Patent Description:
Drug delivery systems (DDSs) refer to a series of techniques for delivering a substance having pharmacological activity to cells, tissues, and organs using various physicochemical techniques.

Drug delivery systems most commonly use an oral administration method, while transcutaneous delivery systems deliver drugs to a portion of the body. Among them, a drug delivery method using a syringe has been widely used for a long time by a method of delivering a liquid drug through a patient's skin with a metal needle.

However, the drug delivery system using a syringe has disadvantages in that it causes inconvenience due to repeated inoculation and pain to the patient whenever the drug is injected, and also causes the patient to be infected due to reuse of the injection needle due to the lack of management of the syringe.

In addition, since the above method requires an inoculator having knowledge of the use of a syringe, there is a disadvantage in that the patient cannot personally administer the drug using a syringe.

Therefore, in recent years, a microneedle array having a plurality of micro-sized percutaneous transmission type microneedles each of which is much smaller than a needle of a pen-type syringe has been made and used for improving a syringe-type drug delivery system.

A microneedle array is a system for percutaneous delivery of a drug through small holes which are physically formed through the stratum corneum. The above system has been actively researched since the beginning of <NUM>, when the possibility that a silicon microneedle array, which can be manufactured by using the semiconductor process technology, can be applied to drug delivery, is originally proposed from a study by the Georgia Institute of Technology. Currently, these microneedle arrays are made in various sizes and shapes based on various materials such as metals, polymers, glass and ceramics as well as silicon.

In addition, such microneedle arrays are used for delivery of active substances such as drugs and vaccines into a living system, detection and biopsy of analytes in the body, and the injection of other cosmetic substances or drugs into the skin tissue, as well as for the purpose of extracting body fluids such as bloods from subcutis. Accordingly, the microneedle array may be considered one of the drug delivery methods that has been rapidly used in various fields in recent years, since it can perform localized and sustained drug injection, and can minimize pain upon insertion into the skin.

However, the conventional microneedle array has a structural drawback that it does not rapidly spread the drug into the body due to the stratum corneum of the skin. That is, since the conventional microneedle array <NUM> has a simple structure having a substrate <NUM> attached to an adhesive sheet (not shown) and a plurality of microneedles <NUM> protruding from the substrate <NUM> in an arrangement in which the microneedles <NUM> are arranged on the substrate <NUM> in a matrix pattern with a specified interval, as shown in <FIG>, drug diffusion using transdermal delivery is inefficient.

Accordingly, in recent years, in order to improve a drug delivery rate, transdermal drug delivery has been continuously developed using chemical enhancers, iontophoresis, electroporation, and ultrasound and heat elements. However, this solution not only complicates the manufacturing process, but also increases the manufacturing cost of the microneedle array. In addition, the solution is often unsuitable depending on the form of the drug and may cause side effects to the skin.

Typically, the microneedle array <NUM> is manufactured in such a way that the substrate <NUM> is formed by a mold, and the molded substrate is subsequently subjected to pressure in a press. Then, the plurality of microneedles <NUM> are pressed so as to be bent and protrude from the substrate <NUM>.

However, since the conventional microneedle array <NUM> has a structure in which the microneedles <NUM> are arranged on the substrate <NUM> at a predetermined interval as described above, the press machine should be equipped with a complicated movable die having pressing punches by which the corresponding microneedles <NUM> are punched and formed.

Further, another problem arises in that, when the plurality of microneedles are pressed by the movable die of the press machine, portions of the substrate <NUM> disposed between the microneedles <NUM> are deformed or damaged due to the influence of the pressing punches.

In particular in the case that the number of the microneedles <NUM> are increased so that the distance between the microneedles <NUM> becomes narrowed so as to enhance a transdermal drug delivery rate, the portions of the substrate <NUM> disposed between the microneedles <NUM> are disposed closer to the pressing punches and may be easily deformed or broken.

Accordingly, the applicant has proposed a novel microneedle array of the present invention in order to solve the above problems, and related prior art documents include Unexamined <CIT> entitled 'Microneedle patch for stimulating the body's painful parts or acupuncture points', as well as <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT> and <CIT>, which all relate to a substrate with a microneedle array.

Further, since the conventional microneedle array requires separate injection devices or prolonged contact with the user's skin in order to smoothly deliver the drug into the body through the shorter microneedles, the conventional microneedle array also has problems in that it is troublesome to use and side effects such as inflammation due to the material of the microneedles may occur.

To solve these problems, the applicant has proposed a microneedle array made of biodegradable metals through patent applications and the like. The proposed microneedle array has excellent drug delivery capability relative to a conventional microneedle array since the microneedles are formed from a metal sheet material having high permeability to the stratum corneum. However, in order to allow a drug to be injected from the outside of the skin using a drug-carrying patch or the like without using a separate drug injection device or the like, the proposed microneedle array requires a faster and more effective injection structure.

Accordingly, the present invention has been made keeping in mind the above problems occurring in the related art, and an object of the present invention is to provide a microneedle array having a multi-type microneedle units arranged to allow a drug to be rapidly delivered to a transdermal tissue of the body and to achieve convenience in manufacturing the microneedle array.

Another object of the present invention is to provide a biodegradable metal plate-type microneedle array capable of injecting a drug more quickly and smoothly without using a separate injection mechanism or the like.

In accordance with the present invention, a microneedle array for subcutaneous insertion having the features of claim <NUM> is proposed, which includes: a substrate; a plurality of needle openings provided in the substrate; and a plurality of needle units disposed around respective needle openings and each having a plurality of microneedles circumferentially arranged at regular intervals around a respective needle opening to protrude from the substrate so as to be inserted into the skin, wherein the substrate and the microneedles are formed of a bioabsorbable metal, wherein the bioabsorbable metal includes at least one element of magnesium and zinc generating hydrogen gas and MgCl, or hydrogen gas and ZnO in a reaction with water, in a decomposition process when inserted into the skin, wherein the microneedle includes a first needle section having a first end connected to the substrate, and a second needle section having a first end connected to a second end of the first needle section, with the first and second needle sections protruding in vertical directions from a surface of the substrate, wherein the first needle section has a gradually narrower width from the first end to the second end thereof in a longitudinal direction, wherein the microneedle includes a carrying recess having a first end partially disposed in the substrate and a second end disposed to extend toward a distal end of the microneedle in a longitudinal direction thereof and a carrying hole being provided in the carrying recess, and wherein a cutout portion is provided at a connection between the first needle section and the substrate, the cutout portion being formed by cutout slits respectively disposed between the opposite widthwise ends of the first needle section and the first end of the carrying hole at the first end of the first needle section.

The needle opening may be provided in the substrate in a circular or regular polygonal shape.

The microneedles of the respective needle unit may be arranged such that, when the needle opening has a regular polygonal shape, the microneedles are respectively provided on the substrate at middle portions of respective sides of the needle opening.

The second needle section may be provided in the form of an arrowhead having a gradually narrower width from the first end to the second end thereof in the longitudinal direction, and may have, on the first end thereof, an engagement protrusion having a width greater than that of the second end of the first needle section.

The carrying recess may be provided in the microneedle or the substrate to provide a flow path for a drug.

A carrying slit may be further provided to communicatingly extend from the second end of the carrying recess to the distal end of the microneedle.

The carrying hole may have an inner diameter gradually decreasing from top toward bottom of the first or second needle section.

The substrate may have a honeycomb structure when the needle opening is provided in the form of a regular hexagon.

The bioabsorbable metal may contain at least one element of magnesium, calcium, zinc, and iron.

According to the present invention having the above-described characteristics, the multi-type microneedle array has a structure in which the plurality of microneedles are arranged in a predetermined pattern around one needle opening, so that the microneedles can be inserted into a predetermined area of skin so as to rapidly deliver a drug to a transdermal tissue.

Since the multi-type microneedle array can have a honeycomb structure by needle openings formed in the form of a regular hexagon, in the process of pressing and bending the microneedles, the substrate can be restricted from being deformed or damaged.

Since the multi-type microneedle array can be provided such that the plurality of microneedles can protrude from the substrate without using the same number of punches provided on the movable die of the press machine as the number of the microneedles, thereby reducing the manufacturing cost of the movable die of the press machine and therefore manufacturing the microneedle array in an economical and simple manner.

The multi-type microneedle array may transmit a drug for treatment into the body, as well as components (magnesium, calcium, zinc, iron, etc.) contained in a bioabsorbable metal so as to supply minerals into the body along with the drug.

In the microneedle array using the bioabsorbable metal, since the microneedles may be easily left under the skin with a simple process of separating the substrate contacting the skin from the skin, a user can receive the bioabsorbable metal ions, which are beneficial to the human body, in the body without being subjected to any other procedure.

Since the microneedle array has a structure in the microneedle so as to facilitate the flow of an active ingredient such as a drug, thereby allowing the active ingredient to more quickly and smoothly pass and spread into the skin through the stratum corneum.

The advantages and features of the present invention and the method of achieving them will become apparent with reference to the below together with the accompanying drawings.

Hereinafter, a microneedle array according to the present invention will be described in detail with reference to <FIG>. In the following description, a detailed description of known functions and configurations incorporated herein will be omitted so as to avoid obscuring the subject matter of the present invention.

<FIG> is a plan view illustrating a multi-type microneedle array according to the present invention; <FIG> is an enlarged view of Section A shown in <FIG>; <FIG> is a perspective view illustrating a state in which microneedles are erected according to the present invention; <FIG> is a cross-sectional view illustrating the microneedle having a carrying recess and a carrying hole according to the present invention; <FIG> shows plan views illustrating the microneedle having a cutout portion according to the present invention; <FIG> is a plan view illustrating a circular needle opening according to an embodiment of the present invention; <FIG> is a plan view illustrating a regular octagonal needle opening according to another embodiment of the present invention; and <FIG> is a perspective view illustrating a conventional microneedle array.

As illustrated in <FIG>, the microneedle array <NUM> includes a substrate <NUM> having a plurality of needle openings <NUM>, and a plurality of needle units disposed around respective needle openings and each having a plurality of microneedles <NUM> circumferentially arranged at regular intervals around respective needle opening to protrude from the substrate <NUM>.

The substrate <NUM> may be in the form of a thin sheet having a predetermined surface area and thickness, and may be attached to the user's skin in the form of a patch while being placed on an adhesive base sheet (not shown) applied with an adhesive material.

In addition, the substrate <NUM> may be provided in various sizes and shapes corresponding to a target skin region, and the periphery of the substrate <NUM> may be formed to have various curvatures so as to be in tight contact with the curved skin region. For example, when the substrate <NUM> is attached to the user's nose, the substrate <NUM> may be formed in the same shape as a known nose pack.

In addition, the substrate <NUM> may carry a drug intended to be delivered to a subcutaneous tissue. The substrate <NUM> may carry the drug by various known methods such as the coating of the drug accomplished through immersion of the substrate <NUM> into a container storing the drug therein, the coating of the drug accomplished through application of the drug onto the substrate <NUM>, and the like.

For example, the drug to be carried on the substrate <NUM> may be not only a drug for prevention and treatment of diseases, but also a genetic material or Epidermal Growth Factor (EGF) or Hyaluronic acid for skin care.

The needle openings <NUM> are components formed by processing the substrate <NUM> with a laser cutting device. As described above, the needle openings <NUM> are formed at regular intervals on the surface of the substrate <NUM>.

The needle opening <NUM> may be provided in the substrate <NUM> in the form of a circular or a regular polygonal shape. For example, the needle opening may be formed in the substrate <NUM> in the form of a regular hexagonal or regular octagonal shape as illustrated in <FIG> and <FIG>, or the circular shape as illustrated in <FIG>.

As illustrated in <FIG>, the microneedle <NUM> includes a first needle section <NUM> having a first end connected to the substrate <NUM> and a second end opposite to the first end, and a second needle section <NUM> having a first end connected to the second end of the first needle section <NUM> and a second end formed as a distal end of the microneedle opposite to the first end of the second needle section, wherein the first and second needle sections are provided in the needle opening <NUM>.

The microneedle <NUM> configured as described above may be bent and protruded in a vertical direction from the surface of the substrate <NUM> by a molding process or a pressing process using a press machine. That is, the microneedle <NUM> may be a portion that is inserted under the user's skin to deliver the drug when the substrate <NUM> contacts the user's skin.

The microneedles <NUM> of the respective needle unit may be arranged such that, when the needle opening <NUM> has the regular polygonal shape, the microneedles are respectively provided on the substrate at middle portions of respective sides <NUM> of the needle opening <NUM>.

If the microneedles <NUM> of the needle unit are provided on the substrate <NUM> at respective corners of the needle opening <NUM>, the microneedles <NUM> may be broken in the process of bending the microneedles <NUM> in a vertical direction (in the pressing process by a pressing machine). Therefore, in order to prevent the microneedles <NUM> from being broken, the microneedles <NUM> are preferably provided on the substrate <NUM> at middle portions of respective sides <NUM> of the needle opening <NUM>.

The first and second needle sections <NUM> and <NUM> of the microneedle <NUM> may have a shape of an arrowhead as a whole so that the needle sections can be easily inserted into the skin. The first needle section <NUM> may be provided in the form of an arrowhead having a gradually narrower width from the first end to the second end thereof in the longitudinal direction.

The second needle section <NUM> may also be provided in the form of an arrowhead having a gradually narrower width from the first end to the second end thereof in the longitudinal direction, and may have, on the first end thereof, an engagement protrusion 132a having a width greater than that of the second end of the first needle section.

A carrying recess <NUM> is also provided in the microneedle <NUM> or the substrate <NUM> to provide a flow path for a drug.

The carrying recess <NUM> is provided in one side or the other side of the substrate <NUM>, and has a first end partially disposed in the substrate <NUM> and a second end disposed to extend toward the distal end of the microneedle <NUM>, i.e. the second end of the second needle section <NUM>, in a longitudinal direction thereof.

The carrying recess <NUM> may be selectively provided in one side or the other side of the substrate <NUM>, or otherwise in both sides of the substrate <NUM>.

The carrying recess <NUM> serves to form a flow path for a drug carried in the substrate <NUM> or the microneedle <NUM> and to provide a space for a drug carried in the substrate <NUM> or the microneedle <NUM> so as to adjust the amount of drug delivered into the body.

As illustrated in <FIG>, the carrying recess <NUM> may have a shape in which the inner diameter gradually decreases in the thickness direction of the substrate <NUM> or the microneedle <NUM>.

The carrying recess <NUM> may have a shape to increase the area of the substrate <NUM> or the microneedle <NUM> so as to allow the amount of the drug carried in the substrate <NUM> or the microneedle <NUM> while providing a flow path for the drug carried in the substrate <NUM> or the microneedle <NUM>.

In other words, if the microneedle <NUM> is made of a flat surface without the carrying recess <NUM> as a drug delivery path, the microneedle <NUM> has a structure in which when inserted into the skin, it is in close contact with the skin so that the drug may not easily flow therethrough. On the contrary, when the carrying recess <NUM> is formed in the substrate <NUM> and the microneedle <NUM>, the microneedle may have a structure in which when inserted into the skin, it allows easy delivery of the drug stored in the carrying recess <NUM> into the body. In addition, the drug carried on the substrate <NUM> or the microneedle <NUM> may flow along the forming direction of the carrying recess <NUM> and be delivered subcutaneously.

A carrying slit <NUM> may be further provided to the microneedle to communicatingly extend from the second end of the carrying recess <NUM> to the distal end of the microneedle <NUM>, i.e. to the second end of the second needle section <NUM>.

The carrying slit <NUM> functions to allow the drug stored in the carrying recess <NUM> or a carrying hole <NUM> to be described later to easily flow to the tip of the microneedle <NUM> so that the drug contained in the substrate <NUM> or the microneedle <NUM> can be more easily delivered to the user's subcutaneous tissue sequentially through the carrying recess <NUM> and the carrying slit <NUM>.

The carrying hole <NUM> is provided in the carrying recess <NUM>. That is, the carrying hole <NUM> is provided in the portion of the substrate <NUM> or the microneedle <NUM> where the carrying recess <NUM> is formed, along a forming direction of the carrying recess <NUM>. That is, the carrying hole <NUM> may be provided in the carrying recess <NUM> along the longitudinal direction of the first needle section <NUM> or the second needle section <NUM> of the microneedle <NUM>.

Since the carrying hole <NUM> communicatingly connects both sides of the substrate <NUM> or the microneedle <NUM>, the carrying hole <NUM> allows the drug contained in one side or the other side of the substrate <NUM> or the microneedle <NUM> to communicate with each other, thereby enabling rapid diffusion of the drug into the user's skin.

In addition, since the carrying hole <NUM> provides a space for storing a drug as in the carrying recess <NUM>, the amount of the drug to be carried on the substrate <NUM> or the microneedle <NUM> can be regulated. That is, since the carrying hole <NUM> can be formed in such a manner that the inner diameter gradually decreases from one side toward the other side and vice versa of the first needle section <NUM> or the second needle section <NUM>, a space can be provided in which a drug coating layer formed through immersion is accommodated in the microneedle <NUM>.

The provision of the above-mentioned carrying recess <NUM>, the carrying slit <NUM>, and the carrying hole, which form a drug flow path in the surface of the microneedle <NUM> and the contact surface of the microneedle with the skin (e.g. the stratum corneum) may be easily adapted to the microneedle array <NUM>, as well as the microneedle array of <FIG> having a structure in which one microneedle is provided in one needle opening.

Since the microneedle array <NUM> according to the present invention is constructed so that the microneedles <NUM> are provided at regular intervals on the substrate <NUM> around the needle opening <NUM>, drugs intended to be supplied into the body can be intensively delivered to the subcutaneous tissues and rapidly spread.

In addition, when the needle openings <NUM> are formed in the shape of a regular hexagon, the substrate <NUM> may have a honeycomb structure. With the honeycomb structure of the substrate <NUM>, the portions (110a, <FIG>) of the substrate <NUM> defining the needle openings <NUM> may be prevented from being deformed or broken in the process of pressing and bending the microneedles <NUM> disposed around the needle openings <NUM> with punches <NUM> of a press machine.

More specifically, the microneedles <NUM> are pressed and bent when the punches of the movable die of a press machine are inserted into the needle openings <NUM>. Here, there is a possibility that the portions 110a (see <FIG>) of the substrate <NUM> disposed on the substrate between the needle openings <NUM> may be deformed or torn due to the influence of the punches of the press machine.

However, the microneedle array <NUM> according to the present invention may form the needle openings <NUM> in a regular hexagon so that the substrate <NUM> may be formed in a honeycomb structure. This increases the whole strength of the substrate <NUM> so that the substrate <NUM> can be prevented from being deformed or broken during a work process using a press machine.

In addition, the plurality of microneedles <NUM> may be pressed and bent by a single pressing punch to be inserted into one needle opening <NUM>. Thus, there is no need to provide the same number of the pressing punches provided on the movable die of the press machine as the number of the microneedles <NUM>, thereby simplifying the whole structure of the movable die of the press machine. Thus, the manufacturing cost of the movable die mat be reduced and the manufacturing cost and process of the multi-type microneedle array <NUM> may be reduced and simplified.

Meanwhile, the microneedle array <NUM> according to the present invention is formed of bioabsorbable metal. That is, the substrate <NUM> or the microneedle <NUM> are formed of bioabsorbable metal composed of components beneficial to the human body.

That is, the substrate <NUM> may be made of metal as a bioabsorbable metal including at least one component of magnesium, calcium, zinc, and iron, so that the microneedles <NUM> provided on the substrate <NUM> may also be made of a bioabsorbable metal.

In addition, when the substrate <NUM> is formed of a bioabsorbable metal, a cutout portion <NUM> is further formed at a connection between the first needle section <NUM> and the substrate <NUM>.

When the cutout portion <NUM> is torn upon separation of the bioabsorbable substrate <NUM> from the user's skin, the microneedles <NUM> may be separated from the substrate <NUM> and remain on the skin.

Here, as illustrated in <FIG>, the cutout portion <NUM> are provided on opposite widthwise sides of the first end of the first needle section <NUM>.

That is, the cutout portion is cutout slits respectively disposed between the opposite widthwise ends of the first needle section <NUM> and the first end of the carrying recess <NUM> at the first end of the first needle section <NUM> as illustrated in <FIG>, while the cutout portion <NUM> may have notches disposed at the opposite widthwise ends of the first end of the first needle section <NUM> so as to communicate with the needle opening <NUM>.

The cutout portion <NUM> is configured to allow the first needle section <NUM> and the second needle section <NUM>, which are inserted subcutaneously, to be subcutaneously left when the substrate <NUM> contacting the skin is separated from the skin, and serves to reduce an area of a connection between the first needle section <NUM> and the substrate <NUM> so that the first end of the first needle section <NUM> is easily broken from the substrate <NUM>.

That is, the first needle section <NUM> and the second needle section <NUM> inserted under the skin can be stuck to the subcutaneous tissue by the contractive force of the subcutaneous tissue. Here, when the first needle section <NUM> and the second needle section <NUM> are pulled by the separation force of the substrate <NUM> from the skin, which is larger than the contraction force of the subcutaneous tissue, the first needle section <NUM> and the second needle section <NUM> are forced to separate from the skin together with the substrate <NUM>.

However, the cutout portion <NUM> is formed at the connection between the substrate <NUM> and the first needle section <NUM>, so that the force exerted to the substrate <NUM> to pull the first needle section <NUM> and the second needle section <NUM> is reduced so as to be smaller than the contraction force of the subcutaneous tissue, thereby allowing the first needle section <NUM> and the second needle section <NUM> to be left under the skin.

The first needle section <NUM> and the second needle section <NUM> can be further adhered to the subcutaneous tissue since the engagement protrusion 132a formed on the second needle section <NUM> can be caught in the subcutaneous tissue. Therefore, when the substrate <NUM>, which is in contact with the skin, is separated from the skin, the connection between the first needle section <NUM> and the substrate <NUM> can be more easily broken by the engagement protrusion 132a.

The first needle section <NUM> and the second needle section <NUM> remaining on the skin can subcutaneously deliver the drug carried in the substrate <NUM> as well as minerals contained in the bioabsorbable metal. That is, magnesium, calcium, zinc, and iron components used as bioabsorbable metals can be subcutaneously transmitted.

For reference, bioabsorbable metals have been made commercially for the application of magnesium based alloy for orthopedic implants. Bioabsorbable metals applied to orthopedic implants were focused on reducing a decomposing rate thereof and improving the corrosion resistance thereof for safe fixation of the fracture.

However, unlike the bioabsorbable metals used for orthopedic surgery, the bioabsorbable metals forming the microneedle array <NUM> according to the present invention accelerates the decomposition rate in the body, so that mechanisms may be applied to supply minerals along with drug release under the skin.

For example, magnesium, calcium, and zinc used as bioabsorbable metals have a mechanism of reacting with water to produce hydrogen gas, as shown in the following Chemical Formulas <NUM> to <NUM>, respectively.

Mg + <NUM><NUM>O → Mg(OH)<NUM> + H<NUM> (gas).

Ca + <NUM><NUM>O → Ca(OH)<NUM> + H<NUM> (gas).

Zn + <NUM><NUM>O → Zn(OH)<NUM> + H<NUM> (gas).

The substrate <NUM> and the microneedles <NUM> formed of the bioabsorbable metal as described above may emit ions and decomposition products under the skin and the hydrogen gas generated by the byproducts provides a swelling effect in the subcutaneous space, thereby being effective against wrinkles.

In addition, ZnO and MgCl, which are byproducts formed by magnesium and zinc, which are inserted into the body as components of the bioabsorbable metal, remain under the skin and serve as a drug delivery enhancer improving the subcutaneous delivery of a drug carried in the substrate <NUM> and the microneedles <NUM>. Therefore, the substrate <NUM> and the microneedle <NUM>, which are formed of the bioabsorbable metal, can effectively deliver the carried drug to the user.

The shapes of the needle openings <NUM> and the microneedles <NUM> formed on the substrate <NUM> may be patterned on the substrate <NUM> by a known lithography or etching technique.

At this time, since the substrate <NUM> formed of a bioabsorbable metal has lower corrosion resistance than a metal material such as stainless steel or iron, the periphery of the microneedle <NUM> becomes corroded and thinner than the thickness of the original material itself so as to be sharpened by the lithography or etching technique. That is, at the periphery of the first needle section <NUM> or the second needle section <NUM>, a sharp inclined surface having a thickness smaller than the thickness of the first needle <NUM> or the second needle <NUM> is formed by the lithography or etching technique, so that the sharp inclined surface can be easily inserted subcutaneously.

Also, since the multi-type microneedle array <NUM> according to the present invention has the needle opening <NUM> having a relatively large diameter or area rather than the needle opening formed in the conventional microneedle array, a light therapy can also be performed through the needle opening <NUM> in parallel.

In other words, even if the substrate <NUM> is attached to the skin, the user's skin can be exposed to the outside through the plurality of needle openings <NUM>, so that the exposed skin can be easily exposed to light beneficial to treatment for skin diseases such as skin pain, acne, atopy, thereby perform the light treatment.

Therefore, since a user can be treated by the drug injected into the skin through the microneedles <NUM> and by the light irradiated through the needle openings <NUM>, a synergy effect between the drug treatment and the light therapy can be expected.

For example, although described in the course of the present invention, beneficial light exposed to the skin through the needle openings <NUM> may be irradiated to the body to receive light therapy, the present invention is not limited thereto. That is, a skin care substance or a skin treatment substance in a liquid state can be applied to the skin exposed through the needle openings <NUM> to perform a skin treatment.

In addition, the substrate <NUM> can be brought into close contact with the user's skin through the needle openings <NUM>.

That is, since the needle opening <NUM> of the present invention accommodates the plurality of microneedles <NUM> in one space so that the needle opening has a relatively large diameter or area than that of the needle opening (which can accommodate only one microneedle) of the conventional microneedle array, when the substrate <NUM> is in contact with the user's skin, the user's skin is easily accommodated by the needle opening <NUM>. Here, a negative pressure is formed at the same time, so that the substrate <NUM> can be more closely adhered to the skin.

Therefore, the microneedle array <NUM> according to the present invention may have a configuration in which the substrate <NUM> can be more closely attached to the user's skin by the needle openings <NUM>.

Since the multi-type microneedle array <NUM> according to the present invention has a structure in which the plurality of microneedles are arranged in a predetermined pattern around a single needle opening, the plurality of microneedles can be inserted into the skin of a predetermined area, so that a drug can be rapidly delivered into the body.

Since the multi-type microneedle array <NUM> according to the present invention has a structure in which the substrate <NUM> has a honeycomb structure by provision of regular hexagonal needle openings <NUM>, the substrate <NUM> may be prevented from being deformed or broken in the process of pressing and bending the microneedles <NUM>.

In the multi-type microneedle array <NUM> according to the present invention, the plurality of microneedles <NUM> can protrude from the substrate <NUM> without having the number of the pressing punches provided on the movable mold of the press machine be equal to the number of the microneedles <NUM>, thereby reducing the manufacturing cost of the movable mold of the press, and thus obtaining reduced manufacturing cost of the microneedles and the simplified manufacturing process.

Claim 1:
A microneedle array (<NUM>) for subcutaneous insertion, comprising:
a substrate (<NUM>);
a plurality of needle openings (<NUM>) provided in the substrate (<NUM>); and
a plurality of needle units disposed around respective needle openings (<NUM>) and each having a plurality of microneedles (<NUM>) circumferentially arranged at regular intervals around a respective needle opening (<NUM>) to protrude from the substrate (<NUM>) so as to be inserted into the skin,
wherein the substrate (<NUM>) and the microneedles (<NUM>) are formed of a bioabsorbable metal, wherein the bioabsorbable metal includes at least one element of magnesium and zinc generating hydrogen gas and MgCl, or hydrogen gas and ZnO in a reaction with water, in a decomposition process when inserted into the skin, wherein the microneedle (<NUM>) includes a first needle section (<NUM>) having a first end connected to the substrate (<NUM>), and a second needle section (<NUM>) having a first end connected to a second end of the first needle section (<NUM>), with the first and second needle sections protruding in vertical directions from a surface of the substrate (<NUM>),
wherein the first needle section (<NUM>) has a gradually narrower width from the first end to the second end thereof in a longitudinal direction,
characterized in that
the microneedle (<NUM>) includes a carrying recess (<NUM>) having a first end partially disposed in the substrate (<NUM>) and a second end disposed to extend toward a distal end of the microneedle (<NUM>) in a longitudinal direction thereof and a carrying hole (<NUM>) being provided in the carrying recess (<NUM>),
wherein a cutout portion (<NUM>) is provided at a connection between the first needle section (<NUM>) and the substrate (<NUM>), the cutout portion (<NUM>) being formed by cutout slits respectively disposed between the opposite widthwise ends of the first needle section (<NUM>) and the first end of the carrying hole (<NUM>) at the first end of the first needle section (<NUM>).