Note: Descriptions are shown in the official language in which they were submitted.
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5 P E C I F I C A T I O N
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Background of the Invention
Field of the Invention. This invention relates generally
to treatment of animal udders to prevent bacterial infection such as
mastitis.
_scri~tion ox the Prior Art
The concept of teat treatment to prevent mas~itis by appli-
cation of a physical barrier such as a film-forming polymer latex
is old in the art as evidenced by the ~ndrews, et al. patent 4,113,854.
The Andrews patent discloses a method for the prevention of mastitis
in milk-producing animals in which the teats of the animal are dipped
into a solution which is comprised of a film~forming polymer latex
and a water soluble polymer thickening agent in an aqueous medium.
In addition, the Andrews patent 4,113,854 in column 1, lines 43 to
63 describes t.he prior film-forming materials containing polyvinyl
acetate and polyvinyl chloride or vegetable oils which Andrews found
to either be ineffective or to produce irritation to the animal's
teat.
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Andrews states his solution should have a thioxotropic
value of 15 to 1200 dynes/cm2 and a practical upper viscosity limi-t
of 10 poise at a shear rate of 250/sec. Anclrews suggests natural or
synthetic water soluble polymers which include the modified polymers
which are derivatives of cellulose. Andrews points out that cellulose
is not water soluble without modification and states that typical
cellulose derivatives include methyl, hydroxyethyl and sodium carboxy-
methyl cellulose derivatives and combinations thereof. Andrews also
requires a polymer latex which has suitable film-forming characteris-
tics. The latexes include latexes of styrene butadiene, acrylicpolymers and acrylic copolymers. He states the preferred polymer
latexes include ethyl acrylate/methyl methacrylate copolymers, methyl
methacrylate/butyl acrylate copolymers and styrene butadiene copoly-
mers. An especially preferred material of Andrews is an ethyl
acrylate/methyl methacrylate copolymer.
In addition, Andrews suggests adding an antiseptic material
such as alcohol, chlorohexidine, iodine, 8-hydxoxy quinoline sulfate
or sodium hypocholrite to his mixture.
Andrews contends that when the teat is dipped in the mix-
ture, it forms a film around the animal's teat which provides a shieldagainst bacterial infections such as mastitis.
One of the problems with the prior art teat coating is that
although the Andrews patent describes such teat coating as water
soluble, in practice it has been difficult to completely remove the
film barriers on the teat with water which may result in plugging the
milk line filters. The sales literature of Andrews' assignee,
Minnesota Mining and Manufacturing Company, titled The Physical tarrier
Against Mastitis, alludes to -the problem of incomplete-removal by
stating "Teat shield will not dissolve in milk. Your filter will trap
any entering the milk line."
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While Andrews emphasizes the physical barrier aspect of a
film formed by the combination of polymer latex and a water soluble
thickening agent, he also suggests one could incorporate an antiseptic
into the material. One of the problems is to provide a workable com-
bination of film and antiseptic that do not react with each other.
We have discovered that the combination of chlorohexidine (typically
as the gluconate) and a water soluble cellulosic film-former,
typically hydroxmethyl cellulose, provides a film that provides long
lasting bacterial protection to an animal's teats.
One of the problems associated with prior art teat dips is
that during storage the tea dip solution may freeze and separate.
The prasent invention overcomes this problem by use of an alcohol
solution which does not freeze under normal barn storage temperatures,
e.g~, temperatures down to minus 18C or thereabouts, but below 0C.
The alcohol readily evaporates when placed on the cow's teat to permit
the film to rapidly form on the animal's teat.
Still other prior art is described in the Journal of
American Veterinary Medical Association article of Farnsworth, Wyman
and Hawkinson titled "Use of a Teat Sealer for Prevention of Intra-
~0 man~ary Infections in Lactating Cows". This article describes theuse of an acrylic latex film as a physical barrier which is removed
by rubbing.
The prior art also shows the use of nonfilm-forming teat
dips marketed under the trade name Tesan. The Tesan dip comprises a
liquid solution and bactericide of chlorhexidine which is claimed to
adhere to the animal's teats.
Another teat dip is described in the product bulletin of
Lonza Technical Service Laboratories. Lonza's product uses chlor-
hexidine gluconate in combination with other ingredients. The Lonza
product is also a nonfilm-forming coating.
Still other publications such as the Journal of Dairy
Science lists a number of germicides for use in teat dip preparation.
The present invention comprises an improvement to the prior
art teat dips by providing a film-forming liquid that is safe and
can be completely removed with water.
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Summary of the Invention
The prevent invention is directed to the discovery of a
teat dip composition containing a cellulosic film former (typically
hydroxypropyl cellulose) and an antiseptic such as chlorhexidine
typically as the gluconate) in a liquid vehicle including a volatile
alcohol. The composition provides a rapidly drying film barrier on
animal teats that can easily be removed with water. The composition
is resistant to freezing.
Description of the Preferred El~odiment
The solution of the present invention is characterized as
a liquid at room temperature in which one can immerse an animal teat
to provide a liquid coating that adheres to the animal's teat. As
the liquid vehicle of the coating evaporates, the coating congeals Jo
Eorm a clear film barrier located on the outside of the teat. In
order to kill bacteria and prevent mastitis spreading, it is preferred
to have an antiseptic material such as chlorhexidine in the film to
kill bacteria and prevent bacteria from entering the milk gland in the
teat. In the present invention one prepares a solution of a film-
forming cellulose derivative such as hydroxpropyl cellulose in a solu-
tion comprising a volatile alcohol. To provide added masti~is pro-
tection one adds an antiseptic material such as chlorhexidine glu- . `
conate to the solution. The alcohol in the solution provides for
rapid evaporation while the hydroxpropyl cellulose worms a physical
film barrier around the teat. When it is time to milk the animal,
the film on the teat can be thoroughly and completely removed with
water.
Examples of the preparation of the solution of the present
invention are as follows:
EXAMPLE I
Five parts by weight chlorhexidine gluconate were mixed with
15 parts by weight of hydroxpropyl cellulose and 80 parts by weight
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of isopropyl alcohol at room temperature (70F). The resulting mixture,
although liquid, exhibited thixotropy and had characteristics of a
light gel solution.
EXAMPLE II
Pive parts by weight of chlorhexidine gluconate were mixed
with 40 parts by weight of water. The watex and chlorhexidine glucon-
ate were mixed together at room temperature (70F). Next, 15 parts by
weight of hydroxpropyl cellulose were mixed with 40 parts by weight
of isopropyl alcohol at room temperature. rrhe resulting solutions
were then mixed together at room temperature.
An animal teat to be treated was dipped in the light gel
solution of the above examples. After removing the teat from the
solution there remained a liquid solution of approximately 2-4 mils
thickness on the teat. In a few seconds after removal of the teat
from the teat dip solution the alconol in the mixture evaporated leav-
ing a continuous film over the teat.
The solution, which was applied after milking, produced a
film coating that remained in the animal teat for approximately eight
hours. The film was then washed off by hosing down the teats with
water. The washing action completely removed the film with no ohserv-
able residual patches of film on the teat. After repeated testing, no
mastitis infection or mastitis spreading was observed in the test
animals.
It should be understood the alcohol provides a rapid evapor-
ation solvent that allow the liquid film to quickly form into a dur-
able coating as the alcohol evaporates. Another benefit of the alco-
hol is that it prevents the unused teat dip solution rom freezing
in the winter time. Such water as may be in the solution functions
to dilute the cellulose material into a light, pourable, gel form as
well as acting as a carrier to disperse the antiseptic material
throughout the mixture.
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The liquid vehicle in which the antiseptic material and
the water soluble cellulose derived film-former is employed preferably
includes from about 80% to bout 100~ by weight of volatile alcohol.
The liquid vehicle may include quantities of water ranging from very
small amounts up Jo about S0~ by weight of the liquid vehicle. When
a teat has been dipped in the teat dip composition, the volatile,
low-boiling alcohol constituent evaporates readily, leaving a film
on the teat. If significant quantities of water, for example, 50~
by weight of the liquid vehicle, are incoxporated in the liquid vehicle,
then the drying of the film appears to proceed in two stages. First,
the majority of the volatile alcohol moiety evaporates, leaving a
soft, tacky residual film on the teat. A secondary, somewhat more
lengthy drying of the coatiny renders the coaxing substantially dry
to the touch. If, on the other hand, the vehicle comprises primarily
a volatile alcohol such as isopropanol (at least about B0% by weiyht),
then, upon evaporation of the alcohol portion ox the liquid vehicle,
the coating itself becomes substantially dry to the touch even though
it may contain a substantial quantity of water. In one embodiment,
in which substantially the entire liquid vehicle is volatile alcohol,
evaporation of the vehicle from the coating occurs quickly--within
about five minutes--and the resulting coating is dry to the touch
and is soft and pliable. It is believed that the film former absorbs
some water from the air. Preferably, the liquid vehicle includes a
sufficient concentration of volatile alcohol so that when the alcohol
moiety evaporates, the film is rendered substantially dry to the
touch.
The composition of the invention generally takes the form
of a lightly viscous, pourable liquid. It is believed that some light
gel formation occurs due to the presence of the cellulosic film former.
Of interest, higher temperatures appear to increase rather than de-
crease the viscosity of the composition. Accordingly, when the
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composition is applied to warm teats, the composition tends to solidify
on the teats rather quickly. The viscosity of the teat dip can be
controlled through judicious selection of the type and quantity of
cellulosic film former, and also through the addition of various
thickening agents such as fumed silica (e.g., Cab~O-Sil~, a product
of Cabot Chemical Company).
Under most milking parlor conditions the preferred range
of the film-forming, water soluble cellulosic material, typically
hydroxyprop~l cellulose, in the solution varies from a minimum of
approximately 10% by weight to a maximum of approximately 20% by
weight depending on the thickness of the coating desired. If the
concentration of hydroxypropyl cellulose is very low, it produces a
thin film coating which may easily break or rupture or even be incom-
pletely applied to the animals' teat. On the other hand, if the
mixture is too thick, i.e., concentrations of hydroxypropyl cellulose
are greater than 20% by weight, it is difficult to apply the mixture
to the teat as one cannot obtain a uniform coating over the teat.
Thus, the range of hydroxypropyl cellulose has as its limit the prac-
tical range at which it can be applied to the animals' teat which may
~0 vary under various environmental conditions. However, it has been
found the preferred amount of hydroxypropyl cellulose for most appli-
cations ranges from a minimum of 10% by weight to a maximum of 20%
by weight. Under most milking parlor conditions a solution of approxi-
mately 15% by weight produces a film of sufficient durability to
last from milking to milking.
The amounts of the bactericide are such that they shoula be
effective over at least an eight hour period. While more or less
bactericide can be used, the preferred range of chlorhexidine as the
bactericide is a maximum of approximately 20% by weight. It should
be understood that other bactericides may be used at greater or lesser
Cab-O-Sil is a trade mark of Cabot Chemical Company
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concentrations; however, it has been found that chlorhexidine glu-
conate is ideally suited since it can be retained in the film to
provide long lasting antiseptic ac~ion~ If desired, the hydroxpropyl
cellulose can be used without the bactericide, but the mastitis pre-
vention that is afforded is then limited to the physical barrier Pffects
of the film.
While hydroxpropyl cellulose is the preferred material,
other cellulosic film formers such as ethyl cellulose or methyl cel-
lulose may also be used.
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