Method and apparatus for preparing liquid formulations

Abstract

An apparatus is disclosed for preparing a liquid formulation using a two-part system including a first part containing a first reagent and a second part containing a second reagent, which react to form an active ingredient of the liquid formulation when the first and second reagents are mixed. The apparatus comprises a reaction chamber (58), a mixing funnel (24) having an inlet area (60) for admitting a quantity of the first part and a quantity of the second part into the reaction chamber, e.g., from a dispensing capsule, to form a reagent mixture in the reaction chamber in use, an outlet (72) with at least one restricted orifice for releasing the reagent mixture from the reaction chamber at a controlled rate, and a primary chamber configured to receive the reagent mixture from the reaction chamber via the restricted orifice.

Description

[Technical field]

[0001] The present invention relates to a method and apparatus for preparing a liquid formulation. In particular, the present invention relates to preparing a germicide formulation using a two-part germicide system in which the two parts are mixed to form a reagent mixture and then diluted with a diluent. [Background technology]

[0002] Many liquid formulations contain active ingredients that degrade over time, limiting the shelf life of the product. This is particularly true for disinfectants or sterilants such as chlorine dioxide, where the active ingredient is formed in situ when needed by mixing two reagents. An example is disclosed in WO 2005 / 011756. Chlorine dioxide can be formed, for example, by mixing a chlorite solution with an acid.

[0003] It is known to provide a dispensing capsule for placement on the neck of a container, the capsule having two internal chambers, each containing a reagent. The reagents can be mixed to produce an active ingredient by expelling the contents of the chambers into the container. An example of such a dispensing capsule is described in WO 2017 / 060677. The dispensing capsule has two or more sealed dispensing chambers, each containing a different substance to be dispensed into the primary chamber. When the cap is screwed or pushed onto the neck of the container, the walls of the dispensing chambers gradually collapse, breaking the internal seal between the chambers and allowing premixing of the contents of the chambers to form a concentrated reagent mixture. Further collapse of the walls as the cap is screwed or pushed down results in the destruction of the external seal and allows the mixture to be expelled into the primary chamber. The premixing accelerates the formation of the active agent. The reaction continues in the primary chamber, which may contain a diluent, so that the appropriate concentration of active agent is obtained in the primary chamber. Typically, the reaction rate is slower in the diluent than during premixing in the capsule, and the user must follow the instructions carefully to ensure that sufficient reaction time has elapsed before the resulting formulation is used.

[0004] WO 2019 / 135065 describes an arrangement in which a dispensing capsule of the type described in WO 2017 / 060677 is received in a base member fixed to the neck of a container containing a diluent, the base member including a cup disposed below the capsule and a drainage opening disposed between the cup and the capsule. When an external seal is removed, the contents of the capsule are received in the cup. After a predetermined premix time, the user inverts or rocks the container to wash the diluent through the drainage opening and mixes the diluent with the concentrated reagent mixture in the cup to produce the final composition. In this arrangement, the premixing of the reagents in the cup produces the active agent more quickly than if the reagents were added directly to the diluent or only for a relatively short premix time.

[0005] Advantageously, these aforementioned configurations allow the disinfectant formulation to be prepared relatively quickly by using concentrated reagents without exposing the user to concentrated reagents or concentrated reagent mixtures. However, the user must follow a set of predetermined process steps and timings to ensure that the resulting disinfectant formulation has an effective concentration of active agent. Furthermore, since reaction rates generally vary with temperature, care must be taken to ensure that appropriate reaction times are observed at extreme temperatures. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2005 / 011756 [Patent Document 2] International Publication No. 2017 / 060677 [Patent Document 3] International Publication No. 2019 / 135065 Summary of the Invention [Problem to be solved by the invention]

[0007] Against that background, it would be desirable to provide methods and apparatus for preparing liquid formulations that simplify the user's experience and / or can easily compensate for the effect of temperature on reaction rates. [Means for solving the problem]

[0008] Aspects of the invention are set out in the independent claims. Preferred features are set out in the dependent claims.

[0009] In a preferred embodiment, a device is provided for preparing a liquid formulation using a two-part system. The system includes a first part including a first reagent and a second part including a second reagent, which react to form an active ingredient of the liquid formulation when mixed. The device includes a mixing funnel having a reaction chamber, an inlet area for admitting a quantity of the first part and a quantity of the second part into the reaction chamber to form a reagent mixture in the reaction chamber in use, and an outlet with at least one restricted orifice for releasing the reagent mixture from the reaction chamber at a controlled rate. The device also includes a primary chamber configured to receive the reagent mixture from the reaction chamber through the restricted orifice. Preferably, the or each restricted orifice is located at a base portion of the mixing funnel, and the reagent mixture flows through the restricted orifice under gravity.

[0010] With this configuration, the two parts of the system have the opportunity to mix and react while in the reaction chamber before they are released into the primary chamber, which may contain a diluent. In this way, the reaction proceeds faster than if the two parts were released directly into the primary chamber, or with only a short premixing stage. The flow rate through the restrictive orifice can be selected so that the mixing and reaction that occurs in the reaction chamber occurs such that by the time all of the reagent mixture is released from the reaction chamber, the resulting formulation in the primary chamber has an effective concentration of the active ingredient. Thus, the need for the user to monitor the reaction time and manually transfer the parts to be mixed into the primary chamber is avoided.

[0011] In the context of the present disclosure, a restrictive orifice is an opening, aperture, or other suitable structure that, by virtue of its size, restricts the gravity-induced flow rate of liquid from the reaction chamber to the primary chamber. In particular, the restrictive orifice allows the reagent mixture to flow out of the reaction chamber at a predetermined, controlled rate that is substantially lower (e.g., at least 0.1 times) than the rate at which the first and second portions can enter the reaction chamber through the inlet region in use, such that the first and second portions remain within the reaction chamber.

[0012] The apparatus may further comprise a dispenser for dispensing a quantity of the first portion and a quantity of the second portion into the mixing funnel. The inlet area of ​​the mixing funnel may include a receiving area for the dispenser. The dispenser may store the first and second portions.

[0013] The dispenser may comprise a capsule having a first and second cavity for storing the respective first and second portions. The capsule may, for example, be of the type described in WO 2017 / 060677, the contents of which are incorporated herein by reference. The device may include an actuator operable to cause the first and second portions to be dispensed from the capsule. When the capsule has first and second cavities for storing the respective first and second portions, the actuator may, for example, be a plunger configured to collapse a wall defining the cavity to increase the pressure in the cavity and rupture a seal.

[0014] The apparatus may include a container defining a primary chamber. The mixing funnel is preferably attachable to the container. The container may be in the form of a bottle or tank, for example. The container may include a neck, and the mixing funnel may be arranged to releasably engage the neck.

[0015] In another example, the mixing funnel is attachable to or integral with the lid of the container. In this case, the lid, if present, can include an actuator for dispensing the first and second portions from the capsule, such that closing the lid transfers the contents of the capsule to the reaction chamber. The lid may include a fill port for admitting a diluent to the container.

[0016] The controlled rate, expressed as volume per unit time, can vary depending on the concentration and nature of the reagents and the volumes of the first and second portions. The controlled rate is preferably 20 mL / s or less, more preferably 15 mL / s or less, and most preferably 10 mL / s or less.

[0017] In some embodiments, the controlled rate may be 5 mL / s or less than 1 mL / s. A higher maximum controlled rate, for example 0.4 mL / s to 10 mL / s, may be suitable for embodiments in which the reaction chamber is sized to accommodate a total volume of 100 mL to 300 mL of the reagent mixture. A lower maximum controlled rate, for example 0.03 mL / s to 0.5 mL / s, may be suitable for embodiments in which the reaction chamber is sized to accommodate a total volume of 5 mL to 20 mL of the reagent mixture. Experience has shown that a suitable controlled rate, expressed in mL / s, may be 0.01 times or less the total volume of the first and second portions placed in the reaction chamber (i.e., the volume of the reaction chamber). Preferably, the controlled rate is at least 0.01 mL / s.

[0018] The or each restrictive orifice may be sized so that the reagent mixture flows from the reaction chamber to the primary chamber in a time period between 30 seconds and 4 minutes, more preferably between 45 seconds and 3 minutes, and even more preferably about 2 minutes. In one embodiment, a single restrictive orifice is provided having a diameter between 0.6 mm and 1 mm. In another embodiment, at least two restrictive orifices are provided, each restrictive orifice having a diameter between 0.8 mm and 2 mm.

[0019] The restrictive orifice preferably provides a permanently open flow path from the reaction chamber to the primary chamber. In other words, the apparatus lacks any form of valve or control device that would allow the user to block or adjust the flow through the restrictive orifice, such that the flow rate is controlled solely by the size of the orifice. Preferably, flow through the restrictive orifice under gravity begins as soon as the first and second portions enter the reaction chamber.

[0020] The mixing funnel may include a vent located in the upper region of the reaction chamber to allow for the evacuation of air and evolved gases from the reaction chamber. Preferably, the vent is in fluid communication with the primary chamber.

[0021] In another embodiment, the invention provides a method of preparing a liquid formulation using a two-part system including a first part containing a first reagent and a second part containing a second reagent, which react when mixed to form an active ingredient of the liquid formulation. The method includes dispensing a quantity of the first part and a quantity of the second part into a reaction chamber to form a reagent mixture in the reaction chamber, and releasing the reagent mixture from the reaction chamber through at least one restricted orifice at a controlled rate into a primary chamber to provide the liquid formulation in the primary chamber.

[0022] The method may further include mixing the reagent mixture with a diluent in the primary chamber to form a liquid formulation. Dispensing a quantity of a first portion and a quantity of a second portion into the reaction chamber may include expelling the first and second portions from a dispensing capsule.

[0023] The method may comprise expelling the reagent mixture from the reaction chamber through at least one restricted orifice into the primary chamber for a time period between 30 seconds and 4 minutes, more preferably between 45 seconds and 3 minutes, and even more preferably about 2 minutes.

[0024] The apparatus and methods are particularly suited to two-part systems in which the active ingredient includes a disinfectant or sterilant, such as chlorine dioxide.

[0025] Preferred and / or optional features of each aspect and embodiment of the invention may be used alone or in any suitable combination in the other aspects and embodiments.

[0026] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which like reference symbols are used for like features and in which: [Brief description of the drawings]

[0027] [Figure 1] FIG. 1 is an exploded perspective view of a portion of an apparatus for preparing a liquid formulation, including a cap, a dispensing capsule, and a mixing funnel. [Diagram 2] FIG. 2 is a cross-sectional view of a capsule of the device of FIG. 1. [Diagram 3] FIG. 2 is a perspective view of a mixing funnel of the apparatus of FIG. 1. [Figure 4] FIG. 4 is a cross-sectional perspective view of the mixing funnel of FIG. [Diagram 5] FIG. 4 is a cross-sectional view of the mixing funnel of FIG. [Figure 6] FIG. 2 is a cross-sectional perspective view of the device of FIG. 1 when assembled. [Figure 7] 2 is another perspective view of the device of FIG. 1 when assembled. [Figure 8a] 2 is an exploded view of an embodiment of a container assembly including a device of the type shown in FIG. 1 that includes a container. [Figure 8b] 1 shows the container assembly when assembled in a two-step operation. [Figure 8c] 1 shows the container assembly when assembled in a two-step operation. [Figure 9] FIG. 13 is a cross-sectional perspective view of another embodiment of a container assembly. [Figure 10] 10 is a cross-sectional perspective view of a lid of the container assembly of FIG. 9. [Figure 11]FIG. 13 is a perspective view of a portion of an alternative lid for a container assembly. [Figure 12] 8 is a graph showing chlorine dioxide concentration as a function of pore size for container assemblies of the type shown in FIGS. 8a-8c. [Figure 13] 4 is a graph showing the time it takes to discharge the contents of a mixing funnel as a function of hole size for a mixing funnel of the type shown in FIG. 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Figures 1 to 7 show portions of an apparatus 10 for preparing a liquid formulation, such as a disinfectant formulation, according to an embodiment of the present invention. The apparatus 10 includes a dispensing capsule 20, a cap 22, and a mixing funnel 24. Figure 1 is an exploded view showing the capsule 20, cap 22, and funnel 24 separated from one another, while Figures 6 and 7 show the capsule 20, cap 22, and funnel 24 in an assembled configuration.

[0029] 1 and 2, the dispensing capsule 20 in this example is of the type described in WO 2017 / 060677 and comprises a capsule body 30 having a first (dispensing) end 32 and a second (upper) end 34. The capsule body 30 includes a first inner wall 36 defining a first cavity 38 and a second inner wall 40 defining a second cavity 42. Each cavity 38, 42 has an opening at the first end 32 of the capsule body 30, and the cavities 38, 42 are separated from each other at the first end 32 of the capsule body 30 by a dividing member 44. Each cavity 38, 42 contains a liquid and is covered by a sealing member (not shown in FIGS. 1-4) that seals the contents of each cavity 38, 42 and prevents mixing of the liquids between the cavities 38, 42. Each cavity 38, 42 may be provided with a separate sealing member or a single sealing member may cover both cavities, for example as disclosed in WO 2017 / 060677.

[0030] Each cavity 38, 42 is provided with a burst pin 46, 48 that projects from an upper (closed) end of the respective cavity 38, 42 toward the first end 32 of the capsule body 30. The walls 36, 40 defining the cavities 38, 42 are collapsible, e.g., in a concertina fashion, when pressure is applied to the walls 36, 40 from the second end 34 of the capsule body 30.

[0031] 3-5, the mixing funnel 24 has a generally tubular funnel body 52 having a closed first (lower) end 54 and an open second (upper) end 56. The lower portion of the funnel body 52 defines a reaction chamber 58. A capsule receiving area 60 is disposed between the reaction chamber 58 and the upper end 56 and is provided by an enlarged diameter region of the body 52. ​​An annular shoulder 62 extends around the funnel body 52 between the receiving area 60 and the reaction chamber 58. An annular ridge 64 (see FIG. 4) is provided on the shoulder 62 such that the shoulder 62 and the ridge 64 provide a stop upon which the capsule 20 may rest during use, as described further below. The enlarged diameter region of the body 52 is tapered such that the diameter of the lower end of the receiving area 60 is less than the diameter of the upper end of the receiving area 60 at the second end 56 of the funnel body 52. The receiving area 60 provides an entrance area for the mixing funnel 24 at the top of the mixing funnel 24 to allow the contents of the capsule 20 to enter the reaction chamber 58 .

[0032] The mixing funnel 24 also includes a downwardly extending outer wall 66 that joins with the receiving area 60 at the upper end 56 of the funnel body 52. ​​The outer wall 66 has threads 68 formed on its inner surface. In this manner, the mixing funnel 24 can be fitted to a suitable container, with a threaded neck of the container disposed between the outer wall 66 and the funnel body 52 and engaging the threads 68. In an alternative embodiment, the mixing funnel can be attachable to the container by a press fit, a clip arrangement, or any other suitable arrangement.

[0033] The reaction chamber 58 of the mixing funnel 24 has a base 70 that is conical in shape, with the center of the base 70 being lower than the perimeter of the base 70. A drain hole 72 is centrally located in the base 70. As will be explained in more detail below, the diameter of the drain hole 72 is selected so that the drain hole 72 acts as a restricting orifice through which the liquid contents of the reaction chamber 58 will flow at a predetermined rate under the force of gravity.

[0034] 4, a vent 74 is formed in the wall of the reaction chamber 58 at the upper end of the reaction chamber 58 adjacent the containment area 60. The vent 74 is not intended for liquid flow, but rather allows displaced air and evolved gases to escape from the reaction chamber 58 without affecting the amount of flow through the drain hole 72.

[0035] A base 70 of the reaction chamber 58, proximate a drain hole 72, is formed at an angle R with respect to the vertical axis of the mixing funnel 24 (see FIG. 5).

[0036] 6 and 7 show the dispensing capsule 20 inserted into the receiving area 60 of the mixing funnel 24. When the capsule 20 is in place, the ridge 64 on the shoulder 62 of the funnel body 52 engages a corresponding formation on the first end 32 of the capsule body 30, and the capsule 20 cannot move further downward.

[0037] When assembled, the cap 22 resides on top of the dispensing capsule 20 and the mixing funnel 24. The cap 22 includes an actuator or plunger 80, in this example formed on the underside of a top 82 of the cap 22. The plunger 80 is configured to exert pressure on the walls of the first and second cavities causing the walls to progressively collapse when the cap 22 is pressed downward to dispense the contents of the capsule 20 into the mixing funnel 24. In this example, the cap is secured and engaged to the mixing funnel 24 by a clip 84 provided on the lower inner edge of a downwardly depending skirt 86 of the cap 22. The clip 84 initially engages an upper ridge 76 formed on the outer wall 66 of the mixing funnel 24, which holds the cap 22 in place after assembly. When the cap 22 is displaced downwardly to dispense the contents of the capsule 20, the clip 84 engages the lower ridge 78 formed on the outer wall 66 of the mixing funnel 24 to provide an audible and tactile confirmation of a successful operation and to prevent subsequent removal of the cap 22 from the mixing funnel 24. Thus, in this embodiment, the cap 22, capsule 20, and mixing funnel 24 are intended to be discarded after a single use.

[0038] The device is intended for use in preparing liquid formulations using a two-part system, where a first part contains a first reagent and a second part contains a second reagent that reacts to form the active ingredient of the liquid formulation when the first and second reagents are mixed. Thus, the capsule 20 is pre-filled with a desired amount of the first part of the system in the first cavity 38 and a desired amount of the second part of the system in the second cavity 42. At least one of the first part and the second part, preferably both, are in liquid form.

[0039] The reagents used in the system may be, for example, reagents that generate a germicide composition when mixed, such as chlorine dioxide or peracetic acid. Suitable reagents are well known to those skilled in the art, for example, reagents for generating chlorine dioxide include chlorite and acid; chlorate, peroxide and acid; and chlorite, hypochlorite, and a suitable buffer. The reagents may be in concentrated form, resulting in rapid formation of the active agent when the contents of the chamber are mixed.

[0040] The operation of the device will now be described with reference to Figures 8a-8c, which show an example in which a dispensing capsule 20, cap 22 and mixing funnel 24 similar to those shown in Figures 1-7 are used in conjunction with a container 90 in the form of a bottle.

[0041] In FIG. 8a, the dispensing capsule 20, cap 22, and mixing funnel 24 are separated from the container 90. The container 90 has a threaded neck 92 and defines a sealed primary chamber 94. The primary chamber 94 of the container 90 may be pre-filled with a predetermined amount of diluent, such as water. The mixing funnel 24 is then attached to the neck 92 of the container 90, the dispensing capsule 20 is inserted into the receiving area 60 of the funnel 24, and the cap 22 is clipped onto the top of the mixing funnel 24 to seal the capsule 20 and form a container assembly 96. It will be appreciated that in some cases, the capsule 20, cap 22, and mixing funnel 24 may be pre-assembled prior to attachment to the container 90.

[0042] To begin the process of preparing the liquid formulation, a downward force is applied to the cap 22, pushing it towards the container 90. The plunger 80 of the cap 22 begins to collapse the walls 36, 40 that define the cavities 38, 42. In this example, a single sealing member 49 covers substantially the entire lower end 32 of the capsule 20, and as pressure increases within the cavities 38, 42, a critical pressure is reached where the bond between the sealing member 49 and the dividing member 44 breaks, allowing the sealing member 49 to deform into a dome (see FIG. 8b). This allows the contents of the cavities 38, 42 to partially mix while the bond between the sealing member and the peripheral wall around the base 34 remains intact.

[0043] As the cap 22 moves further downward, further collapse of the walls 36, 40 of the cavities 38, 42 causes the tips of the burst pins 46, 48 to contact the seal member 49, which then pushes against the seal member 49 to break the circumferential bond or burst the seal member 49, allowing the contents of the capsule 20 to be dispensed into the reaction chamber 58 of the mixing funnel 24 (see FIG. 8c, which does not show the bursting seal member for clarity). In this manner, the capsule 20 and cap 22 together provide a dispenser for dispensing a quantity of a first portion and a quantity of a second portion into the reaction chamber 58 of the mixing funnel 24.

[0044] Thus, after the first and second portions have been dispensed from capsule 20 into reaction chamber 58, reaction chamber 58 contains a reagent mixture formed from a quantity of the first portion and a quantity of the second portion contained in the capsule. In this context, the term "reagent mixture" is used herein to refer to the contents of reaction chamber 58, regardless of the extent of mixing of the two starting components and / or reaction between the reagents that has already occurred prior to delivery to reaction chamber 58, and regardless of the extent of mixing and reaction that has occurred in reaction chamber 58 itself.

[0045] The contents of the reaction chamber 58 then flow under gravity through the drain hole 72 into the primary chamber 94 without further user intervention. The amount of flow through the drain hole 72 is selected so that the reagents have sufficient time to thoroughly mix and react together in the reaction chamber 58 before they are completely released into the diluent in the primary chamber 94. Once sufficient time has passed for the reaction chamber 58 to empty, the container 90 can be shaken or inverted to ensure uniformity of the liquid formulation in the primary chamber 94. The liquid formulation can then be dispensed, for example, by removing the mixing funnel 24, cap 22, and capsule 20 from the neck of the bottle and attaching an appropriate dispensing pump or sprayer.

[0046] It will be appreciated that a portion of the reagent mixture immediately exits the reaction chamber 58 through the drain hole 72 such that the initial droplets are only partially reacted before being diluted in the primary chamber 94. However, the flow rate can be selected so that a significant amount of the reagent mixture remains in the reaction chamber 58 long enough to allow an appreciable reaction to occur within the reaction chamber 58. Thus, the final droplets exiting the reaction chamber 58 can be substantially completely reacted before reaching the primary chamber 94.

[0047] The optimum flow rate, and possibly the optimum time it takes for the contents of reaction chamber 58 to be completely transferred to primary chamber 94, will depend on the nature of the two-part system used, particularly the reaction rates, the initial concentrations of the reagents in the parts, etc.

[0048] The flow rate can be controlled primarily by appropriate selection of the diameter of the drain hole 72. The diameter of the or each drain hole should preferably be between 0.6mm and 3mm, with larger size holes found to result in higher flow rates. The tilt angle R of the base 70 of the reaction chamber 58 near the drain hole 72 can also affect the rate of liquid flow, with a larger angle (i.e. a flatter base) resulting in slower drainage through the drain hole 72. Preferably, the angle R is greater than 10° and less than 90°.

[0049] The reaction rate in a two-part system is also typically temperature dependent. Advantageously, the present invention automatically compensates to some extent for differences in ambient temperature, since the viscosity of the reagent mixture, and therefore the amount of flow through the drain holes, is also temperature dependent. Thus, at lower temperatures, the reaction rate is typically slower and the increased viscosity of the reagent mixture results in a lower flow rate, with the effect of increasing the residence time in the reaction chamber. At higher temperatures, the reaction rate is faster and the reagent mixture has a lower viscosity, with a correspondingly shorter residence time.

[0050] An embodiment of the mixing funnel provided with two or more drain holes is also possible. In such a case, the flow rate can be controlled by the number of drain holes and their diameter.

[0051] Preferably, the flow rate is selected, using an appropriate number and size of drain holes, such that the contents of the reaction chamber are completely transferred to the primary chamber in about 30 seconds to about 4 minutes, more preferably about 45 seconds to about 3 minutes, and ideally about 2 minutes. For chlorine dioxide systems in particular, these times are believed to enable sufficient residence time in the reaction chamber to ensure that an effective concentration of the active ingredient is present in the primary chamber when the reaction chamber is emptied, while minimizing user wait time.

[0052] Figures 9 and 10 show another device for preparing liquid formulations. The principle of operation is similar to that of the device described with reference to Figures 1 to 8. In this case, however, the device is in the form of a tank 100 intended for bench-top use.

[0053] The tank 100 includes a tank body 102 defining a primary chamber 194 and a lid 104 attached to the top of the tank body 102 and secured by a fastening arrangement 108 that penetrates the tank body 102 and engages the underside of the tank body 102.

[0054] The lid 104, shown in isolation in Figure 10, is molded to provide a fill port 110 that allows diluent to be added directly to the primary chamber 194. The tank body 102 is also provided with an outlet port 112 for connecting a tap or similar outlet device. An additional inlet port can also be provided for connection of a water supply line, allowing the primary chamber 194 to be filled with water from a main source. It will be appreciated that in some embodiments, either the fill port 110 or the inlet port can be omitted.

[0055] The lid 104 is also molded to provide an integral mixing funnel 124. Referring to FIG. 10, the mixing funnel 124 has a generally tubular funnel body 152 having a closed first (lower) end 154 and an open second (upper) end 156. A reaction chamber 158 is provided at the bottom of the funnel body 152, and a capsule receiving area 160 provided by an enlarged region of the funnel body 152 is located above the reaction chamber 158. An annular shoulder 162 extends around the funnel body 152 between the receiving area 160 and the reaction chamber 158 to provide a stop against which a capsule can rest during use. A pair of recesses 163 are provided in the upper surface of the lid 104 on either side of the mixing funnel 124 to allow a capsule to be easily inserted into and removed from the receiving area 160.

[0056] In this embodiment, the reaction chamber 158 of the mixing funnel 124 has a base 170 in the shape of an inverted cone, with the center of the base 170 being higher than the perimeter of the base 170. A number of drain holes 172 (6 in this example) are located around the perimeter of the base 170.

[0057] The lid 104 is provided with a cover 114 (see FIG. 9) that connects to the lid 104 at a hinge 116 located adjacent the rear edge of the lid 104. The cover 114 may be closed over the lid 104 and secured to the front edge of the lid 104 by a clip 118. In the closed position, the cover 114 covers the fill port 110 and the second end 156 of the mixing funnel 124. The cover 114 is shaped to provide a plunger 180 for collapsing the walls of the capsule cavity during use.

[0058] In operation of the tank apparatus 100, the cover 114 is lifted to expose the fill port 110 and the mixing funnel 124. An appropriate amount of diluent, when provided, is added to the primary chamber 194 through the fill port 110 or the inlet port. A capsule of the type shown in FIG. 2 (not shown in FIGS. 9 and 10) is inserted into the receiving area 160 of the mixing funnel 124, and then the cover 114 is closed. The plunger 180 contacts the wall of the cavity, causing the release of the capsule's contents into the reaction chamber 158 of the mixing funnel 124. The reagent mixture in the reaction chamber 158 then drips through the drain hole 172 into the primary chamber 194 at a rate that is predetermined primarily by the size of the drain hole 172 and the geometry of the mixing funnel 124. The resulting liquid formulation can then be dispensed as needed through a tap attached to the outlet port 112.

[0059] Once the contents have been dispensed from the capsule, the cover 114 can be lifted and the empty capsule removed and discarded. The tank 100 can then be reused with a new capsule.

[0060] 9 and 10, the outlet port 112 may be fitted with an alternative outlet device, such as a calibrated measuring device designed to dispense a predetermined amount of the liquid formulation. In other variations, the outlet port 112 may be omitted (or unused) and an alternative outlet may be provided, such as a spout or a dispensing pump.

[0061] 11 shows the underside of the lid 204 for a tank apparatus in which the mixing funnel 224 has an alternative shape. In this variation, the mixing funnel 224 has an inverted tri-cuspid crown shape with three drain holes 270, each located at the lowest point of each branch of the crown.

[0062] It will be understood that in any embodiment of the invention, the shape of the mixing funnel may differ from that shown, and many other shapes may be possible. In all cases, the volume of the reaction chamber of the mixing funnel is preferably about 110% of the total volume of the capsule.

[0063] The volumes of the capsule, reaction chamber, and primary chamber can be selected to be appropriate for any desired application, and the number and size of the drain holes and the geometry of the reaction chamber can be selected to obtain the desired flow-through time.

[0064] In the single-use variants described above with respect to Figures 1 to 8, for example, the capsule preferably has a volume of about 3 mL to 10 mL per cavity and the primary chamber preferably has a volume of 200 mL to 1 L. Preferably, a single drain hole is provided in the mixing funnel, with a preferred size of 0.6 mm to 1 mm, more preferably about 0.75 mm. Preferably, the reagent mixture empties from the reaction chamber in 45 seconds to 3 minutes, corresponding to a flow rate through the drain hole of about 0.44 mL / s to about 0.033 mL / s, more preferably in about 2 minutes, corresponding to a flow rate of about 0.17 mL / s to about 0.05 mL / s.

[0065] In the multi-use variant described above with reference to Figures 9 and 10, the capsule preferably has a volume of about 50 mL to about 150 mL, more preferably about 100 mL per cavity, and the primary chamber preferably has a volume of about 2 L to about 10 L, more preferably about 5 L or about 10 L. Preferably, 2 to 6 drain holes are provided in the mixing funnel, more preferably there are 3 drain holes. Each drain hole preferably has a diameter of 0.6 mm to 2 mm, more preferably a diameter of 0.8 mm to 1.4 mm. Preferably, the reagent mixture empties from the reaction chamber in 30 seconds to 4 minutes corresponding to a flow rate of 10 mL / s to 0.42 mL / s, preferably in about 2 minutes corresponding to a flow rate of 2.5 mL / s to 0.83 mL / s.

[0066] It will be appreciated that both larger and smaller volume single use and multi-use versions can be readily provided if desired.

[0067] While the above embodiment advantageously uses a dispenser comprising a dispensing capsule of the type described in WO2017 / 060677 with a plunger, other configurations for dispensing the appropriate amounts of the first and second portions into the mixing funnel are possible. For example, the first and second portions may be provided in alternative two-chamber capsules or separate capsules. Alternative means for expelling the contents of the or each capsule may be provided. Alternatively, the two portions may be provided in a sachet, bottle, or any suitable container, and it is envisaged that the two portions may be manually dispensed into the mixing funnel by a user simultaneously or in quick succession. EXAMPLES

[0068] In the following examples, liquid formulations containing the active ingredient chlorine dioxide in solution were prepared using an apparatus of the type described above with reference to Figures 1-8. Chlorine dioxide solutions were prepared using starting phases (portions) containing 7-10% citric acid in one portion and 3-4% sodium chlorite in the other. Each chemical phase contained 15% amine oxide surfactant. 5 mL portions of each portion were filled into respective chambers of a capsule, sealed, then dispensed into a mixing funnel and dripped into the water in the primary chamber through the single drain hole as described above.

[0069] Example 1 Chlorine dioxide solutions were prepared at different temperatures using a mixing funnel with a drainage hole of 1 mm in diameter. The time it took for the reaction chamber to empty was measured and the chlorine dioxide concentration of the resulting formulations was evaluated, and the results are summarized in Table 1.

[0070] [Table 1]

[0071] The results show that lowering the temperature slows down the flow rate substantially compared to room temperature. However, the generated chlorine dioxide level still meets the requirements for microbial effectiveness. Increasing the temperature increases the flow rate, but again reaches an effective level of chlorine dioxide. In conclusion, this method of chlorine dioxide generation and release effectively mitigates the effects of small temperature fluctuations.

[0072] It will be understood that the temperatures used in this testing are not expected to be observed in normal use environments. Under real world conditions, a maximum temperature variation of + / - 5°C is expected with a target of 20°C. At this level of temperature variation, the effect on flow rate is less noticeable, but is still expected to be adequate to moderate the variation response dynamics.

[0073] Example 2 Chlorine dioxide solutions were prepared at a constant temperature of 20°C using mixing funnels with drainage holes of different diameters. All tests were diluted in 500 mL of tap water in the primary chamber, mixed with slight agitation, and then analyzed to determine chlorine dioxide concentration (via a Hach Lange DR3900 spectrophotometer, high range chlorine dioxide method). Agitation and analysis were performed as soon as the reaction chamber was emptied. For comparison, tests were repeated using water instead of the first and second parts of the system. Results with hole sizes between 0.7 and 0.9 mm, averaged over six replicates of each test, are summarized in Table 2.

[0074] [Table 2]

[0075] Figure 12 is a graph showing chlorine dioxide concentration as a function of drain hole diameter. The graph shows that all hole sizes tested were capable of producing chlorine dioxide strengths above 80 ppm, which is considered microbiologically effective for the purposes of this test.

[0076] 13 is a graph showing the time it takes for the contents of the reaction chamber to pass through the drain hole ("drip time") as a function of the diameter of the drain hole. The graph shows that a preferred hole size of 0.75 mm can provide a residence time of about 2 minutes. All other hole sizes tested were able to meet the desired minimum flow time of 45 seconds.

[0077] It was found that increasing the hole size beyond the preferred maximum of 1.00 mm for the single hole funnel resulted in inadequate chlorine dioxide generation. Conversely, reducing the hole size below 0.6 mm resulted in drip times longer than the preferred target of 2 minutes.

[0078] Table 3 shows the drip times and chlorine dioxide concentrations obtained for drain hole sizes from 0.5 mm to 1.5 mm. Again, the results are the average of six tests.

[0079] [Table 3]

[0080] Table 3 shows that when the hole size is 1.3 mm or greater, the level of chlorine dioxide produced falls below the initial yield considered acceptable for the effectiveness of the product. When the hole size is less than 0.6 mm, the drip time exceeds 120 seconds, which may result in undesirably high concentrations of chlorine dioxide. Furthermore, all tests were performed in an environmentally controlled laboratory at 20°C. When the temperature is below 20°C, the flow rate for the 0.5 mm hole is expected to be slow, with the temperature being low enough to stop flow completely due to a combination of surface tension and viscosity changes. Note that an effectiveness level of 80 ppm is arbitrarily set as a pass / fail indicator.

[0081] Further modifications and variations not expressly described above may be contemplated without departing from the scope of the invention as defined in the appended claims. [Explanation of symbols]

[0082] 10 equipment 20 Dispensing capsules, capsules 22 Cap 24 Mixing funnel, funnel 30 capsule bodies 32 End, first end 34 Second (upper) end, base 36 First interior wall, wall 38 First Cavity, Cavity 40 Second Inner Wall, Wall 42 Second Cavity, Cavity 44 Partitioned parts 46, 48 Burst pin 49 Sealing material 52 Funnel body, body 54 closed first (lower) end 56 Open second (upper) end, upper end 60 Capsule Containment Area, Containment Area 62 Circular shoulder, shoulder 64 Annular ridge, ridge 66 Exterior Wall 68 threads 70 Base 72 Drain hole 74 Ventilation holes 80, 180 Plunger 82 Top 84 clips 86 Skirt 90 containers 92 Threaded neck 94, 194 Primary chamber 100 Tank 102 Tank body 108 Fixed configuration 104 Lid 110 Filling port 112 Exit Port 114 Cover 116 Hinge 118 clips 124 Integrated mixing funnel, mixing funnel 152 Funnel body 154 Closed first (lower) end 156 Open second (upper) end 158 Reaction Chamber 160 Capsule Containment Area, Containment Area 162 Circular shoulder 163 Pair of recesses 170, 172, 270 drainage hole 224 Mixing funnel

Claims

A method for preparing a liquid formulation in which, when a first reagent and a second reagent are mixed using a two-part system including a first part containing the first reagent and a second part containing the second reagent, they react to produce an active ingredient of the liquid formulation, comprising: This method comprises: Dispensing an amount of the first part and an amount of the second part into a reaction chamber of a mixing funnel and forming a reagent mixture within this reaction chamber; Providing a permanently open flow path from this reaction chamber to a primary chamber, having a restricting orifice at the outlet of the mixing funnel, through which the reagent mixture passes at a regulated flow rate and flows by gravity from the reaction chamber into the primary chamber storing a diluent; Mixing the reagent mixture with the diluent in the primary chamber to produce the liquid formulation in the primary chamber. A method characterized by the above. The method according to claim 1, wherein the regulated flow rate when dispensing the amount of the first part and the amount of the second part into the reaction chamber is at least 0.1 times lower than the flow rate at which the first part and the second part are introduced into the reaction chamber. The method according to claim 1 or 2, wherein dispensing the amount of the first part and the amount of the second part into the reaction chamber includes discharging the first and second parts from a dispensing capsule. The method according to claim 1 or 2, comprising discharging the reagent mixture from the reaction chamber through the at least one restricting orifice into the primary chamber over a period of 30 seconds to 4 minutes. The method according to claim 1 or 2, wherein the active ingredient contains chlorine dioxide. An apparatus for using the method for preparing a liquid formulation according to claim 1 or 2, comprising: The apparatus includes: A mixing funnel having a reaction chamber, an inlet region for introducing an amount of the first part and an amount of the second part into the reaction chamber to form a reagent mixture during use, and an outlet having at least one restricting orifice for discharging the reagent mixture from the reaction chamber at a regulated flow rate; and A primary chamber configured to receive the reagent mixture from the reaction chamber through the restricting orifice. The restriction orifice or each restriction orifice is disposed in the base portion of the mixing funnel to provide a permanently open flow path for flowing the reagent mixture from the reaction chamber to the primary chamber under gravity, The apparatus further comprises a dispenser for dispensing an amount of the first portion and an amount of the second portion into the mixing funnel, The inlet region of the mixing funnel comprises an accommodation region for the dispenser, The dispenser is a device comprising a capsule having first and second cavities for storing the respective first and second portions.

7. The apparatus according to claim 6, further comprising an actuator operable to dispense the first and second portions from the capsule.

8. The apparatus according to claim 6, comprising a container defining the primary chamber, the mixing funnel being attachable to the container.

9. The apparatus according to claim 8, wherein the container comprises a neck portion and the mixing funnel is arranged to engage releasably with the neck portion.

10. The apparatus according to claim 8, wherein the mixing funnel is attachable to or integral with the lid of the container.

11. The apparatus according to claim 10, wherein the lid comprises a filling port for introducing a diluent into the container.

12. The apparatus according to claim 6, wherein the regulated flow rate is 10 mL / s or less.

13. The apparatus according to claim 6, wherein the regulated flow rate is 1 mL / s or less.

14. The apparatus according to claim 6, wherein the regulated flow rate in units of mL / s is 0.01 times or less the volume of the reaction chamber.

15. The apparatus according to claim 6, wherein the restriction orifice or each restriction orifice is sized such that the reagent mixture flows from the reaction chamber to the primary chamber in a time of 30 seconds to 4 minutes.

16. The apparatus according to claim 6, wherein a single restriction orifice having a diameter of 0.6 mm to 1 mm is provided, or at least two restriction orifices are provided and each restriction orifice has a diameter of 0.8 mm to 2 mm.

17. The apparatus according to claim 6, wherein the mixing funnel comprises a vent hole disposed in an upper region of the reaction chamber.

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