CA1173367A - Roll-on application of aqueous microencapsulated products - Google Patents
Roll-on application of aqueous microencapsulated productsInfo
- Publication number
- CA1173367A CA1173367A CA000379169A CA379169A CA1173367A CA 1173367 A CA1173367 A CA 1173367A CA 000379169 A CA000379169 A CA 000379169A CA 379169 A CA379169 A CA 379169A CA 1173367 A CA1173367 A CA 1173367A
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- CA
- Canada
- Prior art keywords
- suspension
- metal oxide
- shear
- structure according
- outlet
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Abstract
ROLL-ON APPLICATION OF AQUEOUS MICROENCAPSULATED PRODUCTS Abstract A material (14) such as an antiperspirant con-tained in a shear-sensitive, free-flowing, powdery, sus-pension of aqueous droplets stabilized by a barrier of very fine, hydrophobic metal oxide is dispensed from a roll-on applicator. As the ball (18) is rotated, an adher-ent film (22) of the suspension passes through the annular outlet (20) and is subjected to shear forces. The suspension coalesces into a film (24) of cream or lotion. The sus-pension exhibits excellent flowability through the outlet (20) without any binding or fouling and the lotion or cream film has good adhesion to the ball. Application results in a dry feeling on the skin of the subject, a short dry-out time and excellent antiperspirant efficacy.
Description
~ 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~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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~ 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;
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~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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, ~ , ~ o o ~
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~ 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 ,.
'~"
. '' ~
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
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 ~ :~ '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;
`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~.
.` ' .
~ .
'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:
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
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 ,.
'~"
. '' ~
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
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 ~ :~ '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;
`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~.
.` ' .
~ .
'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:
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.
.
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
.. . _ . ~ .. ....
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.
.
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 ~:~';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 ~ ~'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.
:
' 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:
::
. .
33~ ~' h .,1 ~r ul o rl `
U~
O
:
~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 .
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.
:;
., ;' ' .
, ''~' ,., .: ~
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 ~:~';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 ~ ~'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.
:
' 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:
::
. .
33~ ~' h .,1 ~r ul o rl `
U~
O
:
~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 .
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.
:;
., ;' ' .
, ''~' ,., .: ~
Claims (25)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A structure for applying a water-in-air suspension containing a dispensible material to a target comprising in com-bination a container including: a compartment within the container receiving a body of water-in-air powdery suspension, said water-in-air suspension including a liquid phase comprised of small droplets of aqueous liquid stabilized with an interfacial barrier of very fine, hydrophobic metal oxide particles, an external air Phase in which said droplets are suspended; said dispensible material being present in the liquid phase and/or external air phase; a seat member; and a rotating member received by said seat member to define an outlet therebetween through which said water-in-air suspension is dispensed to said target from said compartment by rotation of said rotating member, said outlet being sized to apply a preselected shear to said suspension in an amount effective to at least partially destabilize the suspension as it passes through said outlet to coalesce said droplets.
2. Structure according to claim 1 wherein the rotating member is a rotating ball and the outlet is an annular opening be-tween the rotating ball and the seat member.
3. Structure according to claim 2 wherein the annular opening is sized to provide sufficient shear to coalesce at least 10% of said droplets to form larger particles.
4. Structure according to claim 3 in which sufficient shear is applied to said droplets during passage through said annular opening to form a continuous phase cream or lotion.
5. Structure according to claim 1 in which the sus-pension includes in parts by weight:
25% to 98.9% of aqueous liquid;
1% to 15% hydrophobic metal oxide; and 0.1% to 16% dispensible material.
25% to 98.9% of aqueous liquid;
1% to 15% hydrophobic metal oxide; and 0.1% to 16% dispensible material.
6. Structure according to claim 5 in which the dis-pensible material is an antiperspirant salt.
7. Structure according to claim 6 in which the den-sity of the suspension is from 0.3 to 1.5 g/cc and the ratio of hydrophobic metal oxide to aqueous liquid is -from 1/1 to 50/1.
8. Structure according to claim 7 in which the hydrophobic metal oxide is selected from silicon, titanium, aluminum, zirconium, vanadium, iron, or mixtures thereof and contains at least 0.5% by weight organic groups.
9. Structure according to claim 8 in which the hydrophobic oxide is a silane treated silica.
10. Structure according to claim 8 in which the hydrophobic metal oxide is a pyrogenic silica.
11. Structure according to claim 8 in which the dispensible material is an antiperspirant compound present in an amount from 5% to 45% by weight, the hydrophobic metal oxide is in an amount from 3 to 10% by weight, water is present in an amount from 30 to 80% by weight and further including from 0 to 5% of a shear control agent.
12. Structure according to claim 11 in which the anti-perspirant compound is an aluminum-halogen compound having at least one Al-halo bond.
13. Structure according to claim 11 in which the anti-perspirant compound is an aluminum-zirconium compound.
14. A method of dispensing a water-in-air powdery suspension onto a target surface, said water-in-air suspension including a liquid phase of small droplets of aqueous liquid stabilized with an interfacial barrier of very fine hydro-phobic metal oxide particles and an external air phase in which said droplets are suspended comprising the steps of:
applying said suspension to a rotating member which is received by a seat member associated with a container, to define an outlet therebetween; and rotating said rotating member in contact with said target surface to dispense said suspension through said outlet and onto said surface, said outlet being sized to apply a preselected shear to said suspension in an amount effective to at least partially destabilize the suspension as it passes through said outlet to coalesce said droplets.
applying said suspension to a rotating member which is received by a seat member associated with a container, to define an outlet therebetween; and rotating said rotating member in contact with said target surface to dispense said suspension through said outlet and onto said surface, said outlet being sized to apply a preselected shear to said suspension in an amount effective to at least partially destabilize the suspension as it passes through said outlet to coalesce said droplets.
15. A method according to claim 14 in which the sus-pension includes in parts by weight:
25% to 98.9% of aqueous liquid;
1% to 15% hydrophobic metal oxide; and 0.1% to 60% dispensible material.
25% to 98.9% of aqueous liquid;
1% to 15% hydrophobic metal oxide; and 0.1% to 60% dispensible material.
16. A method according to claim 15 in which the density of the suspension is from 0.3 to 1.5 g/cc and the ratio of hydrophobic metal oxide to aqueous liquid is from 1/1 to 50/1.
17. A method according to claim 16 in which the hydro-phobic metal oxide is selected from silicon, titanium, aluminum, zirconium, vanadium, iron, or mixtures thereof and contains at least 0.5% by weight organic groups.
18. A method according to claim 17 in which the hydro-phobic metal oxide is silica which is silane treated.
19. A method according to claim 18 in which the hydro-phobic metal oxide is a pyrogenic silica.
20. A method according to claim 14 in which sufficient shear is applied to said droplets to form a continuous phase cream or lotion.
21. A method according to claim 20 in which at least 10% of the droplets coalesce to form larger particles as they pass through said outlet.
22. A method according to claim 21 in which the target is an axilla.
23. A method according to claim 22 in which the dis-pensible material is an antiperspirant compound present in an amount from 5% to 45% by weight, the hydrophobic metal oxide is in an amount from 3 to 10% by weight, water is present in an a-?ount from 30 to 80% by weight and further including from 0 to 5% of a shear control agent.
24. A method according to claim 23 in which the antiperspirant compound is an aluminum-halogen compound having at least one Al-halo bond.
25. A method according to claim 23 in which the anti-perspirant compound is an aluminum-zirconium compound.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000379169A CA1173367A (en) | 1981-06-05 | 1981-06-05 | Roll-on application of aqueous microencapsulated products |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000379169A CA1173367A (en) | 1981-06-05 | 1981-06-05 | Roll-on application of aqueous microencapsulated products |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1173367A true CA1173367A (en) | 1984-08-28 |
Family
ID=4120160
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000379169A Expired CA1173367A (en) | 1981-06-05 | 1981-06-05 | Roll-on application of aqueous microencapsulated products |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1173367A (en) |
-
1981
- 1981-06-05 CA CA000379169A patent/CA1173367A/en not_active Expired
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| Date | Code | Title | Description |
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| MKEX | Expiry | ||
| MKEX | Expiry |
Effective date: 20010828 |