Electroporation Device
Field of the invention
The present invention relates to a device for delivering pharmacological and/or natural and/or cosmetic products by electroporation into skin layers of limited thickness. The present invention relates in particular to a handheld device for delivering pharmacological and/or natural and/or cosmetic products by creating local electrical flux in skin layers of limited thickness.
Background of the invention
Transdermal delivery of products can be achieved with ionophoresis systems. However, such operations only achieve penetration after twenty minutes of treatment, and have the drawback of causing abnormal electrolysis and reddening.
In order to develop safer and more efficient transdermal delivery operations, there is a move towards the adoption of electroporation systems, which use handheld devices in conjunction with ground plates. The application handheld devices are connected to electronic circuits generating electrical pulses whose amplitude and frequency are specific to the electroporation operation. The handheld devices are designed to be applied to and moved over the areas to be treated, interposing the pharmacological and/or natural and/or cosmetic products which are to be delivered between each handheld device's head and the skin. The ground plates serve to close the electronic circuits generating the pulses, and must be applied to the skin on the side opposite the treated side. For example, the ground plate must be applied to the lower abdomen when the buttocks are being treated. The waveform emitted by the applicators at a predetermined frequency opens the interstitial channels very rapidly, in a few seconds, without causing electrolysis. The active principles are delivered through the interstitial channels. These means can be used efficiently when the ground plates are easily placed opposite the handheld devices, and when the penetration of the transdermal delivery does not give rise to problems or contraindications.
It is more difficult, or even impossible, to use these electroporation methods for application to limited skin thicknesses in particular areas of the body, for example, to the scalp for hair regeneration treatment.
Hair loss is a troublesome problem that affects very large numbers of people. Countless attempts have been made to solve the problem by different methods, but the results have always been insignificant and disappointing. In the last decade, specific products have appeared on the market, but these not only give poor results but have also been shown to cause negative side effects.
Some pharmacological products, to be taken orally, have been found to be relatively efficient, but the regrowth of hair often extends to other parts of the body in which this effect is undesirable. In most cases, all the body hairs are affected. The "internal" treatments, in the form of orally administered pharmacological products, thus cause multiple undesirable side effects.
Other products can be applied topically, at specified intervals (usually daily) by rubbing into the scalp, but the results are inadequate or insignificant. The main problem of topical treatments of the prior art applied directly to the scalp arises from the limited penetration of the products under the gentle rubbing action of the fingers, even though there would be virtually no penetration at all without this action.
With the prior art transdermal delivery systems requiring a handheld applicator device and an opposing ground plate, if the handheld device were to be placed on the surface of the cranium for the treatment of the scalp, the ground plate would have to be applied either to the back of the neck or under the chin.
In both cases, the pharmacological and/or natural and/or cosmetic product is delivered not only into the scalp, but also through the cranium. In other words, the depth of transdermal penetration cannot be controlled. In the best case, most of the pharmacological and/or natural and/or cosmetic product would still accumulate in the scalp without reaching the cranium, but there is a possibility that at least some of the delivered product or products would penetrate into the cranium, in unknown quantities, densities and areas.
The risk of the penetration of pharmacological and/or natural and/or cosmetic products into the cranium, which could cause dangerous or at least critical side effects, means that prior art electroporation equipment cannot be used for this specific application. The same applies to all other applications in which similar conditions are present.
Summary of the invention
An aim of the present invention is thus to provide a device for efficiently delivering pharmacological and/or natural and/or cosmetic products by electroporation into skin layers of limited thickness.
Another aim of the invention is to provide a device for delivering pharmacological and/or natural and/or cosmetic products by electroporation into skin layers of limited thickness allowing for a control of the depth of penetration of the applied products. These aims are achieved by a handheld device for delivering pharmacological and/or natural and/or cosmetic products by electroporation into skin layers of limited thickness comprising the features of claim 1 . Variant embodiments are described in the dependent claims.
These aims are achieved in particular by a handheld device for delivering pharmacological and/or natural and/or cosmetic products by electroporation into skin layers of limited thickness, comprising a head, a plurality of transmitter pins made from electrically conductive material projecting from the head, wherein the transmitter pins are electrically isolated from the head and electrically connected to an electroporation wave generator, and a plurality of ground pins made from electrically conductive material projecting from the head, wherein the ground pins are electrically isolated from the head and from said transmitter pins and electrically connected to the ground.
The handheld device of the invention thus allows delivering pharmacological and/or natural and/or cosmetic products directly into skin layers of limited thickness, for example the layer between the surface of the scalp and the bases of the underlying hair follicles, by a fast and painless process, without the products penetrating farther than necessary, i.e. devising a form of topical treatment which is to be applied directly to a skin surface and which provides controlled penetration of the products, to a depth of one or two millimetres for example. The control of the depth of penetration is controlled thanks to the fact that transmitter pins and ground pins are located next to each other on the device's head. The electrical fluxes generated between these pins when the wave generator is switched on are thus local and only penetrate into a limited thickness of the skin of the user to which the device is applied.
The present invention thus provides a transdermal delivery device (of the type known as "electroporation") which can operate within the aforesaid penetration limits.
Consequently, the present invention provides an electroporation system with a special handheld applicator device which has been devised for the purpose of transdermal delivery limited to delivery into the first layers of skin, to a depth of a few millimetres, so that, in the example relating to hair regeneration, the delivery extends to the base of the hair follicles and no farther.
In practice, the penetration of the products applied with the device of the invention takes place only into soft skin layers, such as those of the scalp, without being dispersed or penetrating more deeply, as in the above prior art example relating to the cranium. Brief description of the drawings
The invention is described more fully below, with reference to a preferred embodiment described by way of illustrating but non-limiting example, with reference to the attached drawings, in which: Fig. 1 shows the general electrical circuit of the handheld device according to a preferred embodiment of the invention,
Fig. 2 shows a diagram of the electroporation current flows generated by the device of Fig. 1 , and
Fig. 3 illustrates an example of the construction of the electroporation handheld device of the invention, in a partially cut side view and in a plan view from below.
Detailed description of the invention
With reference to the drawings, the handheld device of the invention for delivering pharmacological and/or natural and/or cosmetic products by electroporation into skin layers of limited thickness S comprises a head 1 , for example an interchangeable head, made from non-conductive material, with a hand grip 1 '. A plurality of pins 2, 3 made from conductive material, such as conductive silicone rubber for example, project from the head 1 . The pins 2, 3 are divided into two groups which are electrically insulated from each other. The pins 2 of the first group are connected through an electrical conductor 4 to a wave generator 5 and the pins 3 of the second group are connected through another electrical conductor 6 to the electrical ground 7. In the present description, the pins 2 of the first group are thus called transmitter pins 2, while the pins 3 of the second group are called ground pins 3. The wave generator 5 is preferably controlled by a power supply, operation and control circuit board 8. The power is either supplied from an embedded power supply such as a battery for example, or from an external power supply through a power cord.
In a preferred embodiment, the pins 2, 3 are aligned in the following sequence: transmitter pin 2 - ground pin 3 - transmitter pin 2 - ground pin 3, etc., in any required number, preferably according to the specific application of the handheld device to specific treatment areas.
The spacing between a transmitter pin 2 and a neighbouring ground pin 3 determines the depth of penetration of the products to be delivered transdermally.
When the wave generator 5 is switched on, electrical pulses of a determined shape and intensity are sent to the transmitter pins 2, thus generating current fluxes T between each transmitter pin 2 and its neighbouring ground pin or ground pins 3. When the head 1 is applied with the pins 2, 3 against the skin S of a user, the current fluxes T penetrate into the skin S by a depth which depends on the intensity of the fluxes T and on the spacing of the transmitter and ground pins.
The penetration depth of the products applied to the skin S is thus increased or decreased by providing heads 1 with transmitter pins 2 and ground pins 3 which are closer to or farther from each other, thus producing current fluxes T which are larger or smaller and therefore penetrate deeper or shallower into the skin S.
According to the invention, the depth of penetration of the products to be delivered, which depends on the depth of penetration of the current fluxes T, is controlled by the spacing between transmitter pins 2 and the neighbouring ground pins 3, which is thus preferably adapted to a specific application of the handheld device of the invention and/or to the applied product. The locally applied current fluxes T locally open the interstitial channels and allow the penetration of the pharmacological and/or natural and/or cosmetic products applied between the skin S and the handheld device 1 in a limited thickness of the skin S.
The theoretical depth of penetration is the half of the distance between a transmitter pin 2 and the neighbouring ground pin 3. The actual depth of penetration however depends on the volatility of the solvents, on the ambient temperature, on the temperature of the treated surface, on the temperature of the applied products, on the state of the treated skin (hard skin layer more or less thick), on the emitting power of the device. The actual depth of penetration can thus vary by more or less 50% from the theoretical value.
Preferably, the depth of penetration is kept low, usually around one to a few millimetres. For example, for a penetration of products into the scalp, the depth of penetration is typically around 1 .5 to 2 mm. The spacing between two neighbouring pins of opposite polarity is thus typically 3 to 4 mm for such an application.
The circular arrangement of the pins 2, 3 as shown for example in Fig. 3 is considered to be the most simple and functional arrangement, because it enables a perfect alternating sequence of transmitter pins 2 and ground pins 3 to be created, thus generating regular and well controlled electrical fluxes.
However, it is possible to use different arrangements for different applications, for example annular, polygonal or combined arrangements, in single or concentric lines, or various other arrangements.
As explained above, a spacing of three millimetres between the transmitter pins 2 and ground pins 3 will cause the depth of transdermal penetration into the scalp to be limited to about one or two millimetres.
According to the invention, undesirable penetration of the products beyond the required depth is thus avoided, since there are no ground plates connected to the human body, but the electrical pulses of specified amplitude and frequency, which are applied to the transmitter pins 2, are generated in a circuit which is closed on the ground pins 3 adjacent to each of the transmitter pins 2. In other words, the opening of the interstitial channels takes place only between a transmitter pin 2 and an adjacent ground pin 3.
When the pharmacological and/or natural and/or cosmetic product has been applied on the area to be treated, for example the patient's scalp, the head 1 of the handheld device is to be applied to the same area and a rubbing action is to be applied to the area through the conductive silicone rubber pins 2 and 3, by a manual movement which is for example slow and rotational. The treatment time is very brief, being in the range from 5 to 10 minutes and can be performed by any person, even by the user being treated himself. Because of the effective depth of penetration of the specific product for the regrowth of the hair, the treatment is preferably repeated periodically, once per week for example, until the desired result is achieved.
The head 1 of the handheld device of the invention is preferably interchangeable, for example in order to comply with the established hygiene standards. Several interchangeable heads 1 can thus be foreseen, where each head comprises transmitter pins and ground pins distributed in another arrangement adapted to a specific application. According to an embodiment of the invention, the electroporation system is thus a set comprising a plurality of interchangeable heads, each head being adapted to the application of another specific product and/or to the application of products to another part of the human body. As already mentioned, the pins 2, 3 are preferably made of conductive silicone rubber or any other flexible and conductive material. The use of flexible transmitter pins 2 and ground pins 3 allow for a better adaptation of the head 1 to the shape of the treated surface. Indeed, the flexible pins 2, 3 of the head 1 can for example all be in contact with the skin S, even if the head 1 is flat while the treated surface is slightly curved. Due to their flexibility, some pins 2, 3 will be bent and/or compressed when applied against the concave parts of the treated surface, thus allowing the other pins to also be in contact with the skin. The distribution of the electrical fluxes T over the treated area thus remains substantially constant relative to the position of the head 1 , allowing for a regular penetration of the applied product into the skin S.
The flexible material used for the pins 2, 3 is furthermore electrically conductive for conducting the electric pulses generated by the handheld device of the invention to the tip of the transmitter pins 2, where the electrical fluxes T will be created to the tip of the neighbouring ground pin(s) 3. The pins 2, 3 thus act as electrodes of opposite polarity that are placed in direct contact with the treated skin surface. From the above description of an application to the treatment of the scalp, provided by way of example, it will be clear that the handheld device according to the present invention can be used efficiently for the transdermal delivery of pharmacological and/or natural and/or cosmetic products by electroporation, in all applications in which a requirement is to limit the depth of penetration of the products into the skin.
Essentially, the principle of transdermal delivery according to the invention is not limited to products for hair regrowth, but can be extended efficiently to any specific product for other transdermal treatments, such as treatments for psoriasis, dandruff and various skin pathologies, including chemotherapy for the treatment of benign skin tumours or for the removal of visible signs of malignant skin tumours, and the like.
Although the invention has been described and illustrated with reference to one embodiment thereof, provided as a non-limiting example for illustrative purposes, the one skilled in the art will be able to make various changes and/or modifications to the content of the description and to the applications within the frame of the present invention.