Drug – bio-affecting and body treating compositions – Designated organic active ingredient containing – Radical -xh acid – or anhydride – acid halide or salt thereof...
Reexamination Certificate
2001-06-26
2003-03-11
Jones, Dwayne C. (Department: 1614)
Drug, bio-affecting and body treating compositions
Designated organic active ingredient containing
Radical -xh acid, or anhydride, acid halide or salt thereof...
C424S489000
Reexamination Certificate
active
06531508
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to pharmaceutical antibacterial compositions containing a penem antibiotic as an active ingredient, which are stable and show good gastrointestinal absorption.
PRIOR ART
Penem compounds are non-natural &bgr;-lactam compounds the design of which is based on the concept of fusing the structures of penicillin and cephalosporin (for example, see Woodward, R. B., In Recent Advances in the Chemistry of &bgr;-Lactam Antibiotics, Elks, J., Ed., The Chemical Society, London, 1977, Spec. No. 28, pp. 167-180; Japanese Patent Public Disclosure(Kokai) Nos. 207387/86, 162694/88, 222486/85 and 119486/79). They are a novel type of antibiotic having both the wide antibacterial spectrum and high safety of penicillin and cephem antibiotics belonging to &bgr;-lactam antibiotics, as well as the potent antibacterial activity and high &bgr;-lactamase stability of carbapenem antibiotics. Sodium (+)-(5R,6S)-6-[(R)-1-hydroxyethyl]-7-oxo-3-[(R)-2-tetrahydrofuryl]-4-thia-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate 5/2 hydrate (faropenem sodium, hereinafter referred to as compound 1) is currently used as an oral drug for various infectious diseases and is reported to show potent antibacterial activity against not only methicillin-sensitive
Staphylococcus aureus
(MSSA),
Streptococcus pyrogenes
and
Streptococcus pneumoniae
but also gram-positive bacteria for which conventional &bgr;-lactam drugs have proved ineffective such as penicillin-resistant pneumococci (PRSP), oral staphylococci and enterococci, also showing a wide antibacterial spectrum covering gram-negative bacteria such as
Haemophilus influenzae
and anaerobic bacteria such as the genus Bacteroides, which activity is due to its novel skeleton penem ring ((Kagaku Ryoho no Ryoiki The Field of Chemotherapy), Vol. 13, No. 10, pp. 74-80, 1997). This compound is also reported to have potent antibacterial activity against pathogenic bacteria of periodontis such as
Porphyromonas gingivalis
(CHEMOTHERAPY, Vol. 42, S-1, pp. 38-50, 1994) as well as potent antibacterial activity against bacterial strains from dental infectious diseases which have recently become more and more resistant (Journal of Japan Chemotherapy Society, Vol. 45, No. 11, pp. 965-971, 1997).
However, penem compounds are chemically unstable materials susceptible to hydrolysis, oxidation, photoisomerization and the like, in much the same way as other &bgr;-lactam compounds.
Moreover, water-soluble &bgr;-lactam compounds are known to show poor gastrointestinal absorption as compared with fat-soluble compounds (Akinobu Otsuka et al., Pharmaceutics, Revised 2nd Edition., Nankodo). Such drugs tend not to produce a reliable therapeutic effect, and, antibacterial compounds such as penem compounds also have a tendency to affect the flora of enteric bacteria thereby inducing loose stools or diarrhea.
Thus, the application range, administration route and dosage form of penem compounds have been limited due to their instability and poor gastrointestinal absorption.
Syrup is a dosage form which is easy to swallow even for seniors and children. It is a dosage form with excellent characteristics which masks a bitter or unpleasant taste of drugs with the sweetening effect and consistency of sugars and various flavoring agents, and improves palatability with suitable colorants giving a pleasant color and the like. Dry syrups to be dissolved or suspended before use have been studied in the case of active ingredients unstable in water. Dry syrups are dissolved or suspended before use in an aqueous liquid such as water, juice or milk as a solvent.
Several dry syrup formulations have been developed for antibiotics which are generally unstable in water. Examples include macrolide antibiotic formulations such as josamycin propionate (Josamy Dry Syrup® from Yamanouchi Pharmaceutical) or erythromycin ethylsuccinate (Erythrocin Dry Syrup® from Dainippon Pharmaceutical) and cephem antibiotic formulations such as cefpodoxime proxetil (Banan Dry Syrup® from Sankyo), all of which are used as suspensions in water added before use.
When dry syrups are used as suspensions in hospitals, for example, they are often combined with water and kept to stand before they are taken by inpatients. Also at home, dry syrups are mostly taken in divided portions after being dispersed or dissolved in water. In these cases, suspensions are allowed to stand and insoluble ingredients precipitate to affect homogeneity of active ingredients and therefore the dosage regimen is not faithfully followed.
From the viewpoint of palatability, patients' rejection of medication must be avoided, especially in the case of children having a disease. However, suspensions are not only disliked for their texture but are also responsible for oral or digestive discomfort due to the presence of insoluble ingredients, leading to children to reject second and subseqeuent doses. In seniors, insoluble ingredients may enter the gaps between false teeth to cause pain. This decreases patient compliance and therefore the dosage regimen is not faithfully followed.
It is known that &agr;,&ohgr;-diamineacetate compounds form complexes with a metal ion such as copper or iron, and thus inhibit decomposition reactions which are catalyzed by heavy metals, making them suitable for use as stabilizers against components susceptible to such reactions such as fats and the active ingredients of some drugs.
Among &agr;,&ohgr;-diamineacetate compounds, disodium ethylenediaminetetraacetate is thought to increase penetration into intercellular spaces by forming a complex with a calcium ion thereby retaining the structure of intracellular spaces of gastrointestinal mucosa (Ryuji Iga et al., Recent Advances in Biopharmacy, 1994, Yakujinippo).
As described above, there are demands for widely applying penem compounds having high safety and potent antibacterial activity as pharmaceutical antibacterial compositions, but the actual demands have not been sufficiently satisfied because any techniques for formulating them into various dosage forms such as oral formulations or solutions have not been developed. For children and seniors, safe and effective antibacterial compositions which ensure proper patient compliance and require only an easy-to-follow dosage regimen would be especially desirable.
SUMMARY OF THE INVENTION
As a result of careful studies of formulation techniques focusing on stability in aqueous solution and gastrointestinal absorption of penem compounds with a view to developing a technique for administering penem compounds as pharmaceutical antibacterial compositions, the present invention has been accomplished. Specifically, the inventors have found that penem compounds are stable in solvents comprising water and, more surprisingly, improved gastrointestinal absorption can be imparted to these compounds by incorporating an &agr;,&ohgr;-diamineacetate compound into the composition.
Accordingly, the present invention provides pharmaceutical antibacterial compositions containing a penem compound as an active ingredient which can be formulated into various dosage forms such as oral formulations and solutions, particularly syrups, especially dry syrups which allow highly water-soluble penem compounds to be administered to seniors and children as clear aqueous solutions with good compliance.
Compositions of the present invention are pharmaceutical antibacterial compositions containing a penem compound as an active ingredient, &agr;,&ohgr;-diamineacetate compound and optionally other additives.
DETAILED DESCRIPTION OF THE INVENTION
Penem compounds used in the present invention are not specifically limited so far as they have antibacterial activity and safety including the absence of immunogenicity and oral toxicity and are pharmaceutically acceptable. These may be free carboxylic acids or pharmaceutically acceptable salts thereof with alkali metals or alkali earth metals such as sodium, potassium, calcium or magnesium, or amino acids such as lysine, or ammonium, and may also be us
Nomura Masaaki
Sugita Osamu
Delacroix-Muirheid C.
Jones Dwayne C.
Nixon & Vanderhye P.C.
Suntory Limited
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