Method for analyzing a spray generated by a device for discharging a liquid pharmaceutical product

Description

[0001] The present invention relates to a method for analyzing spray generated by a pharmaceutical fluid product spraying device.

[0002] Pharmaceutical fluid spray devices are well known. Particularly in nasal spray applications, the therapeutic efficacy of the sprayed fluid may depend on the properties of the spray generated when the device is actuated. As is known, at the end of the assembly line, i.e. when the spray device is assembled, and just before being shipped to the pharmaceutical fluid manufacturer for assembly on a corresponding reservoir, a number of samples of assembled devices are tested in the laboratory to verify whether the spray properties correspond to the predefined specifications.

[0003] A disadvantage of this system is that it involves assembled devices, and therefore destroys these devices which, after being tested, cannot be delivered to the customer. In addition, this system requires human verification of the tested devices, and is therefore not fully automatable.

[0004] The document "Assessment of fuel spraying using schlieren system" by Marek Klimkiewicz, Agriculture No. 65, Vol. 2015, pp. 119-126, describes the use of strioscopy to analyze fuel sprays from different fuel injectors. EP 3 047 912 A1 discloses detection means that comprise at least one thermographic sensor for capturing at least one image of the temperature difference between at least a portion of a nebulized fluid ejected from a dispenser and a contrast space and / or projecting said image onto said contrast space.

[0005] The present invention aims to overcome the above-mentioned drawbacks.

[0006] In particular, the present invention aims to provide a spray analysis method which is non-destructive to the devices tested.

[0007] The present invention also aims to provide a spray analysis method which is largely automated.

[0008] The present invention also aims to provide a spray analysis method which is simple and / or inexpensive to manufacture, assemble and use.

[0009] The present invention therefore relates to a method for analyzing a spray generated by a device for spraying a pharmaceutical fluid product as described in claim 1. Advantageous embodiments are described in the dependent claims. These characteristics and advantages and others will appear more clearly during the following detailed description, made with reference to the attached drawings, given as non-limiting examples, and in which: there figure 1 is a schematic view of a device for analyzing a spray, according to a first advantageous embodiment, the figure 2 is a schematic view of a device for analyzing a spray, according to a second advantageous embodiment, the figure 3 is a schematic view similar to that of the figure 2 , of an advantageous embodiment variant, the figures 4 to 6 are schematic views showing images obtained by a method according to the invention, the figure 7 is a schematic view of a compliant test fluid spray, obtained by a method according to the invention, and the figure 8 is a view similar to that of the figure 7 , showing a non-compliant test fluid spray.

[0010] One objective of the invention is to improve the quality of sprayer control. To this end, the invention provides for the use of strioscopy to automatically analyze the spray cone emitted by sprayer devices.

[0011] Schlieren strioscopy, or the Schlieren method, is an optical visualization method that allows the isolation of details and small variations in an image, particularly small variations in index, such as during the compression of air or other fluids. In an image-based manner, the fundamental idea of this method is to remove the light that has not been deflected by the object, for example the fluid being studied. Indeed, only the rays deflected by it correspond to turbulence or high spatial frequencies in optics. To achieve this, an image is first created of the light source, preferably an incoherent light source, for example using a converging lens. The rays that have not been deflected (zero spatial frequencies) pass through the precise location of the geometric image. They are eliminated with a filter. The other rays, which have been deflected, are not focused at the same location and can therefore pass through to form a filtered image.In summary, the continuous background of the image is eliminated and, consequently, the details or turbulence of the object, which were "drowned" in this continuous background, become apparent.

[0012] The filter used can be simply a point, a wire, or a blade, for example of the "Foucault knife" type.

[0013] Schlieren is an application of spatial filtering in Fourier optics. Indeed, Fraunhofer diffraction tells us that the lens creates, in its image focal plane, the Fourier transform of the object in question. We thus visualize, in this plane, the spatial frequencies associated with the object, and the filter is placed in this same plane in order to eliminate some of these spatial frequencies. This wave interpretation of Schlieren makes it comparable to high-pass filtering.

[0014] In the context of the present invention, the objective is to highlight a test fluid flow, namely a jet of air at a temperature different from ambient temperature, for example heated air, coming from the spray orifice 2 of a spray head 1 of a device for spraying a pharmaceutical fluid product, and its observation through a camera. Alternatively, it is also possible to use a jet of air at a temperature lower than ambient temperature.

[0015] There figure 1 shows a strioscopic bench 20 according to a first advantageous embodiment.

[0016] In this example, a camera 21 associated with a lens 22 is arranged on one side of the bench 20 and a light source 23 is arranged on the opposite side. Compressed air generating means 24 are provided to pass a flow of air, preferably at a temperature different from ambient temperature, through a spray head 2, arranged in a viewing area 25, arranged between two collimating lenses 26, 27. A blade or diaphragm 28 is provided in front of the lens 22 to cut the beam and thus filter the image, and thus view the spray, as explained above.

[0017] The following standard components can be used for this implementation: Components Description Camera Manta 1292x964 @ 30Hz Objective 85mm f:1.8 Collimating lens 50mm Collimating lens 50mm Lamp White LED Diaphragm 2mm Pulse Smartek 10µs, 12A

[0018] THE Figures 2 and 3show two variants of another advantageous embodiment, in which the strioscopic bench comprises a concave and / or parabolic mirror 29. This embodiment is more compact, with the light source 23 and the camera 21 arranged on the same side, and the mirror 29 arranged on the opposite side. The overall operation is similar to the bench of the figure 1 .

[0019] The visualization includes videos.

[0020] It should be noted that the images obtained by visualizing the spray may include, in addition, static images (photos).

[0021] To carry out the analysis of the sprays displayed, the invention comprises analysis means 30 for determining whether the test fluid spray coming from said spray head complies or does not comply with predetermined specifications.

[0022] These analysis means 30 may in particular comprise means for measuring the opening angle of the test fluid spray.

[0023] Optionally, image processing means of the test fluid spray visualizations may be used to perform said analysis.

[0024] Thus, the predetermined specifications include a predetermined spray opening angle, such that sprays having an opening angle greater than or equal to said predetermined spray opening angle are classified as compliant and sprays having an opening angle less than said predetermined spray opening angle are classified as non-compliant.

[0025] THE figures 4 to 6 illustrate images obtained with the method and device of the invention, on which it is possible to measure and / or evaluate the opening angle of the spray, as illustrated by the conical lines.

[0026] THE figures 7 and 8 illustrate images showing respectively a spray of test fluid classified as compliant ( figure 7) and a test fluid spray classified as non-compliant ( figure 8 ).

[0027] The present invention has many advantages, including: it allows automated spray control on various types of spraying devices; it allows non-destructive analysis of said spraying devices; it uses a compact and easily adaptable assembly; it uses simple and standard components, therefore generally inexpensive; it allows robust image processing, which can be carried out in real time; it ensures good repeatability and good discrimination of compliant and non-compliant sprays.

[0028] The present invention has been described with reference to various advantageous embodiments, but it is understood that a person skilled in the art may make any modifications thereto, without departing from the scope of the present invention as defined by the appended claims.

Claims

1. A method of analyzing a spray generated by a spray device for spraying pharmaceutical fluid, comprising the following steps: - providing a spray head (1) of a spray device for spraying pharmaceutical fluid, said spray head (1) including a spray orifice (2), - causing a test fluid to pass through said spray head (1) towards said spray orifice (2), said test fluid being air at a temperature that is different from ambient temperature, - displaying, by strioscopy, the flow of test fluid leaving said spray orifice (2), and - analyzing said display of the test-fluid flow so as to determine whether or not the test-fluid spray coming from said spray head complies with predetermined specifications, wherein said display comprises videos, wherein said predetermined specifications include a predetermined spray cone angle, such that test-fluid sprays having a cone angle that is greater than or equal to said predetermined spray cone angle are classed as being compliant, and test-fluid sprays having a cone angle that is less than said predetermined spray cone angle are classed as being non-compliant.

2. A method according to claim 1, wherein said analyzing step includes determining the cone angle of the test-fluid spray.

3. A method according to claim 1 or claim 2, wherein said analyzing step includes an image-processing step for processing said display of the test-fluid flow.