Patent Publication Number: US-2023149966-A1

Title: Unit dose aseptic aerosol misting device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a divisional of U.S. application Ser. No. 15/337,417 filed Oct. 28, 2016, which claims the benefit of U.S. provisional application 62/248,736, filed Oct. 30, 2015, the complete disclosures of which are hereby incorporated herein by reference for all purposes. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a unit dose aseptic misting device employing a permanent sonic generator and a replaceable liquid reservoir and nozzle. 
     BACKGROUND OF THE INVENTION 
     Spray and/or misting devices are often used to delivery cosmetic and general health care liquids. Low cost systems employ droppers and/or squeeze bottles with some form of nozzle through which the liquid is forced to provide a relatively uncontrolled dosage and droplet size. 
     Expensive systems may employ metering pumps and/or expensive aerosol forming components. For example, Hseih et al. U.S. Pat. No. 7,992,800 and Hseih et al. U.S. Pub. Pat. Appn. No. 20120318260 disclose nebulizers driven by piezo-electric and/or magnetic drives to generate an aerosol mist. 
     Other examples include The Technology Partnership PLC, EP615470B1; Hailes et al., U.S. Pat. No. 7,550,897, and Brown et al. U.S. Pat. No. 7,976,135, which disclose liquid projection apparatus employing transducers to project liquid droplets from an outer face of a nozzle. 
     Finally, Terada et al. U.S. Pat. No. 6,863,224, Yamamoto et al. U.S. Pat. No. 6,901,926, and Esaki et al. U.S. Pat. No. 8,286,629 disclose ultrasonic liquid atomizing devices. Unfortunately, these expensive components can be contaminated through repeated uses and require careful cleaning or disposal. 
     What is needed is a relatively low cost system for delivering controlled individual or unit doses and particle/droplet size aerosol mists. 
     SUMMARY OF THE INVENTION 
     Surprisingly, we have found that ultrasonically atomizing a liquid through submillimeter-sized nozzles using a deformable membrane maintains the integrity of the membrane throughout the use to enable aseptic atomization by preventing the liquid encapsulated in the reservoir-membrane assembly from touching the ultrasonic horn. 
     In one aspect of the invention, a unit dose capsule for use with a sonic generator includes a deformable membrane adapted to releasably engage the distal end of the elongate horn, a nozzle including at least one delivery opening; a nozzle including at least one delivery opening; and a reservoir containing a liquid composition disposed therebetween. When the unit dose capsule is engaged to the distal end of the elongate horn, the nozzle is disposed in an outwardly facing orientation, and the reservoir is in liquid communication with the at least one nozzle. 
     In another aspect of the invention, the unit dose capsule is included in a kit with a handheld misting device comprising a housing having a dispensing window arranged and configured to contain a sonic generator and a power source coupled to the sonic generator. The sonic generator includes a converter and an elongate horn having a proximal end coupled to the converter and a distal end arranged and configured to transmit sonic energy outside of the housing. 
     In another aspect of the invention, a method of generating an aerosol mist includes coupling a first unit dose capsule to the handheld misting device, energizing the device to generate an aerosol mist, removing the first unit dose capsule from the distal end of the elongate horn, coupling a second unit dose capsule to the distal end of the elongate horn; and energizing the sonic generator to generate an aerosol mist. Each unit dose capsule is coupled to the distal end of the elongate horn, each unit dose capsule includes a deformable membrane adapted to releasably engage the distal end of the elongate horn, a nozzle including at least one delivery opening; a nozzle including at least one delivery opening; and a reservoir containing a liquid composition disposed therebetween. The step of energizing the sonic generator includes engaging the distal end of the elongate horn with the deformable membrane, and transmitting sonic energy through the deformable membrane to the liquid composition. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG.  1    is a perspective view of a unit dose aerosol misting device according to one embodiment of the present invention. 
         FIG.  2    is a top plan view of the unit dose aerosol misting device of  FIG.  1   . 
         FIG.  3    is a side view of the unit dose aerosol misting device of  FIG.  1    with the housing removed to reveal interior elements. 
         FIG.  4    is an end view of the front, dispensing portion of the unit dose aerosol misting device of  FIG.  1   . 
         FIG.  5    is a back view of a unit dose capsule useful in the unit dose aerosol misting device of  FIG.  1   . 
         FIG.  6    is a cross-section along line  6 - 6  of the unit dose capsule of  FIG.  5   . 
         FIG.  7    is a front view of the unit dose capsule of  FIG.  5   . 
         FIGS.  8 A- 8 C  are alternative forms of delivery openings in the unit dose capsule of  FIG.  5   . 
         FIG.  9    is an enlarged view of the distal end of the elongate horn prior to engaging the unit dose capsule. 
         FIG.  10    is an enlarged view of the distal end of the elongate horn while engaged with the unit dose capsule to generate an aerosol mist. 
         FIGS.  11 A  is a plan view of the horn-engaging side of a multi-unit dose revolver configured for engagement with the horn of a sonic misting device. 
         FIG.  11 B  is a side view of the multi-unit dose revolver of  FIG.  11 A . 
         FIG.  11 C  is a plan view of the opposite, exterior side of the multi-unit dose revolver of  FIG.  11 A . 
         FIG.  12    is a perspective view of a multi-unit dose sonic misting device according to an alternate embodiment of the present invention. 
         FIG.  13    is a perspective view of the multi-unit dose sonic misting device of  FIG.  12    with the housing removed. 
         FIG.  14    is an exploded, perspective view of a multiple unit dose revolver, such as shown in  FIG.  13   . 
         FIG.  15    is a cross-section along line  15 - 15  of the assembled multiple unit dose revolver of  FIG.  14   . 
         FIG.  16    is an exploded, perspective view of an alternative multiple unit dose revolver, such as shown in  FIG.  13   . 
         FIG.  17    is a cross-section along line  17 - 17  of the assembled multiple unit dose revolver of  FIG.  16   . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention relates to a handheld sonic misting device that is more economical than conventional sonic misting devices, because the relatively expensive sonic generator and horn are isolated from unit dosage liquids dispensed by the misting device. Thus, the misting device can be replenished with liquids without any build-up of liquids on the horn. 
     In one form of the device, shown in  FIGS.  1 - 4   , the handheld misting device  100  includes a housing  200  containing a sonic generator  300  and an electric power and control system  400 . The handheld misting device  100  can be used with a series of unit dose capsules  500 . 
     As shown in  FIG.  1   , the housing  200  includes an elongate, generally cylindrical outer sleeve  202  having a back end  204  and a front end  206 . The outer sleeve  202  has a generally uniform cross section from the back end  204  extending towards the front end  206  that contains the electric power and control system  400  and the converter  302  of the sonic generator  300 . A front portion  208  of the outer sleeve  202  tapers towards a receptacle  210  having a dispensing window  211  arranged and configured to accommodate a unit dose capsule  500 . An elongate horn  304  extends from the sonic converter  302  toward the front end  206  of the housing  200 . 
     The electric power and control system  400  includes a power source, such as a battery  402 , one or more control boards  404 . 
     In the embodiment of  FIGS.  1 - 4   , the housing  200  includes an inner sleeve  212  that is slidable within the outer sleeve  202 . The back end  214  of the inner sleeve  212  protrudes outwardly beyond the back end  204  of the outer sleeve  202 , and the inner sleeve  212  provides a frame on which the battery  402 , control board  404 , and sonic generator  300  are secured. A spring  216  is disposed between the sonic converter  302  and the front end  206  of the outer sleeve  202 . This spring  216  provides resistance to movement of the inner sleeve  212  towards the front end  206  of the outer sleeve  202  except when desired to activate the device. 
     One example of a unit dose capsule  500  is shown in  FIGS.  5 - 7   . The unit dose capsule  500  is cylindrical reservoir with a thickness less than a diameter. The reservoir has a first substantially planar surface  502  having at least one delivery opening  504  through which the liquid  310  contained therein can be dispensed in the form of the aerosol mist, described generally above. The opposite substantially planar surface  506  of the reservoir is in the form of a thin membrane  508  anchored in the walls  510  of the reservoir, e.g., in slot  512 . 
     The delivery opening(s)  504  are dimensioned to deliver an aerosol mist. Preferably, each delivery opening has a maximum dimension (across the opening) of less than about 200 microns (μm), more preferably, between about 50 and about 150 μm. Preferred delivery openings are generally circular, but one of ordinary skill in the art may modify this to achieve specifically desired aerosol properties. The number of delivery openings is selected to deliver a desired misting flow. Capsules with one delivery opening have been shown to produce a useful aerosol plume, and other capsules with 6 and 7 openings have also produced useful aerosol plumes. Therefore, one of ordinary skill in the art may select from one to more than ten delivery openings. The delivery openings may have a constant channel (as shown in  FIG.  6   , or they may vary from the reservoir surface to the exterior surface of the unit dose capsule. Tapering or other funneling of the side walls can help to control the aerosol plume. Examples of such forms are shown in  FIG.  8 A  (tapered, or fruso-conical),  8 B, (“Y-shaped”, having a fruso-conical first section  504   a  and a constant channel second section  504   b ), and  8 C (having a hemispherical first section  504   a′  and a constant channel second section  504   b.    
     In use, an operator may turn activate the power switch  406  to energize the sonic generator  300 , hold the outer sleeve  202  of the housing  200  (e.g., between a thumb and one or more fingers), and use another finger to press on the back end  214  of the inner sleeve  212  to urge the inner sleeve  212  toward the front end  206  of the outer sleeve  202  to overcome the resistance of the spring  216 . As shown in  FIGS.  9  and  10   , this movement (indicated by arrow  218 ) forces the distal end  306  of the elongate horn  304  to directly engage the membrane  508  of the unit dose capsule  500  and to drive the liquid  310  through the delivery opening(s)  504 , thereby generating the aerosol mist  308 . The size, shape, number, and arrangement of delivery opening(s)  504  define the plume of mist  308  generated by the misting device  100 . 
     The present invention is useful in the delivery of aerosol plumes of medication and/or moisturizing solutions in a more sanitary manner than currently provided. Sonic generation of aerosol plumes can provide very fine mists, having a droplet size between about 20 and about 60 μm, given by the practical range of frequencies for the ultrasonic horn between 20 kHz and 200 kHz. 
     In an alternative embodiment, a plurality of unit dose capsules can be incorporated into a revolver. In  FIGS.  11 A-C , a four-unit dose revolver  600  is shown. As shown in  FIG.  11 A , a circular revolver  600  includes four unit dose capsules  602 . Each capsule  602  has a membrane  604  disposed on the side facing the horn, and a removable, protective tab  606  covering the delivery openings (not shown) on the exterior side. This tab  606  may be removed by the user, or automatically via a scraper (not shown). The revolver  600  is rotatable about axle  608 , and it may be indexed to align with the horn through a mechanical linkage, or through a solenoid-controlled rotator (not shown). 
     In a further alternative embodiment, shown in  FIGS.  12  and  13   , includes a sonic generator  300 ′, including a converter  302 ′ an elongate horn  304 ′, and a multiple unit dose revolver  600 ′ enclosed in a housing  200 ′. The unit dose revolver  600 ′ is removable from the housing  200 ′ to permit replacement thereof after use. The housing  200 ′ also contains a battery  402 ′ a control board  404 ′ and a control shaft  220  on which a pair of control springs  216   a  and  216   b  are located. These control springs cooperate with a control lever  222  to control movement of the sonic generator  300 ′. When the control lever  222  is in an upright position ( 222   a , in solid line), it bears on the front of the sonic converter  302 ′ and compresses the rear control spring  216   a  holding the horn  304 ′ away from the revolver, permitting a user to rotate a unit dose capsule  602 ′ into position, in alignment with the horn  304 ′ by movement of a knurl  224 . When the control lever  222  is in a forward position ( 222   b  in phantom), the rear control spring  216   a  (which is stronger than the forward control spring  216   b ) urges the horn  304 ′ toward the unit dose capsule  602 ′ aligned therewith to generate an aerosol mist through a window  226  in the front of the device. 
     In one embodiment shown in  FIGS.  14 - 15   , the multiple unit dose revolver  600 ′ comprises a top cover  6002 , a reservoir disk  6004  and a membrane  6006  disposed therebetween. These components are arranged and configured for snap-fitting the top cover  6002  to the reservoir disk  6004  using a plurality of inner catches  6008  disposed about a center portion of the top cover  6002  and outer catches  6009  disposed about the periphery of the top cover  6002 . The resulting assembly provides a plurality of unit dose capsules  6020  having the features as described above. Inner catches  6008  engage the rim  6010  of a central aperture  2012  of the reservoir disk  6004 , and outer catches  6009  engage the outer perimeter  2013  of the reservoir disk  6004 . A plurality of knurls  224  is disposed about the outer perimeter of the top cover  6002 . 
     One of ordinary skill in the art will recognize useful materials for these elements. However, a general guidance follows. The top cover  6002  is preferably formed from a material that is less rigid than the reservoir disk  6004 . The ultrasonically deformable membrane  6006  is preferably between 25 and 75 microns thick made of a material capable of standing higher temperatures but still deformable while heated (with thermalized ultrasonic energy in this case). The reservoir disk  6004  is preferably formed of a material rigid enough not to dampen the ultrasonic energy through deformation during the misting (while the ultrasonic transducer advances into the cavity deforming the membrane). 
     In another embodiment shown in  FIGS.  16 - 17   , the multiple unit dose revolver  600 ″ comprises a top cover  6002 ′, a reservoir disk  6004 ′ and a membrane  6006 ′ ( FIG.  17   ; similar to that of  FIG.  14   , but not shown in  FIG.  16   ) disposed therebetween. These components are arranged and configured for ultrasonically welding the top cover  6002 ′ to the reservoir disk  6004 ′ using a plurality of columns  6016  disposed about the top cover  6002 ′. These columns  6016  are fitted into a plurality of apertures  6014  of the reservoir disk  6004 ′. These columns  6016  provide an engagement at the bottom surface  6018  of the reservoir disk  6004 ′ to enable ultrasonic or other form of thermal welding (including precision laser welding) or even adhesives, such as UV-cured epoxy between the distal ends  6019  and the bottom surface  6018  of the reservoir disk  6004 ′. The resulting assembly provides a plurality of unit dose capsules  6020 ′ having the features as described above. A plurality of knurls  224  is disposed about the outer perimeter of the top cover  6002 ′. 
     As indicated above, as sonic generators are more expensive than traditional squeeze and spray bottles, it is important to separate the expensive and reusable sonic generator and horns from the relatively inexpensive and potentially disposable liquid reservoirs. One of ordinary skill in the art will recognize the general assembly of the handheld sonic misting device of the present invention. However, the interaction of the following elements is important to consider. First the distal end  306  of the horn  304  and the membrane  508  engage intimately to minimize energy loss due to inefficient motion transfer from the horn to the wall of the nozzle opposite the delivery openings to minimize heat buildup and to maximize control of the resulting aerosol plume. In addition, the distal end  306  of the horn  304  should engage the center of the membrane  508  throughout the operation. In the event that the distal end  306  of the horn  304  and the walls  510  of the reservoir approach too closely, the membrane  508  can be ruptured, thereby permitting the liquid  310  to contaminate the horn  304 . 
     The housing may comprise any suitable material or combination of materials. Preferably, it includes one or more hard, heat-resistant material(s). Examples of suitable materials include, without limitation, metals, alloys, plastics or composite materials containing one or more of those materials, or ceramics. Plastics can include thermoplastics that are suitable for food or pharmaceutical applications, for example, polypropylene, polyether etherketone (PEEK) and polyethylene. Preferably, the material is light and non-brittle. The housing may be fabricated by plastic injection molding, or any other suitable technique, and it is preferably ergonomic and adapted to fit comfortably in a hand of a user. In a preferred embodiment, the housing has a maximum linear dimension (length) of up to about  20  cm, more preferably, up to about  15  cm, and most preferably up to about 10 cm. Preferably, the maximum dimension perpendicular to the length is 8 cm, more preferably, 5 cm. 
     Again, the electric power and control system  400  includes a power source, such as a battery  402 , one or more control boards  404 . The power source  402  is sized to provide sufficient power for the sonic generator and any additional control circuitry and/or electromechanical subsystems. For example, the manual operation driving the sonic horn into contact with the unit dose capsule may be replaced by a linear motor for greater control. The power source is preferably replaceable and/or rechargeable and may include devices such as a capacitor or, more preferably, a battery. In a presently preferred embodiment, the power source  402  is a rechargeable battery including, without limitation, lithium-based cells, including lithium polymer batteries. One example of an internal power source is a lithium polymer cell providing a voltage of about 3.7 V that has a capacity of at least about  200  milliamp hours (mAh). 
     The unit dose capsule  500  (which may also be described as a pod or a cartridge) can be packaged in an air-tight container, such as a metallic foil or plastic pouch or blister pack. Each unit dose capsule will provide sufficient liquid for the desired treatment. For example, for application to a human eye, a capsule may contain about 5 to about 20 microliters (μl); for application to a human nasal cavity, a capsule may contain about 50 to 150 μl; and for an antiseptic wound care product, a capsule may contain more than 200 μl. One of ordinary skill in the art will recognize that these volumes may be modified for these and other desired applications. 
     The capsule  500  may be formed of several components, such as the walls  510 , first surface  502  having the delivery opening(s)  504 , and the membrane  508 . The walls and first surface are preferably manufactured of rigid plastic. For example, the unit dose capsule can be formed of metal or engineering plastic and machined or molded within appropriate tolerances to fit into the receptacle at the distal end of the elongate horn. A non-limiting list of useful materials include acetal resins (such as available from DuPont® Engineering Polymers under the DELRIN® brand), polyether ether ketones, amorphous thermoplastic polyetherimide (PEI) resins (such as available from SABIC under the ULTEM® brand), polycarbonate resins, polyester resins, and the like. 
     To provide effective aerosolization, the membrane should be (1) as thin as possible in the 25 to 75 μm thick, (2) manufactured of a high temperature plastic (fluorinated such as PFA), (3) flexible, and (4) susceptible to ultrasonic welding during manufacture. The capsule can be assembled by forming the nozzle surface and side walls from one of the materials listed above and the membrane can be joined thereto by adhesives, thermobonding, ultrasonic welding, clamping the membrane between the side walls and an additional ring which can then be screwed or bolted to the side walls. 
     The specification and embodiments above are presented to aid in the complete and non-limiting understanding of the invention disclosed herein. Since many variations and embodiments of the invention can be made without departing from its spirit and scope, the invention resides in the claims hereinafter appended.