Note: Descriptions are shown in the official language in which they were submitted.
~ Docket No. 43-2~9 -1-
~'73~t7
.
ROLL-ON APPLICATION OF
AQUEOUS MICROENCAPSULATED PRODUCTS
_ _ .
TECHNICAL FIE D
The present invention relates to the dispensing of
; 5 materials from a container and, more particularly, to a novel
roll-on application of a water droplet in-air suspension and
system for dispensing such materials.
BACKGROUND OF THE PRIOR ART
Pressurized dispensing systems, commonly referred to
as aerosols, experienced first significant commercialization
in the early 1950s resulting in a proliferation of products.
Despite their high costs, aerosol products gained
immediate consumer acceptance. The single most important
factor behind this success story is the convenience ofered
15 by these pressurized products.
~ Recently, the aerosol market was thrown into a state
,~ of disarray as a result of the Rowland-Mollina ozone aepletion
theory which hypothesizes that a certain percenta~e of halo-
hydrocarbon propellants find their way to the stratosphere
causing a depletion of ozone in that stratum. With a deple-
tion of the ozone in the stratosphere, a greater amount of
ultraviolet radiation enters the atmosphere resulting in an
increased incidence of skin cancer.
Packaging alternatives to halohydrocarbon propelled
aerosols include: products propelled with liquefied hydro-
carbon propellants (LPG) such as butane, isobutane and pro-
pane and mixtures thereof. Because of the flammability of the
LPG gases a substantial amount o~ water is necessary in the
formulation to provide a dousing effect. Products propelled
30 with compressed gas propellants such as nitrogen or the more
soluble nitrous oxide and carbon dioxide are usually quite wet
because thPir low solubilities and low concentrations (as com-
pared with halohydrocarbon and hydrocarbon propellants) deprive
~ .
,'' .
.
33~
the product of breakup power. Combinations of liquefied and
compressed gas propellants ofer no synergistic advantage in
terms of achieving a dry spray.
There are, also, the ever-present dangers of aerosols:
5 flammability (in the case of hydrocarbon propelled products),
explosion hazard, inhalation toxicity potential, inadvertent
misuse o product, valve malfunction, etc.
Pump sprays are high cost, low efficiency substitutes
or pressurized products. Antiperspirant pump sprays are
10 currently on the market as non-aerosol counterparts. Their
acceptance, has been poor primarily because of the wetness
of the application.
Other packaging forms including separative devices,
elastomeric membranes with a memory, spring loaded devices,
lS etc., are of little commercial value because of the inordin-
ately high cost, the exotic nature of the hardwar~ and the
lack of basic improvement over existing lower cost systems.
In addition to spray application, another means o
applying antiperspirant products is by powder application.
The major disadvantages o conventional powder products
include dusting and lack of adhesion.
In 1979, sales of roll-on antiperspirant and deodor-
ant increased significantly due to the disenchantment of
the public with aerosol products and the introduction o
new products in roll-on form such as the suspension of anti-
perspirant salts in a volatile silicone ~Gillette's 'IDry
Idea'l) and powder roll-ons (such as Carter Product's 'IArrid
- Dry Powder Roll-on"). Roll-on deodorants/antiperspirants
are, additionally, more effective than other product forms
such as aerosol and pump sprays in reducing sweat.
Roll-on deodoranks and antiperspirants, however,
suffer from the lack of application aesthetics. The average
aqueous roll-on lotion takes a long time to dry and passes
through an uncomfortable sticky and tacky stage prior to drying.
Attempts to overcome these negative attributes have not been
entirely successful. The solution to one problem gave rise to
--3--
3~i~
other problems. For example, although the suspension of
antiperspirant salts applied by roll-on means eliminated
the sticky/tacky sensation, the oiliness from the volatile
silicone vehicle persists for fifteen minutes, more or ~ess.
Although dry powder roll-ons eliminate the sticky/
tacky sensation and are not oily, the adhesion of the appli-
cation is very poor; the powdery material falls out on the
; clothing and in the general vicinity of the application The
powdex does not flow readily between the ball and housing and
10 the net result may be less than the desirable amount of pro-
duct applied to the axilla with commensurately less efficacy.
Recently, it was discovered that aerated, hydrophobic
metal po~dex oxide microPncapsulated aqueous droplets could
- be ~ormulated in a powder-like dry feeling shear-sensitive
suspension. However, when this suspension is subjected to
shear such as by passage through the outlet orifice o~ a
spray container or by rubbing, combing, etc~, the droplets
coalesce to fonn a smooth, elegant cream or lotion having
good adhesion to a surface.
Bioaffecting materials such as antiperspirants or
deodorants can be added to the powder or aqueous phase o~
the bulk liquid-in-air emulsion or suspension without affect-
ing its ability to form a stable, shear-sensitive suspension
or its ability to dispense the particles thereof. The micro-
encapsulated suspension is the subject of applicant's Can-
adian Patent Application Seria;l No. 409,810, filed August 19,1982.
Roll-on applicators operate by attaching material to
the underside of the ball and conveying the suspension to the
axilla where it is deposited. It was not known nor believed
that the powdery-like suspension would adhere to the ball since
it does not adhere to most surfaces nor was it known whether the
powder suspension nor the sheared lotion or cream form thereof
would permit con~istent operation of the roll-on applicator
without fouling or seizing o~ the ball.
;, . .
BRIEF SU~RY OF THE INVENTION
It has now been discovered in accordance with this
invention that the free flowing, powdery aqueous suspension
can be reliably dispensed from a roll-on applicator. The
; 5 suspension exhibits excellent flowability through the annular
space between the ball and socket without any binding or foul-
ing. The suspension when sheared has good adhesion without
undesirable powder fallout. The application of an antipers-
piran~ from the aqueous suspension by roll-on results in a
10 dry feeling on the skin of the subject, a short dry-out time,
and excellent efficacy equalling or exceeding the sweat reduc-
tion of an aqueous solution of the same antiperspirant used
as a control for these studies. The product is absent sticki-
ness, tackiness, oiliness and long dry-out time of convention-
15 al lotion roll-on applications. The efficacy is substantially
higher than the earlier squeeze-bottle spray version and in
some tests exceeds the efficacy of aqueous solution of the same
antiperspirant compound.
During application of the air emulsion suspension by
20 roll-on, shear is applied to the suspension during passage
through the ball-fi~ment and/or by rubbing between the ball
; and the axilla. The powdery substance which is an aqueous,
aerated microencapsulation of the bioactive, fragrance, clean-
25 sing or other agent desired to be conveyed to the substrate can
be adjusted to a shear sensitivity for the given application.
A roll-on dispensing system generally includes a con-
tainer having a compartment for receiving the bulk liquid-in-air
suspension and a seat member for receiving a rotating ball de-
30 fining therebetween an annular outlet for dispensing the compo-
sition. The container or ~all can be plastic or glass. The
annular outlet dimension or clearance of the orifice can be
sized to pass the powdery particles with or without shear,
generally with shear destabilization as the particles pass
35 through the orifice. The complete or partial destabilization
to a continuous or lotion-like dispersion of powder in the water
phase can occur after deposit of the suspension on the surface
with rubbing.
~73~
Whereas, propellant aerosol or pump sprays must have
: small particle size and must have little or no water or alco-
hol to deliver a dry application, the system of the present
invention can have a large particle size and can contain sub-
stantial amounts o water (60-70~) and still dry quickly.
It is surprising that the substantial amount of water in the
formulation of the invention does not deter the quick dry out
of the dispensed material.
It is important to emphasize that the products of the
invention are not powders. Although existing in "powdery form"
they differ from powders in virtually all respects; a more
accurate description for the aqueous encapsulated vehicle com-
ponent of the system is detailed in Table 1.
-6- ~a73~
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0 t ) tv ~1 0 0 0 O ~ h ~1 Il)
~ ~ ~ ) O ~ tl~ -I ~ ~ ~ 3
tn ~I td rl Sl ttJ tJ~ ~a td (a td O
~ 1 3 ~ u ~ v a ~ ~
~ o ~ ~ 1 tt~ a~ rl rn ~ o
C) a~ O ~ a
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U~ ~ ~ ~ ~ ~rl U ~ a) o
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O ~ ~1 3 u~ O s ~ rl
R ~ ~ 0 S~ OE3 -
rl Q j L~ ~4 0u~ ~rl ~i
t~ ~rl ~rl Ul Ul q~ ~ O ~1 (U
rd ~ ~ a) O ~ O ~ ~ ~rl
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rl r~) w tH rd c~ h ~ ~d w~ ~6 rl
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cd 0 3 ~ ~ ~R rdS~
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S-l O ~ ,4 ~ rl O rl ~rl a) ~l ~ WQ~ ~ rd
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E~ ~ Z ~ a
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U~ C) ~ E-l ~ H ~C æ ~
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0 5 ~ l O O H O
~ i'3367
"
Bioactive materials such as astringents or antimicro-
bial agents, or other materials such as fragrances or pigments
used for makeup products can be introduced in either the aqueous
or hydrophobic metal oxide phase or in both phases. The shear
sensitivity of the bulk is adjusted so that on its passage
through the roll-ball applicator and subsequent application to
the substrate, the microencapsulated powdery substance is con-
verted to a lotion with good adhesion. The more shear resist-
ant the bulk, the drier the lotion. The shear sensitivity of
the bulk is determined by the time and intensity of mixing,
the nature and amount of hydrophobic metal oxide, the nature
and amount of system affecting additives, the nature and amount
of the bioactive substances or other substances such as frag-
rance, and other factors. The net sheax efect, however, is
the sum of the shear effects of the product as it passes through
the annular space comprising the ball and housing dispenser and
:` applicator, and the subsequent shear effect of the ball appli-
cator applying the product to the substrate.
The system of the invention provides all or any combina-
tion of the following properties: good adhesion to target, non~
occlusiveness, breathability, good coverage of target area, no
build-up, is noncaking in the pacXage and on the skin, has good
- slip properties, provides controlled cooling, is cosmetically
', elegant and is a safe, effective and economical product.
These and many other features and attendant advantages
of the invention will become apparent as the invention becomes
better understood by reference to the following detailed des-
cription when consid~red in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is an elevationa~, partially in section view
of a first embodiment of a roll-on application system of the
invention;
Figure 2 is an elevational partially in section view
of the system of Figure 1 shown in inverted position; and
Flgure 3 is a schematic view illustrating the suspension.
~ L'7~
DETAILED DESCRIPTION OF THE INVENTION
Referring now to Figure 1, the roll-on dispension
system includes a container 10 having chamber 12 receiving
a charge 14 of the water-in-air emulsion or suspension con-
5 taining an antiperspirant and/or deodorant. The top of thecontainer contains seat member 16 for receiving a rolling
ball 18 defining an annular outlet 20 therebetween.
Referring now to Figure 2, the container 10 may be
inverted prior to use. The suspension 14 will slide and flow
10 by gravity downward and move into contact with underside of
the ball 18 forming an adherent film 22 on the bottom sur-
face of the ball 18. As the ball is rotated and the film
22 passes through the annular outlet 20, the suspension is sub-
jected to shear forces and the suspension coalesces into a
15 continuous or semi-continuous cream or lotion film 24 on the
top surface of the ball 18. The powder barrier is disrupted
and dispersed into the now continuous water phase. Usually
the ball is rolled onto the underarm 5 to 15 times to dispense
40 mg to 400 mg of suspension, usually 75 to 300 mg. The de-
20 gree of shear imparted depends on the pressure and velocityof the ball and the clearance through the annular outlet. The
ball may be smooth or rough and can be formed of glass, metal
or synthetic resin such as polystyrene or polypropylene.
It is difficult to specify the optimum clearance since
25 there appears to be wide tolerances of the order of several
mils permitted in the available commercial fitments and balls.
Furthermore, the more rigid ball is mounted in a more flexible
fitment member and can move up and down in the fitment depend-
ing on the pressure applied by the user. This, of course, will
30 affect the clearance during application of the suspension. The
commercial ball-fitments utilized for antiperspirants do provide
pickup, shear and deposition of the suspension of the invention.
Figure 3 illustrates the microencapsulated aqueous
phase 30. In the manufacturing process, the primary hydrophobic
35 metal oxide particles 32 fuse together to form chained particles
34 which have a strong tendency to interact with each other to
1~73367
form a three dimensional network or lattice structure 36
encapsulating discrete water globules 38 wi~h approximate-
ly seventy parts of air trapped in the void space. When the
aqueous phase and the hydrophobic metal oxide are subjected
to high shear mixing the aqueous droplets 38 are trapped in
the three dimensional lattice structure, where air is the
continuous phase of the dispersion. The air cushioned hydro-
phobic aggregates surround the small aqueous droplets prevent~
ing coalescence and stabilizing the system. When the shear
10 potential is exceeded, such as during travel through the out-
let 20, the aqueous phase will coalesce in a whole or in part.
Total coalescence can occur on the target surface by rubbins
the material on the body.
Optimum functioning of the system and delivery of the
desired material depends on the dispensed particle size and
its density, the changing size and density of the particles on
the ball and on the target, the delivery rate, the degree of
hydrophobicity and the nature o the application (dry, moist
or creamy). Optimum functioning of the system also depends
on the shear stability of the suspen~ion which, in turn, i5
influenced by the following factors:
1. The ratio of the hydrophobic metal oxide to the
aqueous phase;
2. The type of hydrophobic metal oxide used;
3. The amount and nature of the actives;
4. The amount and nature of the system affecting
adaitives;
5. Processing techniques;
6. Delivery system parameters.
Synthesis of hydrophobic metal oxide by reaction of
metal oxides and metalloid oxides, particularly colloidal
silicas, with various organosilicon compounds has been rather
extensively developed. Various organosilicon compounds bearing
at least one functional moiety per molecule can be reacted
through sald functional moiety with the hydroxyl groups exist-
ing on the surface of the metal or metalloid oxides. The
`~ -10-
1~ ~33~ ~
resulting reaction product is characterized as a metal
oxide or metalloid oxide having chemically bonded to
the surface thereof organosilicon groups xepresented
generally by the formula:
eO-MRa~b
where e represents the oxide surface; 0 is oxygen; M
is a metal or metalloid such as silicon, each R is any
alkyl, aryl, arylalkyl, alkoxy or aryloxy group, a is
a number from 1 through~3, X is any halogen or hydroxyl
10 group b,is a number from O through 2, and a+b - 3O
The organo~ilicon group~ are introduced ont~
the surface of the metall~c oxide in a~ amount ~uffi-
cient to render the surface of the metal oxide hydro-
phobic. Generally, at le2~t 50% of the available
15 oxygen groupA on the surface such a~ silanol groups
are converted, typically about 70%. Hydrophobic,
pyrogenic ~ilica can be produced in accordance wt th
the teaching~ of U.S. Patent ~o. 3,393,155 or other
patents such a~ U. S ,. Patent No~. 2, 510 ~ 661, 2, 589, 705,
20 2, 705, 206, 2, 705, 222 and 3,023,181~
In preparing the disperqion of aqueous liquid
in fine solid particulates for u~e in the present
invention, in addition to or in pla~::e of the hydro-
phobic pyrogenic silic:as used in U,. S. Patent ~o.
: 25 3,393,155 other ~trongly, hydrophGbic metallic oxides
having an average equivalent spherical diameter of
les~ than about 100 millimicron~, typically from ~ to
20 millimicr~ns, can also be used. For example, other
finely divided oxides such as aluminas, titanlas,
ziconias, vanadium oxide~, iron oxides or mixed oxides
with or without ~ilica can form the basic oxide par-
ticles whether produced pyrogenically or otherwise,
e.g., by wet precipitation techniques. Also, wet
precipitated silicas ~uch as those produced by acidi-
fication or neutralization of aqueous alkali metal
- silicate ~olutions make ideal starting materials when
,.
'~"
. '' ~
-1 1
3~'~
availa~le in partic:ulate ~orm of th{~ desired finenes~
For example, U.S. Paten~ No~3. 2,865,777, 2,900,~48,
~,~13,419, ~,995,422, ~010,791, 3,034,!~13, 3,17~,7~,
3,208,823 and 3,250,5g4 degcribe a few of 'che many
5 different technique~ for precipi~a~ing particulate
qilicas :Erom aqueous medium in a orm which i~ ~uffi
c~ently non-st1cky and nnn-gelatinuouA to. be washed,
filtered, dried and ~ubdivided t~ colloidal powder
form.
Specif ic examples of organo~ilicon eom-
pounds which are often reacted with colloidal metallic
oxides to form surface }~tructl~res like t}lo~e de~cribed
above are; organohalosilane~ ~3uch a~ (CH3)3SiCl,
( CH2 ) 2siar;2 ~ ~ CH3 ) 2SiC~ 2 and ( C 4Hg ) 3SiC l; organO_
15 ~ilylamineEI ~uc:h a~3 ~CH30)3Si(C:H2)3 NH(CH2)2 ;~
2 3 . 2 3 2NHCH~CH2NH;~; organodi~il-
3)3SlNHS$~CH3)3 and ~C4H ) -SiNHS~
~ C4Hg ) 3, etc~ In mos~ cases " the sur:~ace treatments
s~ust be sufficie~t to attach organo group~ totalins~ at
20 least 0.5 percent and preferably at lea~;t 1 percent by
weight based on the dry weight o:l~ the metallic oxide
particles treated. In many cases, ~specially with the
most preferred high surface area oxide~, the concen-
tration of organo groups thereon will equal 2 percent
25 or more by weight.
Examples of commer~::ially available hydro-
phobic ~ilicas are described in the following tableO
TABI-E 2
Silica ~ Sousce
B 30QUS0 WR50 Wet Precipitation Proce~3s Philadelphia
Quartz
QUS0 WR82~ Wet Precipitation Process Philadelphia
Quartz
Aerosil~R 972 Fumed Silica-Pyrogenic Degussa
35 Tullano~ 500 Fumed Silica-Pyrogenic Tulco Inc.
-12- ~ ~ 73,3~
The mPtal oxide starting materials contain
substantial amounts of occluded air in a stable con-
figura-tion. The air i9 retained in the hydrophobizing
reaction resulting in a very low apparent density, i.e.,
as low as 0.04g/cc; the real density of the hydrophobic
metal oxides is about 2g/cc. The density of the water-
- in-air emulsion can be from about 0.30 to 1.5, generally
from about 0.45 to 0.90.
The pyrogenically produced metal oxides have
moxe occluded air than do their precipitated counter
parts and result in a lower density bulk. For any
given system the pyrogenic material contributes con-
siderably more shear resistance to the bulk than do pre-
cipitated metal oxides. Thus, if a more shear pronev moist
to creamy application is desired, a precipitated metal oxide
may be more desirable than the pyrogenic variety; conversely
the pyrogenic metal oxide will provide a more shear resistantr
drier application. Based on the num~er of controllable vari-
ables, however, each type of metal oxide can be ormulated
to yield the entire spectrum o~ application characteristics.
The ratio of hydrophobic metal oxide to aqueous
liquid can be from 1/1 to 50/1, generally from 5/1 to 20/1.
If the ratio of the hydrophobic metal oxide to water is high
(all other factors being equal~ the encapsulated aqueous
base will ~e more shear resistant as a result of the mechan-
ical crowding of the hydrophobic metal oxide particle at the
aqueous/air interface and additional energy or scrubbing
action will be required as the bulk passes throuyh a given
annular outlet to effect shear (if such is desired) result-
ing in the coalescence or partial coalescence o the aqueous
phase with an increase in both particle size and density;
conversely, if the ratio o hydrophobic metal oxide to the
aqueous phase is low, the bulk will be more shear prone
as it passes through the annular outlet.
Formulations useful in the present invention nor-
mally contain 1-15% by weight of hydrophobic metal oxide,
. . .
,~:
:
. I ,
~.~L ;'3;~7
25 to 98.9% by weight of water and 0.1 to 60% by weight
of dispensible material.
Processing is vital to achievlng the desired degree
of shear resistance for a given roll-on system. The minimum
5 amount of mixing to form the water-in air dispersion will
provide the greatest degree of shear stability when the bulk
passes through a given outlet. As mixing continues the
bulk will collapse to form a totally coalesced creamy ma-
terial. Processing is also a function of the type of hydro-
10 phobic metal oxide used. Pyrogenic hydrophobic metal oxideswill tolerate substantially more shear than identical systems
made with precipitated hydrophobic metal oxides. Generally,
the preblended solids are added to a vortex of the liquids
in a high speed mixer such as a blender and mixed or 2 to
15 60~ seconds, generally 5 to 300 seconds. Alternatively,
the preblended powders and aqueous liquid phase are com~
bined and then blended as above.
The shear potential or resistance of the system is
an aggregate of the entire shear experienced during passage
20 through the annular outlet resulting in partial or total
coalescence of the aqueous phase, tha further shearing of
the bulk by rubbing on the skin causing additional coales-
cence.
The elegance and function of the lotions and creams
(from the "powdery substance") for cosmetic and pharmaceu-
tical and household applications are enhanced by the incor-
poration of materials for the purposes indicated~ These
materials include well tolerated humectant polyols such as
glycerin, propylene glycol and sorbitol; sun screening agents
30 such as para-aminobenzoic acid and other benzoate and cinna-
mate derivatives; deodorant chemicals such as formaldehyde
donor compounds and halogenated phenyl and other aromatic
derivatives; antiperspirant chemicals such as aluminum and
zirconium salts; therapeutic substances including steroids
35 and antibiotics; pigments of the type normally used for
make-up items such as for face powders, lipsticks, eyeshadows
-14-
~ :~ '7~336'~
and rouyes; cleansing surfactants of the anionic, nonionic
and amphoteric types including ethoxylated phenoxyphenol
derivatives, alkyl sulfate salts and imidazolinium deriv-
atives; viscosity modi~ying agents including polyvinyl
5 pyrolidone, water soluble acrylate and cellulose polymers
and natural gums including guar, alginate and carraghenates;
and emollient, conditioning and modifying agents including
ethoxylated and propoxylated fatty esters, sucrose fatty
esters, lanolin derivatives and cationic polymers nor-
10 mally used to condition the hair and skin. Metallic fattyesters such as aluminum, magnesium, calcium and zinc stear-
ates are useful to improve adhesion to the skin. Starches
and fine talcs may be incorporated in the system to improve
the feel of the product on the skin. Fragrance and color
15 may be added as desired.
Other additives include oils, solvents and surfact-
ants. Generally, chemicals with a high hydrogen bonding
capability are better tolerated by the system than inter-
mediate to low hydrogen bonding chemicals. Thus r for sol-
20 vents, ethanol, glycerol or propylene glycol are bettertolerated than xylenol or chlorinated solvents; for sur-
factants, linear alkyl sulfates are better tolerated than
ethoxylated fatty acids although when the ethoxylate is the
predominant portion of the molecule (such as FEG 2000 stear-
25 ate) the surfactant becomes less oleophylic and is bettertolerated by the system. Virtually all oils have a profound
effect on the system. The mechanism involves the wetting out
of the hydrophobic metal oxide resulting in the displacement
of air and the collapse of the system. Additives such as lip-
30 ids, may, however, be introduced into the system by dispersingthem in the aqueous phase as an oil-in-water emulsion or by
; incorporating them into the system as spray-dried powders.
Thus, it can be seen that controlled destabilization resulting
in the desired degree of shear when the bulk passes through
;35 the outlet can be obtained by the judicious addition of rela-
tively non-hydrogen bonding solvents, surfactants and lipids;
-15-
`7~
-`~ these materials may contribute to humectancy, creaminess and elegance of application.
The basic system is extremely hydrophobic no~-
withstandin~ the act that it can contain as much as 90%
5 water. The system notwi~hstanding the water content
assumes the properties of the hydrophobic metal oxide.
Hydrophobicity is highly desirable in many products, in-
cluding make-up items and certain topical pharmaceuticals
to provide long-term protection while resisting wash-off
by the elements and body fluids or to protect the affected
area from moisture and provide a protec-tive, controlled
release matrix for the actives. The degree of hydropho-
bicity can be altered by modifying the hydrophobic inter-
face. When the cohesive forces of the hydrophobic barrier
are reduced, the bulk becomes more shear sensitive, the
degree of coalescence and breakdown of the aqueous phase
; being a function of the intensity of shear as the bulk
passes through the annular outlet plus any subsequent scrub-
bing action on the skin.
The water sensitivity can also be controlled by con-
trolling the hydrophile-liphophile balance of the system, or
by the introduction of hydrophyllic components such as hydro-
phyllic hydrocolloids or hydrophyllic metal oxides in suffi-
cient ~uantity to disrupt the hydrophobic metal oxide barrier
and provide the desired degree of hydrophyllicity.
A very particular application of the system of the
- invention is in the dispensing of an antiperspirant. A
suitable general formulation follows:
Ingredient Amount, % W/W
30 Antiperspirant 5~45
Hydrophobic silica 3-10
Metal stearate 0-5
Water 30-80
Shear controlling agent, e.g.,
35 ethanol or surfactant 0-5
; Other additives such as talc or insoluble starch can
be added to the formulation in amounts up to 25%, preferably
5 to 15~.
.` ' .
~ .
-16-
'7~3367
Di~pensing of antiperspirant i9 one of the
primary applications of the sy~tem of the invention.
The U.S. Department of Health, Education and Welfare
ha~ published a monograph on antiper~pirant products
for human use. Most of the active antiperspirants are
aluminum halides or complexes thereof. Representative
antiperspirants that can be u~ilized in the dispensing
system of the invention are:
Aluminum bromohydrate
Aluminum dichlorohydrate
Aluminum chlorohydrex PG
Aluminum dichlorohydrex PG
Aluminum sesquichlorohydrex PEG
Aluminum chloride
Aluminum zirconium chlorohydrate~
Aluminum zirconium trichlorohydrate
Aluminum zirconium trichlorohydrex
Aluminum zirconium pentachlorohydrate
Aluminum zirconium pentachlorohydrex Gly
Aluminum zirconium tetrachlorohydrate
Aluminum zirconium tetrachlorohydrex Gly
- Aluminum zirconium octachlorohydrate
Aluminum zirconium octachlorohydrex Gly
Aluminum chlorohydrate
Aluminum sesquichlorohydrate
Aluminum sesquichlorohydrex PG
Aluminum chlorohydrex PEG
Aluminum dichlorohydrex PEG
Aluminum sulfate
30 Buffered aluminum sulfate
: Po~assium aluminum sulfate
Sodium aluminum chlorohydroxy lactate
The antiper~pirant material may be incor-
porated into the formulation either as a solid or in
solution. In the former case, the stearate and the
hydroph~bic ~ilica are blended together with the solid
. ; - - .
~ ~7~
l~l 73~ ~
antiperspirant and t~is is then fed into a vortex of a
mixer containing water and any optional material which
may be dissolved or suspended therein. In the latter case,
the preformed blend of stearate and hydrophobic silica is
fed into the vortex of a mixer containing in the aqueous
phase a suspension or solution of the antiperspirant ma-
terial plus any optional materials to be incorporated in
the aqueous phase~ If desired, the antiperspirant may be
incorporated in the integral aqueous phase or in the ex-
ternal powder phase or in both phases. In another pro-
cedure the aqueous and powder phases are separately formu-
lated and are then combined and blended.
The system of the invention will now be illustrated
by the following examples which are presented for purposes
15 of illustration only and not intended to limit the inven-
tion.
All formulations are for 200 grams. Identification
of the materials is provided in the following table:
TABLE 3
20 T 500 Tullanox~500 (hydrophobic silica)
Zn(St)2 Zinc Stearate
Propaloid T~ A refined hectorite ore chemical-
ly modified to improve hydration
properties
25 Vulca 90* A cross-linked, insoluble, glyceryl starch
ACH 50% 50% Aqueous solution of Aluminum
Chlorhydrate
Cab-O-Sil Fumed Silica
Rezal 36 ~ Aluminum Zirconium Chlorhydroxide -
35% aqueous solution
AlC13 6H20 Aluminum Chloride Hexahydrate
- Finsolv TN-~ Cl2-Cl5 Alcohols Benzoate
~k ~ ~P
':
:;
1 ~-
Examples of the roIl-on system follows:
EXAMPLE I
Anti~erspirant Roll-on Product
Material ~ W/W
5 1. Tullanox 500 4.25
2. Zinc Stearate 1.00
3. Propaloid T 2.00
4. Aluminum Oxide C 1.00
5. Vulca 90 2.00
6~ Aluminum Chlorhydroxide, 50%
Aqueous Solution 50.00
7. Aluminum Oxide C 1.00
8. Water 37.50
9. Dow-Corning 345 Fluid 0.25
15 10. Spray Dried Fragrance 1.00
Processing instructions:
.. . _ . ~ .. ....
A. Combine 1-4 and blend at high speed for ten seconds
in a Waring Blender.
B. Combine 5-8 and bland at high speed for thirty seconds
in a Waring Blender.
C. Add 9 to B and blend at high speed for five seconds in
a Waring Blender.
` D. Add A to C and blend at high speed for fifty seconds in
- a Waring Blender.
E. Add 10 to D and blend at high speed for five seconds in
a Waring Blender.
The density of the bulk is 0.63 g/cc.
~ The product contains 25% active aluminum chlorhydrox-
; ide astringent salt. When applied to the axilla using ten
strokes, the amount of application was approximately 300mg
; which is equivalent to 75mg of the astringent salt. The
: aqueous microancapsulation of the astringent salt, which is a
powdery substance, was converted to a lotion with excellent
adhesion and virtually no powdery fall-out. The application
dried in approximately fifteen seconds wi-th little apparant
tackiness. A 0.995 inch polyethylene ball and standard poly-
,
ethylene housing were used in the above test.
.
--1 9--
336~
EXAMPLE II
Antiperspirant Roll-on Product
Material ~ W/W
1. Tullanox 500 4.25
5 2. Zinc Stearate 2.00
3. Propaloid T 4O00
4. Vulca 90 4.00
5. Cab-O-Sil 1.00
6. Aluminum Zirconium Chlorhydroxide,
35~ Aqueous Solution (Rezal 36G) 83.50
7. Spray Dried Fragrance 1.00
Density of bulk = 0.56 g/cc
Processin~ instructions: Same as for Example I.
EXAMPLE III
15 Antiperspirant Roll-on Product
-
Material % W/W
__
1. Tullanox 500 4.5
2. Zinc Stearate 2.0
3. Propaloid T 4.0
20 4. Aluminum Chloride Hexahydrate 15.0
5. Cab-O-Sil 1.0
6. Water 1.0
7. Spray Dried Fragrance 1.0
Density of bulk = 0.53 g/cc
Processing_instructions: Same as for Example I.
Many of the air suspension formulations disclosed in
the previously referenced patent applications can be dis
pensed from a roll-on. The suspension is destabilized by
the shear forces experienced during pickup by the ball,
30 passing through the annular opening and rubbing during de-
position on the skin of the user.
The following compositions were prepared for an
efficacy skudy of the air emulsion suspension roll-on appli-
cation.
20~
~ ~ '73~6~
EXAMiPLE IV
Ingredient ~ W/W
Rezal 36G (35~ aqueous solution)83.5
Vulca 90 4O0
5 Tullanox 500 4.5
Zinc stearate USP 2.0
Cab-O-Sil 1~0
: Fragrance SL79-868 (Spray Dried)lo O
Propaloid T (NL) 4.0
100 . 00%
EXAMPLE V
Ingredient % W/W
Rezal 36G (35~ aqueous solution)83.5
Tullanox 500 4.5
15 Propaloid T 4.0
. Vulca 90 3.6
.~ Zinc stearate USP 2.0
Spray Dried Fragrance compound PFW
Carrier No. 4C (36% oil) 1.4
20 Cab-O-Sil M5 1.0
'i- 100. 0096
EXAMPLE VI
.
Ingredient % W/W
Rezal 36G (35% aqueous solution)83.5
25 Tullanox 500 4.85
Vulca 90 3.00
Propaloid T 2.65
~: Zinc stearate USP 2.00
;~ Encapsu}ated Fragrance Compound (PFW
Carrier No. 4C, PFW fragrance oil) 2.00
Finsolv TN 1.00
Cab-O-Sil M5 1.00
' _
100 . 00%
. .
:
:
-21~ 33~ ~'
EX~MPLE VII
In~redient % W/W
Rezal 36G (35~ aqueous solution) - ~3.5
D.I. Water 16.5
100.00
EXAMPLE VIII
Ingredient ~ W/W
Rezal 36G (35~ aaueous solution) 85.2
Tullanox 500 4.~47
Vulca 90 3.06
Propaloid T 2.602
Zinc stearate USP 2.041
Finsolv TN 1.~3
Cab-O-Sil M5 l.Q2
10~0.000%
EXAMPI.E IX
A nationally marketed roll-on antiperspirant, Dry
Idea, consisting of a suspension of an aluminum/zirconium
chlorohydrate in a volatile silicane,oil modified with sus-
pendin~ agents was included in the following antiperspirantstudies.
Four antiperspirant studies were run including two
studies which tested compositions of the invention ~Examples
IV and VIII) against an aqueous solution containing the same
antiperspirant in the same concentration as that in the pro-
duct on the market. Two other compositions of the invention
(Examples V and VI) were tes~ed against a product on the mar-
ket (Example IX) known to have the maximal efficacy exhibited
by the aqueous control ~Example VII). Therefore, if the
first tests showed that the compositions of the invention ex-
hibited efficacy lower than the aqueous control, it would be
anticipated that the commercial product of Example IX would
also exhibit better efficacy than the compositions of the in-
vention. If the first test showed parity efficacy, the com-
~ -22~ 3~ ~
position of the invention should also exhibit comparable
efficacy to the commercial product (Example IX). Conversely,
if the first test showed the compositions of the invention
to have better efficacy than the aqueous control, this
5 would be totally unexpected and one would predict that the
composition should be more efficacious than the commercial
product.
The results were:
Test l - 16 subjects - The aqueous air suspension
10 roll-on of Example IV was applied to one axilla and the
aqueous solution of Example VII was applied to the other
axilla of each subject (about 0.25 gms)~ The powder roll-
on was 12.55~ more effective than the aqueous solution. Hypo-
thesis test of the differencè between the means of the two
15 treatments showed a probability of 0.07.
Test 2 - 36 subjects - The aqueous air suspension
of Example V was tested versus no treatment and versus the
; commercial product and the commercial product was tested
versus no treatment. Example V was found to have 64.5%
20 efficacy vs. 59.1% for the commercial product. Hypothesis
test of the mean differences gave probability of less than
0.10%.
Test 3 - 16 subjects - Example VII applied to
~ one axilla, and Example VIII was applied to the other.
s~ 25 The powder roll-on was 19.0% more effective than the
aqueous solution. Hypothesis tests of the differences
between the means of the two treatments gave probability
of 0.08.
Test 4 - 36 subjects - The air emulsion of
30 Example VI was tested versus the commercial product and
versus no treatment. The commercial product was also tested
versus no treatment. Example VI was found to have 63.3%
efficacy vs. 59.4~ for the commercial product. Hypothesis
tests of the mean differences between the two products gave
-23-
~:~';133~7
probability greater than 0.10.
On the average, testing the product of the in-
vention versus a solution of its active ingredient showed
the product to be about 15% more efficacious. This is a
S surprising result indicating that the vehicle has enhanced
the efficacy of the active ingredient. One possible rationale
is that the Tullanox may prevent the active from being washed
away by perspiration because of its hydrophobic nature, thus
making more of the active available to perform its anti-
perspirant function. The other two tests confirm that theproduct should be more active than competitive products.
An investigation of the system produced the following
observations:
; 1. The product after shearing action by the roll-on
dries more quickly and is less sticky than a con~entional
a¢ueous based roll-on~
2. The concentration of water in the product is
approximately equal to that of a conventional roll-on.
3. The antiperspirant activity as measured is at least
; 20 equivalent to an aqueous solution of the active.
These observations are not to be expected. The effect of
shearing is to change the system from a free-flowing powder to a
cream or lotion with the aqueous phase no longer encapsulated.
If that is true, then it is difficult to explain why the product -
quickly dries and is non-sticky. The original free-flowing pow-
der like material is dry to the touch and this has been recognized
in the past. It has never been recognized that the product after
shear should retain this dry feel. If the reason is that the
active in water has not been completely released, then it would
be expected that there would not be antiperspirant activity e~uiv-
alent to the a~ueous solution. This is contrary to the results
of the antiperspirant efficacy experiment. One possible explana-
24~ 7~ ~ ~
tion may be that even though the effect of shearing is torelease the aqueous solution of the active completely, the
inherent dryness of the hydrophobic metal oxide is sufficient
to giv~ a perception of dryness and lack of stickiness to the
5 user. This would then permit the active to work maximally
without the associated negatives of wetness and stickiness.
Efficacy studies show that maximum efficacy is
achieved by roll-on application when compared to an aqueous
solution of the active ingredient. Moreover, the more
10 effective aluminum-zirconium salts are permitted in roll-on
formulations but are prohibited in spray applications.
The stickiness, tackiness, oiliness and lengthy
dry-out time of conventional lotion roll-on application is
overcome by means o~ a free-flowing aqueous microencapsula-
15 tion of the antiperspirant chemica7 which displays goodflowability through the annular space between the ball and
socket without sacrificing the efficacy associated with con-
ventional roll-on forms of product This invention achieves
good application aesthetics and flow characteristics with
20 good adhesion of the product and without undesirable powder
fall-out.
The basis of this invention is an aqueous micro-
encapsulation, said aqueous phase being reduced to small
droplets by high intensity mixing and stabilized with a hydro-
25 phobic metal oxide. Bioactive materials such as astringentsor antimicrobial agents, or other materials such as fragrances
or pigments used for make-up produc~s can be introduced in
either the aqueous or hydrophobic metal oxide phase or in
both phases. The shear sensitivity of the bulk is adjusted
30 so that during its passage through the roll-ball applicator
and application to ~he substrate, the microencapsulated pow-
dery substance is converted to a lotion with good adhesion.
The more shear resistant the bulk, the drier the lotion. The
final shear sensitivity is a function of the intensity of
35 mixing, the nature and amount of hydrophobic metal oxide, the
-25-
~ ~'7~
nature and amount of system affectiny additives, the nature
and amount of the bioactive substances or other substances
such as fragrance, and other factors. The net shear effect,
however, is the sum of the shear effects of the product as it
5 passes through the annular space comprising the ball and
housing dispenser and applicator, and the subsequent shear
efrect of the ball applicator applying the product to the
substrate.
Thus, the invention demonstrates the use of shear to
10 provide products of varying properties from powdery particles
to creamy applications. During processing of the bulk suf-
; ficient energy is added by high speed mixing to render the
~ulk shear sensitive so that on passage through an outlet of
preselected clearance a controlled amount of destabilization
15 and coalescence can occur. The clearance is sized to impartan amount of shear efective to at least partially destabilize
; the interfacial barrier. At the point of total coale~cence the
barrier is dastroyed and the internal, discontilluous waker
phase becomes an external continuous phase. At coalescence,
20 the hydrophobic metal oxide appears to impart water resistance
to the surface of the target such as the skin of the user. The
delivery rate can be varied over wide ranges from 40 to 500 mg
per application usually 60 to 300 mg per application.
Three hundxed samples of the water-in-air suspension
25 antiperspirant composition of Example VI were packaged in a
plastic molded bottle containing an integrally molded fitment
receiving a 1.000 inch ball. The samples were tested for de-
livery rate, in milligrams for each sample per axilla, fall out,
dusting and density. In each case seven passes or strokes
30 were used to apply the product to the axilla in amounts from
190 to 360 milligrams per application. There was no percep-
tion of oiliness or tackiness after application.
With respect to fall-out of unsheared powder on a
rating scale of from 0 (no fall-out) to 4 (maximum fall-out)
35 only a portion of the samples in the 300 milligram application
range exhibited some fall-out (rating of 1). No sample re-
ceived rating higher than 1.
:
-26-
'
3~7
Dusting was evaluated by a visual observation of
powder which became airborne during application. Using a
similar rating, dusting was only observed for some of the
;~ large application samples and no sample received a rating
higher than 1.
Initial and twenty-four hour densities are re-
corded below for a number of the batches:
::
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.,1
~r ul
o
rl `
U~
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:
~rl tl~
æ ~ ~ ~ O ~ O ~ u~ O ~ O O In O ~ O O O u~ O O
O ~ ~ ~ cr~ o ~ r~ ~ o co ~ O ~ ~ r~ oo ~ ~ c~ a) o~ co
H rl ~ ~I r-J r-l r-l
~ X
H
W
a
E~S~
H
a ~
~rl `
~rl ~ . . ~ . ~ . ~ ~ . . . . . .
U~
O ~
h O
~rl In
O o o o In o In u~ o u~ o o o u~ o In O O
~rl (U ~ O ~0 r-l a~ 1~ 1~ r-l
rl
.
-28-
It is to be realized that only preferred embodi-
ments of the invention have been described and that numerous
substitutions, modifications and alterations are permissible
without departing from the spirit and scope of the invention
as defined in the following claims.
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