Abstract:
A dose cup for dispensing liquid medication is disclosed. An inner cavity of the dose cup is surface-coated with a plurality of microstructures that provides a hydrophobic surface that aids in the self-evacuation of liquid medicine. Because the dose cup is self-evacuating, the volume of liquid medicine that is dispensed can be accurately controlled.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a non-provisional of U.S. patent application Ser. No. 61/884,505 (filed Sep. 30, 2013) the entirety of which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The subject matter disclosed herein relates to dose cups for dispensing a measured quantity of liquid, for example, liquid medication. 
         [0003]    Many dose cups have gradations for measuring a dose of a liquid medication intended for a patient. The gradations are scaled to account for an average amount of liquid medication that remains in the dose cup after use. For example, a variable amount of liquid medication may adhere to an internal surface and impact the amount of liquid medication that remains in the dose cup. Unfortunately, this average amount can vary substantially from one dose to the next dose. Internal surfaces of many dose cups are also prone to accumulate contamination which can result in accidental poisoning of the patient. An improved dose cup is therefore desired that addresses at least some of these problems. 
         [0004]    The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0005]    A dose cup for dispensing liquid medication is disclosed. An inner cavity of the dose cup is surface-coated with a plurality of microstructures that provides a hydrophobic surface that aids in the self-evacuation of liquid medicine. Because the dose cup is self-evacuating, the volume of liquid medicine that is dispensed can be accurately controlled. 
         [0006]    In a first embodiment, a dose cup for dispensing liquid medication is provided. The dose cup comprises a vertical sidewall and a bottom wall joined together by a curved inner surface to define an inner cavity, where the inner cavity is surface-coated with a plurality of microstructures that provides a hydrophobic surface to produce a contact angle greater than 90° when tested in accordance with ASTM D7334-08(2013). The dose cup comprises a polymeric material. 
         [0007]    In a second embodiment, a dose cup for dispensing liquid medication is provided. The dose cup comprises a vertical sidewall and a bottom wall joined together by a curved inner surface to define an inner cavity, where the inner cavity is surface-coated with a plurality of microstructures that provides a hydrophobic surface to produce a contact angle greater than 90° when tested in accordance with ASTM D7334-08(2013). The dose cup comprises a polymeric material. The plurality of microstructures comprise columns, each with a height, a width and a top planar surface, the height being at least twice the width, the columns being spaced apart by a gap that is equal to or less than the width. 
         [0008]    This brief description of the invention is intended only to provide a brief overview of subject matter disclosed herein according to one or more illustrative embodiments, and does not serve as a guide to interpreting the claims or to define or limit the scope of the invention, which is defined only by the appended claims. This brief description is provided to introduce an illustrative selection of concepts in a simplified form that are further described below in the detailed description. This brief description is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all disadvantages noted in the background. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    So that the manner in which the features of the invention can be understood, a detailed description of the invention may be had by reference to certain embodiments, some of which are illustrated in the accompanying drawings. It is to be noted, however, that the drawings illustrate only certain embodiments of this invention and are therefore not to be considered limiting of its scope, for the scope of the invention encompasses other equally effective embodiments. The drawings are not necessarily to scale, emphasis generally being placed upon illustrating the features of certain embodiments of the invention. In the drawings, like numerals are used to indicate like parts throughout the various views. Thus, for further understanding of the invention, reference can be made to the following detailed description, read in connection with the drawings in which: 
           [0010]      FIG. 1A ,  FIG. 1B  and  FIG. 1C  provide a perspective view, side view and cross section view, respectively, of an exemplary dose cup; 
           [0011]      FIG. 2A  and  FIG. 2B  are schematic depictions of microstructures that accentuates the ability of a dose cup to dispense a controlled volume of liquid medication; 
           [0012]      FIG. 3  depicts the microstructures in further detail; 
           [0013]      FIG. 4A  and  FIG. 4B  schematically depict the microstructures along a curved inner surface; 
           [0014]      FIG. 5A ,  FIG. 5B  and  FIG. 5C  provide a side view, a bottom plan view and a bottom plan view, respectively, of an exemplary dose cup; 
           [0015]      FIG. 6A ,  FIG. 6B ,  FIG. 6C  and  FIG. 6D  provide a plan side view, a cross section view, another plane side view in a tipped state and a top perspective view of an exemplary dose cup; 
           [0016]      FIG. 7  is a bottom perspective view of an exemplary dose cup; 
           [0017]      FIG. 8A ,  FIG. 8B ,  FIG. 8C  and  FIG. 8D  provide a plan side view, a cross section view, a bottom perspective view and a bottom plan view of an exemplary dose cup; and 
           [0018]      FIG. 9  is a top perspective view of the exemplary dose cup of  FIG. 8A  showing a concave cavity. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0019]    The dose cups disclosed herein are useful in dispensing liquid medications. The dose cups have a bottom wall and a sidewall which are joined to one another by a curved inner surface such that a cavity of the dose cup is smooth and lacks corners. Advantageously, because there are no corners, liquid medications do not become stuck in the corners. This permits dose cup manufacturers more accurate control over dosing—the gradations are based on actual volumes of liquid medications and are not based on a theoretical average amount of residual medication that remains in the dose cup after use. The dose cup may be formed from a polymeric material, such as polypropylene. Suitable manufacturing methods include, for example, injection molding. In one embodiment, the dose cup is surface treated after molding to increase the hydrophobicity of the inner surface. This surface treatment further accentuates the ability of the dose cup to dispense a controlled volume of liquid medication. 
         [0020]      FIG. 1A ,  FIG. 1B  and  FIG. 1C  are depictions of a dose cup  100 .  FIG. 1A  is a perspective view of the dose cup  100 .  FIG. 1B  is a side view of the dose cup  100 .  FIG. 1C  is a cross section view along line A-A of  FIG. 1B . The dose cup  100  comprises a vertical sidewall  102  and a bottom wall  104  joined by a curved inner surface  106 . In the exemplary embodiment the dose cup  100  also has a curved outer surface  108  that is opposite the curved inner surface  106  and the bottom wall  104  is curved to provide a fully rounded bottom such that its curved outer surface lacks a planar surface. A user recognizes the exemplary dose cup  100  is not intended to be set down on the bottom wall  104 . In the embodiment of  FIG. 1C  the vertical sidewall  102  is tapered at an angle θ to provide a tapered flange such that the opening  110  of the dose cup  100  has a diameter greater than that of a concave cavity  112 . This tapered configuration facilitates the dose cup  100  being placed on a medicine bottle cap and permits the dose cup  100  to fit a variety of different sizes of medicine bottle caps. The tapered flange also influences the evacuation of the liquid medication during use. Additionally, the tapered flange also provides added structural strength to the dose cup that permits the vertical sidewall  102  to be substantially thinner than a corresponding dose cup that lacks the tapered flange. For example, in one embodiment, the vertical sidewalls and bottom wall are between 0.1 and 0.5 mm thick. This results in a significant reduction of the mass of the dose cups and a corresponding reduction in the amount of plastic that is used. The angle θ of the tapered flange may be, for example, between 5° and 20°. In another embodiment, the angle θ is between 5° and 10°. 
         [0021]      FIG. 2A  and  FIG. 2B  are schematic depictions of surface treatments that accentuates the ability of a dose cup to dispense a controlled volume of liquid medication. The surface treatments may be applied to any of the dose cups described in this disclosure. A dose cup  200  is depicted that comprises an inner surface  206  and an outer surface  208 . For example, the inner surface  206  may be on the vertical sidewall  102  and/or the bottom wall  104  of the dose cup  100 . The inner surface  206  faces the concave cavity  112  such that the inner surface  206  contacts liquid medication disposed in the concave cavity  112 . The inner surface  206  is surface-coated with a plurality of microstructures  201  that increase the hydrophobicity of the inner surface  206 . Hydrophobicity may be measured by, for example, contact angle with water. For example, the inner surface  206  strikes a contact angle θ 206  with a drop of water  203 . The contact angle θ 206  is greater than 90° when tested in accordance with ASTM D7334-08(2013) “Standard Practice for Surface Wettability of Coatings, Substrates and Pigments by Advancing Contact Angle Measurement.” In one embodiment, the contact angle θ 206  is greater than 140°. In contrast, the exemplary embodiment of  FIG. 2B  depicts the outer surface  208  striking a contact angle θ 208  with a drop of water  205 . The contact angle θ 208  is less than 90° when tested in accordance with ASTM D7334-08(2013). 
         [0022]    The plurality of microstructures  201  may be surface-coated by known methods. For example, the techniques disclosed in U.S. Pat. No. 8,310,760 may be used to form the plurality of microstructures  201 . In one embodiment, the disclosed dose cups are manufactured by injection molding and the surface-coating is performed after the injection molding. The specified microstructures may be machined into a steel core mold with a laser. In another embodiment, the microstructures are added to the inner surface after molding has been completed. The tapered flange facilitates removal of the dose cup from a mold after injection molding. The dose cups described in this disclosure may have their gradations made in the polymeric material as grooves during the injection molding. Forming the gradations as grooves during injection molding provides significantly more accurate control over the placement of the gradations compared to printed gradations placed after the dose cup has been formed. Volume labels (e.g. “5 mL”) may be pad printed adjacent the gradations because the positioning of the labels does not impact the volume of liquid medication delivered. 
         [0023]      FIG. 3  depicts the plurality of microstructures  201  in further detail. In the exemplary embodiment of  FIG. 3 , the plurality of microstructures  201  are elongated columns with a height  300  and a width  302 , wherein the height  300  is greater than the width  302 . In one embodiment, the height  300  is at least twice as large as the width  302 . In one embodiment, the height  300  is between twenty microns and one hundred microns and the width  302  is between ten microns and fifty microns. In another embodiment, the height  300  is between forty microns and sixty microns and the width is between twenty microns and thirty microns. In one such embodiment, the height  300  is about fifty microns and the width  302  is about twenty-five microns. Each column is spaced from neighboring columns by a gap  301 . In one embodiment, the gap  301  is about the same size as the width  302 . In one such embodiment, the gap  301  is about twenty-five microns. The columns may have any suitable shape. For example, the columns may be shaped as cylinders with circular lateral cross sections (see  FIG. 2A ) or the columns may be shaped as rectangles with square or rectangular lateral cross sections. 
         [0024]    The presence of a curved inner surface, such as the curved inner surface  106  of the dose cup  100 , raises special considerations. The gap  301  may be controlled to minimize disruptions in the contact angle caused by changes in the microstructures  201  as the drop of water travels over the curved inner surface. For example, and with reference to  FIG. 4A , microstructures, including microstructure  201   a  and an adjacent microstructure  201   b  are disposed on a curved inner surface  206 . The microstructures  201   a  and  201   b  are laterally spaced from one another along the curved inner surface  206 . A top planar surface of the microstructure  201  a defines a first plane. A top planar surface of the microstructure  201   b  defines a second plane. Due to the curvature of the curved inner surface  206 , the first plane and the second plane intersect, but are not coplanar. In one embodiment, the first plane and the second plane are offset at an angle that is greater than 0° and is less than 5°. The ratio of the gap  301  to the width  302  minimizes the angle θ 201  between the first plane and the second plane and therefore reduces the disruptions in the contact angle. In one embodiment, the ratio of the gap  301  to the width  302  is about a 1:1 ratio. In another embodiment, the ratio is less than 1:1, for example, 0.5:1.  FIG. 4B  is a perspective view of the microstructures shown in cross section in  FIG. 4A . 
         [0025]      FIG. 5A  is a side view of an exemplary dose cup  500 .  FIG. 5B  is a perspective bottom view of the dose cup  500 .  FIG. 5C  is a bottom plan view of the dose cup  500 . Like dose cup  100 , the dose cup  500  has a bottom wall  504  with a curved surface. Accordingly, the dose cup  500  will tip when placed on a plane  501 . The user recognizes the dose cup  500  is not intended to be set down and instead grips the dose cup  500  in his or her hand. Gravity causes any liquid medication disposed within the dose cup  500  to form a level plane. The dose cup  500  includes circular gradations that extend over at least 75% of the perimeter of the dose cup  500 . Because the circular gradations are present along most of the perimeter of the dose cup  500 , the user can align the level plane formed by the liquid medication with the entire circular gradation to achieve more accurate dosing. 
         [0026]      FIG. 6A ,  FIG. 6B ,  FIG. 6C  and  FIG. 6D  depict a dose cup  600 .  FIG. 6A  is a plan side view of the dose cup  600 .  FIG. 6B  is a cross section view of the dose cup  600  taken along line A-A of  FIG. 6A .  FIG. 6C  is a plane side view of the dose cup  600  in a tipped state.  FIG. 6D  is a top perspective view of the dose cup  600  showing its inner cavity. The dose cup  600  comprises a vertical sidewall  602  and a bottom wall  604  joined by a curved inner surface  606 . The bottom wall  604  further comprises a convex bump  601  that is circumvented by a concave trough  605 . The concave trough  605  contacts the curved inner surface  606 . The bottom, outward side of the concave trough  605  defines a plane  603  that provides a flat surface. The convex bump  601  has a vertex that is a distance  607  above the plane  603 . In one embodiment the distance  607  is about 0.3 to 0.6 mm. In another embodiment, the distance  607  is about 0.5 mm (about 0.018 inches). In use, the convex bump  601  encourages liquid to flow into the concave trough  605  and away from the center of the dose cup  600 . Such a configuration promotes complete evacuation of the dose cup. 
         [0027]      FIG. 7  is a bottom perspective view of a dose cup  700 . The dose cup  700  comprises a raised foot  703  that extends from the outward side of a concave trough  705  that circumscribes a convex bump  701 . In the embodiment of  FIG. 7 , there are three such raised feet. In other embodiments, the raised feet may have alternative configurations such as a single raised foot in the shape of, for example, a raised ring. In other embodiments, two or more raised feet are present, each in the shape of a partial circle. In yet another embodiment, three or more raised feet are present, each in the shape of a protrusion. In the embodiment of  FIG. 7 , three such protrusions are shown at the interface between the convex bump  701  and the concave trough  705 . 
         [0028]      FIG. 8A ,  FIG. 8B ,  FIG. 8C  and  FIG. 8D  depict a dose cup  800 .  FIG. 8A  is a plan side view of the dose cup  800 .  FIG. 8B  is a cross section view of the dose cup  800  taken along line A-A of  FIG. 8A .  FIG. 8C  is a bottom perspective view of the dose cup  800 .  FIG. 8D  is a bottom plan view of the dose cup  800 .  FIG. 9  is a top perspective view of the dose cup  800  showing its concave cavity. Dose cup  800  comprises a vertical sidewall  802  is tapered at an angle θ to provide a tapered flange such that the opening  810  of the dose cup  800  has a diameter greater than that of a concave cavity  812 . Dose cup  800  further comprises a raised foot  803  that, in the embodiment of  FIG. 8C , is in the shape of a raised ring. The dose cup  800  further comprises a gripping feature  805  in the vertical sidewall  802 . In dose cup  800 , the gripping feature  805  is a surface with a curvature that is different than the curvature of the portion of the  802  that circumscribes the gripping feature  805 . 
         [0029]    This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.