Abstract:
The present invention provides a dispensing device for applying fluid comprising a pressurized reservoir equipped with a dosing module having at least one dosing chamber which is able to communicate with the reservoir and with a nozzle provided for dispensing a dose of fluid, characterized in that the dosing chamber comprises a moving and/or deformable member which delimits at least a first and a second compartments of variable volume, each compartment having an inlet and an outlet associated with valve means, wherein valve means are controlled according to a first configuration in which the inlet of the first compartment and the outlet of the second compartment are open while the other inlet and outlet being closed, and according to a second configuration in which the inlet of the second compartment and the outlet of the first compartment are open while the other inlet and outlet being closed.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates generally to a device for dispensing a dose of fluid. 
         [0002]    The present invention relates more particularly to a dispensing device for applying fluid comprising a pressurized reservoir equipped with a dosing module, the dosing module having at least one dosing chamber which is able to communicate, on one hand, with the reservoir and, on the other hand, with at least one nozzle provided for dispensing a dose of fluid. 
         [0003]    This type of dispensing device is particularly useful for delivering ophthalmic drugs topically. Such a dispensing device is disclosed, for example, in document WO-A-98/12511, wherein a piston slidable between a first and a second priming position, upon action of a pre-loaded spring, is actuated by means of a trigger in order to cause a fluid charge to be expelled through a nozzle. 
         [0004]    This type of dispensing device is not completely convenient because it comprises a lot of components, the precision of the dose delivering is not guaranteed, the complexity of the mechanism causes reliability problems and high fabrication costs. 
         [0005]    The present invention is aimed to solve the above problems and others. 
       SUMMARY OF THE INVENTION 
       [0006]    According to the present invention there is provided a dispensing device for applying fluid comprising a pressurized reservoir equipped with a dosing module, the dosing module having at least one dosing chamber which is able to communicate, on one hand, with the reservoir and, on the other hand, with at least one nozzle provided for dispensing a dose of fluid, characterized in that the dosing chamber comprises a moving and/or deformable member which delimits at least a first and a second compartments of variable volume, each compartment having an inlet and an outlet associated with valve means, wherein valve means are controlled according to a first configuration in which the inlet of the first compartment and the outlet of the second compartment are open while the other inlet and outlet being closed, and according to a second configuration in which the inlet of the second compartment and the outlet of the first compartment are open while the other inlet and outlet being closed, such that, in the first configuration, the first compartment is refilled with a dose of fluid, under reservoir pressure, while the dose of fluid contained in the second compartment is expelled and, in the second configuration, the second compartment is refilled with a dose of fluid, under reservoir pressure, while the dose of fluid contained in the first compartment is expelled. 
         [0007]    The dispensing device according to the present invention provides a great ability to deliver a precise dose of drug independently from the orientation of the device, contrarily to conventional eye droppers. 
         [0008]    The dispensing device according to the present invention prevents a patient to influence or to compromise dose size by incorrect manipulations. 
         [0009]    The characteristics of the product stream produced by each nozzle permit to overcome the blink reflex of the eyes. 
         [0010]    The structure of the dispensing device according to the present invention permits extremely small dimensions for the device. For example, a dispensing device of three milliliters (typically one hundred doses) can be as small as about fifteen cubic centimeters. 
         [0011]    The characteristics of the dispensing device make the device particularly compact and easy to use compared to usual eye droppers and also to other devices. It is very convenient for elderly people, children and persons with reduced mobility, avoiding assistance of a second person for drug administration. 
         [0012]    The dispensing device according to the present invention is provided with a fully disposable fluidic path, which can be fabricated for very low cost. Hence, the dispensing device can be made only with plastic components and a metallic or plastic spring, without requiring any other additional energy source. 
         [0013]    Thanks to its simple structure, the dispensing device can be easily safely secured for shelf life and shipment. During shipment, the drug fluid is separated from the dosing module by the septum which avoids fluid degradation and contamination. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0014]    The preferred embodiment of this invention will be described in detail, with reference to the following figures, wherein like designations denote like elements, and wherein: 
           [0015]      FIG. 1  shows schematically an axial section of a dispensing device in accordance with a preferred embodiment of the present invention; 
           [0016]      FIG. 2  shows schematically an exploded perspective view of the dispensing device of  FIG. 1 ; 
           [0017]      FIG. 3  shows schematically an axial section of the dosing module equipping the dispensing device of  FIG. 1 ; 
           [0018]      FIG. 4  is a view similar to  FIG. 1  showing the dispensing device in a starting configuration before use; 
           [0019]      FIG. 5  is a view similar to  FIG. 1  showing the dispensing device in operation with the slider in an intermediate position; 
           [0020]      FIG. 6  is a view similar to  FIG. 1  showing the dispensing device in operation with the slider in its lower position just before the stream of fluid is released; 
           [0021]      FIG. 7  is a view similar to  FIG. 1  showing the dispensing device releasing a dose of fluid; 
           [0022]      FIG. 8  is a view similar to  FIG. 1  showing the dispensing device at the end of operation; 
           [0023]      FIG. 9  is an axial section of a perspective view showing the dispensing device provided with a casing. 
       
    
    
     DETAILED DESCRIPTION  
       [0024]    Referring to  FIG. 1 to 2 , a dispensing device  10  for delivery of ophthalmic drug in accordance with a preferred embodiment of the present invention is shown. 
         [0025]    The dispensing device  10  is based on use of a pressurized reservoir  14  (drug primary packaging), preferably but not limited to a cylindrical glass cartridge  12  with a spring loaded piston  18 , and a self-dosing delivery module  20  namely the dosing module  20 . 
         [0026]    The cartridge  12  comprises a tubular end portion  22  housing a pre-loaded spring  16  biasing the piston  18  axially towards the dispensing front end  24  of the cartridge  12 . The dispensing front end  24  is initially sealed with a septum  26 . The reservoir  14  contains the ophthalmic drug in the form of a fluid F to be expelled. 
         [0027]    For comprehension purpose, an axial orientation from rear to front, along the cartridge axis A 1 , will be used. 
         [0028]    The dosing module  20 , as shown on  FIG. 3 , comprises a support member  28  in the form of a cap which is clipped on the dispensing front end  24  of the cartridge  12 , a slide valve assembly  30 , and a front cap  32  which is mounted on the front end of the support member  28 . 
         [0029]    The support member  28  comprises an upper  34  and a lower  36  channels in communication with a tubular needle  38  which extends axially at a rear face of the support member  28  in order to pierce the septum  26  so as to set the dispersion device  10  operational. 
         [0030]    The slide valve assembly  30  comprises a tubular slider  40  delimiting an inner dosing chamber  42  which is able to be in communication with the reservoir  14  through the channels  34 ,  36 . 
         [0031]    The slider  40  is slidably mounted in a guide groove  44  arranged on the front face of the support member  28 , along a sliding axis B 1  transversal to the cartridge axis A 1 . 
         [0032]    The slider  40  is able to move between two indexed positions, a lower and an upper positions, upon manual actuation such as finger pressure on one transverse end of the slider  40 .  FIG. 3  shows the slider  40  in its upper position, and  FIG. 8  shows the slider  40  in its lower position. 
         [0033]    Preferentially, the slider  40  is bistable such that it can not stay in an intermediate position between its two indexed positions. A mechanical feature such as a hard point can be provided in the slide valve assembly  30  in order to prevent the slider  40  to stay in an intermediate position. 
         [0034]    The slider  40  comprises an upper  46  and a lower  48  inlets which are able to match with the orifices of the upper  34  and the lower  36  channels of the support member  28  when the slider  40  is in its upper and in its lower positions respectively. 
         [0035]    The slider  40  comprises an upper  50  and a lower  52  outlets which are able to communicate with the opening  54  arranged in the front face  56  of the front cap  32 , when the slider  40  is in its lower and in its upper positions respectively. 
         [0036]    In a different construction, the outlets  50  and  52  can be joined via a fluidic channel built in the slider  40 , so that the dispensing device  10  has only one output nozzle instead of two. 
         [0037]    According to the present embodiment, each outlet  50 ,  52  constitutes a nozzle designed for producing a stream S of fluid F through the opening  54  and towards an eye  58  of the patient. Each outlet  50 ,  52  has a general axis of projection which is inclined relatively to the cartridge axis A 1  and which is directed towards the cartridge axis A 1  such that, when the dispensing device  10  is well positioned in front of the eye  58 , the stream S is directed towards the center of the eye  58 . Inclination of the general axis of projection improves the precision of delivery. 
         [0038]    The support member  28  and the front cap  32  are provided with some sealing surfaces  70  selectively facing external orifices of the inlets  46 ,  48  and of the outlets  50 ,  52  when the slider  40  occupies some given transversal positions, in order to close selectively the inlets  46 ,  48  and the outlets  50 ,  52 . 
         [0039]    According to a first configuration, wherein the slider  40  is in its upper position, the sealing surfaces  70  are closing the upper outlet  50  and the lower inlet  48  and, according to a second configuration, wherein the slider  40  is in its lower position, the sealing surfaces  70  are closing the lower outlet  50  and the upper inlet  46 . 
         [0040]    When the slider  40  is in an intermediate position, illustrated by  FIG. 5 , the sealing surfaces  70  are closing every inlet  46 ,  48  and every outlet  50 ,  52 . 
         [0041]    According to the present embodiment, the sealing surfaces  70  belong to a front  66  and to a rear  68  inserts arranged respectively on the rear face of the front cap  32  and on the front face of the support member  28 . 
         [0042]    The slider  40  comprises a shuttle plunger  60  which is slidably mounted in the dosing chamber  42 , coaxially to the sliding axis B 1  of the slider  40 , between an upper position in which the shuttle plunger  60  closes the upper outlet  50  and the upper inlet  34 , and a lower position in which the shuttle plunger  60  closes the lower outlet  52  and the lower inlet  36 . 
         [0043]    The shuttle plunger  60  delimits, in the dosing chamber  42 , an upper compartment and a lower compartment of variable volume. 
         [0044]    The volume of fluid F which can be contained in one compartment of the dosing chamber  42 , when the shuttle plunger  60  occupies its upper or its lower position, matches with a given dose D of fluid F to be dispensed to the eye  58  of a patient. 
         [0045]    The given dose D is defined solely by geometry, i.e. by the chamber dimension (diameter) and by the shuttle plunger stroke. 
         [0046]    The shuttle plunger  60  is actuated by a differential fluid pressure on its lower  62  and its upper  64  sides, in the dosing chamber  42 , following a displacement of the slider  40  from an extreme position to the other. 
         [0047]    The operation of the dispensing device according to the embodiment disclosed will be explained referring to  FIGS. 4 to 8 . 
         [0048]    Starting from the rest position illustrated on  FIG. 4 , where the slider  40  is in its upper position, the shuttle plunger  60  is in its lower position, and the dosing chamber  42  is in communication with the reservoir  14  through the upper inlet channel  46 , a manual pressure is applied on the upper extremity of the slider  40  such that it slides down. 
         [0049]    During its transversal displacement, the slider  40  comes to an intermediate non stable position, illustrated by  FIG. 5 , in which all its channels  46 ,  48 ,  50 ,  52  are closed by the sealing surfaces  70 . 
         [0050]    In this intermediate position, the shuttle plunger  60  stays down since the dosing chamber  42  is filled with fluid F. 
         [0051]    At the end of this displacement, the slider  40  reaches its lower position, illustrated by  FIG. 6 , in which the lower inlet  48  matches with the lower channel  36  of the support member  28  establishing communication with the reservoir  14 , and in which the upper outlet  50  emerges into the opening  54  of the front cap  32 . 
         [0052]    The lower side  62  of the shuttle plunger  60  is under fluid pressure of the reservoir  14  which causes the shuttle plunger  60  to slide up expelling the fluid F contained in the upper compartment of the dosing chamber  42  through the upper outlet  50  in the form of a stream S directed towards the eye  58  of the patient, while simultaneously inducing refilling of the lower compartment of the dosing chamber  42 , as illustrated by  FIG. 7 . 
         [0053]    Advantageously, the upper outlet  50  emerges into the opening  54  slightly before the opening of the lower inlet  48  such that, when the stream S of fluid F starts, the upper outlet  50  is completely open, in order to obtain an accurate and continuous stream S. 
         [0054]    During stream S production, the piston  18  slides towards the dispersing front end  24  of the cartridge. 
         [0055]    At the end of its displacement, the shuttle plunger  60  is in its upper position, as shown on  FIG. 8 , closing the upper outlet  50  and the upper inlet  46 , and a new dose D of fluid F is ready in the lower compartment of the dosing chamber  42 . 
         [0056]    The quantity of fluid F expelled through the nozzle channel  50  corresponds to a dose D of fluid F. 
         [0057]    Symmetrically, the next fluid injection can be realized pressing up the slider  40 , as illustrated by the arrow on  FIG. 8 . 
         [0058]    A correct alignment of the dispensing device  10  with the eye  58  is ensured when the patient can see the outlet  50 ,  52  through the opening  54 . An additional visual alignment feature can be easily included along the dispensing device  10 , for example a hole and a visible element in black or in another color, or a groove. 
         [0059]    The delivery of the fluid F occurs in a single stream S within a time of approximately forty milliseconds for an “usual dose” in the range of thirty micro-liters. This timing is crucial to overcome the blink reflex. 
         [0060]    Of course, dose range and time range for delivery could be different. Dose can be chosen by geometry, typically between five and fifty micro-liters. Time range is given by pressure, friction, and nozzle geometry and can be chosen typically between five and fifty milliseconds. 
         [0061]    Thanks to adequate design of the spring  16 , of the channels  34 ,  36 , of the inlets  46 ,  48 , of the outlets  50 ,  52 , of the piston  18 , and of the shuttle plunger  60 , the delivery time varies only within an acceptable range when the reservoir  14  is being emptied. 
         [0062]    The actuation speed of the slider  40  has no impact on the delivery time, neither on dose D. The slider  40  is provided with appropriate hard points to make stop impossible during opening of the inlets  46 ,  48  and of the outlets  50 ,  52 . 
         [0063]    The embodiment has been described with dispensing of fluid in the form of a stream S. The fluid F could also be dispensed in the form of a spray. The choice of a spray or a stream S depends on the medication to be delivered and can be chosen by adapting the nozzle shape. 
         [0064]    Advantageously, the dispensing device  10  can be provided with a casing  72 , improving ergonomics. 
         [0065]    In the example shown on  FIG. 9 , the casing  72  is enveloping entirely the dosing module  20  and the cartridge  12 . An upper  74  and a lower  76  press buttons are arranged on the dosing module  20  in order to permit actuation of the slider  40 . A front disc  78 , with a hole facing the opening  54  of the dosing module  20 , closes the front end of the casing  72 . 
         [0066]    The casing  72  could also be provided with additional features (not shown) such as dose counter, timer, reminder, delivery tracking, etc. 
         [0067]    It should be noted that, in a different—more sophisticated—embodiment, manual actuation can be replaced by an actuator of any type such as linear, electromagnetic, lever mechanism or whatever, which could be located in the casing  72 .