Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form
Reexamination Certificate
2000-05-24
2003-06-10
Page, Thurman K. (Department: 1625)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
C424S404000, C424S484000, C424S486000
Reexamination Certificate
active
06576246
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention in is the field of chewable articles intended primarily as chew toys for dogs or other domestic animals.
2. Description of the Background Art
Chewable animal articles such as artificial bones for dogs have been made of many materials and in many configurations and sizes. These have been made of compressed natural or food materials with a binding agent; some are made of synthetic polymers, as polymers mixed with protein (U.S. Pat. No. 4,681,758), nylon (U.S. Pat. No. 3,871,334) or polyurethane (U.S. Pat. Nos. 4,557,219 and 4,513,014).
Chewable articles are frequently constructed from degradable materials that possess at least a substantial component which degrades or otherwise diminishes substantially in structural integrity with usage and over time. The degradation, typically accelerated by the chewing action of the animals, is frequently accelerated by exposure to the moisture and/or digestive enzymes in saliva. The durability of such articles is therefore intrinsically limited.
If a chewable article is too soft, it is too easily ripped apart or shredded during use. On the other hand, if the article is too hard, it may tend to crack, shatter, or splinter. This tendency to splinter upon breakage or when otherwise structurally damaged is highly undesirable. Splintering leads to sharp edges that can cause injury and lead serious health problems for the animal, especially if sharp-edged material is swallowed. Moreover, small pieces breaking from the articles may also be swallowed and contribute to health problems.
Of the digestible type of mastication article, rawhide is the most popular type of mastication article (e.g., U.S. Pat. Nos. 5,114,704; 5,310,541; 5,476,069). Simulated rawhide mastication articles comprise oil seed protein, a polyol plasticizer, lecithin, and water, extruded into a ribbon (U.S. Pat. No. 4,419,372).
U.S. Pat. No. 5,407,661 discloses a digestible mastication article for a pet in which a starch, a cellulosic fibrous material (e.g., corncob fractions), a humectant, a proteinaceous binder and a tarter-control oral care additive. U.S. Pat. No. 5,419,283 discloses a molded mastication article comprising a starch material and a biodegradable ethylene copolymer. Other edible materials can be added as plasticizers or as lubricants. These materials are mixed in the presence of water for subsequent injection molding into desired shapes (e.g., a bone).
U.S. Pat. No. 5,477,815 discloses a molded dog mastication article comprising water absorbing nylon in which at least a surface layer has sugar incorporated therein. U.S. Pat. No. 5,485,809 discloses animal chewing toys that shave away when chewed without puncturing, cracking, splintering or shattering, while providing satisfaction to the chewing animal. The chewing action is said to produce a desirable roughening and bristling of the surface that scours and cleans the animal's teeth. Flavoring material is uniformly dispersed throughout the body of the toy rather than just on the surface. The article is made from an ethylene/methacrylic acid copolymer, ionically cross-linked ionomer resin. This document discloses a desirable range of hardness (on a “D” scale—from 65 to 99, preferred range from 75 to 85).
U.S. Pat. No. 4,364,925 ('925) discloses chew-resistant products made from feed particulates with supporting fibers incorporated into the food components prior to compacting. Chew resistance is controlled primarily by the amount of such fibers. A multilayer article comprises at least one layer of a higher chew-resistance than the other layer, controlled by the amount and type of structure-supporting fibers. For example, supporting fibers are incorporated in the base layer of dry dog food and then a second layer is prepared without such fibers to yield a multilayer article having an inner hard, chew-resistant layer and an relatively soft and crumbly exterior layer. Alternatively, an inner layer is prepared without supporting fibers and a second layer with fibers is superimposed, leading to a hard exterior layer and soft interior layer. By starting with a soft-core layer and alternating the type of layers, multiple alternating harder and softer layers are produced. Such materials can serve as chew-resistant products that are sufficiently hard to exercise a pet's teeth and jaws and to remove plaque and tartar.
Suitable structure-supporting fibers are said to be any fibers that perform the function of binding the food into a unitized chew-resistant product and are not harmful. Such fibers may or may not be digestible by the animal. Safely digestible fibers include collagen. Indigestible fibers include cellulosic fibers or mixtures of animal-based digestible fibers and such indigestible fibers. Suitable sources of digestible fibers are animal tissue—for example, skin, muscles, tendons, intestines, etc. The amount of animal hide material used as a source of collagen depends upon factors such as the type and amounts of fibers in the hide, the type of food in the product, whether swollen or unswollen collagen or hide binders or gels are employed, etc. As defined in this document, “collagen” includes other fibrous protein such as elastin, reticulin, etc. The bundles of fibers are said to be theoretically broken and realigned to form fiber interlocks. For maximum strength the cut fibers re-interlock in the final product so that relatively continuous fiber linkage bonds are maintained. Useful collagen fibers include those obtained from hides as well as those prepared by dissolving protein, precipitating the protein from solution and aligning the molecules to obtain a fibrous material. Protein fibers may also be derived from soy protein, egg white, wheat gluten, etc. The fibrous form of these proteins are spun into continuous aligned filaments to yield food forms which simulate the fiber of natural beef. The document cites Belgian Pat. 634,140, U.S. Pat. Nos. 3,071,477 and 3,197,310 and
Cereal Chem
43 (2) 195 (1966).
According to the '925 patent, the supporting fibers are present in amounts sufficient to render the products chew-resistant, self-contained and unit-integral and to enable them to remain in compacted, shaped and molded form. The percent by weight of the indigestible fibers, or the mixture of the indigestible and digestible fibers in a unilayer food article may comprise up to about 50% or more, about 0.5-40%, about 1-30%, of about 1-10%, but preferably from about 1-5%. The optimum amount depends on factors such as the thickness, length, etc., of the fibers and the desired chew-life.
It is noteworthy that the '925 patent does not discuss breakage or splintering of the articles and the dangers they pose, nor does it address the objectives of the present invention. Rather, the '925 patent is primarily directed to pressed animal matter with added fibers that are intended to enable the overall material to retain a structure. Further, the processing involved in the '925 patent is that of baking, in essence making cookies or biscuits (wherein the added fibers provide a cohesiveness to the overall structure). Thus, the '925 patent deals essentially with baking of compacted animal flesh or feed incorporated with structure-supporting fibers; in the preferred mode, the fibers mutually interlock so that a continuous fiber network spans the article. Regardless, the processing and nature of the materials involved ensure that the fibers are of a static and correlated nature, closer in function and, in fact, closer to being a second matrix which intertwines with the first matrix.
SUMMARY OF THE INVENTION
According to the invention, a chewable, biodegradable article for pets (as a pet toy) comprises:
(a) as a matrix, a natural polymer, a synthetic organic polymer or a mixture thereof,
(b) a natural or synthetic fibrous material that comprises fibers and that is bonded chemically or physically with the matrix material, and
(c) optionally, one or more microbe inhibiting agents that inhibit the growth of microbes in or on the a
Denesuk Matthew
Uhlmann Donald R.
McGarry Bair PC
Page Thurman K.
Seefar Technologies, Inc.
Sheikh Humera N.
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