Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Matrices
Reexamination Certificate
2000-01-18
2004-01-20
Webman, Edward J. (Department: 1617)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Matrices
C424S486000, C424S465000, C424S470000, C424S409000, C424S400000, C510S193000
Reexamination Certificate
active
06680070
ABSTRACT:
TECHNICAL FIELD
This invention relates to new binders for particulate solids, and to the formation of new compacted products formed by use of such binders. In one of its embodiments this invention relates to novel 1,3-dihalo-5,5-dimethylhydantoin compositions which, by virtue of their physical forms and characteristics, are superlative biocidal water-treating agents and brominating agents.
GLOSSARY
As used herein the terms “halogen”, “halogenated”, and “halo” are with reference to bromine or chlorine, or both.
BACKGROUND
As is well known, a wide variety of different products in the form of powders or small particles are converted into larger end use forms such as prills, flakes, granules, pills, caplets, tablets, wafers, briquettes, pucks, and the like. In producing such products, it is common to utilize materials known as binders. Such materials, when mixed in suitable proportions with the powder or small particles to be compacted, facilitate the production of materials having desirable physical and mechanical properties. While some binders have relatively broad application to various powdery or small particle sized products, there are a number of instances where the binder can only be used for compaction of certain products and not for others. A principal reason for such limitation is chemical incompatibility as between the binder and certain powdery or small particle sized materials. A second reason for such limitation relates to the property of certain binders to modify the solubility characteristics of the powdery or finely-divided substrate material. For example, some binders are chosen not only for their ability to facilitate compaction, but to enable more rapid disintegration of the compacted form of the material, e.g., for more rapid uptake of a pharmaceutical by a consumer.
One type of material that tends to be difficult to produce in compacted forms such as tablets, granules, and briquettes is halogenated hydantoins, especially N,N′-dihalogenated dialkylhyantoin products such as 1,3-dichloro-5,5-dimethylhydantoin, N,N′-bromochloro-5,5-dimethylhydantoin, and 1,3-dibromo-5,5-dimethylhydantoin. Such materials are useful as biocides for treating water such as recreational water, cooling water, process water, and wastewater.
The N,N′-dihalogenated dialkylhydantoin products are usually formed as powdery solids. For use in many applications such as water treatment, the dry powders need to be converted into larger forms such as granules, tablets, or briquettes. This in turn has presented problems associated with providing densified or compacted products with sufficient strength to withstand the physical stresses encountered in packaging, conveying, handling, shipping, storage, and use. The nature of these problems have been described, for example, in U.S. Pat. Nos. 4,532,330; 4,560,766; 4,654,424; 4,677,130; 4,745,189; and 5,565,576. The approaches described in these patents for alleviating one or more such problems involve use of other materials. Thus in U.S. Pat. Nos. 4,532,330 and 4,621,096, halogenated dimethylhydantoins are mixed with calcium chloride and water, and the mixture is compacted by compression into the desired shape. In U.S. Pat. Nos. 4,560,766 and 4,654,424, halogenated ethylhydantoins are used instead of halogenated dimethylhydantoins and are compacted as such, or are melt blended with halogenated dimethylhydantoins. U.S. Pat. No. 4,677,130 describes forming dry blends of the halogenated dimethylhydantoin with particulate alkali metal or alkaline earth metal salt followed by compression to form a compacted product such as a tablet.
Manufacturers of halogenated hydantoins have sought to overcome these limitations by blending the materials with process additives designed to improve compaction characteristics. The presence of other halogenated hydantoins has also been indicated to provide benefits. For example, published PCT Application WO 97/43264 describes the use of 1,3-bromochloro-5-methyl-5-propylhydantoin as a binder in making compacted forms of halogenated hydantoins. The presence of hydantoins having at least one ethyl group in the 5-position is indicated to provide free flowing, dust-free powders which can be compressed into shapes without resorting to binders, as detailed in U.S. Pat. Nos. 4,427,692 and 4,560,766. In U.S. Pat. No. 4,677,130 a series of inorganic salt additives ranging from sodium carbonate to sodium metasilicate was indicated to improve the crush strength of halogenated hydantoin tablets. Inert binders such as fatty acid salts and a hectorite clay were advocated in U.S. Pat. No. 5,756,440, while the use of fatty acid amide binder additives were described in U.S. Pat. No. 5,565,576 and indicated to improve the compaction properties of halogenated hydantoins. U.S. Pat. No. 5,780,641 describes a chemical composition comprising a halogenated hydantoin mixed with dry calcium hydroxide for the purpose of facilitating processing and achieving a shape-retentive form.
Unfortunately, almost all prior efforts in the compaction of halogenated hydantoins have not provided binders having satisfactory compaction characteristics along with good chemical compatibility. Some of the classical binders (e.g., polyvinylpyrrolidinone, cellulose compounds, glues, gums, sugars, and starches) which are used to compact other products would react with halogenated hydantoins, in some cases vigorously. Moreover, a number of binder systems proposed for use with halogenated hydantoins do not provide compacted products having sufficient physical and mechanical stability. Low crush strength is often another deficiency of such compacted products.
In addition to having a binder suitable for use with a wide variety of materials, and capable of producing compacted products having desirable physical and mechanical properties, it would be of considerable advantage if such binder could be employed with materials suitable for human consumption.
It can be seen that a need exists for a new type of binder having widespread applicability to powdery and finely-divided substrate materials, especially halogenated hydantoins. It would be of particular advantage if such binders could provide compacted products having superior physical and mechanical properties. Moreover, it would be of inestimable value if the binder having these characteristics could itself be suitable for consumption by humans and animals.
This invention is deemed to fulfill most, if not all, of the foregoing needs.
SUMMARY OF THE INVENTION
Pursuant to this invention, a new type of binding agent for powdery or finely-divided materials has been discovered. These binders produce compacted compositions of great mechanical and physical strength. This highly beneficial result can be achieved with a wide variety of such materials inasmuch as these binders have good compatibility with a wide range of powdery or finely-divided materials. Moreover, the binders used pursuant to this invention are suitable for ingestion by humans and animals. Furthermore, these binders are strongly hydrophobic, and consequently can be used for modifying the dissolution or release rate of the compacted material in aqueous media. Also, because they are produced and used for other purposes, a number of the materials discovered to be binders pursuant to this invention are available in the marketplace at reasonable cost. Thus, the invention enables the production of compacted compositions such as granules, caplets, tablets, briquettes, pucks, and other shapes with very desirable properties on a highly cost-effective basis.
Thus, in one of its embodiments, this invention provides a shape-retentive compacted composition. The composition comprises a pressure compacted blend of a powdery or finely-divided active ingredient and a binder quantity of a micronized synthetic polyolefin-based hydrocarbon wax and/or a micronized synthetic polyfluorocarbon wax. The wax used pursuant to this invention is compatible with the active ingredient.
In particular, prior small particle sized product, when released from a tableting die, normally wo
Howarth Jonathan N.
Peters Bruce C.
Albemarle Corporation
Spielman, Jr. Edgar E.
Webman Edward J.
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