Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Tablets – lozenges – or pills
Reexamination Certificate
2000-07-31
2001-11-06
Reamer, James H. (Department: 1614)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Tablets, lozenges, or pills
Reexamination Certificate
active
06312723
ABSTRACT:
FIELD OF THE INVENTION
The invention generally relates to novel pharmaceutically active compounds, compositions comprising the same, pharmaceutical formulations of the same, methods of making the same, and methods of using the same.
BACKGROUND OF THE INVENTION
Various compounds used in inhibiting gastric acid secretion are known in the art and include a class of benzimidazole-substituted compounds, one of which is omeprazole. Omeprazole is currently commercially available in the formulation PRILOSEC®. In particular, U.S. Pat. No. 4,255,431 proposes such benzimidazole-substituted compounds generally described by the formula (III) in the '431 patent that allegedly encompasses omeprazole. Various methods of making these compounds are also proposed in the '431 patent.
European Patent No. 0 124 495 B1 proposes various salts of omeprazole, namely alkaline salts of the formula (I) in the '495 reference which includes lithium, sodium, Potassium, magnesium, and calcium salts, along with methods of making the salts. The methods of forming these salts may involve employing a hydroxide, alkoxide, or amine base, or cation exchange using a metal salt.
Erlandsson, P., et al.
J. Chromatography
, 532 (1990) pp. 305-319 propose separating the (−) and (+) enantiomers of omeprazole utilizing chromatographic techniques. In this publication, the separation is proposed to take place on a preparative scale using a cellulose-based chiral phase, e.g., trisphenyl-carbamoyl cellulose coated on 3-aminopropyl silica. It is appreciated that other schemes and processes are available for this separation.
PCT Publication No. WO 94/27988 proposes salts of the single enantiomers of omeprazole and methods of making the same. The process involves separating the two stereoisomers of a diastereomer mixture of an acyloxymethyl-substituted benzimidazole compound described by the formula (IV) set forth in this published application, followed by solvolysis of each separated diastereomer in an alkaline solution. Salts of the single enantiomers are formed and isolated by neutralizing aqueous solutions of the salts of the single enantiomers of omeprazole with a neutralizing agent.
PCT Publication No. WO 96/02535 proposes a process for the enantioselective synthesis of single enantiomers of omeprazole or its alkaline salts. The process employs an oxidizing agent and a chiral titanium complex which may include a titanium(IV) compound.
PCT Publication No. WO 98/54171 proposes the magnesium salt of the (−) enantiomer of omeprazole. The '171 publication also proposes a method of synthesizing the above magnesium salt as well as the potassium salt of (−) omeprazole that may be used as a suitable intermediate for preparing the magnesium salt. The potassium salt is taught to be useful in treating gastrointestinal diseases.
U.S. Pat. No. 5,386,032 to Brändström proposes an improved method for synthesizing omeprazole which involves reacting 5-methoxy-2-[(4-methoxy-3,5-dimethyl-2-pyridinyl)-methyl-thio]-1H benzimidazole with m-chloroperoxybenzoic acid in a methylene chloride solution.
The teachings regarding the methods of making omeprazole as referred to in these references, salts thereof, enantiomers thereof, and salts of the enantiomers, as well as formulations which may include these compounds, all rely on the chemical structure of omeprazole being accurately determined and the referenced compound or compounds being consistently prepared using the referenced techniques. More specifically, a methoxy group on the benzimidazole ring has been explicitly stated in the literature to be present at the 5-position, in omeprazole, a racemic mixture, and an optically pure isomer of omeprazole designated as esomeprazole or s-omeprazole. Applicants have now unexpectedly discovered that the complexity of omeprazole and the intricacies of the bioactivity of each of its previously undiscovered attributes has never been disclosed. More specifically, Applicants have confirmed that the methods of the prior art do not yield a single compound having the methoxy group in the 5-position on the benzimidazole ring as previously taught, nor do all of the methods of the prior art yield consistent results. In fact, omeprazole as conventionally referred to as a bulk drug substance (in its solid state) is confirmed to be present in the form of two pharmaceutically active compounds having the methoxy group on the benzimidazole ring at the 6- and 5-positions. Additionally, Applicants have discovered the presence of a second chiral location at the pyridine ring plane in each of the two compounds such that each compound has two positional isomers and four diastereomers. Therefore, the present invention provides these individual compounds, along with any salts, hydrates, solvates, combinations thereof, and polymorphs thereof, compositions of the above, and methods of making the same that are not taught or suggested by the prior art.
SUMMARY OF THE INVENTION
The present invention generally provides compounds represented by formula (Ia), co-crystallized compositions of compounds represented by formulae (Ia) and (Ib) (as well as the potential presence of amorphous compound, typically of compounds represented by formula (1b), the presence or amount of which can increase as the percent of such (1b) compounds increases), each described in detail herein, one or more pharmaceutically acceptable salts, solvates, hydrates, or combinations thereof, and complexes thereof. Diastereomers of the above are also provided. The invention also provides compositions and pharmaceutical formulations of the above. Methods of making the above are also provided by the present invention.
More specifically, the present discovery pertains to novel compounds, particularly a compound having a methoxy moiety at the 6-position on the benzimidazole ring, and compositions comprising compounds having methoxy groups at the 5- and 6-positions respectively. It is unexpected that these individual compounds are present in co-crystalline form which comprise a single composition. Ratios of the above isomers can be manipulated, and novel compounds encompassing a myriad of ratios of diastereomers of such compounds are also provided. Each of these is described in greater detail hereinafter.
The invention also provides methods of administering the above compounds represented by formula (Ia) and the compositions of compounds represented by formulae (Ia) and (Ib) described in detail herein, along with one or more optional pharmaceutically acceptable salts, solvates, hydrates, complexes, or combinations of these compounds, diastereomers thereof, compositions thereof, and pharmaceutically acceptable formulations of the above, to a mammal in need of treatment.
As used herein, the plural forms of the terms salts, solvates, hydrates, and the like, refer to both two singular and plural, e.g., a single salt, multiple salts, singular solvate, multiple solvates, singular hydrate, multiple hydrates, and the like, and combinations thereof, of the term.
These and other aspects of the invention are set forth in greater detail herein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention is described hereinbelow in greater detail with reference to its preferred embodiments. These embodiments, however, are set forth to illustrate the invention and are not to be construed as a limitation thereof, the invention being defined by the claims.
In one aspect, the invention relates to a compound represented by formula (Ia) as set forth below. Applicants have unexpectedly discovered that this compound, in solid state, has not been taught or suggested by the prior art. Additionally, it has been unexpectedly discovered that this newly-discovered compound has two distinct chiral locations in solid state: (1) a chiral center at the sulfoxide group and (2) a chiral plane located at the pyridinal moiety of such compound. More specifically, it has been furthered discovered that when R
4
is alkoxy, or other appropriate substituents, such group is locked into a fixed configuration
Fontana Steven A.
Jenkins Douglas John
Meyer Glenn Alan
Sancilio Frederick D.
Stowell Grayson Walker
Fontana, Esq. Steven A.
Myers Bigel Sibley & Sajovec P.A.
Reamer James H.
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