The present invention relates to a needleless injection system and to a process for the treatment, especially cosmetic treatment, of human keratin materials using such a system.

Prior art

Publications US 6673081 Bl, US 6283936 Bl, WO 0027339 disclose needleless injectors comprising a hand piece, a reservoir containing a liquid composition, and a source of pressurized gas, the reservoir being connected both to the hand piece and to the source of pressurized gas via hosing. The injection of gas into the reservoir makes it possible to generate, by positive pressure, a stream of the liquid composition contained in the reservoir in the direction of the hand piece. A nozzle present at the hand piece makes it possible to break up this stream into microdroplets dispersed in a gas stream, the spray thus formed being injected into the skin.

Such needleless injectors in which a positive pressure in the reservoir containing the liquid composition is necessary for generating a flow of this composition do not make it possible to dispense solid compositions.

Moreover, publications US 8800551 B2, US 8317740 Bl and US 9457151 B2 describe needleless injectors comprising a Venturi tube, a reservoir of a liquid composition comprising a piston, and a source of pressurized gas connected both to the reservoir and to the Venturi tube. The actuation of the piston by the gas makes it possible to dispense the composition contained in the reservoir in the choke of the Venturi tube which is passed through by a stream of gas. Due to the acceleration of the speed of the stream of gas at the choke of the Venturi tube, the liquid composition is broken up into microdroplets dispersed in the gas stream, the spray thus formed being injected into the skin.

Such needleless injectors in which the liquid composition contained in the reservoir is dispensed by the actuation of a piston are not suited to a solid composition such as a powder, especially due to the risk of clogging of the pipe connecting the outlet of the reservoir to the Venturi tube by the powder.

There remains a need to enable the injection of a solid product into the human keratin materials using a needleless injector, especially in order to prevent, treat and/or reduce a relief and/or a fold in an area of skin and/or a skin-colour disorder. Summary of the invention

The invention meets this need by virtue of a needle less injection system comprising:

- a mixing chamber in which particles of a solid dermatological or cosmetic composition are mixed with a volume of gas with a view to the injection thereof into the human keratin materials,

- a mechanism for propelling the particles of the solid composition that are present in the mixing chamber into the human keratin materials.

“Needleless injection system” should be understood as being a system in which mechanical forces are used to propel a composition through the epidermis without the penetration of an injection needle through the epidermis.

“Skin” denotes the dermis and the epidermis and the surface region of the mucous membranes, such as the lips.

The propulsion mechanism may comprise a first reservoir containing a pressurized gas and/or a piston.

The needleless injection system according to the invention may comprise at least one second reservoir containing and/or intended to receive the solid composition.

The needleless injection system according to the invention may comprise a transfer and/or disintegration member in contact with the solid composition contained in the second reservoir, made to perform a relative movement in relation to said solid composition in order to dispense the solid composition in particulate form into the mixing chamber.

The invention offers an easy-to-use, reliable, robust, compact and ergonomic solution for the needleless injection of a composition.

The invention enables the transfer of the solid composition contained in the second reservoir towards the mixing chamber and the dosing of the amount of composition dispensed by the transfer and/or disintegration member.

The second reservoir according to the invention may be produced so as to be ready to use and to not require any setting-up on the part of the user prior to use. It may be specifically intended, due to the nature of the solid composition which it contains, for a particular application.

The second reservoir may initially contain a single dose of the solid composition. As a variant, the second reservoir contains several doses of the solid composition. It may contain the solid composition in a sufficient amount to perform an entire treatment session with several injections, without it being necessary to replace the second reservoir, thereby reducing handling operations during the treatment.

The second reservoir may make it possible to effect a number of injections greater than or equal to 3, better still greater than or equal to 10, without having to be replaced.

A dose of the solid composition may correspond to an amount of the solid composition of between 0.01 mg and 5 mg. Thus, an injection of one dose of the solid composition into the human keratin materials may correspond to an amount of the solid composition dispensed into the human keratin materials of less than or equal to 5 mg.

The duration of an injection may be between 0.1 ms and several seconds.

During the use of the injection system, the solid composition contained in the second reservoir may be dispensed in particulate form into the mixing chamber. Within said mixing chamber, the particles of the composition may be mixed with a volume of gas.

The particles of the composition mixed with a volume of gas within the mixing chamber may be expelled, via a propulsion mechanism, out of the injection system, i.e. towards the outside, in the form of a high-speed jet of particles with a view to injection thereof into the keratin materials.

The needleless injection system according to the invention may comprise any propulsion mechanism making it possible to expel particles of the solid composition loaded within the mixing chamber towards the outside, so as to enable the particles to at least partially penetrate into the human keratin materials.

In the case in which the propulsion mechanism comprises a piston, the latter may make it possible to pressurize the mixing chamber. The piston may be actuated by a pressurized gas and/or a spring. The compression of the spring may be manual or motorized, for example using an electric or pneumatic motor. The piston may also be actuated manually, by an electromagnetic force or a motor, especially electric or pneumatic motor.

As a variant, the propulsion mechanism does not comprise a piston for pressurizing the mixing chamber but comprises a first reservoir containing a pressurized gas configured to dispense a gas jet into the mixing chamber. Within said mixing chamber, particles of the composition are mixed with a gas jet and carried by the gas jet towards the human keratin materials so as to enable the particles to penetrate into said human keratin materials. The gas jet may be continuous or not continuous. In the latter case, the gas jet may be pulsed. The treatment may thus consist of several successive shots of particles of the composition into the human keratin materials to be treated, each shot corresponding to a pulse of gas. The properties such as the pressure, flow rate, duration, frequency and number of pulses of gas may be adapted as a function of the targeted application.

The system according to the invention may comprise a regulation and control system configured to dispense pulses of gas.

The regulation and control system may comprise means for regulating and controlling pressure, flow rate, duration and/or frequency of the pulses of gas delivered. For example, the regulation and control system comprises at least one electrovalve and/or at least one pressure-reducing valve.

The regulation and control system may be configured to allow triggering of a single injection of particles of the composition into the human keratin materials or of one or more sequences of a plurality of successive injections. This may make it possible to effect injections one by one or as a burst. The regulation and control system may make it possible to regulate parameters such as the number and frequency of injections in the course of the sequence, the duration of the sequence, and where appropriate the number of sequences and the duration between each sequence.

The mixing chamber may be a Venturi tube. Preferably, the solid composition taken from the second reservoir is dispensed in particulate form at the choke of the Venturi tube. In this area, the gas jet is accelerated, which may cause reduced pressure and/or turbulence. This may facilitate the transfer of the particles of the solid composition contained in the second reservoir to the Venturi tube and the dispersion of said particles in the gas jet, while avoiding any problem of clogging associated with the aggregation of particles.

The Venturi tube may be connected upstream, especially via at least one valve, especially an electrovalve and/or at least one pressure-reducing valve, especially which can be regulated, at the outlet of a source of pressurized gas.

As a variant, the mixing chamber is not a Venturi tube. The latter may be replaced by a simple tube which does not have a choke.

The injection system according to the invention may be configured to receive the first reservoir containing a pressurized gas. The first reservoir containing a pressurized gas may be configured to dispense the gas jet into the mixing chamber. “Pressurized gas” is understood to mean a compressed gas stored in gaseous and/or liquefied form at a pressure suited to the desired application. The gas used may be air, nitrogen, C0 ₂ or any other propellant gas.

Preferably, the gas used is air or C0 ₂ . Indeed, the latter is biocompatible and the likelihood of generating a bubble in the skin is very small compared with other gases.

The source of pressurized gas may also be external to the injection system.

Preferably, the system according to the invention comprises a hand piece comprising and/or intended to receive at least a part of the first reservoir containing the pressurized gas and the mixing chamber. This may make it possible to benefit from a compact injection system which proves easier to handle and use.

The relative movement between the transfer and/or disintegration member and the solid composition contained in the second reservoir may be triggered by a computer interface and/or by an action of the user on a control member such as a push-button for example, the latter possibly being located on the hand piece.

The relative movement between the transfer and/or disintegration member and the solid composition contained in the second reservoir may be triggered by an electromagnet, by the actuation of the piston or by the gas jet.

The transfer and/or disintegration member and the solid composition contained in the second reservoir may be brought into relative movement using an electromagnet, a motor, especially an electric or pneumatic motor, or manually.

The relative movement between the transfer and/or disintegration member and the solid composition contained in the second reservoir may be a movement of said member relative to the mixing chamber. In this case, the second reservoir containing the solid composition may be stationary relative to said chamber.

The transfer and/or disintegration member may be rotary, especially may comprise a roller, of rotationally cylindrical, spherical or ovoid form.

The possibility of choosing the speed of rotation of the transfer and/or disintegration member and also the contact pressure between the transfer and/or disintegration member and the solid composition contained in the second reservoir makes it possible to act precisely on the amount of composition transported between the second reservoir and the mixing chamber. The speed of rotation of the transfer and/or disintegration member is adapted to the amount to be taken.

The rotation of the transfer and/or disintegration member may be performed during the presence of a stream of gas in the mixing chamber and/or prior to this.

This rotation may be carried out manually or using a pneumatic or electric motor. The rotation may be continuous or be carried out in increments. The rotational movement may be unidirectional or alternating.

The injection system may comprise means to block the transfer and/or disintegration member in rotation when the chamber has not been supplied for example.

The rotary transfer and/or disintegration member may have a portion of the surface area thereof able to come into contact with the composition contained in the second reservoir and a portion of the surface area thereof able to be exposed to the gas jet within the mixing chamber, said portions being for example opposed when said member is rotary.

The movement of the transfer and/or disintegration member may make it possible to transport a load of composition between the second reservoir and the mixing chamber. This may make it possible to transfer an amount of the solid composition taken from the second reservoir to the mixing chamber so as to supply the mixing chamber with composition.

The possibility of choosing the extent of the contact surface area between the transfer and/or disintegration member and the solid composition contained in the second reservoir, and also the contact pressure, makes it possible to act precisely on the loading of the transfer and/or disintegration member in terms of composition, in order to better adapt it to the nature of the solid composition and to the dose to be dispensed. It is thus possible to supply the mixing chamber with particles of the solid composition in a controlled manner.

The transfer and/or disintegration member may have a portion of the surface thereof configured to be loaded with composition on contact with the latter. Additionally, this portion may be configured to release the composition when exposed to the gas jet. For example, the portion of this surface is porous and/or rough.

The surface of the transfer and/or disintegration member may thus be non-smooth, fibrous, cellular and/or have flocking.

Additionally, the transfer and/or disintegration member may have a portion of its surface contributing to reducing the solid composition contained in the second reservoir into particulate form, especially by grinding, crushing, grating and/or abrasion. For example, said portion may be granular, especially abrasive, and/or have reliefs. In the case in which the composition contained in the second reservoir is a cohesive solid, this may make it possible to facilitate its reduction into particulate form, especially into the form of a loose powder, by the relative movement of the transfer and/or disintegration member in relation to the solid composition.

It is possible to act on the particle size of the particles of composition obtained from the cohesive solid of composition contained in the second reservoir by altering the roughness of the contact surface between the transfer and/or disintegration member and the composition contained in the second reservoir, and also the contact pressure.

As a variant, the transfer and/or disintegration member is made to perform a relative movement in relation to the solid composition, which movement is different from a purely rotational movement.

The relative movement between the transfer and/or disintegration member and the solid composition contained in the second reservoir is a translational and/or vibratory movement.

In the case in which the composition contained in the second reservoir is a loose powder, the transfer and/or disintegration member may be a flap valve, the opening of which enables the loose powder contained in the second reservoir to be transferred into the mixing chamber.

The system according to the invention may comprise several transfer and/or disintegration members, especially arranged to turn in contact with one another and having cooperating reliefs.

The transfer and/or disintegration member may be made of a solid or cellular plastic material, having open or closed cells, this plastic material possibly being an elastomer, an elastomer foam, polyethylene or polyurethane in particular. The transfer and/or disintegration member may also be produced in a composite or metallic material, especially obtained by sintering.

The transfer and/or disintegration member may be deformable under the contact pressure between said member and the solid composition in order to conform to the shape thereof with a view to effectively loading the solid composition onto the transfer and/or disintegration member. The injection system according to the invention may comprise an electric motor in order to effect the relative movement of the transfer and/or disintegration member in relation to the solid composition. The motor may optionally be of variable speed.

The injection system according to the invention may comprise a pushing member, especially an elastic return member, configured to urge the solid composition and the transfer and/or disintegration member to come to bear against one another.

The solid composition may especially be pressed by the pushing member against the transfer and/or disintegration member.

In another variant, or additionally, the transfer and/or disintegration member is pressed by the pushing member against the solid composition.

The pushing member may be a spring, especially a helical spring.

The pushing member may be configured to exert a uniaxial pushing force on the solid composition and/or on the transfer and/or disintegration member.

The pushing force may be greater than or equal to 0.1 N.

The needleless injection system according to the invention may comprise an injection nozzle in communication with the mixing chamber.

The nozzle comprises at least one outlet channel, the or each outlet channel comprising an opening through which the particles of the composition are expelled towards the outside.

The injection nozzle may comprise several outlet channels; the arrangement of the outlet channels may match the form of the area to be treated, for example match the form of a wrinkle to be filled.

Preferably, the cross section of the opening of the or each outlet channel of the injection nozzle is less than or equal to 2 mm ² .

The injection nozzle may, on account of its geometry and dimensions, be specifically intended for a particular application. For example, the geometry and the dimensions of the injection nozzle are adapted to the nature of the solid composition, especially the size, shape, density and/or volume of the particles of the composition in the gas in which the latter are dispersed, with a view to carrying out a given treatment.

During the injection, the mixing chamber may be pressurized in various ways.

The piston may be connected to a pushrod, the piston sliding along the longitudinal axis of the mixing chamber and being driven by the pushrod. The pressure exerted on this piston during the injection is sufficient for the speed at which the jet of particles is ejected from the injection system in the direction of the skin to give rise to a turbulent flow of the jet of particles within the mixing chamber. This makes it possible to avoid any problem of clogging associated with the aggregation of particles, in particular in the or each outlet channel of the injection nozzle.

For example, the pressure exerted on this piston during injection is between 4 and 20 bar.

The second reservoir, the mixing chamber and the injection nozzle may be at least partially defined by a body formed as a single part. Such a one-piece construction may offer enhanced strength and prove easier to handle and use. This one-piece part may be removable and replaceable.

During an injection, all or some of the contents of the mixing chamber may be dispensed to the user. In other words, the mixing chamber may be emptied in one go during injection or, as a variant, a plurality of injections are performed using the contents of the mixing chamber before it is reloaded with particles of the composition, where appropriate.

The mixing chamber may be tubular in form. Its wall may converge at its distal end, especially up to the outlet channel of the injection nozzle.

The volume of the second reservoir may be greater than or equal to 100 mm ³ .

The second reservoir may of annular form and extend around the mixing chamber. This therefore gives a compact construction, and the communication between the second reservoir and the mixing chamber may occur simply via the transfer and/or disintegration member.

The second reservoir may be closed at one of the axial ends thereof by a piston sliding along the longitudinal axis of the second reservoir. This piston may be pushed in the direction of the distal end of the second reservoir so as to press the solid composition contained in the second reservoir against the transfer and/or disintegration member. The pressure may be exerted permanently, by a spring for example, or only be exerted when dispensing the solid composition in particulate form into the mixing chamber.

The transfer and/or disintegration member may isolate the solid composition contained in the second reservoir, which improves the leaktightness of storage and the preservation of the composition. The injection system according to the invention may be configured to be positioned facing and/or to come into direct contact with the human keratin materials to be treated.

The injection system may comprise an enclosure arranged in the extension of the mixing chamber. This enclosure may be subjected to a pressure lower than atmospheric pressure. This may make it possible, during injection, to increase the speed at which the composition is ejected from the injection system towards the skin, so as to allow the composition to at least partially penetrate the skin.

The needleless injection system according to the invention may comprise a system for automatic recognition of the treated area, which is configured to automatically determine the location and the depth of the area to be treated when the injection system is brought close to the skin and to automatically adapt the injection parameters, especially the injection depth. This system may generate information regarding the nature of the solid composition to be used and/or the pressure to be applied in the mixing chamber, so as to obtain the desired penetration into the skin.

The solid composition according to the invention may have various formulations as a function of the desired goal.

The solid composition may be a cohesive solid, preferably suited to being reduced to particulate form by the relative movement thereof in relation to the transfer and/or disintegration member. For example, the composition is a compact powder.

The solid composition may be in the form of a rod, granules or beads.

As a variant, the solid composition is a loose powder. This loose powder may comprise coated or uncoated particles.

The solid composition according to the invention may comprise at least one active agent. Depending on the targeted application, the active agent(s) may especially be selected from fillers, aggregating agents, dyes, or skin depigmenting, lightening and/or bleaching agents.

The solid composition according to the invention may comprise a solid, especially particulate, support, comprising the active agent(s) chosen.

The active agent(s) may be present at the surface of the support particles, especially in adsorbed and/or grafted form, and/or contained within them, especially encapsulated within the particles of the support and/or incorporated in the bulk thereof. For example, the particles of the composition are support particles coated with one or more active agents.

The support may make it possible to convey the active agent(s) to within the human keratin materials.

The support may be a mineral or organic filler, or metal particles.

The composition may be intended for the treatment and/or prevention of wrinkles and comprise at least one filler, especially a biopolymer such as hyaluronic acid and/or one of the salts thereof, hydroxyapatite particles, polylactic acid, an alginate, sodium monomethyltrisilanol orthohydroxybenzoate, collagen, an acrylic polymer such as polyacrylamide, a methacrylic polymer and/or dextran microbubbles.

The composition may especially comprise at least one aggregating agent causing, after injection of said composition in particulate form into the human keratin materials, the aggregation of said particles in situ in the human keratin materials.

Preferably, the composition comprises at least one biopolymer, especially an alginate, and a salt, especially a divalent salt.

The invention makes it possible to combat the cutaneous signs of ageing and especially to maintain and/or to restore the viscoelastic or biomechanical properties of the skin with a view to improving the firmness, elasticity and tonicity of the skin and preventing the appearance of cutaneous signs of ageing.

In the context of the present invention,“viscoelastic or biomechanical properties of the skin” is understood to mean the extensibility, tonicity, firmness, suppleness and/or elasticity properties of the skin.

“Cutaneous signs of ageing” is understood to mean any modifications in the external appearance of the skin due to ageing, whether chronobiological and/or extrinsic, chiefly photo-induced ageing, such as, for example, wrinkles and fine lines, withered skin, flaccid skin, thinned skin, dull skin lacking in radiance, lack of skin elasticity and/or tone.

As a variant, the invention is used to prevent, treat and/or reduce a skin-colour disorder.

In exemplary embodiments of the invention, the composition is thus a skin dyeing composition comprising at least one dyeing agent, especially chosen from pigments, especially interference pigments, and dyes. The composition may especially comprise at least one skin depigmenting, lightening and/or bleaching agent, especially selected from depigmenting molecules, especially hydroquinone and derivatives thereof, in particular ethers thereof such as hydroquinone mo no methyl ether and monoethyl ether, kojic acid, arbutin, iminophenols, ascorbic acid and derivatives thereof, the combination of carnitine and quinone, aminophenol derivatives and benzothiazole derivatives, natural extracts and anti-pigmenting molecules.

Preferably, the composition is a cosmetic composition but in a variant it exerts a dermatological action.

Another subject of the invention, according to another of its aspects, is also a process for the treatment, especially cosmetic treatment, i.e. non-therapeutic treatment, of human keratin materials, especially using the needleless injection system according to the invention as defined above, comprising the steps consisting in:

a) loading a mixing chamber with particles of a solid dermatological or cosmetic composition,

b) ejecting the particles loaded into the mixing chamber outside said mixing chamber by a gas jet that passes through the mixing chamber so as to enable the particles to be ejected out of the needleless injection system, especially to penetrate at least partially into the human keratin materials.

Step a) of the process according to the invention may be carried out during all or part of step b). As a variant, step a) is carried out before step b).

Step b) of the process according to the invention may be carried out in a single ejection or one or more sequences of several successive ejections. This may make it possible to effect injections one by one or as a burst.

The invention also relates to a process for the cosmetic, non-therapeutic treatment, of human keratin materials, especially using the needleless injection system according to the invention as defined above, comprising the steps consisting in:

i. loading a mixing chamber with particles of a solid dermatological or cosmetic composition,

ii. ejecting the particles loaded into the mixing chamber outside said mixing chamber by a movement of a piston within the mixing chamber so as to enable the particles to be ejected out of the needleless injection system, especially to penetrate at least partially into the human keratin materials.

Step i. of the process according to the invention may be carried out during all or part of step ii. As a variant, step i. is carried out before step ii.

Step ii. of the process according to the invention may be carried out in a single ejection or one or more sequences of several successive ejections. This may make it possible to effect the injections one by one or as a burst.

Step a) and/or step i. may be carried out by a relative movement of a transfer and/or disintegration member in relation to the solid composition, enabling particles of the solid composition to reach the mixing chamber.

The process may comprise, prior to step ii., a step consisting in raising the piston in the mixing chamber in order to load, by suction, the mixing chamber with particles of the solid composition and/or in order to generate turbulence in the mixing chamber so as to suspend said particles in a volume of gas within the mixing chamber.

The loading of the mixing chamber with particles of the solid composition by raising the piston in the mixing chamber may be carried out outside the hand piece. The mixing chamber loaded with the particles of the solid composition may be introduced into the hand piece prior to the use of said hand piece.

The mixing chamber and the piston making it possible to pressurize said mixing chamber may be located outside the hand piece.

The speed of raising the piston in the mixing chamber may be chosen so as to be sufficient for the suction generated within the mixing chamber to correspond to a turbulent flow. This makes it possible to facilitate the suspension of the particles of the composition in the gas within the mixing chamber.

In the case in which the propulsion mechanism comprises a piston actuated especially by a pressurized gas and/or a spring, the pressure exerted on this piston during the injection may be between 4 and 20 bar.

In the case in which the propulsion mechanism does not comprise a piston but comprises a first reservoir containing a pressurized gas configured to dispense the gas jet in which the particles of the composition are dispersed, the pressure at the outlet of the first reservoir containing the pressurized gas for generating the gas jet may be between 2 and 14 bar, better still between 4 and 12 bar and even better still between 6 and 10 bar. The speed of the gas jet passing through the mixing chamber may be chosen so as to be sufficient to obtain a turbulent flow of the gas jet within the mixing chamber. This may facilitate the transfer of the particles of the solid composition contained in the second reservoir and the dispersion of said particles in the gas jet, while avoiding any problem of clogging associated with the aggregation of particles. For example, the speed of the gas jet passing through the mixing chamber is greater than or equal to 100 m/s.

The speed with which the jet of particles is ejected from the injection system towards the skin is chosen so as to be sufficient to enable the particles of the composition to at least partially pass through the skin and in particular the comified layer or stratum corneum. The stratum corneum corresponds to the outermost part of the skin and provides a barrier function between the body and the environment. The stratum corneum is composed of dead cells, which are flattened and rich in keratin, and are referred to as comeocytes.

Preferably, the composition is injected into the keratin materials to a depth of between 10 pm and 2 mm. the invention especially makes it possible to inject the composition into the epidermis and/or the dermis.

In order to act on the injection depth, it is possible to act for example on the pressure at the outlet of the first reservoir containing the pressurized gas for generating the gas jet, the speed of the gas jet passing through the mixing chamber, the speed with which the jet of particles is ejected from the needleless injection system towards the skin, the distance between the mixing chamber and the area of skin to be treated when the injection system is positioned facing the area of skin to be treated, the size, shape and/or density of the particles, and/or the volume of the particles in the gas in which said particles are dispersed.

The process according to the invention may comprise, prior to the injection of the particles of the composition into the human keratin materials, a step consisting of a pre- treatment applied to the area of skin to be treated or around said area. This pre-treatment may make it possible to reduce the mechanical resistance of the skin to the penetration of the particles of the composition, especially by promoting the opening of the pores of the skin, or else by reducing the thickness of the skin, in particular the thickness of the comified layer or stratum corneum.

This pre-treatment may consist of moisturization of the skin, for example by application of a topical composition to the skin and/or opening of the pores of the skin, for example by wetting and/or applying heat to the skin. This pre-treatment may also consist of an exfoliation of the skin, especially chemical or mechanical exfoliation such as microabrasion, or consist in stretching the area of skin to be treated prior to the injection of the particles of the composition into said area.

This pre-treatment may make it possible to facilitate the penetration of the particles of the composition into the human keratin materials and thereby improve the effectiveness of the treatment. This pre-treatment may especially make it possible for the particles of the composition to pass at least partially through the skin, and in particular the comified layer or stratum corneum.

The process according to the invention may comprise, subsequent to the injection of the particles of the composition into the human keratin materials, a step of cleaning the treated human keratin materials. This step may consist in using a cleansing wipe to be applied to the treated human keratin materials and may make it possible to remove the particles of the composition present at the surface of the human keratin materials after the injection.

The process according to the invention may make it possible to prevent, treat and/or alleviate a disorder or defect in human keratin materials, preferably an aesthetic, i.e. non- pathological, disorder or defect of the skin.

The process according to the invention may further comprise a step consisting in observing an alleviation or even a disappearance of the aesthetic disorder in question.

Another subject of the invention, according to another aspect thereof, is a cartridge for a needleless injection system according to the invention as defined above, comprising and/or defining a second reservoir intended to receive a solid dermatological or cosmetic composition, the cartridge possibly comprising the abovementioned transfer and/or disintegration member.

The cartridge according to the invention may comprise means for fastening to an injection device comprising a mixing chamber.

These fastening means may enable removable mounting. The cartridge may then be configured to be removably fastened, especially by screw- fastening, bayonet fixing, click fastening, friction fitting and/or any other means, to the injection device. The user can thus change the cartridge easily to suit his/her needs.

The cartridge may comprise at least one transparent window making it possible to observe the solid composition contained therein. Another subject of the invention, according to another aspect thereof, is the cosmetic, i.e. non-therapeutic, use of a needleless injection system according to the invention as defined above, for improving the appearance, especially aesthetic appearance, of the skin.

In particular, the needleless injection system according to the invention may be used to prevent, treat and/or alleviate an aesthetic, i.e. non-pathological, defect or disorder of an area of skin, such as a relief and/or a fold in an area of the skin, especially a fine line, wrinkle and/or scar.

In a variant, the invention relates to the cosmetic, i.e. non-therapeutic, use of a needleless injection system according to the invention as defined above for reducing or even eliminating bags and/or dark circles under the eyes.

In another variant, the invention relates to the cosmetic, i.e. non-therapeutic, use of a needleless injection system according to the invention as defined above for increasing the volume of the lips.

Solid composition

The solid composition according to the invention may be a cohesive solid in the form of one or more blocks, especially of rod(s), granule(s) and/or bead(s).

The cohesive solid may be suited to being reduced to particulate form by the relative movement thereof in relation to the transfer and/or disintegration member. The cohesive solid may be readily friable and/or be readily reduced to particulate form.

This may be a block of particles, such as a compact powder, shaped for example by pressing (at approximately 10 bar), compacting (at approximately hundred bar) or pouring and comprising a binder, especially a fatty binder.

The density of the cohesive solid is for example between the density of water and that of gold.

As a variant, the solid composition according to the invention is pulverulent, especially in the form of a loose powder.

The solid composition according to the invention is mixed during the use of the injection system with a gas jet in order to form a jet of particles.

“Jet of particles” is intended to mean a gas jet in which particles of the composition are dispersed. Preferably, the particles of the composition represent less than 10% by volume of the gas in which said particles are dispersed, at room temperature and atmospheric pressure.

The particles forming the jet of particles may have a D50 dimension by weight of between 100 nm and 1 mm, better still between 5 pm and 100 pm.

The composition according to the invention may comprise at least one active agent chosen as a function of the targeted application.

The solid composition according to the invention may comprise a support having a conveying function in order to make it possible to transport the active agent.

The support may be particulate. It may be a mineral or organic filler, or metal particles.

The active agent(s) chosen may be present at the surface of the support particles, especially in adsorbed and/or grafted form and/or contained within said particles. A wet impregnation method from impregnation solutions containing the active agent(s) chosen and/or precursor thereof may be used in order to prepare particles of the support comprising the active agent(s) at the surface thereof.

As a variant, the active agent(s) chosen, especially when they are available in solid form, may constitute the whole of the solid composition.

The solid composition according to the invention may comprise a fatty phase which is in solid form at room temperature and at the time of the injection. The fatty phase may especially comprise waxes.

The solid composition according to the invention may comprise at least one compound with a thermal effect, such that the user actually feels a hot effect or a cold effect during the injection of the composition into the human keratin materials at the injection site or around the injection site. The solid composition may comprise a frozen liquid or a gas in solid form, such as dry ice. This may make it possible to provide a cold effect during the injection of the composition into the human keratin materials. This cold may make it possible to cool the human keratin materials at the injection site or around the injection site, which makes it possible especially to reduce the potential pain sensation that may be felt by the user during treatment, to provide a decongestant and/or vasoconstrictive effect to the cutaneous and/or subcutaneous vessels at the injection site or around the injection site.

Preferably, the solid composition is sterile and biocompatible. The solid composition may be a cosmetic composition, in which case it comprises a physiologically acceptable support, that is to say a non-toxic support that can be injected into the skin of human beings.

The solid composition may furthermore be a dermatological composition.

Active agents for treating and/or preventing a relief and/or a fold in an area of skin

Fillers

As mentioned above, the composition according to the invention may comprise at least one filler.

Preferably, the filler comprises at least one biopolymer.

Owing to the mechanism of action of biopolymers and because, by virtue of the invention, they are injected into the skin in quantities and to depths that cannot be achieved by the use of topical compositions, lasting and visible effects may be obtained.

The filler may be resorbable or semi-resorbable.“Resorbable” denotes a filler that can dissolve completely within the skin in 3 to 6 months and“semi-resorbable” denotes a filler that can dissolve completely within the skin in 6 to 24 months. These time scales correspond to the time for which the action of the filler lasts. As a variant, the filler is non- resorbable.

The composition according to the invention may comprise at least one filler such as hyaluronic acid and/or one of the derivatives thereof and/or one of the salts thereof.

The hyaluronic acid is preferably crosslinked. Crosslinking makes it possible to form a rigid, elastic, crosslinked gel that hydrates and swells in water. Crosslinked hyaluronic acid is used for its filling properties, especially with regard to fine lines and/or wrinkles in the skin, because of the stiffness of the gel and also its highly viscoelastic properties and very high hydrating ability.

As a variant, the hyaluronic acid is not crosslinked.

The composition according to the invention may comprise hydroxyapatite particles, especially calcium hydroxyapatite particles, polylactic acid, an alginate, sodium monomethyltrisilanol orthohydroxybenzoate, collagen, an acrylic polymer such as polyacrylamide, a methacrylic polymer, and any mixture of the above compounds.

The composition according to the invention may comprise any filler in powder form. Aggregating agents

The composition according to the invention may comprise at least one aggregating agent causing, after injection of the particles of the composition into the human keratin materials, the aggregation of said particles in situ in the human keratin materials. Shortly after the injection of the particles of the composition comprising at least one aggregating agent into the human keratin materials, after said particles have reached their destination in the skin, it is possible to observe the in situ aggregation thereof by gelling or by any other physical phenomenon which causes particles or molecules of the composition to agglomerate, for example under the effect of electrostatic or coalescence forces, which leads to the creation of a sort of network or mesh.

The aggregation process may be triggered by heat, when the temperature of the composition increases above a certain value, which is preferably chosen to be close to 37°C. Thus, the injection of the composition in the form of a jet of particles is facilitated without damaging the performance thereof in terms of filling skin defects.

The composition may comprise at least one biopolymer, especially an alginate, and a salt, preferably a divalent salt. The biopolymer gels in the skin until it becomes solid. Owing to the mechanism of aggregation of the biopolymers and the injection thereof into the skin in quantities and to depths that cannot be achieved by the use of topical compositions, lasting and visible effects may be obtained.

One of the biopolymers considered according to the invention may be the Novabel ^® alginate by Merz, which can be resorbed in 3 to 6 months.

In a preferred embodiment, the composition comprises a sodium alginate and a calcium salt, preferably calcium carbonate CaC0 ₃ . The improved reactivity of alginates with calcium ions has been described in the paper by B. Larsen et al. entitled“Caracterisation rheologique d'un systeme de gel d'alginate injectable” [“Rheological characterization of an injectable alginate gel system”], BMC Biotechnology 2015, pages 15-29. Calcium carbonate makes it possible, by ionic energy transfer, to generate in situ a precipitate that forms a film or a scaffold within the layers of the skin.

One very particularly suitable sodium alginate is derived from brown algae and may be an injectable polymer powder.

The aggregation of the composition is advantageously triggered by heat after injection into the skin. The composition may be resorbable or semi-resorbable or non-resorbable.

Active agents for treating and/or preventing a skin-colour disorder in an area of skin

Skin dyes

The composition according to the invention may be a composition containing at least one skin dye.

The dye may be carried by a particle of the support, for example adsorbed onto such a particle.

The dyeing agent may be selected from pigments, especially interference pigments, and dyes.

The presence of at least one skin dye within the composition makes it possible to correct a skin-colour disorder or to achieve long-lasting or permanent make up.

The pigments of use in the present invention are preferably in the form of powder.

The term“pigments” should be understood as meaning white or coloured mineral or organic particles or composite mineral/organic particles that are insoluble in an aqueous or oily medium, which are intended to colour and/or to opacify.

The term “interference pigments” should be understood as meaning coloured particles of any form, which may or may not be iridescent, preferably synthesized, and which have a colour effect via optical interference.

The composition may comprise at least one pigment, especially chosen from mineral or organic pigments, and especially from non-lamellar mineral pigments.

Preferably, the pigment is a pigment approved by the CTFA for use in cosmetics and by the FDA for use in cosmetic formulations.

Preferably, the pigment used is adapted to the colour of the user’s skin.

Use may be made of metal oxides as pigments.

In a variant, the pigment used is an organic pigment selected from synthetic or natural pigments.

The composition may also comprise fillers with a high refractive index or reflective particles or particles that alter the path of the light in order to prevent reflection.

Skin depigmenting, lightening and/or bleaching agents At various periods of their life, some people see the appearance on their skin, and more specifically on the hands, of darker and/or more coloured spots, which are for example brown in colour, which give the skin heterogeneity. These spots are also due to a high concentration of melanin in the skin.

Thus, when the pigmentation process is modified, this can result in pigmentation defects, hypopigmentations, or, conversely, in excess pigmentation, hyperpigmentations. Among the benign unattractive pigment alterations, characterized by an abnormal accumulation (aside from tanning) of melanin, mention may especially be made of actinic lentigo (also referred to as solar lentigo or more commonly“sun spots”), senile lentigo (commonly referred to as“liver spots”,“age spots”,“senile keratoma”,“graveyard daisies” or“graveyard flowers”), lentigines, freckles. Mention may also be made of the benign unattractive pigment alterations able to be induced by a benign pigment disorder chosen from hyperpigmentation, melasmas such as idiopathic melasmas which arise during pregnancy (“pregnancy mask” or chloasma) or from oestro-progestogen contraception, pigmentary sequelae of acne, post-inflammatory pigmentation, phytodermatitis, pigmentation associated with the plant poison ivy, or else benign dyschromias of the face.

The composition according to the invention may be a composition comprising at least one agent for skin depigmenting, lightening and/or bleaching.

The skin depigmenting, lightening and/or bleaching agent may be chosen from depigmenting and anti-pigmenting agents.

The presence of at least one skin depigmenting, lightening and/or bleaching agent within the competition makes it possible to eliminate or reduce the presence of these benign unattractive pigment alterations.

The term“depigmenting agents” is understood to mean molecules capable of reducing the activity of melanin synthesis in melanocytes, especially by interfering with one of the steps of melanin biosynthesis, either by inhibiting one of the enzymes involved in melanogenesis, or by inserting itself as a structural analogue of one of the chemical compounds of the melanin synthesis chain, which chain can then be blocked, thus ensuring depigmentation.

The term“anti-pigmenting agents” is understood to mean molecules capable of limiting the action of the stresses responsible for pigmentation, which are due for example to ultraviolet radiation. The depigmenting agents are for example chosen from hydroquinone and derivatives thereof, in particular ethers thereof such as hydroquinone monomethyl ether or monoethyl ether, kojic acid, arbutin, iminophenols, ascorbic acid and derivatives thereof, the combination of carnitine and quinone, aminophenol derivatives, and benzodiazole derivatives, natural extracts, etc.

The use of depigmenting agents makes it possible to effectively depigment and/or lighten, or even bleach, the skin, and/or to prevent, reduce and/or treat an alteration in the skin’s complexion, that is to say especially to improve the homogeneity of the complexion and/or to revive the skin’s radiance.

The injection of the composition into the dermis may stimulate deep cell renewal and thus move the melanin from the dermoepidermal junction towards the upper layers.

Additives

The composition according to the invention may comprise at least one conventional cosmetic ingredient other than a filler, aggregating agent, dye, skin depigmenting, lightening and/or bleaching agent which may especially be selected from antioxidants, sunscreens, vitamins, such as vitamins C, A, E or B5, moisturizers, anti- wrinkle active ingredients, embodiments, hydrophilic or lipophilic active ingredients, agents combating free radicals, and mixtures thereof.

The injection of the composition into the human keratin materials may produce instant results, especially smoothing and improving the firmness of the skin. These results may be explained, inter alia, by the mechanical effect of the jet of particles on the skin.

In the long term, the injection of the composition into the human keratin materials may stimulate the user’s own collagen production by collagen producing cells and lasting effects may thus be observed, such as the filling of fine lines and/or wrinkles on the skin.

The invention may be better understood from reading the following detailed description of non- limiting exemplary embodiments thereof and from studying the appended drawing, in which:

- Figure 1 schematically shows a perspective view of an example of a needleless injection system according to the invention, - Figure 2 is a view similar to Figure 1 , without the hand piece,

- Figure 3 shows the Venturi tube and the cartridge of the injection system from Figure 2, in isolation,

- Figure 4 shows a detail of Figure 3,

- Figure 5 shows an elevation view of a detail of a variant injection system,

- Figure 6 schematically shows a perspective view of an example of a cartridge according to the invention,

- Figure 7 schematically shows an example of an injection system according to the invention,

- Figure 8 shows a longitudinal section of a variant needleless injection system according to the invention, and

- Figure 9 shows an embodiment detail of Figure 8.

Needleless injection system

Figure 1 shows an example of a needleless injection system 100 according to the invention.

The system 100 generally extends along a longitudinal axis X.

The system 100 comprises a body 102 made of thermoplastic material for example, defining a grasping surface.

This surface may be given various shapes. Preferably, this surface has a shape which is elongated along the X axis, making it easier to hold in the hand and to handle.

The system 100 comprises a reservoir containing a pressurized gas. This reservoir may be a gas cartridge 103.

If desired, a compact injection system 100 may be used, incorporating the gas cartridge 103 into the body 102, as illustrated in Figure 1. The body 102 may comprise, at the proximal end thereof, a housing for receiving the cartridge 103.

The cartridge 103 may be removable and replaceable. It may or may not be rechargeable. Preferably, the gas cartridge 103 contains compressed air or liquefied C0 ₂ .

Preferably, the cartridge 103 is compact. It has, for example, a gas mass of less than 50 g, for example 12 g or 16 g, a length of less than 10 cm and a diameter of less than 2 cm. The cartridge 103 may contain a quantity of gas sufficient to perform a number of injections of greater than or equal to 100. Such autonomy may for example allow treatment of all facial wrinkles.

The pressure within the cartridge 103 is, for example, greater than 25 bar, and better still greater than 50 bar.

The system 100 comprises, as illustrated in Figure 2, a reservoir 105 intended to receive a solid dermatological or cosmetic composition.

The reservoir 105 is connected to the body 102 at a lateral opening 107 thereof.

Injection may be triggered by user action on a control member 110. The system 100 may thus comprise a push-button 104 which allows the user, by depressing same, to trigger the injection. Preferably, the push-button 104 is located on the body 102.

The system 100 has a distal end 106 through which the composition in particulate form is ejected from the system 100 as a mixture in a gas jet towards the human keratin materials.

Preferably, the end 106 is configured to be positioned facing and/or to come into direct contact with the human keratin materials to be treated.

The cross section and the radius of curvature of the end 106 are chosen, as appropriate, according to the type of keratin materials treated, the end 106 then being applied directly in contact with the keratin materials treated. The radius of curvature may be chosen such as to substantially conform to the curvature of the treated area. This makes it possible to facilitate the application of the inj ection system 100 to certain body surfaces. For example, the end 106 has a shape that is outwardly concave.

Preferably, the end 106 is deformable on contact with the keratin materials to be treated in order to conform to the shape thereof.

The speed of the jet of particles at the outlet of the injection system 100, at the end 106, is chosen so as to be sufficient to cause the composition to at least partially penetrate into the skin.

As illustrated in Figure 2, the gas cartridge 103 is connected to the injection system 100 by a connector 108. Preferably, this connector 108 is located in the body 102.

The gas cartridge 103 is configured to connect removably to the connector 108, especially by means of screw- fastening or bayonet fixing. Preferably, this connection is achieved rapidly and securely, without tools. The connector 108 may comprise a quick connection with O-ring, making it possible to ensure the leaktightness of the connection. When the gas cartridge 103 is closed by a cap that can be pierced, the connector 108 may comprise a needle for piercing this cap.

The injection system 100 comprises a mixing chamber 101 which may be a Venturi tube, as shown in Figure 2, connected upstream to the gas cartridge 103, via the connector 108 and/or a regulation and control system 109.

The gas cartridge 103 is configured to dispense gas jets passing through the Venturi tube towards the outside 106 of the injection system 100.

As illustrated in Figure 7, the regulation and control system 109 may be electrically connected to an electrical supply 300. The power supply may be a fuel cell or a battery, especially rechargeable, a mains power supply, or any other source of energy.

The regulation and control system 109 comprises for example at least one valve 302, especially an electro valve. This regulation and control system 109 is controlled by the control member 110 via action of the user on the push-button 104. This regulation and control system 109 may make it possible to control the operating parameters of the injection system 100, for example the pressure, flow rate, and duration of the gas jet dispensed at the inlet of the Venturi tube. In the case in which the treatment consists of several successive shots of particles of the composition into the human keratin materials to be treated, the regulation and control system 109 may make it possible to dispense gas jets in the form of pulses, making it possible to control for example the frequency and number of gas jets dispensed at the inlet of the Venturi tube.

The Venturi tube comprises a first conical portion lOla which is in communication with a second conical portion 10 lb via a choke lOlc.

The Venturi tube comprises, at the choke lOlc thereof, a connector 111 enabling the connection thereof to the reservoir 105, as illustrated in Figure 3.

As illustrated in Figure 4, the injection system 100 comprises a transfer and/or disintegration member 3, such as a rotating roller, in contact with the solid composition C contained in the reservoir 105.

The roller 3 is able to turn about a geometric rotation axis Z which is for example perpendicular to the longitudinal axis of the Venturi tube and to the longitudinal axis of the reservoir 105. The roller 3 has a portion 3a of its surface which comes into contact with the composition C contained in the reservoir 105 and a portion 3b of its surface which opens into a mixing chamber, i.e. the choke lOlc of the Venturi tube, said portions 3a and 3b being opposed.

The surface 3 a is able to be loaded with composition C contained in the reservoir 105 on contact with said composition.

The surface 3b is able to be exposed to the gas jet passing through the mixing chamber 101, and to release the composition loaded in the mixing chamber 101 when exposed to the gas jet.

The rotation of the roller 3 about the axis Z makes it possible to transport a load of composition C between the reservoir 105 and the mixing chamber 101.

The rotation of the roller 3 may occur during the presence of a stream of gas in the mixing chamber and/or prior thereto. This rotation may be carried out manually or, as illustrated in Figure 7, using a motor 301, especially a pneumatic or electric motor. The motor may be carried by the body 102 or the reservoir 105 and optionally be of variable speed.

The rotation may be continuous or be carried out in increments. The rotational movement may be unidirectional or alternating.

The regulation and control system 109 may make it possible to control the operating parameters of the motor which acts on the rotation of the roller 3, i.e. the direction, speed and duration of rotation of the roller 3.

The system 109 also makes it possible to control the operating sequence between the release of the gas by controlling the electrovalve 302 and the rotation of the roller 3. This sequence may be triggered by pushing on the push-button 104, as indicated above.

The reservoir 105 comprises a pushing member, such as a helical spring 5, configured to exert a pushing force, especially a uniaxial pushing force, on the composition C so as to push the latter against the roller 3.

In one variant, the pushing member is configured to exert a pushing force, especially a uniaxial pushing force, on the composition C and an opposite force, especially a uniaxial force, on the rotary roller 3 so as to bring them into contact with one another.

A gasket (not shown) may be inserted between the spring 5 in the composition C and bear sealingly against the inner surface of the reservoir 105.

As illustrated in Figure 5, the injection system 100 may comprise an enclosure 200 placed in the continuation of the Venturi tube, in the exit path of the composition. This enclosure 200 comprises an opening (not apparent) through which the composition to be injected is expelled towards the outside. This enclosure 200 may be subjected to a pressure lower than atmospheric pressure by being connected, for example, to a vacuum source (not depicted). That makes it possible, during injection, to increase the speed at which the composition is ejected from the injection system 100 towards the skin, so as to allow the composition to at least partially penetrate the skin.

Figure 8 shows a longitudinal section of a variant needleless injection system 100 according to the invention.

The body 102 of the system 100 may comprise a first proximal portion l02a and a second distal portion l02b coming into the extension of the former, having a smaller cross section than the former.

The second distal portion l02b may comprise an end piece 404 configured to engage in the proximal portion of the mixing chamber 101.

The system 100 may comprise, at its distal end, an injection nozzle 415 in communication with the mixing chamber 101. The injection nozzle 415 may have an outlet channel 415a and an end face 415b to be positioned facing or in contact with the human keratin materials to be treated.

The outlet channel 415a may have a constant cross section, for example a circular cross section, along its entire length.

As a variant, the injection nozzle 415 comprises a plurality of outlet channels 4l5a, each being connected to the bottom of the mixing chamber 101 and each opening out at the end of the nozzle 415 via a corresponding opening 415c.

The opening 4l5c of the or each outlet channel 4l5a of the injection nozzle 415 may be covered before first use by a removable cap (not shown) that adheres to the end of the injection nozzle 415. This cap preserves and maintains the sterility of the solid composition contained in system 100.

The propulsion mechanism may be actuated by gas originating from the gas cartridge 103 which is received in a housing 405 of the first proximal portion l02a of the body 102. The propulsion mechanism comprises a first actuator 406 configured to slide within a housing 407 along the longitudinal axis of the system 100. The gas cartridge 103 may make it possible to cause the first actuator 406 to expel particles of the composition dispersed in a gas within the mixing chamber 101 with force into the human keratin materials.

As an alternative, the first actuator 406 is actuated by an electromagnet or a spring, the compression of which may be manual or motorized.

The first actuator 406 may, as illustrated in Figure 8, comprise at least one elastic return member 409 configured to assist the movement of the first actuator 406 during injection or, on the other hand, to damp this movement or assist the actuator in returning to its initial position after injection.

The first actuator 406 at its distal end comprises a head 406a connected by a coupler 410 to a pushrod 4l l .

The pushrod 411 is connected at its distal end to a first piston 414 which is configured to slide within the mixing chamber 101 along the longitudinal axis of the system 100.

The injection system 100 may comprise a second actuator 408 configured to cause a second piston 412 to slide within the reservoir 105 along the longitudinal axis of the injection system 100. This makes it possible to press the solid composition contained in the reservoir 105 against the transfer and/or disintegration member 3.

The gas cartridge 103 may make it possible, where appropriate, to cause the second actuator 408 to press the solid composition contained in the reservoir 105 against the transfer and/or disintegration member 3.

The second actuator 408 may be urged by an actuating mechanism powered by a spring 413. As an alternative, the second actuator 408 is moved by any other actuating means. For example, the second actuator 408 is actuated by a source of pressurized gas, and especially by the gas cartridge 103.

The second actuator 408 may be annular in shape.

In one variant, the needleless injection system 100 may comprise a plurality of reservoirs 105 arranged all around the mixing chamber 101 and each closed by a second piston at the proximal end thereof.

In another variant, the device comprises several second actuators 408.

Figure 9 shows an embodiment detail of a variant needleless injection system 100 according to the invention.

Cartridge The reservoir 105 of solid composition C may be removable and contained in a cartridge 1.

Such an example of a cartridge 1 is shown in Figure 6.

The cartridge 1 generally extends along an elongation axis Y. The cartridge 1 is configured to be mounted on the body 102.

The cartridge 1 may be fixed to the body 102 by any means.

The cartridge 1 defines or has a housing 2 which receives the reservoir 105 containing the solid composition C.

The cartridge 1 may comprise a visual indicator enabling the user to monitor the state of filling and/or the colour of the composition C contained in the reservoir 105, for example a transparent window.

The injection system 100 and/or the cartridge 1 may comprise sealing means making it possible to protect them from the relative humidity of the ambient air. This makes it possible for example to protect the composition C from the relative humidity of the ambient air so as to preserve the properties thereof.

The injection system 100 and/or the cartridge 1 may comprise dehumidifying means making it possible to reduce the moisture within them. For example, the cartridge 1 comprises means for heating the composition C and/or the injection system 100 comprises means for drying the gas dispensed from the gas cartridge 103.

The composition C may be specifically intended for a particular application, especially for the treatment and/or prevention of folds on the surface of the skin, for example folds in the labionasal area (also referred to as smile lines), in the crow’s feet area, in the area between the eyebrows and/or in the forehead area. The composition C may be intended for use on fine lines, surface wrinkles and/or deep wrinkles.

The nature of the active compound present in the composition C to be injected is adapted to the application targeted.

The injection system 100 may be offered to the user with one or more cartridges 1 containing one or more compositions to be injected, for example within common packaging, it being possible for these cartridges each to be adapted to a particular application.

The injection system 100 may constitute a portable, autonomous system.

The injection system 100 may, where appropriate, comprise a system for recognizing the cartridge 1, for example by means of an electromechanical sensor, electrical contacts, or an electronic chip. For example, the cartridge 1 comprises an RFID chip read by the injection device. The cartridge 1 may thus be automatically recognized by the injection device. The fact that the device is aware of which cartridge is in place may allow operating parameters of the device, for example pressure, duration, flow rate, frequency and/or number of pulses of gas leaving the gas cartridge 103, to be adapted automatically.

As a variant, the operation and/or setting of the injection system 100 is remotely controlled, for example with a smartphone. The injection system 100 then comprises a wireless communication interface.

The invention is not limited to the examples that have just been described. For example, in one variant, the transfer and/or disintegration member in contact with the solid composition is a disc that turns about a geometric rotation axis Y, this disc comprising reliefs to reduce the composition C contained in the reservoir 105 to a loose powder, and perforations enabling the loose powder to be transferred into the mixing chamber.

The term“comprising” should be understood in its commonly accepted meaning, namely as being synonymous with“comprising at least one”, unless specified to the contrary.