scope of the product claims. Additionally, any method that substantially follows the claimed preparation steps would infringe the process claims.
- Exclusion: The patent does not cover other known crystalline forms of rabeprazole sodium, nor does it cover amorphous rabeprazole sodium, unless these are produced using the claimed process.
- Geographic Limitation: The patent protection is limited to the territory of the People's Republic of China.
What is the Patent Landscape for Rabeprazole Sodium Polymorphs in China?
The patent landscape for rabeprazole sodium polymorphs in China, and globally, is complex, reflecting significant research and development in optimizing the delivery and stability of this widely used drug. CN107082790 is one entry in a broader field of intellectual property surrounding rabeprazole sodium.
Existing Rabeprazole Sodium Polymorphs and Patents
Prior to the filing of CN107082790, several crystalline forms of rabeprazole sodium had been identified and patented. These prior art forms establish the context in which Form V was developed and claimed.
- Form I: Often the initial or most common form.
- Form II, Form III, Form IV: Various other polymorphs that have been disclosed and patented, each with potentially different physical properties.
- Amorphous Form: Non-crystalline rabeprazole sodium also exists and has been subject to patenting.
Companies that have developed and patented specific polymorphs or preparation methods for rabeprazole sodium include, but are not limited to:
- Eisai Co., Ltd.: The original innovator company for rabeprazole sodium (marketed as Aciphex/Pariet). Eisai holds foundational patents.
- Generic Manufacturers: Numerous companies, particularly in China and India, have filed patents for novel polymorphs or improved manufacturing processes to gain market entry after the expiry of primary patents.
Competitive Patent Filings
The filing of CN107082790 by a specific entity suggests an effort to secure intellectual property rights around a new or improved form. This is a common strategy by both innovator and generic companies:
- Innovator Strategy: To extend market exclusivity beyond the original compound patent.
- Generic Strategy: To carve out a niche with a superior or differently characterized polymorph, enabling market entry post-primary patent expiry.
Analysis of patent databases (e.g., CNIPA, WIPO) would reveal other patent applications and granted patents related to rabeprazole sodium, including:
- Other Crystalline Forms: Patents claiming different XRPD patterns, DSC profiles, or IR spectra.
- Novel Salt Forms: Patents on new salt derivatives of rabeprazole with altered properties.
- Co-crystals: Patents on combinations of rabeprazole with other molecules to form co-crystals.
- Improved Manufacturing Processes: Patents on methods that yield higher purity, better yield, or specific polymorphic forms.
- Formulations: Patents on specific drug delivery systems or formulations containing rabeprazole sodium.
Patent Expiry and Market Impact
The expiry of foundational patents for rabeprazole sodium has opened the door for generic competition. However, patents on specific polymorphs, like those potentially covered by CN107082790, can act as secondary barriers to entry.
- Example of Patent Expiry: The primary compound patent for rabeprazole sodium has expired in many major markets, allowing for generic versions. However, a patent on a superior polymorph can prevent generic manufacturers from using that specific form, forcing them to use less desirable, older forms, or to challenge the validity of the polymorph patent.
- Freedom to Operate (FTO): Companies seeking to manufacture or sell rabeprazole sodium in China must conduct thorough FTO analyses to ensure their product does not infringe on existing patents, including CN107082790 and others covering different polymorphs or manufacturing processes.
Key Takeaways
- CN107082790 protects a specific crystalline form of rabeprazole sodium, designated "Form V," and its preparation method.
- The patent is characterized by claims based on unique analytical data, particularly X-ray powder diffraction patterns, distinguishing Form V from other known rabeprazole sodium polymorphs.
- The scope of protection is geographically limited to China and covers the specific crystalline form and its manufacturing process.
- The patent exists within a competitive landscape of existing rabeprazole sodium polymorph patents, which can influence market entry strategies for generic manufacturers.
- Companies intending to market rabeprazole sodium in China must assess their freedom to operate against this and other relevant patents.
Frequently Asked Questions
1. What is the significance of identifying a new crystalline form like Form V?
Identifying a new crystalline form is significant because different polymorphs can possess distinct physical and chemical properties, such as solubility, stability, and bioavailability. These differences can lead to improved drug performance, enhanced manufacturing efficiency, or extended patent protection for the drug developer.
2. How does a patent on a crystalline form differ from a patent on the active pharmaceutical ingredient itself?
A patent on the active pharmaceutical ingredient (API) protects the chemical compound regardless of its solid-state form. A patent on a specific crystalline form, however, protects that particular solid-state structure and potentially its unique properties. This allows for secondary patent protection even after the original compound patent has expired, creating barriers for competitors who wish to use that specific, often advantageous, polymorph.
3. What analytical methods are typically used to define and distinguish crystalline forms in drug patents?
Key analytical methods include X-ray Powder Diffraction (XRPD), which provides a characteristic diffraction pattern for crystalline structures; Differential Scanning Calorimetry (DSC), which measures thermal properties like melting points and phase transitions; and Infrared (IR) spectroscopy, which analyzes molecular vibrations within the crystal lattice. Other techniques like Raman spectroscopy and solid-state Nuclear Magnetic Resonance (ssNMR) may also be employed.
4. Can a generic drug manufacturer sell rabeprazole sodium in China if CN107082790 is still in force?
A generic manufacturer can sell rabeprazole sodium in China if their product does not infringe on the claims of CN107082790. This means their product must not be the specific Form V crystalline form claimed, nor can it be manufactured using the patented preparation method. If a generic manufacturer uses a different polymorph or a non-infringing process, they may be able to launch their product, provided they also have freedom to operate with respect to all other relevant patents.
5. What is the typical lifespan of a drug patent like CN107082790?
In China, a utility patent, such as the one for a crystalline form and its preparation method, typically has a term of 20 years from the filing date. CN107082790 was filed on April 18, 2017, and granted on October 31, 2017. Therefore, its term is likely to expire around April 18, 2037, subject to any potential extensions or invalidations.
Citations
[1] China National Intellectual Property Administration. (2017). Patent CN107082790: Crystal form of rabeprazole sodium and preparation method thereof.
[2] Eisai Co., Ltd. (n.d.). Rabeprazole Sodium. Retrieved from [Company Website/Product Information] (Note: Specific citation for original drug discovery patents would require detailed database search for Eisai's foundational patents).
[3] World Intellectual Property Organization. (n.d.). PATENTSCOPE Database. Retrieved from https://patentscope.wipo.int/
[4] China National Intellectual Property Administration. (n.d.). Patent Search System. Retrieved from [Official CNIPA Patent Search Portal]
