DEVICE FOR TESTING THE LEAKAGE OF A PUMP ASSEMBLY FOR HIGH-PRESSURE SPRAY APPLICATORS

Description

TECHNICAL FIELD

[0001] The invention relates to a device for testing the tightness of a pump assembly for high-pressure spray applicators. Such high-pressure spray applicators can be, in particular, high-pressure atomizers such as inhalers, but also sprays such as nasal or eye sprays. Spray applicators are primarily used when the administration of an active ingredient is dose-dependent and / or droplet-size-dependent.

[0002] Inhalers are medical devices (applicators) for generating aerosols or vapors; these aerosols or vapors can then be inhaled by patients. Inhalers are used primarily in the treatment of various respiratory diseases such as asthma or COPD (Chronic Obstructive Pulmonary Disease). The inhalers allow active ingredients to reach the lungs, where they have a localized effect. This can reduce side effects; and often only a smaller dose of the active ingredient is required. The active ingredient can also enter the bloodstream via the alveoli of the lungs and have a systemic effect. Here, too, smaller doses are often sufficient, as the liver's first-pass effect is bypassed. Furthermore, due to the large absorption surface of the lungs, the active ingredients reach the bloodstream more quickly, so the effect occurs very quickly. STATE OF THE ART

[0003] The inhalers can, for example, be designed as soft mist inhalers (SMI, high-pressure atomizers). Such inhalers are described in particular in WO 91 / 14468 A1, WO 97 / 12687 A1, or WO 2009 / 047173 A2. The soft mist inhalers have an atomizer with a mechanical pump that can generate a long-lasting, fine spray cloud of a fluid. The fluid is usually an aqueous or ethanolic solution of the active ingredient. No propellant is required to generate the spray mist. The fluid is usually contained in a cartridge. After such a cartridge has been used up, it can often be replaced at least several times.

[0004] The inhaler itself has a sturdy capillary tube that is inserted into the cartridge containing the fluid. The capillary is immersed slightly in the fluid, causing it to be drawn upwards within the capillary by capillary forces. A high-pressure check valve for dosing the fluid is located at the top of the capillary. This check valve serves both to shut off and to control the flow of the fluid within the capillary. The fluid can flow upwards within the capillary, but not back down and thus back into the cartridge.

[0005] High pressure is generally defined as a pressure above 10 bar. In this case, the high-pressure check valve should withstand a pressure between 100 bar and 1,000 bar, preferably a pressure of approximately 250 bar.

[0006] The upper end of the capillary tube terminates in a high-pressure pump assembly, which forms the central unit of the Soft Mist Inhaler—and other spray applicators as well. Correct assembly of this pump assembly is crucial for the proper functioning of the inhaler, so even minor errors or deviations can lead to malfunction.

[0007] After the inhaler has been fully assembled, a quality inspection usually takes place. This quality inspection allows any malfunctions in the inhaler to be detected before delivery, ensuring that no inhalers that do not meet specifications are distributed. Furthermore, it must also be ensured that the fluid dosage is reproducible. Such an inspection of the inhalers can be performed as part of a full inspection (100% inspection), in which all inhalers are routinely tested accordingly. It would also be possible to conduct the inspection of the inhalers as part of random sampling.

[0008] WO 2017 / 060328 A1 (US 2019 / 0113418 A1) discloses a test system and method in which the fully assembled inhaler is tested with a test fluid. For this purpose, the finished inhaler is connected to a test cartridge containing the test fluid and mechanically actuated several times. Various measurements are taken, particularly with regard to the distribution of the spray mist and the quantity of atomized fluid. If the inhaler fails to deliver correct measurements during this test, the inhaler is rejected. However, rejecting inhalers at this stage is economically disadvantageous, as the value chain is already almost complete. In particular, if only one component malfunctions, the entire inhaler must still be rejected.

[0009] Furthermore, at this stage after complete assembly, determining the cause of a failed test is either impossible or only possible with considerable effort – particularly requiring at least partial disassembly of the inhaler. Such a determination of the cause is particularly important when similar malfunctions occur in several inhalers. However, since different components are tested and checked together, errors can spread, making it impossible to clearly attribute the malfunction to a specific component. However, with an individual test for just one function, the problem can be quickly identified and which component may be faulty.

[0010] Various other applications are known from US 2008 / 0202526 A1, US 2013 / 0041241 A1 and EP 3 299 144 A1 in which a check for the presence of leaks is to be carried out by means of negative or positive pressure. PRESENTATION OF THE INVENTION

[0011] Based on this prior art, the invention is based on the object of providing an improved testing device by means of which an individual test of the tightness of the pump assembly is possible.

[0012] The testing device according to the invention is defined by the features of main claim 1. Useful developments of the invention are the subject of further claims following this claim.

[0013] The device according to the invention for testing the tightness of a pump assembly of inhalers comprises a pump assembly with a nozzle unit, wherein the nozzle unit is mounted pressure-tight on a housing. The device has a coupling element through which the testing device can be connected to the pump assembly. Furthermore, the testing device has a negative pressure and / or positive pressure generator unit connected to the coupling element and a sensor unit through which the pressure within the pump assembly can be measured.

[0014] By using a negative pressure and / or positive pressure generation unit, the tightness of the pump assembly can be tested without the use of a test fluid. This eliminates the need for time-consuming cleaning of the pump assembly after quality control, significantly accelerating the inhaler assembly process. Furthermore, eliminating the cleaning process allows for 100% testing.

[0015] The testing device according to the invention enables individual testing, allowing the tightness of the pump assembly to be checked directly in the process line. Furthermore, the testing device according to the invention allows for the pump assembly to be inspected immediately after its assembly. This allows testing to be performed very early in the process chain and thus also very early in the value chain, saving time and money during inhaler assembly.

[0016] Preferably, the test device can include a vacuum pump as a negative pressure generating unit. Corresponding pressure increase tests have proven to be particularly fast and sufficiently accurate in terms of resolution. A defined negative pressure is applied to the pump assembly, and the pressure increase is measured as a measure of the leak size.

[0017] The pump assembly has a nozzle unit. This nozzle represents a leak in the pump assembly, albeit a very small one. This leak can be determined over several samples and subtracted as an offset to determine the actual leaks. In a preferred embodiment, the test device can have a closure element by means of which the spray opening of the pump assembly and thus the leak through the nozzle unit can be sealed. The closure element can, for example, also be a liquid that is introduced into the spray opening of the pump assembly. In this case, the liquid should evaporate quickly and without residue, as is the case, for example, with low-chain alcohols, particularly ethanol.

[0018] The nozzle unit is mounted pressure-tight on a housing. This pressure-tight mounting can be achieved, in particular, by means of at least one seal. The tightness of the pump assembly depends largely on the functionality of this at least one seal between the nozzle unit and the housing.

[0019] In a first embodiment of the invention, the coupling element can comprise a capillary tube as an adapter, which can be inserted pressure-tight into the nozzle unit of the pump assembly. Since the nozzle unit will be equipped with a corresponding capillary tube later in the assembly process, the nozzle unit is already designed accordingly, thus enabling easy connection to the test device.

[0020] In a second embodiment of the invention, the pump assembly may already be equipped with a capillary. In this case, the coupling element can be releasably attached to the free end of the capillary via an attachment piece.

[0021] Alternatively, the negative pressure and / or positive pressure generation unit could also be connected to the nozzle unit of the pump assembly using a coupling element. In this case, the capillary connected to the pump assembly or the corresponding capillary adapter on the pump assembly would have to be sealed.

[0022] The test device can be operated manually, semi-automatically, or fully automatically. The test device can be integrated into the inhaler assembly process so that each pump assembly is tested by the test device, ensuring 100% testing. However, random testing is also possible.

[0023] A corresponding examination would involve the following procedural steps: 1. The test device is connected to the pump assembly in a pressure-tight manner. 2. A negative pressure or positive pressure is generated in the pressure chamber (interior of the nozzle unit and the capillary of the test device or the pump assembly). 3. The pressure increase or pressure drop within the pressure chamber is monitored using a sensor unit.

[0024] The measured values ​​from the sensor unit can then be read electronically, allowing the pressure increase or pressure drop to be evaluated. Based on this evaluation, a manual or automatic assessment of the assembly's function can then be performed.

[0025] In principle, multiple test fixtures could also be integrated into the inhaler assembly process. For example, a first version of the test fixture could be provided initially, testing the pump assembly without the capillary. Later in the assembly process, a second version of the test fixture could then be provided to retest the pump assembly with the capillary inserted.

[0026] Further advantages and features of the invention can be found in the features further specified in the claims and in the following exemplary embodiment. SHORT DESCRIPTION OF THE DRAWING

[0027] The invention is described and explained in more detail below with reference to the exemplary embodiment shown in the drawing. It shows: Fig. 1 shows a schematic longitudinal section through a first embodiment of the test device according to the invention, which is connected to the capillary of a pump assembly, Fig. 2 shows a schematic longitudinal section through a second embodiment of the test device according to the invention, which is connected to the nozzle unit of a pump assembly. WAYS TO CARRY OUT THE INVENTION

[0028] A first embodiment of the device 10 according to the invention for testing the tightness of a pump assembly 12 for inhalers is shown in Fig. 1 shown schematically.

[0029] The pump assembly 12 has a housing 20 and a nozzle unit 22. A seal 24 is located between the nozzle unit 22 and the housing 20, so that the nozzle unit 22 is mounted pressure-tight on the housing 20. The nozzle unit 22 is attached to the upper end of a capillary 26. Between the capillary 26 and the nozzle unit 22 is another seal 28, which belongs to the nozzle unit 22.

[0030] In particular, the tightness of the seal 24 between the housing 20 and the nozzle unit 22 and the tightness of the seal 28 between the nozzle unit 22 and the capillary 26 are to be checked with the test device 10 according to the invention.

[0031] In the present example, the capillary 26 is part of a coupling element 30. The coupling element 30 can be used to connect the test device 10 to the pump assembly 12. The coupling element 30 is connected to a vacuum pump 34 and a sensor unit 36 ​​via a line 32. A defined negative pressure can be generated in the interior of the capillary 26 and the nozzle unit 22 (pressure chamber 38) via the vacuum pump 34.

[0032] The sensor unit 36 ​​can measure and record how the negative pressure in the pressure chamber 38 changes over a defined period of time. Assuming the seals 24, 28 are functioning properly, there should be no significant pressure increase in the pressure chamber 38 after a certain settling period.

[0033] A slight pressure increase in the pressure chamber 28 may result from a certain mini-leakage through the spray orifice 42 in the housing 20 of the pump assembly 12. The leakage of the spray orifice 42 can be precisely determined through several calibration measurements. During the actual test, this leakage can then be subtracted from the measured values.

[0034] In the present embodiment, the test device 10 has a closure element 44 through which the spray opening 42 of the pump assembly 12 can be sealed. This eliminates the need for additional calibration measurements, as there is no longer any leakage through the spray opening 42. Therefore, there should be no pressure increase in the pressure chamber 38 during the test. The closure element 44 can, for example, also be a liquid that is introduced into the spray opening 42. This liquid should evaporate quickly and without residue; this is particularly the case with low-chain alcohols such as ethanol.

[0035] In contrast to the embodiment shown in the drawing, an overpressure generator unit could also be used instead of the vacuum pump 34. In this case, an overpressure would be generated in the pressure chamber 38. In this case, the sensor unit 36 ​​would measure whether the overpressure in the pressure chamber 38 drops over a defined period of time.

[0036] In contrast to the embodiment shown in the drawing, the pump assembly 12 could already be equipped with a capillary 26 during the leak test. In this case, the coupling element would have a corresponding attachment piece that can be releasably attached to the free end of the capillary.

[0037] A second embodiment of the device 10.2 according to the invention for testing the tightness of a pump assembly 12 for inhalers is shown in Fig. 2shown schematically. The test device 10.2 can be connected to the nozzle unit 22 of the pump assembly 12 by means of a coupling element 30.2. The coupling element 30.2 is connected to the vacuum pump 34 and the sensor unit 36 ​​via a line 32. A defined negative pressure can be generated in the interior of the nozzle unit 22 (pressure chamber 38) via the vacuum pump 34. For this purpose, the capillary 26 present on the pump assembly 12 is sealed by a closure element 44.2.

[0038] If in this embodiment no capillary 26 is present on the pump assembly 12, the pump assembly 12 can also be sealed using a pin-shaped closure element.

Claims

1. Device (10, 10.2) for testing the tightness of a pump assembly (12) for spray applicators, wherein the pump assembly (12) has a nozzle unit (22), which is mounted in a pressure-tight manner on a housing (20), characterized in that the device comprises: - a coupling element (30, 30.2) by way of which the testing device (10, 10.2) is connectable to the pump assembly (12), - a generating unit (34) for negative and / or positive pressure, which is connected to the coupling element (30, 30.2), - a sensor unit (36) by way of which the pressure inside the pump assembly (12) is able to be measured.

2. Device according to Claim 1, - characterized in that - the nozzle unit (22) is mounted in a pressure-tight manner on the housing (20) by means of at least one seal (24).

3. Device according to Claim 1 or 2, - characterized in that - the coupling element (30) has a capillary (26), - the capillary (26) is insertable in a pressure-tight manner into the nozzle unit (22) of the pump assembly (12).

4. Device according to Claim 1 or 2, - characterized in that - the pump assembly has a capillary which is fastened in a pressure-tight manner to the nozzle unit, - the coupling element has an attachment (40) which is able to be releasably fastened to the free end of the capillary (26).

5. Device according to Claim 3 or 4, - characterized in that - the capillary of the pump assembly (12), or the capillary (26) of the testing device (10), is fastened, or able to be fastened, to the nozzle unit (22) by means of at least one seal (28).

6. Device according to one of the preceding claims, - characterized in that - there is a closure element (48) by way of which the spray opening (32) of the pump assembly (12) is able to be sealed.

7. Method for testing the tightness of a pump assembly (12) for spray applicators, characterized by the following method steps: - a testing device (10, 10.2) is connected in a pressure-tight manner to the pump assembly (12), - in a pressurized chamber (38) of the pump assembly (12), a positive or a negative pressure is generated by means of a generating unit (34) for negative pressure and / or positive pressure, - the pressure increase or the pressure drop within the pressurized chamber (38) is monitored by means of a sensor unit (36).

8. Method according to Claim 7, - characterized in that - the measured values of the sensor unit (36) are read electronically, as a result of which the pressure increase or the pressure drop can be evaluated.

9. Method according to Claim 8, - characterized in that - a manual or automatic assessment of the assembly function is carried out on the basis of the evaluation.