Compositions and methods for delivery of caffeine
United States Patent: 7,560,465
Issued: July 14, 2009
Richard (River Falls, WI)
Appl. No.: 11/094,016
Filed: March 31, 2005
Pharm Bus Intell
& Healthcare Studies
Methods for delivery of caffeine,
compositions including caffeine, and methods of making such compositions
are disclosed. Generally, the method of delivering caffeine includes
topically administering to a mucosal skin surface of a subject a dose of
caffeine effective to increase alertness in the subject. The compositions
generally include a lip balm base and caffeine. The methods of making the
compositions generally include melting a lip balm base, dissolving
caffeine in a solvent, adding the dissolved caffeine to the molten lip
balm base, and allowing the lip balm base/caffeine mixture to cool.
Description of the
Caffeine is a mild stimulant that may be found in the leaves, fruits,
and/or seeds of many plants such as, for example, Thea species, Camellia
species, Theobroma cacao, Coffee arabica, and Cola species. The most
common sources of caffeine include coffee (e.g., seeds of Coffee arabica),
tea (e.g., leaves of Thea sinensis, Camellia sinensis, etc.), cola soft
drinks (e.g., extracts of the nuts of Cola acuminata, Cola nitida, etc.),
chocolate (e.g., the seeds of Theobroma cacao), and over-the-counter
Caffeine is recognized as having many physiological and/or pharmacological
effects: it may, for example, stimulate the central nervous system,
promote analgesia, temporarily increase metabolic function, relax smooth
muscle, and/or act as a diuretic. Caffeine is a xanthine compound and,
therefore, has been included in certain topical cosmetic products as an
anti-cellulite agent. However, the efficacy of caffeine, whether ingested
or applied topically, for managing cellulite is not confirmed.
The ability of caffeine to stimulate the central nervous system is one
reason for the popularity of caffeine-containing beverages (e.g., coffee,
tea, and/or caffeinated soft drinks). There are many reasons that people
turn to caffeinated beverages and/or caffeine-containing stimulants
products as to promote alertness. Recuperation from certain illnesses may
leave one drowsy. Many jobs require a high level of alertness and/or
overnight working hours in which drowsiness on the job may be dangerous to
the worker and/or others (e.g., police officer, security guard,
over-the-road truck driver, etc.). The demands of a school- or job-related
deadline may force one to remain alert working or studying into the night.
The use of caffeine to increase alertness typically involves ingesting a
"dose" of caffeine so that it is absorbed into the bloodstream through the
lining of the digestive tract.
A six-ounce cup of coffee can contain from about 40 milligrams (mg) to
more than 150 mg of caffeine. A generally accepted "average" caffeine
content for a cup of coffee is 100 mg, although many coffee-based drinks
typically contain many times that amount. For example, espresso may
contain 100 mg of caffeine per fluid ounce. Also, many popular coffee
drinks are sold in sizes much larger than the generally accepted "average"
six fluid ounce serving.
Certain soft drinks and energy drinks can contain from about 35 mg to
about 80 mg of caffeine per serving and, like the coffee-based beverages
just described, are often sold in sizes larger than a single serving.
Chocolate can contain up to about 15 mg of caffeine per ounce. Certain
over-the-counter stimulants contain 100 mg to 200 mg of caffeine.
Despite their popularity, ingestible forms of caffeine such as certain
foods, caffeinated beverages, and ingestible over-the-counter medications
may not be suitable for all instances in which one might desire to use
caffeine to stay alert. For example, a food (e.g., chocolate) may be an
undesirable vehicle for delivering caffeine because it may raise
nutritional concerns, be messy, or for reasons of personal taste. As
another example, caffeinated beverages and over-the-counter medications
can require the co-ingestion of fluids, sometimes in large volume. When
combined with the diuretic effect of caffeine, this can result in diuresis
or an undesirable frequency of urination, particularly if one desires to
remain alert in either an environment in which adequate facilities are
unavailable or circumstances in which urination would be inconvenient.
Consequently, a need exists for alternative methods of delivering caffeine
that do not require co-ingestion of liquids and/or are convenient, neat,
It has been found that application of a caffeine-containing formulation
(e.g., a caffeinated lip balm) to a mucous membrane surface (e.g., lip
skin) can deliver a dose of caffeine adequate to improve attentiveness.
Consequently, in one embodiment, the present invention provides a lip balm
that includes a lip balm base and caffeine. In certain embodiments, the
lip balm can include from at least about 80 micrograms (.mu.g) to at least
about 400 milligrams of caffeine per gram (g) of lip balm base. In certain
embodiments, the lip balm may further include at least one additive.
In another aspect, the present invention provides a method of making a lip
balm. Generally, the method includes melting a lip balm base, dissolving a
quantity of caffeine in a solvent, adding the dissolved caffeine to the
molten lip balm base, and allowing the lip balm base/caffeine mixture to
cool. In some embodiments, the quantity of caffeine may range from at
least about 80 mg per kilogram (kg) of lip balm base to at least about 400
g per kg of lip balm base. In certain embodiments, the method may further
include adding at least one additive to the molten lip balm base.
In yet another aspect, the invention provides a method of systemically
delivering a dose of caffeine to a subject. Generally, the method includes
topically administering to a mucosal membrane of the subject a dose of
caffeine effective to increase alertness in the subject. In some
embodiments, the mucosal membrane may include an oral lip. In certain
embodiments, the dose of caffeine may be formulated in a lip balm.
Various other features and advantages of the present invention should
become readily apparent with reference to the following detailed
description, examples, and claims. In several places throughout the
specification, guidance is provided through lists of examples. In each
instance, the recited list serves only as a representative group and
should not be interpreted as an exclusive list. Also, recitation of a
numerical range by endpoints includes all numbers subsumed within that
range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS OF THE INVENTION
The present invention provides a caffeinated formulation capable of being
topically administered to a mucous membrane surface of the body. For
example, one embodiment of the invention is a caffeinated lip balm that
may be applied to the mucous membrane surface of lip skin. Thus, one can
combine the standard benefits of a lip balm--protecting the lips from
heat, cold, sun, wind, etc.--with providing a dose of caffeine sufficient
to improve alertness. This may be particularly desirable for those who
desire a temporary aid to remain alert but prefer to refrain from
ingesting typical ingestible sources of caffeine. One may prefer to avoid
such sources of caffeine, for reasons such as, for example, convenience,
personal taste, and/or to avoid co-ingestion of liquid.
Some typical dietary sources of caffeine may be inconvenient and/or
potentially messy to carry in some circumstances. Chocolate, for example,
may melt easily. In contrast, typical lip balms require exposure to much
higher temperatures than chocolate before they begin to melt. Caffeinated
beverages may be susceptible to spilling and/or are stored in containers
that may be inconvenient to carry while participating in certain
activities. In contrast, lip balm may be packaged in a tube, pot, or
covered tin that substantially prevents spilling. Moreover, typical lip
balm tubes, pots, or tins are small and may be conveniently carried in
even a small pocket.
Caffeine is a diuretic--it induces urination. Thus, co-ingestion of
liquids (e.g., a caffeinated beverage or liquid to assist swallowing a
caffeine-containing over-the-counter stimulant) in order to obtain an
alertness-promoting dose of caffeine can exacerbate the diuretic effect of
caffeine, causing one to experience a frequent and/or strong urge to
urinate. In circumstances in which one desires to remain alert but in
which urination is inconvenient or impossible (e.g., because adequate
facilities are unavailable, one cannot be excused to use available
facilities, and/or social or legal restrictions), it may be desirable to
be able to obtain an alertness-promoting dose of caffeine without
Consequently, in one aspect, the present invention provides a lip balm
that contains, generally, a lip balm base and caffeine. The amount of
caffeine contained in the lip balm should be at least enough to provide a
dose of caffeine effective to promote alertness when the lip balm is
topically applied to the mucous membrane surface of lip skin. Such a dose
may be, for example, the equivalent of a dose of caffeine that may be
obtained by ingesting one of the various dietary or medicinal sources of
caffeine described above. The caffeine content of such sources may range
from about 1 mg (e.g., the caffeine content of a one ounce serving of some
milk chocolates) to more than 100 mg (e.g., the caffeine content of some
coffee drinks and some over-the-counter stimulant products). Thus, the
total amount of caffeine contained within the lip balm may be
approximately the intended dose per use (e.g., from about 1 mg to about
100 mg per dose) times the expected number of doses contained in the
container of lip balm. Because the volume of lip balm may vary depending
upon the size of the container in which the lip balm is stored, it is
impractical to set forth the amount of caffeine that can be included in
the lip balm for all potential applications. One of skill in the art,
however, can readily formulate a lip balm capable of delivering a desired
dose of caffeine per use.
In some embodiments, the amount of caffeine necessary to promote alertness
may be less than the amount in one of the dietary sources described above.
For example, a standard lip balm tube that includes 4.3 g of lip balm
containing 1.4 mg of caffeine per gram of lip balm base (i.e., a total of
about 6 mg caffeine per tube) can provide enough lip balm for more than
one hundred applications--i.e., more than 100 doses of caffeine in an
amount sufficient to promote alertness. Thus, a lip balm according to one
embodiment of the invention may provide microgram quantity doses of
caffeine that are effective to increase alertness.
Accordingly, in some embodiments, the lip balm may include caffeine in a
concentration from at least 80 .mu.g per gram of lip balm base to about
400 mg per gram of lip balm base, although in certain embodiments, the lip
balm may include a concentration of caffeine outside of this range. In
some embodiments, the lip balm may include at least about 1.4 mg of
caffeine per gram of lip balm base. In other embodiments, the lip balm may
include at least about 22 mg of caffeine per gram of lip balm base. In
other embodiments, the lip balm may include at least about 44 mg of
caffeine per gram of lip balm base. In still other embodiments, the lip
balm may include at least about 400 mg of caffeine per gram of lip balm
The lip balm base may be any suitable lip balm base. A suitable lip balm
base can be solid at room temperature (e.g., approximately 23.degree. C.),
but have a reasonably low melting point so that it can be easily melted
Many lip balm bases are known in the art. For example, some lip balm bases
contain, generally, approximately 40% cosmetic grade oil that is liquid at
room temperature (unless otherwise indicated, all percentages herein are
weight/weight percentages), approximately 25% cosmetic grade oil that is
solid at room temperature, approximately 20% cosmetic grade beeswax, and
approximately 15% cosmetic grade oil that is brittle at room temperature.
Cosmetic grade oils that are liquid at room temperature include, for
example, sweet almond oil, apricot kernel oil, avocado oil, grapeseed oil,
hemp seed oil, macadamia oil, olive oil, and sunflower oil.
Cosmetic grade oils that are solid at room temperature include, for
example, coconut oil, lanolin, palm oil, mango butter, and shea butter.
Cosmetic grade oils that are brittle at room temperature include, for
example, cocoa butter and palm kernel oil.
In this general formulation, increasing the percentage of beeswax can
increase the hardness of a lip balm base. Conversely increasing the
percentage of oil that is liquid at room temperature can soften the lip
Alternatively, the lip balm base may include, for example, aloe
barbadensis leaf extract, alumina, arachidyl propionate, butylated
hydroxytoluene (BHT, a preservative), cetyl alcohol, colloidal silicon
dioxide, carnauba wax, isopropyl lanolate, isopropyl myristate, lanolin,
methylparaben, mineral oil, octyldodecanol, oleyl alcohol, paraffin,
phenyl trimethicone, polyhydroxystearic acid, propylparaben, saccharin,
silica, titanium dioxide, vitamin E acetate, and white wax.
As another example, the lip balm base may contain, for example, petroleum,
lanolin, cocoa butter, and a mixture of waxes.
As another example, the lip balm base may contain beeswax, camphor, cetyl
alcohol, cetyl palmitate, candelilla wax, lanolin, lanolin oil,
methylparaben, mineral oil, ozokerite, paraffin, petrolatum, cocoa butter,
polybutene, and propylparaben.
As another example, the lip balm base may include coconut oil, beeswax,
sweet almond oil, peppermint oil, vitamin E, lanolin, comfrey root
extract, and rosemary extract.
As another example, the lip balm base may include beeswax, coconut oil,
sunflower oil, vitamin E, lanolin, peppermint oil, comfrey root extract,
As another example, some lip balm bases can contain approximately 10%
petrolatum, approximately 10% glycerol, approximately 3.4% silicone
elastomer, approximately 64.3% cyclomethicone, approximately dimethicone
copolyol, approximately 0.3% preservative, and approximately 7% ozokerite
As yet another example, the lip balm base may be a commercially available
lip balm base. Commercially available lip balm bases are available from
numerous sources and the particular ingredients may vary considerably. For
example, one commercially available lip balm base (The Chemistry Store,
Pompano Beach, Fla.) lip balm base contain hydrogenated soybean oil, cocoa
butter, shea butter, apricot kernel oil, sweet almond oil, vitamin E, and
butylated hydroxytolune (BHT, a preservative).
Another commercially available lip balm base (Soap Crafters Co., Salt Lake
City, Utah) contains avocado oil, beeswax, natural jojoba, and flavor. Yet
another commercially available lip balm base (Rachel's Craft Supply,
Gautier, Miss.) contains olive oil, carnauba wax, candelilla wax, and
In one particular embodiment, the lip balm base is a commercially
available lip balm base (Le Melange Home Fragrances, Wellington, Fla.) and
includes hexyldecyl laurate, lexydecanol, ozokerite wax, dipropylene
glycol dicaprylate-caprate, and isononanoate.
The lip balm may include one or more additives such as, for example, a
colorant, a flavorant, a preservative, a skin penetration enhancer, a
moisturizer, a vitamin, or a sweetener. As used herein, "a," "an," "the,"
"at least one," and "one or more" are used interchangeably. Thus, for
example, a lip balm comprising "a" flavorant can be interpreted to mean
that the lip balm includes at least one flavorant. Many suitable
flavorants, sweeteners, and cosmetic grade additives are commercially
Some suitable sweeteners include, for example, stevia, coconut oil, sugar,
saccharin, aspartame, sucralose, honey, and the like.
Generally, the lip balm may be prepared by heating the constituents of the
lip balm base until the lip balm base is melted, dissolving the desired
quantity of caffeine in a solvent, adding the dissolved caffeine to the
melted lip balm base, and then allowing the lip balm base to cool.
In some embodiments, the method may further include, for example, pouring
the molten lip balm base/caffeine mixture into a mold such as, for
example, a tin or a lip balm tube.
In some embodiments, the method may further include adding one or more
additives to the molten lip balm base. The additives may be added to the
molten lip balm base before, after, or at the same time as the dissolved
caffeine is added to the molten lip balm base.
The solvent used to dissolve the caffeine may be any suitable solvent or
any suitable mixture of solvents. Caffeine is soluble to some extent in,
for example, water, boiling water, alcohol, chloroform, pyrimidine,
petroleum ether, benzene, acetone, pyrrole, tetrahydrofuran. The solvent
may be selected on the basis of its suitability for use in a product that
is intended for use in a manner that contemplates that constituents of the
lip balm may be absorbed into the blood stream and/or ingested. In some
cases, the solvent may be selected on the basis of the amount of caffeine
that can be dissolved in a unit volume of the solvent. In other cases, a
solvent may be selected on a basis that includes considerations other than
merely the solubility of caffeine in the solvent. For example, one may
elect to use an alcohol (e.g., ethanol)--or a mixture of an alcohol and
another solvent (e.g., water)--because alcohols tend to evaporate easily,
thereby permitting more of the solvent to evaporate after the caffeine is
dissolved. In this way, the amount of solvent that remains in the lip balm
after the molten lip balm base has cooled may be limited, if desired.
The solvent may include one or more solubilizing agents to increase the
solubility of caffeine. For example, the solvent may include approximately
0.1% sodium benzoate.
In another aspect, the present invention provides a method of systemically
delivering a dose of caffeine to a subject. Generally, the method includes
topically administering to a mucous membrane surface of the subject a dose
of caffeine effective to increase alertness in the subject.
The mucous membrane surface may be any mucous membrane surface of the
subject to which a dose of a caffeine-containing formulation may be
topically applied such as, for example, a mucous membrane surface of the
lips and/or oral cavity. The mucous membrane surface of lip skin contains
non-keratinized skin (i.e., the stratum corneum of the epidermis is
extremely thin or completely absent). It also contains many capillaries
near its translucent surface, thus giving rise to the red color of the
so-called vermilion zone.
The caffeine may be provided in a formulation suitable for topical
administration. The caffeine may be formulated as, for example, a
solution, a suspension, an emulsion, or any form of mixture. The caffeine
may be delivered in formulation with any pharmaceutically acceptable
excipient, carrier, or vehicle. The formulation may be delivered in any
conventional dosage form including but not limited to a wax, a stick, a
cream, an ointment, an aerosol formulation, a non-aerosol spray, a gel, a
lotion, and the like.
Topical administration of the caffeine-containing formulation may be by
any suitable method including, for example, use of an applicator. A
suitable applicator may be any device capable of applying a layer of the
caffeine-containing formulation to a mucous membrane surface, including,
for example, a finger, a brush, a spatula, a cotton swab, or a wipe.
Alternatively, the caffeine-containing formulation may be applied directly
from a container (e.g., a standard lip balm tube), without using an
Caffeine is considered an anti-cellulite agent for certain topical
cosmetic products. However, topical application of such products involves
applying the product to a keratinized skin surface affected by cellulite
for a localized effect that is limited to the site of administration. As
noted above, the epidermis of keratinized skin contains a stratum corneum
that provides a barrier function that substantially limits molecules from
passing into and out of the skin. Thus, the stratum corneum can reduce and
even prevent absorption into the bloodstream of substances applied
topically to keratinized skin.
In contrast, the method of the present invention involves topical
administration of a caffeine-containing formulation to a mucous membrane
surface such as may be found, for example, the in lip skin. The skin of
the lip is different than typical (i.e., keratinized) skin: it lacks sweat
glands and hair follicles, and the stratum corneum is extremely thin or
completely absent. Therefore, caffeine topically applied to a mucous
membrane surface may more readily pass through the skin, enter the
bloodstream, and provide a systemic effect.
The following examples have been selected merely to further illustrate
features, advantages, and other details of the invention. It is to be
expressly understood, however, that while the examples serve this purpose,
the particular materials and amounts used as well as other conditions and
details are not to be construed in a matter that would unduly limit the
scope of this invention.
Lip balm base, sweetener, coloring, and flavoring were obtained from Le
Melange Home Fragrances, Wellington, Fla. Approximately 453 grams (g) of
lip balm base was heated over low heat until melted. Sweetener, flavoring,
and coloring were added according to the manufacturer's instructions, then
stirred until blended well.
630 mg of caffeine (Natural Food Supplements, Inc., Sherman Oaks, Calif.)
was dissolved in approximately 30 milliliters (mL) of boiling water. Once
dissolved, the caffeine was added to the molten lip balm base mixture,
then stirred until blended well.
The molten mixture was poured into empty lip balm tubes and allowed to
cool. Each tube contains approximately 4.3 g of lip balm that includes
approximately 6.3 mg of caffeine.
Lip balm base is melted and sweetener, flavoring, and coloring are added
as described in Example 1.
20 g of caffeine is dissolved in approximately 40 mL of boiling water.
Once dissolved, the caffeine is added to the molten lip balm base mixture.
The molten mixture is poured into empty lip balm tubes and allowed to
cool. Each tube contains approximately 4.5 g of lip balm that includes
approximately 200 mg of caffeine.
Claim 1 of 20 Claims
1. A lip balm comprising: a lip balm
base; and caffeine, wherein a majority of the caffeine is dissolved in
either the lip balm base or a solvent phase of an emulsion comprising the
lip balm base.
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