WO1999044750A1

WO1999044750A1 - Squeezebottle powder dispenser

Info

Publication number: WO1999044750A1
Application number: PCT/IB1999/000360
Authority: WO
Inventors: Gary Eugene Mckibben; Christopher Miles Miller; Liezl Gonzales Peterson; William David Hoenninger
Original assignee: The Procter & Gamble Company
Priority date: 1998-03-02
Filing date: 1999-03-02
Publication date: 1999-09-10
Also published as: AU2438099A

Abstract

The present invention provides a powder delivery system comprising a squeezebottle (12) defining a semi-enclosed container having resilient outer walls and a discharge orifice located at one end which is provided with a resilient, self-closing valve (28). The valve (28) is self-biasing toward a closed condition but openable in response to an increase in internal pressure within the squeezebottle (12) when the internal pressure exceeds a threshold pressure. The powder delivery system further comprises a product contained within the squeezebottle (12) in the form of an aerated powder and at least partially filling the interior of the squeezebottle (12) to define a powder level (66). The squeezebottle (12) defines a continuous flowpath for the product from the powder level (66) to the discharge orifice when the squeezebottle (12) is oriented with the discharge orifice located below the powder level, such that when external compressive forces are applied to the squeezebottle (12) the valve (28) opens to discharge the product substantially uniformly as a spray of dispersed powder particles.

Description

SQUEEZEBOTTLE POWDER DISPENSER

FIELD OF THE INVENTION

The present invention relates to dispensers for powders, and more particularly to manually-operated squeezebottle-type dispensers which dispense the powder in the form of a dispersed spray of powder particles.

BACKGROUND OF THE INVENTION

Powder dispensing is not as well understood as liquid dispensing because powder dispensing involves a two-phase fluid containing a compressible gas and a plurality of independently-mobile solid particles. Even powders dispensed by gravity or by shaking a canister have air mixed with the solid particles. Flowability of a powder is believed to be influenced by multiple factors, including the size and shape of the particles, the tendency for particles to stick to each other (agglomeration), the density of particles, and the volume of air between particles. Particles may stick to each other due to electrostatic attraction as well as adhesive forces. Moisture absorbent powders in particular are prone to caking and resist flow when moisture is sufficiently absorbed. Therefore, moisture absorbing powders are typically contained in relatively air-tight dispensers so that they remain flowable for dispensing after being stored for extended periods in the presence of moist ambient air, such as often exists in a bathroom.

Moisture absorbent powders are useful in maintaining body surfaces dry and feeling soft. Where body surfaces are substantially smooth and upwardly-facing, it is relatively easy to shake a powder from a canister onto the surface and distribute the powder evenly by using one's fingers. However, finger distribution is considered messy because one's hands must then be washed after powder application to remove powder residue. Delivering powder to a body surface having hair or which faces substantially horizontally or downwardly is made easier by a delivery system which effectively directs a pressurized stream of powder onto the surface without the need for subsequent manual distribution of the powder. Such dispensers may be preferred for such applications, especially when powder is directed to body locations where manual powder transfer may be considered unsanitary.

Squeeze type powder sprayers are known in the art. In one common version a resilient bulb is squeezed to cause a burst of air to flow past a container of powder. The powder is drawn into and mixed with the airstream, presumably because the movement of the air generates a low pressure zone adjacent the powder surface. Bulb type powder dispensers are typically limited to very low powder doses. Also, such powder sprays tend to be highly aerated and form an undesirable dust cloud when fine particles are sprayed in this fashion.

Squeezebottles which contain powder typically have an air headspace. Powder is discharged by squeezing the bottle to cause headspace air to push a portion of powder and air out of the bottle. Air pressure may force the powder out of the container through an always-open orifice, or an orifice which may be closed between dispensing operations and open during a session of use such as those formed as a pivoting spout. A disadvantage of such discharge orifices that are always open is that they expose the powder remaining inside the container to the effects of moisture and/or other contamination. Removable closures are available for such powder dispensers, but removable closures may not be reliably replaced after spraying due to inattention on the part of the user and/or loss of the closure. Closures which may be selectively closed or left open are subject to being left open inadvertantly by the user and thus likewise subjecting the contents to contamination.

In order to deliver a powder onto substantially vertical surfaces and downwardly- facing horizontal surfaces, and in such a manner that powder always covers the discharge orifice so that a high concentration of powder is delivered, it is believed beneficial to have the discharge orifice located at or near the bottom end of the dispenser. Diptubes are generally required with squeezebottle powder dispensers intended for bottom dispensing to bring air to the discharge point below the powder level. Such diptubes are generally needed when powder compacts at the bottom of the container and cannot otherwise be aerated for spraying. However, diptubes and air/powder mixing provisions are an added expense to the squeezebottle, and diptubes provide an opportunity for powder plugging if a powder should become compacted in the diptube

Accordingly, it would be desirable to provide a delivery system for powdered products which reliably and uniformly distributes powder to a target surface.

It would also be desirable to provide such a delivery system which distributes powdered products in an efficient manner with minimal waste and messiness.

It would further be desirable to provide such a delivery system which provides with user with significant control over the dispensing operation both in terms of aiming the delivered powder for delivery to a desired location and also in terms of controlling the dosage of powder delivered.

SUMMARY OF THE INVENTION The present invention provides a powder delivery system comprising a squeezebottle defining a semi-enclosed container having resilient outer walls and a discharge orifice located at one end which is provided with a resilient, self-closing valve. The valve is self-biasing toward a closed condition but openable in response to an increase in internal pressure within the squeezebottle when the internal pressure exceeds a threshold pressure. The powder delivery system further comprises a product contained within the squeezebottle in the form of an aerated powder and at least partially filling the interior of the squeezebottle to define a powder level.

The squeezebottle defines a continuous fiowpath for the product from the powder level to the discharge orifice when the squeezebottle is oriented with the discharge orifice located below the powder level, such that when external compressive forces are applied to the squeezebottle the valve opens to discharge the product substantially uniformly as a spray of dispersed powder particles.

The valve preferably comprises a resilient slit valve which functions as both a discharge valve and a return air valve, and the threshold pressure for discharge is at least about 1.0 psi. The threshold pressure for return airflow is preferably less than the threshold pressure for product discharge. The continuous fiowpath also functions as a return air fiowpath, and external compressive forces needed for dispensing are preferably between about 5.0 and about 7.0 pounds force (about 22 to about 31 Newtons). The delivery system preferably further includes a secondary closure which may be selectively positioned over said discharge orifice.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims which particularly point out and distinctly claim the present invention, it is believed that the present invention will be better understood from the following description of preferred embodiments, taken in conjunction with the accompanying drawings, in which like reference numerals identify identical elements and wherein:

Figure 1 is an exploded perspective view of a preferred embodiment of the powder dispenser of the present invention, showing a squeezebottle, a housing, a resilient slit valve, a snap-on fitment, and a slide button closure;

Figure 2 is a front elevation view thereof, showing the assembled powder dispenser; Figure 3 is a side elevation view thereof, showing the effect of an upper portion of the dispenser being squeezed to dispense powder from the slit valve near the bottom of the dispenser;

Figure 4 is a sectioned side elevation view thereof, taken along section line 4-4 of Figure 2, showing a cross-section of a lower portion of the dispenser, including the slit valve with slide closure open;

Figure 5 is a side elevational view of an experimental apparatus suitable for use in evaluating the performance of the powder delivery systems according to the present invention; and

Figure 6 is a graphical representation of powder pattern distribution data presented in Table 1.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, Figure 1 depicts a preferred embodiment of a powder dispenser of the present invention, generally indicated as 10. Dispenser 10 preferably includes a squeezebottle 12 defining a semi-enclosed (having at least one opening) container as an upper portion and a lower portion, preferably connected together by a snap-fit. Squeezebottle 12 is preferably made of low density polyethylene by conventional blow molding in order to have a resilient sidewall 14 which may be deflected manually when subjected to an external compressive force F, as shown in Figure 3, and which returns to an unsqueezed condition, as shown in Figure 2 after the compressive force is discontinued. The lower portion is substantially rigid, and includes a housing 22, which may be made of polypropylene by conventional injection molding. The lower portion also includes a fitment 24, a slide closure 26, and a resilient slit valve 28. Fitment 24 is preferably injection molded of polypropylene and is snap-fit into housing 22. Slide button 26 is preferably injection molded of polypropylene and is snap- fit into fitment 24. Slit valve 28 is preferably injection molded of silicone rubber and is sandwiched in place between fitment 24 and housing 22.

Squeezebottle 12 preferably has an outwardly domed top 16 and housing 22 preferably has a flat bottom 30 so that dispenser 10 may be rested on flat bottom 30 rather than on domed top 16. Squeezebottle 12 also has a substantially downward-facing bottle finish 18. Bottle finish 18 is preferably substantially more rigid than resilient sidewall 14 because of its smaller size and/or heavier wall thickness. Bottle finish 18 preferably has a cylindrical wall shape. Housing 22 has an internal annular wall 32 which has a complementary shape with and snugly fits within the cylindrical wall of finish 18 in order to provide an air-tight and product-tight seal. This construction allows sidewall 14 to be deflected, such as by externally-applied compressive force F, in order to reduce the interior volume of the squeezebottle and thus generate air pressure inside dispenser 10 without air leakage at the connection between annular wall 32 and bottle finish 18. Squeezebottle 12 also preferably has external provisions for snap-fitting together with housing 22. In a preferred embodiment, squeezebottle 12 has a circumferential groove 20 into which internal projections 34 of housing 22 snap for engagement.

Housing 22 has an opening 36 into which fitment 24 snap-fits by means of resilient lugs 38 on fitment 24. Fitment 24 also has a cylindrical opening 40 having a rim 42, which contacts slit valve 28 at a flange 44. Fitment 24 has an opening 46 surrounding a resilient cantilevered beam 48 which has at its outermost end a projection 50 perpendicular to beam 48. Slide button 26 has resilient lugs 52, which snap-fit into opening 46 of fitment 24. Slide button 26 also has two detents 54 and 56, which engage projection 50 of beam 48 so that slide button 26 maintains one of two positions with fitment 24. When detent 54 engages projection 50, slide button 26 uncovers opening 40; and when detent 56 engages projection 50, slide button 26 tightly closes opening 40.

Resilient slit valve 28 has a seat portion 58 and a normally inwardly (toward the interior of the dispenser) domed portion 60. Domed portion 60 has a substantially centered, preferably straight, slit 62. Housing 22 has a circular opening 64 in the side of internal wall 32 into which seat portion 58 fits. When fitment 24 is snapped into opening 36 of housing 22, rim 42 of fitment 24 presses flange 44 of resilient slit valve 28 against the edge of opening 64 to facilitate a seal between slit valve 28 and housing 22. Therefore, any pressure developed inside squeezebottle 12 as a result of squeezing with a force F (as shown in Figure 3) can only escape through slit 62 of slit valve 28 as a dispersed spray 68 of product powder. The resilient dome of slit valve 28 is normally concave inward such that any pressure against the dome from inside the squeezebottle tends to seal the slit opening more tightly. The curvature of the dome therefore makes the valve self-sealing. Once a threshold pressure is overcome, the valve inverts such that the dome is convex outward and the slit spreads open to relieve the internal pressure from the squeezebottle. A similar slit valve is disclosed in a commonly owned U.S. Patent No. 4,728,006 to Drobish et al., which is hereby incorporated herein by reference. Figure 4 depicts the functionality of the slit valve 28 with the closed orientation shown in solid lines and the open orientation shown in dotted lines. Also shown in Figure 4 is the powder 66 and its relationship to the interior of the squeezebottle 12 and the various elements which form a continuous fiowpath between the uppermost level of powdered product within the interior of the squeezebottle and the slit valve when the squeezebottle is oriented with the discharge orifice (slit valve) below the level of the powder. Although not depicted in Figure 4, various projecting elements such as pins, blades, or the like may be incorporated into the flowpath to reduce any tendency of the powder to become packed or caked in the flowpath, which would restrict or prevent free flow of powder to the slit valve. Also clearly shown in the drawings figures, particularly Figure 4, is the relationship between the longitudinal axis of the container and the discharge axis defined by the discharge orifice. As shown in Figure 4, the discharge axis forms a substantially perpendicular relationship to the longitudinal axis of the container, which aids in the ergonomic characteristics of the package where a user may utilize the delivery system to deliver powder to surfaces of his or her own body, especially portions of the body which are more difficult to see and/or reach.

Powder delivery systems in accordance with the present invention provide a controlled delivery of a powder product in the form of a spray pattern. Accordingly, the powder and the dispenser act in conjunction with one another to provide a synergistic effect upon the dispensing operation. While the powder must be designed to address key consumer needs in terms of powder performance once present upon the target surface (skin, etc.), the powder must also be designed to successfully flow through the elements of the dispenser and spray effectively from the dispenser onto the target surface. The dispenser must likewise be designed for both aesthetic and ergonomic attributes in and of itself, as well as to facilitate controlled and effective dosing and delivery of the pattern in the desired spray pattern.

Important characteristics from a consumer standpoint which determine successful delivery system performance are the ability to deliver the desired dosage of powder to the desired location, the ability to do so without clumping of excess powder which may fall to the floor or other undesirable location, and the ability to do so without creating an undesirable airborne cloud of very fine powder particles.

By way of example, the particle size and flowability of the powder are believed to be key factors in determining successful performance in a delivery system. Each of these factors are in turn influenced by the powder composition and processing techniques. For a given set of powder properties and physical characteristics, the physical properties of the dispenser components may be tailored to provide the desired performance attributes in terms of spray dosage and pattern. Also important in terms of spray quality characteristics are the individual conditions which comprise the dynamic dispensing operation such as the amount of externally-applied compressive force exerted by a user, the rate at which this force is applied and released, the force profile, squeezebottle resiliency, etc. The slit length and the resiliency of the valve are important physical characteristics of the dispenser in determining the spray characteristics of the powder spray. If the slit is too short, the spray may have clumps of powder in it. If the slit is too long, the spray may produce a greater dust cloud. Also, a given spray impulse sprays a larger dose of powder when the slit is longer. While the dispensers in accordance with the present invention preferably include a slit valve, other types of resilient, self-closing valves are also within the scope of the present invention, such as bullet valves, etc. The self-closing nature of such valves is important not only to protect the powder product from contamination and/or degradation, but also to maintain a pressure differential across the valve (described hereafter) and to aid in breaking up any clumps which may tend to form in the flowing powder. The use of slit valves is believed to be preferred because, without wishing to be bound by theory, it is believed that an elongated slit forms an exit stream of greater surface area per cross-sectional area than a circular orifice, and thus creates greater instability in the exit stream due to contact with stagnant environmental air. Instability is in turn believed to be an important factor in generating an outwardly- expanding conical spray pattern from a small exit orifice.

Squeezebottle sidewall materials which have less resiliency provide lower forces to resist changes in bottle shape may cause some unsupported portions of the bottle to deflect outwardly during handling, thereby taking up some of the deflection needed to produce an adequate volume of air and powder displacement or dosage. Sidewall materials with resiliency providing higher forces is also undesirable because of the difficulty producing a rapid squeeze while aiming the discharge orifice. Hence, the proper selection of sidewall material properties is important in determining overall dispensing performance.

Also, the valve material and thickness should provide for a highly resilient valve, but also one which inverts at a low threshold pressure so that powder doesn't explode when the valve finally opens. Limiting threshold pressure helps to reduce dust clouding, since greater threshold pressures result in a greater pressure differential across the valve at the instant of valve opening and a more rapid change in pressure once opening occurs. The existence of a pressure differential at or substantially adjacent to the exit of the dispenser is believed to be an important aspect of the present invention in terms of providing for a dispersed spray of powder in contrast to a tightly-constrained powder stream. As described in greater detail in the aforementioned Drobish et al. patent, the normally-closed valve structure ensures that sufficient pressure for proper dispensing will build up within the dispenser before the valve opens at the designed threshold pressure, the valve will remain open so long as sufficient pressure remains available within the package, and the valve will close when sufficient pressure no longer exists. Varying the pressure within the dispenser above the threshold pressure influences the qualities of the resulting powder spray. The pressure response properties of the valve are selected so as to provide the desired spray characteristics for the particular properties of the powder to be utilized. A resilient domed slit valve of circular cross-section with a domed portion diameter of about 0.36 inches and a dome radius of about 0.75 inches, made of 0.025 inch thick silicone rubber having a Shore A durometer of about 50, and having a single centered straight slit about 0.3125 inches long has performed satisfactorily.

The user also has the ability with the dispensing systems of the present invention to tailor the dosage and spray pattern by controlling the manner of manipulating the squeezebottle. For example, the squeezebottle may be manipulated in a series of short, shallow compressions to deliver a series of small doses or a longer, deeper compression for a more sustained dose. The squeezebottle may also be squeezed quickly to develop a sharp, strong spray of powder or more gently to develop a smaller, more diffuse spray of powder. Because the user has the ability to control the pressure profile of the dispenser, as well as to control the aiming of the dispenser and distance from the target surface, the delivery systems of the present invention provide satisfactory results for a wide variety of users in a wide variety of circumstances.

From a consumer standpoint, in the field of personal hygiene-type powders it is believed desirable to have a compressive force to actuate in the vicinity of about 5.0 to about 7.0 pounds force (about 22 to about 31 Newtons) and an average dosage per actuation of about 0.05 to about 0.3 grams of powder product.

The preferred powder spray discharges from the slit in a substantially conical shape. The cone expands from the slit to a substantially circular diameter of about 3 inches to about 4 inches at a distance about 6 inches from the slit. The preferred powder has an aerated bulk density, a spray velocity, an air to powder ratio, and a mean particle size that enable the powder to impact a target surface and stay there without rebounding or falling off onto a floor. Powder that does not remain on the target surface typically generates a mess and results in inefficient product dosing. The cross-sectional shape of the resulting conical discharge pattern may be circular, oval, or any other desired shape (i.e., it need not be a truly circular cone).

For repeat spray impulses, it is preferable that the powder remain aerated between discharges. The preferred powder seems to remain aerated after a single spray for a period of at least 24 hours when the dispenser is left undisturbed. Such extended aeration is believed due to be due to the low density of the powder and its fine mean particle size. The aerated bulk density of the preferred powder ranges from about 0.01 grams/cc to about 0.06 grams/cc. At higher aerated densities, the period of powder aeration in an undisturbed dispenser decreases to an undesirably short time, such that shaking may be required between uses. During product shipping from manufacturer to consumer, the powder in the dispenser typically undergoes compacting form vibration and other disturbances. When first used it may be necessary for a consumer to shake the dispenser in order to aerate the powder. Thereafter, shaking should not be necessary.

In addition to the preferred tendency of the powder to remain in an aerated state for extended periods of time, the design of the delivery systems of the present invention also aids in aeration of the powder within the container. The slit valve forms not only the delivery and dispensing orifice for the discharged air/powder mixture, but also a return air vent to allow outside air to enter the interior of the container to replace lost air and powder when the external forces are removed and the resiliency of the bottle causes it to return to its original shape. The returning air traverses the entire powder flowpath from the valve slit itself all the way through the powder to the powder surface adjacent the headspace above the powder within the container. This ensure a constant aeration effect each time the dispenser is squeezed and released, thereby aiding in the resistance of the delivery system to powder packing and clogging.

Since the powder dispensers of the present invention have a single passageway to the outside environment which alternatively functions as both a dispensing flowpath and a return air flowpath, and the orientation of the exit orifice relative to the rest of the dispenser is always below the upper surface of the powder, the only air that is expelled during a dispensing operation is air which is entrained within the powder. This permits tailoring of the powder and the components of the delivery system for the desired dispensing characteristics.

The resiliency of the squeezebottle is also an important design consideration in terms of the "suck back" feature for returning air to the interior of the bottle and "re- aerating" the powder inside. It is desired that the bottle be sufficiently resilient so as to generate a strong positive flow of air through the powder and overcome the natural resistance to airflow that the powder presents. If the airflow is too weak and slow in velocity, it is believed that the dispensing system will be less robust and more prone to packing of the powder depending upon powder characteristics. The self-closing nature of the valve geometry also preferably facilitates return airflow. In the instance of the preferred slit valve, the valve is normally positioned such that it is concave inwardly such that it takes a greater threshold pressure to invert the valve past the "over center" position and open the valve based on internal pressure for product dispensing than to open the valve inwardly for return airflow. 10

Since the desired delivery from the dispenser is a two-phase product consisting of atomized, dispersed powder particles suspended in a moving current of air, air which returns to the dispenser after a delivery cycle replenishes the supply of air within the dispenser and thus a portion of the product expelled is recovered. As stated previously, this not only replaces the displacement of the delivered powder but also re-aerates the powder within the dispenser.

The spray quality and valve performance depend upon not only the powder physical characteristics, but also the ratio of air to powder that is to be delivered. While this air/powder ratio is believed to vary as the level of product within the squeezebottle varies during its useful life, it is desirable that the delivery system (powder and dispenser) be designed to maintain satisfactory performance throughout the useful life of the system (i.e., until the product is exhausted).

The slit in the slit valve may be oriented in any direction desired for purposes of fabrication, assembly, and/or spray pattern orientation. It may even be made to have an adjustable orientation. The orientation shown in the drawings was chosen for convenience of illustration. In addition, if desirable the dispenser may be designed to accommodate refill cartridges and/or have removable plugs, caps, or housings so as to permit refilling of the dispenser from another product source (larger container, etc.)

The slide button provides a secondary closure for the opening in the fitment through which a spray is discharged from the slit valve when the squeezebottle is squeezed. Although the slit valve is self-sealing by virtue of its normally concave domed shape, the use of the dispenser for a feminine powder typically occurs in a bathroom after showering, where the humidity can be high. In order to minimize moisture entering the dispenser from the bathroom through the slit valve, the slide button closure acts as a secondary closure. In addition, when traveling with the powder dispenser, inadvertent squeezing of the squeezebottle may discharge powder within a travel bag, thereby causing a mess. Having the secondary closure minimizes this problem.

Although other powder sprayers may have openable secondary closures, such closures may be easily misplaced or left off the dispenser. The slide closure provides the benefit of remaining with the dispenser at all times. Because of its ease of one-handed use, the slide closure is ideal for a dispenser which is gripped in the palm of the user's hand.

The squeezebottle may be designed for any desired ergonomic or other characteristics and may have any desired shape and/or internal volume. For the presently preferred application, the squeezebottle has an internal volume of approximately 160 ml. In typical fashion, powder delivery systems of the present invention are preferably filled 11

by weight rather than volume, and in the case of a 160 ml vessel may be filled with approximately 28-30 grams of powdered product. Due to the compressibility of aerated powders, it is essential that the internal volume of the container exceed the aerated volume of the powder at maximum fill level to allow sufficient free space for powder mixing and aeration. It is believed that free space in excess of aerated powder volume should equal approximately 10-20% of total container volume.

With the powder delivery systems of the present invention incorporating a downwardly-dispensing discharge orifice and a simple but effective internal powder flowpath, the delivery systems of the present invention provide easy-to-use functionality for applying powder to hard to reach areas of the human body such as the back, buttocks, underarms, and genital area.

REPRESENTATIVE POWDER COMPOSITIONS:

While powder dispensing and delivery systems of the present invention may be designed to effect the desired dosage and spray pattern for a wide variety of powder compositions, powders for topical application to the human body have been found to be of high interest for use with the present invention. What follows is a description of this type of powder, along with specific illustrative compositions which have shown desirable flowability and other physical characteristics for use with the present invention. This description is in turn followed by exemplary experimental procedures useful in evaluating powder/package performance.

POWDER CARRIER

The odor absorbers, highly effective moisture absorbers, and other optional ingredients should be dispersed in a pharmaceutically-acceptable powder carrier for convenient, uniform application and disbursement onto the skin. The term "pharmaceutically-acceptable", as used herein, means a powder suitable for topical use on the skin without undue toxicity, irritation, allergic response, and the like. Powder carriers include powders known in the art to be safe for human skin. Such powders include but are not limited to cornstarch (topical starch), talc, rice starch, oat starch, tapioca starch, microcrystalline cellulose (for example Avicel®), aluminum starch octenyl succinate (sold by National Starch & Chemical Co. as Dry Flo® Pure, Dry Flo® XT, and/or Dry Flo® PC), kaolin, and mixtures thereof. Preferred is cornstarch. The powder carrier will typically comprise from about 10% to about 100%, preferably from about 15% to about 80%, more preferably from about 25% to about 55%, by weight of the composition. 12

OPTIONAL INGREDIENTS

Odor Absorbers: The powder may comprise odor absorbers such as uncomplexed cyclodextrin, zeolites, carbon odor-controlling agents, sodium bicarbonates, antimicrobial agents and or antiperspirant ingredients for added body odor control.

As used herein, the term "cyclodextrin" includes any of the known cyclodextrins such as unsubstituted cyclodextrins containing from six to twelve glucose units, especially alpha-cyclodextrin, beta-cyclodextrin, gamma-cyclodextrin and/or their derivatives and/or mixtures thereof.

The term "uncomplexed cyclodextrin" as used herein means that the cavities within the cyclodextrin in the composition should remain essentially unfilled prior to application to skin in order to allow the cyclodextrin to absorb various odor molecules when the composition is applied to the skin. A more complete description of cyclodextrins, cyclodextrin derivatives, and cyclodextrin particle sizes, and their use in body powders is described in U.S. Patent Application Serial No. 08/736,838, Peterson et al., filed on October 28, 1996; and in U.S. Patent No. 5,429,628, Trinh et al., issued July 4, 1995, which are both incorporated herein by reference in their entirety.

The term "zeolite", as used herein, refers to non-fibrous zeolites. When included in the powder, zeolites may be present from about 0.1% to about 25%, preferably from about 1% to about 15%, by weight of the composition. A detailed description of zeolites useful in the such powders is found in U.S. Patent No. 5,429,628, Trinh et al., issued July 4, 1995, incorporated herein by reference in its entirety.

Carbon odor-controlling agents described in U.S. Patent No. 5,429,628 may be used at a level of from about 0.1% to about 25%, by weight of the composition.

Sodium bicarbonate is known in the art for its use as an odor absorber. An example of sodium bicarbonate and its use as an underarm deodorant is found in U.S. Patent No. 4,382,079, to Marschner, issued May 3, 1983, which is incorporated herein in its entirety by reference. When included, sodium bicarbonate may be present from about 0.1% to about 50%, by weight of the composition.

The antimicrobial agents are selected from a group consisting of antibacterial agents, antifungal agents, and mixtures thereof. Antimicrobial agents help destroy and/or control the amount of bacteria and/or fungi present on the skin. Preferred antimicrobial agents are zinc phenolsulfonate, zinc oxide, triclosan, Zelec® AM by DuPont, zinc ricinoleate, zinc undecylenate, and mixtures thereof. More preferred are zinc phenolsulfonate, zinc oxide, and triclosan. Triclosan is available from Ciba-Geigy as Irgasan DP-300. Examples of antimicrobial agents are found in the Cosmetic Bench 13

Reference, 1994 Edition, page 10, which is incorporated herein by reference. When included, the antimicrobials are at a level of from about 0.01% to about 25%. Preferably from about 0.1% to about 10%, by weight of the present composition.

When used on the underarms, antiperspirant ingredients may be included. Examples of antiperspirants known in the art are found in the Cosmetic Bench Reference, 1994 Edition, page 13, which is incorporated herein by reference. When included, antiperspirants may be present from about 0.1% to about 25%, by weight of the composition.

Moisture Absorbers: Powders can also, optionally comprise highly effective moisture absorbers to aid in reducing excess moisture on occluded skin. Highly effective moisture absorbers also increase the flowability (the ability to flow without caking due to moisture) of the compositions. As used herein, the phrase "highly effective moisture absorbers" refers to silicas (silicone dioxide), silicates or carbonates wherein the silicates and carbonates are formed by reaction of a carbonate or silicate with the alkali (IA) metals, alkaline earth (IIA) metals, or transition metals.

Preferred highly effective moisture absorbers are silicas which are in the form of microspheres, ellipsoids, barrel-shapes, and the like. Silica ellipsoids which are useful are available from DuPont as ZELEC® Sil. Silica microspheres are available from KOBO as MSS-500, MSS 500/3, MSS-500/H, MSS-500/3H, MSS-500/N, and MSS- 500/3N. Additionally, it is preferred that some of the silica be fumed silica for increased flowability of the powder. Fumed silica is available from Cabot Corporation (Cab-O-Sil ®) and from Degussa (Aerosil®). Preferred highly effective moisture absorbers are calcium silicate, amorphous silicas, calcium carbonate, magnesium carbonate, or zinc carbonate, and mixtures thereof. Some specific examples of the silicates and carbonates are more fully explained in Van Nostrand Reinhold's Encyclopedia of Chemistry, 4th Ed. pages 155, 169, 556, and 849, (1984), which is incorporated herein by reference.

Preferred are synthetic versions of the highly effective moisture absorbers, particularly in regards to silicas and silicates due to safety risks related to crystalline silica. Synthetic versions are formed by controlled chemical reactions in a manufacturing process rather than using a natural, mined version of these compounds which is then further refined. Also preferred are moisture absorbers which are in the form of microspheres.

Synthetic carbonates can be obtained from various suppliers such as Mallinckrodt or Whittaker, Clark, and Daniels. Examples of synthetic calcium silicates useful in the present invention are Hubersorb® 250 or Hubersorb® 600 available from J.M. Huber. 14

It is preferred that the highly effective moisture absorbers comprise from about 1% to about 60%; more preferred, from about 10% to about 50%; and most preferred, from about 20% to about 40% by weight of the total composition.

Skin Aids: The compositions also optionally include skin aids. The term "skin aids", as used herein, refers to skin protectants, emollients, and moisturizers. Skin protectants which are useful are found in the Cosmetic Bench Reference, 1994 Edition, page 53; and the Monograph on Skin Protectant Drug Products for Over-the-Counter Human Use, 21 CFR 347. Preferred skin protectants are corn starch, kaolin, mineral oil, sodium bicarbonate, dimethicone, zinc oxide, colloidal oatmeal, and mixtures thereof. When present, the skin protectants comprise from about 0.1% to about 80%, preferably from about 0.1% to about 30%, most preferably from about 0.1% to about 10%, by weight of the composition.

Emollients and moisturizers which are suitable can be found in the Cosmetic Bench Reference, 1994 Edition, pages 27-32 and 46-48, incorporated herein by reference. Preferred emollients and moisturizers are tocopherol, tocopheryl acetate, aloe, vegetable oils, mineral oil, petrolatum, jojoba oil, and mixtures thereof. More preferred are encapsulated or spray/freeze dried emollients. The use of spray/freeze dried or encapsulated emollients keeps the emollients protected in the powder carrier until they are released through shearing (such as rubbing against undergarments or clothes) or through contact with skin moisture. Examples of preferred commercial spray/freeze dried aloe useful in the present invention are Terra-Dry™ Freeze Dried Aloe, Terra-Pure ™ Freeze or Spray Dried Aloe, and Terra-Spray ™ Spray Dried Aloe, all from Terry Laboratories. When present, the emollients/moisturizers comprise from about 0.1% to about 50%, preferably from about 0.1% to about 25%, most preferably from about 0.1% to about 10%, by weight of the composition.

Slip Compounds: The present compositions may optionally comprise slip compounds. The term "slip compounds", as used herein, refers to compounds which have unique structures which provide enhanced slip/lubrication characteristics of powders and/or reduced skin to skin friction between intertriginous skin sites. For example, platelet and spherical structures allow particles to move over each other with enhanced perceived slip. Other structures which similarly provide enhanced slip are those such as fatty acid derivatives.

Slip compounds which are suitable include polyethylene; nylon; polytetra- fluoroethylene; mica; lauroyl lysine; talc; silicone (e.g. dimethicone) and metallic stearates (e.g. zinc or magnesium stearate); and mixtures thereof. When present, the slip 15

compounds comprise from about 0.1% to about 60% , preferably from about 1% to about 30%, by weight of the composition.

Binders: The powder compositions may optionally also include dry or wet binders to help promote adhesion of the powder and active ingredients to the skin. Binders which are useful are found in the Cosmetic Bench Reference, 1994 Edition, pages 13-14, which is incorporated herein by reference. Preferred binders are calcium stearate, zinc stearate, magnesium stearate, isopropyl myristate, magnesium myristate, silicone, and mixtures thereof. More preferred are zinc stearate, magnesium stearate, dimethicone, and mixtures thereof. When included in the composition, the binders are at a level of from about 0.1% to about 25%, preferably from about 1% to about 15%, by weight of the composition.

Flow Aids: Flow aids such as those known in the art may be included in the compositions where increased flowability (and/or anti-caking) of the powder is desired. Examples of flow agents known in the art are found in McCutcheon's Functional Materials, 1992 Edition, Vol. 2, pp. 11-12, incorporated herein by reference.

Anit-pruritics: Anti-pruritic agents such as those known in the art may be included in the powder compositions. Examples of anti-pruritic agents useful in the present invention are Magnesium-L-Lactate, hydrocortisone, hydrocortisone acetate, and colloidal oatmeal. A description of anti-pruritic agents are found in the Handbook of Non Prescription Drugs, 10th Edition, p. 529, 1993; which is incorporated herein by reference. When included in the composition, anti-pruritic agents may be present from about 0.1% to about 40%, by weight of the composition.

Colorants and Fragrances: Colorants, dyes, and/or fragrances can be optionally added to the compositions for visual appeal and performance impression. Colorants suitable for use in the present invention are found in the Cosmetic Bench Reference, 1994 Edition, pages 21-22, which is incorporated herein by reference. Fragrances known in the art may also be added to the powders herein.

PROCESS OF MAKING COMPOSITIONS

The compositions disclosed above as being suitable for use with powder delivery systems of the present invention are prepared by the following steps: creating a mixture by mixing cyclodextrin, highly effective moisture absorbers, and optional ingredients in a powder carrier via a commercially available mixer such as a vee-blender, double cone blender, or ribbon blender until the mixture is uniform; and creating a reduced size mixture using a commercially available size reduction technique such as hammer 16

milling, impact milling, ball milling, or fluid energy milling until the desired particle size distribution is achieved (which may require repeating milling steps).

Perfume composition, whether encapsulated or free, may be added to the present compositions in many different ways. One suitable method of including encapsulated perfume involves forming cyclodextrin complexes in the manner described in U.S. Patent 5,429,628, to Trinh et al., issued July 4, 1995, which is incorporated herein by reference, and blending the perfume/cylcodextrin complexes with the composition above in a final or in an intermediate step. Where desired, free perfume (not complexed with cyclodextrin) may be incorporated by spraying the cyclodextrin, carrier, or any of the powder ingredients with the free perfume. Preferably, the free perfume is blended with one or more of the liquid ingredients herein, such as the skin aids, prior to the spraying. Additionally, where liquids are included in the formula, such as wet binders, skin aids, or fragrances, an additional milling step may needed to follow the addition of the liquids for optimal performance in the delivery system of the present invention.

Ingredient %W/W

Corn Starch (Topical Starch) 54.50

Silica (Ellipsoids) 5.00

Fumed Silica 3.00

Zinc Phenolsulfonate 2.00

Triclosan 0.10

Cyclodextrin 2.90

Nylon- 12 10.00

Lauroyl Lysine 20.00

Dimethicone 2.50

Total 100.00

EXAMPLE II

Ingredient %w/w

Corn Starch (Topical Starch) 42.50

Silica (Ellipsoids) 17.00

Fumed Silica 3.00

Zinc Phenolsulfonate 2.00

Triclosan 0.10

Cyclodextrin 2.90

Nylon- 12 10.00

Lauroyl Lysine 20.00

Dimethicone 2.50

Total 100.00 17

EXPERIMENTAL PROCEDURES:

A variety of experimental procedures are known in the art for defining and characterizing a spray of particulate material such as the powders utilized with the present invention. What follows is a discussion of two particular methods which have been found useful to characterize the pattern of powder delivered in the spray pattern and the efficiency of the delivery system in delivering powder to a target surface. Figure 5 depicts a test apparatus useful in performing these evaluations, with identifying numerals in the figure corresponding to equipment numbers in parentheses below. While these test procedures are intended to resemble real-world delivery system performance in some aspects, the focus for these procedures is on repeatability and reliability rather than on true representations of consumer scenarios.

Pattern Test

Objective: To determine the spray pattern developed by the powder delivery system of the present invention.

Equipment:

• Entran model EPX-VO 1 -50P-/RS 0-50 PSIG pressure transducer. ( 100)

• Nicolet oscilloscope. (Not shown)

• Entran power supply/amplifier PS 30A (Not shown)

• Entran Easy Connect adapter: EC-AR. (Not shown)

• Spray bottle with powder modified with transducer. (10)

• Miller 3 way valve and regulator. (Not shown)

• Pressure guage. (Not shown)

• Load cell with sensor (150,140)

• Gralab Model 605 solenoid controller. (Not shown)

• Bimba model PFC-091 2 direction air piston. (Cylinder 120, ram 130)

• Custom squeeze test fixture. (190, positioned on support surface 110)

• Patternator, comprising a square grid of 64 square test tubes 1cm x 1cm x 4.5cm deep. (160, with tubes 170, supported by an angled support 180)

Preparation:

• Install transducer into top of spray bottle.

• Connect transducer to power supply/amplifier via adapter. 18

• Connect oscilloscope to read signal output of amplifier.

• Fill test bottle over ^lA full (28g).

• Place test bottle into squeeze test fixture.

• Adjust Entran PS 30A to maximum zero offset.

• Oscilloscope

Channel 1 = 1.2

Time = 500uS

Channel 1 User Units = 4.584 X EE 0 PSI

• Set air pressure to 10 Lbs. ( Should produce between 1 lbs. and 1.1 lb.)

• Set solenoid controller to 0.5 seconds, (based on panelist time to initiate force to peak force of ~0.25 seconds.)

Data:

• Maintain record of internal pressure after each squeeze. This data should be graphed to determine if there is an upward trend in pressure which would indicate clogging.

Procedure:

1. Place patternator at 4 inches from bottle output

2. Initialize the test equipment.

3. Activate automatic squeezing of bottle and record internal pressure.

4. Remove bottle from test fixture and entrain air into the powder, (gently shake the bottle)

5. Place bottle back into the test fixture.

6. Activate solenoid 5 times

7. Weigh and record the powder in each patternator cell

8. Repeat the process 3 times.

9. To obtain the spray pattern, average the data and graph.

Table 1 presents results for the composition in accordance with Example 1 at a 4 inch target distance for the patternator, with at total of 6 squeezes into the patternator and results tabulated by weight and by percent of total weight. The results (weight) are presented graphically as Figure 6.

TABLE 1

4 inches from target Sumation of Six Squeezes 1.1 lbs of internal pressure

Left 2 3 4 5 6 7 Right 19

Bottom 0007 0008 0011 0011 0009 0012 0011 0007

2 001 0015 0058 0033 0024 0014 0013 001

3 0008 0064 0423 0053 0023 0011 0007 001

4 001 0199 0274 0034 0014 001 001 0006

5 0011 0682 0785 0032 0012 0011 0006 0007

6 0006 008 0519 0029 0015 001 0005 0008

7 ooos 0051 0214 0042 0016 0007 0003 0006

Top 0 0013 0028 0014 0008 0005 0003 0001

Weight/column 00₅7 1112 2312 0248 0121 008 0058 0055

Total Weight Sprayed 4043 Grams

Total Volume 1352174 cc

% Percent Profile

Left 2 3 4 5 6 7 Right

Bottom 0173139 0197873 0272075 0272075 0222607 0296809 0272075 0173139

2 0247341 0371012 1434578 0816226 0593619 0346278 0321543 0247341

3 0197873 1582983 1046253 1310908 0568884 0272075 0173139 0247341

4 0247341 4922088 6777146 084096 0346278 0247341 0247341 0148405

5 027207₅ 1686866 1941628 0791491 0296809 0272075 0148405 0173139

6 014840₅ 1978729 12837 0717289 0371012 0247341 0123671 0197873

7 0123671 126144 5293099 1038833 0395746 0173139 0074202 0148405

Top 0 0321543 0692555 0346278 0197873 0123671 0074202 0024734

As shown in Table 1 and Figure 6, the data reflects an oval pattern aligned with the axis of the slit valve with the heaviest powder dosing forming a central band across the pattern.

Spray Efficiency Test

Objective: To determine the efficiency of a spray pattern developed by the powder delivery system in terms of delivery to the target surface.

Note: The experimental setup for this test method is the same as that shown in Figure 5, with the exception of the patternator which is replaced by the felt target described below.

Equipment:

• Entran model EPX-V01 -50P-/RS 0-50 PSIG pressure transducer. ( 100)

• Nicolet oscilloscope, (not shown)

• Entran power supply/amplifier PS 30A (not shown)

• Entran Easy Connect adapter: EC-AR. (not shown)

• Spray bottle with powder modified with transducer. (10)

• Miller 3 way valve and regulator, (not shown)

• Pressure gauge, (not shown)

• Load cell with sensor (150,140)

• Gralab Model 605 solenoid controller, (not shown)

• Bimba model PFC-091 2 direction air piston, (cylinder 120, ram 130)

• Custom squeeze test fixture. (190, positioned on supporting surface 110) 20

• 8" x 8" Piece of Black Felt Cloth Target attached to sturdy support board, (positioned in place of patternator 160 of Figure 5)

• 12" wide collection plate (positioned on supporting surface 110 under Target).

Preparation:

• Install transducer into top of spray bottle.

• Connect transducer to power supply/amplifier via adapter.

• Connect oscilloscope to read signal output of amplifier.

• Fill test bottle over ^lA full (28g).

• Place test bottle into squeeze test fixture.

• Adjust Entran PS 30A to maximum zero offset.

• Oscilloscope

Channel 1 = 1.2

Time = 500uS

Channel 1 User Units = 4.584 X EE 0 PSI

• Set air pressure to 10 Lbs. ( Should produce between 1 lbs. and 1.1 lb.)

• Set solenoid controller to 0.5 seconds, (based on panelist time to initiate force to peak force of -0.25 seconds.)

Data:

• Maintain record of pre-weight of the spray bottle, felt, and collection plate. After spraying, record final weights of bottle, felt, and collection plate.

• Calculate and record efficiency of spray package:

(Δ weight of spray package / Δ weight of black felt) X 100% = Percent Spray Efficiency

Procedure:

1. Place Black Felt Cloth adhered to a self standing solid board at 4 inches from bottle output

2. Initialize the test equipment.

3. Record pre-weights of bottle, black felt, and collection plate.

4. Activate automatic squeezing of bottle with internal pressure between 1.0 and 1.1 psi.

5. Record post weight of bottle, felt, and collection plate.

6. Calculate efficiency of powder in terms of percent landing on target, percent falling to collection plate, and percent lost as dust cloud. 21

Table 2 is a presentation of results for a composition in accordance with Example 1 at two target distances, 4 inches and 6 inches. The reference to "Floor" in the chart refers to the amount of powder collected in the horizontal plate under the felt which would fall upon the floor if not otherwise intercepted, while the reference to "Unaccounted" refers to powder not measured upon the felt or in the plate, and thereby lost to airborne dust.

TABLE 2

Adherence Data At 4" from Target Internal Pressure 1 05 psi

BO - Grams in CO - Grams Cloth L0 - Grams Bottle Bl - Grams Cl - Grams Cloth LI - Grams Bottle Imtital Initial Bottle After After Bowl After

1 64 572 5 406 6 86 64 312 5 621 6 871

2 64 312 5 48 6 86 64 054 5 689 6 878

3 63 824 5 49 6 86 63 644 5 634 6 871

4 63 644 5 322 6 871 63 548 5 347 6 887

Change in Bottle '=' Change in Cloth Change in Bowl % on cloth % on Floor % Unaccounted

1 0 26 0215 0 011 82 69 0 04 17 27

2 0 258 0209 0 018 81 01 0 07 18 92

3 0 18 0 144 0 011 80 00 0 06 19 94

4* 0 096 0 025 0 016 26 04 0 17 73 79

* Clogged

Adherence Data from 6 inches

B0 - Grams in C0 - Grams Cloth L0 - Grams Bottle B 1 - Grams Cl - Grams Cloth LI - Grams Bowl Bottle Imtital Initial Bottle After After After

1 66 35 5 318 6 864 65 995 5 589 6 884

2 65 995 5 724 6 884 65 673 5 966 6 906

3 65 673 5 551 6906 65 359 5 798 6 924

4 65 359 5 287 6924 65 02 5 55 6 941

5 65 02 6 178 6 941 64 676 6447 6 962

Change in Bottle •=' Change in Cloth Change in Bowl % on cloth % on Floor % Unaccounted

1 0 355 0 271 0 02 76 34 0 06 23 61

2 0 322 0 242 0 022 75 16 0 07 24 78

3 0 314 0 247 0 018 78 66 0 06 21 28

4 0 339 0 263 0 017 77 58 0 05 22 37

5 0 344 0 269 0 021 78 20 0 06 21 74

22

As shown in Table 2, at 4 inches target distance the powder delivery systems provide a target efficiency of at least about 80%. Powder delivery systems in accordance with the present invention preferably provide an efficiency at 4 inches of at least about 50%o, more preferably at least about 70%, and most preferably at least about 80%. At a distance of 6 inches, the powder delivery systems of the present invention deliver an efficiency of at least about 75%. %. Powder delivery systems in accordance with the present invention preferably provide an efficiency at 6 inches of at least about 50%, more preferably at least about 70%, and most preferably at least about 75%.

While particular embodiments of the present invention have been illustrated and described, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention, and it is intended to cover in the appended claims all such modifications that are within the scope of the invention.

Claims

23What is claimed is:

1. A powder delivery system comprising:

(a) a squeezebottle defining a semi-enclosed container having resilient outer walls and a discharge orifice located at one end which is provided with a resilient, self-closing valve, said valve being self-biasing toward a closed condition but openable in response to an increase in internal pressure within said squeezebottle when said internal pressure exceeds a threshold pressure; and

(b) a product contained within said squeezebottle, said product being in the form of an aerated powder and at least partially filling the interior of said squeezebottle to define a powder level; wherein said squeezebottle defines a continuous flowpath for said product from said powder level to said discharge orifice when said squeezebottle is oriented with said discharge orifice located below said powder level, such that when external compressive forces are applied to said squeezebottle said valve opens to discharge said product substantially uniformly as a spray of dispersed powder particles.

2. The powder delivery system of Claim 1, wherein said valve comprises a resilient slit valve.

3. The powder delivery system of Claim 1 or Claim 2, wherein said continuous flowpath also functions as a return air flowpath.

4. The powder delivery system of any one of Claims 1 to 3, wherein said delivery system further includes a secondary closure which may be selectively positioned over said discharge orifice.

5. The powder delivery system of any one of Claims 1 to 4, wherein said spray of dispersed powder particles forms an outwardly-expanding conical pattern.

6. The powder delivery system of any one of Claims 1 to 5, wherein said valve functions as both a discharge valve and a return air valve. 24

7. The powder delivery system of Claim 6, wherein said valve has a lower threshold pressure for return airflow than for product dispensing.

8. The powder delivery system of any one of Claims 1 to 7, wherein said semi- enclosed container is elongated in shape and defines a longitudinal axis, and wherein said discharge orifice has an axis which is substantially perpendicular to said longitudinal axis.

9. The powder delivery system of any one of Claims 1 to 8, wherein said powder delivery system exhibits a spray pattern efficiency of at least 50% at a 6 inch target distance.

10. The powder delivery system of any one of Claim 1 to 9, wherein said spray of dispersed powder particles forms an oval spray pattern having a major axis parallel to a slit in said valve.