JP6342668B2 - Composite powder - Google Patents

Description

The present invention, synthetic stevensite, L- ascorbyl magnesium phosphate (hereinafter, abbreviated as APM), containing silica-coated ultrafine titanium dioxide free of alumina and aluminum hydroxide, comprising the silica-coated ultrafine titanium dioxide in the outer shell The present invention relates to a method for producing a spherical composite powder having a core-shell structure for a solid powder cosmetic .

  In recent years, whitening cosmetics have attracted attention, and the market for quasi-drugs that has the effect of suppressing the production of melanin and preventing spots and freckles caused by sunburn is also expanding. In the whitening cosmetics, ingredients having a whitening effect are usually blended, but among these ingredients, APM has a poor solubility in water despite being a stable ascorbic acid derivative. Therefore, when APM is dissolved and blended in a system containing water, a method of dissolving a very small amount of APM in water and a method of dissolving 2-3% by weight of APM in an aqueous solution of an organic base or the like The prescription design is done by etc.

  On the other hand, makeup cosmetics tend to have a lot of ingredients composed of powder or the like and no or little moisture in the formulation. The amount of moisture in the composition is large, and it is in a form different from basic cosmetics such as lotion, beauty essence, milky lotion, cream and the like in which whitening ingredients are dissolved in water. For this reason, mixing APM in makeup cosmetics in water is disadvantageous in terms of stability over basic cosmetics, such as crystal precipitation, and it is easier to formulate a formulation if APM is blended in powder form. Become.

However, in the method of blending APM into a solid powder cosmetic as it is in powder form, it cannot be expected that APM which is difficult to dissolve in water will penetrate into the skin efficiently. Therefore, in Patent Document 1, a composite powder of clay mineral and APM is prepared, and APM is easily dissolved in moisture even from the powder state, and is dissolved in moisture of the skin and a small amount of water in the makeup base to the skin. To penetrate.

  However, when the composite powder of Patent Document 1 is blended into a solid powder cosmetic such as a powder foundation and used repeatedly, a granular aggregate appears on the surface of the cosmetic due to the influence of moisture during use. In some cases, the sexiness decreased.

  Furthermore, when a large amount of the composite powder of Patent Document 1 was added to the solid powder cosmetic, there was a tendency that the smoothness during application gradually decreased.

  For this reason, a new coating and outer shell have been provided on the APM composite powder to achieve both water agglomeration and APM solubility, and a new composite that does not impair the usability of solid powder cosmetics. The need for powder development has arisen. As a countermeasure for this, the conventional composite powder of Patent Document 1 was subjected to a hydrophobic treatment such as silicone treatment, but the property of dissolving in a small amount of water from the powder state was lost, and the permeability of APM could not be expected. .

  On the other hand, as a method for providing the outer shell part, there is a method of providing a silica part of Patent Document 2, which is intended to maintain the stability of the organic compound in the interior and to provide dispersion stability. In Patent Document 3, a hydrophilic material is encapsulated in a multinuclear microcapsule. However, since this method aims to stabilize an internal substance, release from a powder state to the outside cannot be expected. In Patent Document 4, a physiologically active ingredient is encapsulated with a biocompatible polymer. However, the stability to moisture is poor, the raw material is very expensive, and the particles are fine and squeezed. Mixing into the ingredients was limited.

JP 2003-155217 A JP2009-263171A JP2013-136054A JP 2006-321863 A

The problem to be solved by the present invention is that even when APM is blended in powder cosmetics as it is, the APM dissolves from the powder state into a small amount of water, and the cosmetics are used during continuous use. An object of the present invention is to provide a method for producing an APM composite powder that does not generate aggregates on the surface and does not impair smoothness during application.

The present invention is a method for producing a spherical composite powder having a core-shell structure for a solid powder cosmetic containing silica-coated fine particle titanium oxide that does not contain synthetic stevensite , APM, alumina, and aluminum hydroxide. This is a method for producing a spherical composite powder having a core-shell structure for a solid powder cosmetic containing the silica-coated fine particle titanium oxide.

In addition, the spherical composite powder having the core-shell structure has a characteristic that when immersed in water, the inside elutes and the outer shell portion remains and does not collapse. In the case where the outer shell portion is silica-coated fine particle titanium oxide containing no alumina or aluminum hydroxide , it has the characteristic that it does not collapse.

Further, in the present invention , APM is dissolved in an aqueous dispersion in which synthetic stevensite is previously dispersed in water at a concentration range of 1.9 to 2.2% by weight , and silica-coated fine particle titanium oxide is further dispersed. after the mixture liquid was prepared so that the solid concentration of 15 to 30% by weight, a method of obtaining spherical composite powder of the core-shell structure by the steps of spray-drying the mixture liquid.

In the present invention, synthetic stevensite is a fine-grained clay mineral obtained by hydrothermal synthesis or the like, and swells when dispersed in water, and a thixotropic gel is obtained as the concentration increases. This synthetic stevensite is a component necessary for dissolving APM during preparation, and is indispensable for forming a core-shell structure including APM in the spray drying process.

Furthermore, Ionite-T (Mizusawa Chemical Co., Ltd.) as a raw material for cosmetics is used because of transparency when dispersed in water as this synthetic stevensite .

  L-ascorbyl magnesium phosphate used in the present invention, that is, APM, which is also called ascorbic acid magnesium phosphate, phosphoric acid L-ascorbic acid magnesium, is stable with the physiological activity of ascorbic acid. Any derivative can be used as long as it can be usually used in cosmetics.

The silica-coated fine particle titanium oxide used in the present invention is obtained by coating silica with fine particle titanium oxide as a base material. Further, alumina and aluminum hydroxide are not included in the silica-coated fine particle titanium oxide for the purpose of suppressing the activity of the fine particle titanium oxide or as a silica coating aid .

In general, the fine particle titanium oxide of the base material of the silica-coated fine particle titanium oxide is substantially spherical or spindle-shaped with an average particle diameter of 10 to 100 nm (the particle diameter is a catalog value or by direct observation with an electron microscope. Spindle-shaped particles In this case, both the minor axis and the major axis fall within the particle diameter range.) The silica of the coating layer is anhydrous silicic acid or hydrous silicic acid, and it is preferable that the surface of the fine particle titanium oxide is coated on the surface of the fine particle titanium oxide with respect to the total amount of fine silica particle coated titanium oxide. Commercially available products of silica-coated fine particle titanium oxide containing no alumina or aluminum hydroxide include Maxlite TS-01 and Maxlite TS-04 from Showa Denko KK, MT-100WP from Teika Co. , Ltd., and STR from Sakai Chemical Co., Ltd. -100W etc. are sold.

As the silica-coated fine particles of titanium oxide in the present invention, alumina and silica-coated fine particles of titanium oxide containing no aluminum hydroxide, highly water-dispersible, the spherical core-shell easily molded, easily form a stable outer shell I will use it .

In the present invention, APM is easily dissolved in a small amount of moisture even from a powder state, does not impair the smoothness at the time of application, and further, a spherical composite powder having a core-shell structure for solid powder cosmetics is produced industrially. In order to manufacture, it carries out with the following manufacturing methods.

First, in the present invention, the synthetic stevensite is previously dispersed in water in a concentration range of 1.9 to 2.2% by weight . By dispersing in advance, the synthetic stevensite swells in the aqueous dispersion and can prevent sedimentation, and a uniform aqueous dispersion is obtained. In addition, since the water dispersion and swelling operations are performed with a general stirrer such as a pulsator or a homomixer , the synthetic stevensite concentration of 1.9 to 2.2% by weight is such that the synthetic stevensite is not gelled and difficult to stir. Is appropriate.

Furthermore, APM can be easily dissolved by preparing an aqueous dispersion of synthetic stevensite in advance in the production process. When APM is added to only water and stirred, a general stirrer such as a pulsator or a homomixer tends to remain in a hydrated state of APM and it is difficult to sufficiently dissolve the required amount of APM.

Next, in the present invention, silica-coated fine particle titanium oxide is further dispersed in a synthetic stevensite aqueous dispersion in which APM is dissolved to obtain a mixed liquid . In the method in which the silica-coated fine particle titanium oxide is dispersed prior to the dissolution of APM, the mixed liquid itself becomes white and it is difficult to confirm the dissolution of APM.

  In the dispersion operation of the silica-coated fine particle titanium oxide, it is preferable to preliminarily disperse with a general stirrer such as a pulsator or a homomixer and further disperse with a powerful stirrer such as a bead mill or an ultrahigh pressure homogenizer. In particular, since inorganic solids such as metal oxides are strongly dispersed, it is most preferable to use a bead mill, which is a medium agitation type pulverizer with less equipment consumption, as a powerful agitator.

  Furthermore, as a medium to be filled in this bead mill, the silica-coated fine particle titanium oxide is prevented from cracking and a new active surface of the titanium oxide is prevented from appearing on the surface, while efficiently contacting the dispersoid and increasing the dispersion efficiency. In particular, a medium having a particle size of 30 μm or less is preferable.

  Further, zirconia beads or yttrium-stabilized zirconia beads are preferable as a material for the medium in order to prevent contamination to the dispersion.

In the present invention, synthetic stevensite, APM, alumina and silica-coated fine particles of titanium oxide or the like which does not contain aluminum hydroxide and solids, but to obtain a mixed liquid by the operation of dissolution and dispersion, the (1) the silica-coated ultrafine titanium dioxide Sufficient agitation can be achieved by the dispersing operation, (2) prevention of clogging of the liquid feed pipe and the spray port in the spray drying process, etc. (3) spraying uniform droplets continuously when spray drying is used. The viscosity of the mixed liquid is adjusted so that the solid content concentration in the mixed liquid is 15 to 30% by weight .

  In the present invention, a method of obtaining a spherical composite powder having a core-shell structure by spraying uniform droplets continuously in the spray-drying step is preferable. In this case, in order to maintain atomization and uniformity of the droplets, Further, in order to enable quick and complete evaporation of moisture in the cooling tower of the spraying device, a method of spraying droplets of 100 μm or less is preferable. Specifically, droplets are formed by a nozzle method or a disk method, but with a commercially available spray drying method, a two-fluid nozzle, a three-fluid nozzle, a four-fluid nozzle, a rotary atomizer, Okawara Kakoki from Fujisaki Electric Co., Ltd. This is carried out using a pressurized two-fluid nozzle, twin jet nozzle, M-type disk, etc.

  In the present invention, since the APM is easily dissolved in a small amount of moisture even from the powder state and the smoothness at the time of application is not impaired, the particle diameter of the core-shell structure spherical composite powder is preferably 10 μm or less. In order to achieve this particle size by spray drying, a nozzle system capable of forming droplets of 30 μm or less is more preferable. From the viewpoint of obtaining uniform particles, the above-described three-fluid nozzle, four-fluid nozzle, and twin jet nozzle are used. The spraying method is the best.

As described above, in the present invention, a spherical composite powder having a good core-shell structure can be obtained. In particular, APM is dissolved in an aqueous dispersion in which synthetic stevensite is previously dispersed, and alumina and aluminum hydroxide are further dissolved. A method of obtaining a spherical composite powder having a core-shell structure through a step of spray-drying a mixed liquid after preparing a mixed liquid by dispersing silica-coated fine particle titanium oxide not containing a liquid is disclosed in Patent Literature 1. The mass productivity is superior to those obtained by the reaction of alkoxysilane in the phase and the method of forming a polymer layer from a monomer. That is, since the continuous drying process and the spray drying process by instantaneous solidification of droplets are used, the mass productivity is excellent.

  Furthermore, even though it is produced by the simple method described above with excellent mass productivity, it is characterized by elution of the inside leaving the outer shell part when immersed in water (such as a granule that is totally disintegrated by water) In other words, the APM, which is a medicinal ingredient contained in the skin, is gradually released by being dissolved in the moisture of the skin and a small amount of water in the makeup base, and even after the APM is released, the spherical outer shell The part remains in a hollow state, and the characteristic of maintaining a smooth use feeling is useful as a novel drug capsule.

  In particular, in a powder foundation that is used with water contained in a cosmetic puff, the surface of the solid foundation is contacted with water by actual use, and swelling and drying with water are repeated. At the time of this use, in the general granule which completely disintegrates, aggregates are likely to be generated on the surface of the foundation, and there is a high possibility of reducing the commercial value. In the spherical composite powder of the core-shell structure of the present invention, even when APM is released, the outer shell portion remains in a hollow spherical state, so that the generation of aggregates is reduced and the smoothness during coating is not impaired by the rolling effect. .

From the above, the spherical composite powder of the core-shell structure of the present invention is blended into solid powder cosmetics such as powder foundation, face powder, cheek color, eye shadow and the like.

In the present invention, silica-coated fine particle titanium oxide not containing synthetic stevensite , APM, alumina, and aluminum hydroxide is cited as a component contained in a spherical composite powder having a core-shell structure, but it is generally used for cosmetics and pharmaceuticals. A raw material can be included in the range which does not impair this invention. In particular, in the case of a drug such as APM, which is a weak acid metal salt that is weakly alkaline and has increased solubility, a good core-shell structure is formed, and a drug capsule can be prepared. Examples of these agents include trisodium ascorbyl palmitate, sodium tocopheryl phosphate, dipotassium glycyrrhizinate, and the like.

The spherical composite powder of the core-shell structure of the solid powder cosmetic of the present invention has a feature that the drug inside is gradually dissolved and released with a small amount of water and has a smooth and smooth feeling because it is spherical. It is a novel powdery drug carrier. Such a material design has the potential to be used as a drug capsule carrying a drug inside, and the production method of the present invention is highly useful in that mass production is possible.

SEM observation sample preparation flow for spherical composite powder with core-shell structure Appearance of spherical composite powder with core-shell structure Split section image of spherical composite powder with core-shell structure Split section image of spherical composite powder with core-shell structure after water immersion Dent powder Umeboshi-like powder with dents

Next, although the manufacturing method of the spherical-shell composite powder of the core-shell structure for solid powder cosmetics of this invention is demonstrated in detail, an Example is given, This invention is not limited to these.

<Water dispersion concentration of synthetic stevensite >
In the present invention, spray drying is performed in the final step. For this reason, in order to form uniform droplets, it is necessary to spray the mixed liquid without clogging the spray port. In contrast, aqueous dispersion of synthetic stevensite becomes a thixotropic with elevated concentrations of synthetic stevensite gel. Therefore, in order to determine an appropriate concentration range of the synthetic stevensite aqueous dispersion prepared in advance , various concentrations of the synthetic stevensite aqueous dispersion were prepared, the states were confirmed, and the results were summarized in Table 1.

From Table 1, the concentration change of the synthetic stevensite in the aqueous dispersion is good up to 4% by weight when fluidized with stirring, but 5% by weight is difficult to stir with some of the devices with weak stirring power, Further, since APM as a solid content and silica-coated fine particle titanium oxide are added, it is appropriate to prepare a synthetic stevensite aqueous dispersion in advance at a sufficiently fluidity of 4% by weight or less.

<APM solubility>
In order to verify the solubility of APM in the present invention, 100 g each of purified water only, 2 wt% synthetic stevensite aqueous dispersion, 2 wt% tripotassium citrate aqueous solution ( tripotassium citrate monohydrate aqueous solution) While stirring with a pulsator, 3 g of APM was added to the solvent, and the dissolved state was confirmed. The results are shown in Table 2.

From the results in Table 2, APM is completely dissolved in the synthetic stevensite aqueous dispersion and the tripotassium citrate aqueous solution, but it is difficult to dissolve with purified water alone.

<Preparation method of spherical composite powder with core-shell structure>
Based on the preliminary test results described above, the core-shell structured spherical composite powder of the present invention was prepared by the method shown below with the amounts of the constituent components of the production examples and comparative examples in Table 3 .
(1) While stirring with a pulsator, synthetic stevensite was gradually added to ion-exchanged water and pre-dispersed, and further sufficiently dispersed with a homomixer to obtain an aqueous dispersion of synthetic stevensite. (When tripotassium citrate of Comparative Example 1 was used, it was dissolved only with a pulsator.)
(2) APM was gradually added to the aqueous dispersion of synthetic stevensite while stirring with a pulsator or a homomixer, and completely dissolved.
(3) Further, while stirring with a pulsator or homomixer, silica-coated fine particle titanium oxide was gradually added and predispersed, and dispersed with a bead mill under the following conditions to obtain a mixed liquid.
Bead mill: Ultra Apex Mill UAM-015 (manufactured by Kotobuki Industries Co., Ltd.)
Medium used: 30 μm yttrium-stabilized zirconia beads Processing time: 30 minutes In addition, Comparative Example 4 was prepared by adding additional ion-exchanged water after being dispersed in a bead mill for examination of the solid content concentration.
(4) The obtained mixed liquid was spray-dried under the following conditions to prepare a spherical composite powder having a core-shell structure according to the present invention.
Spray dryer: MDL-050B type (Fujisaki Electric Co., Ltd.)
Droplet formation method: Three-fluid nozzle PN3005 type (manufactured by Fujisaki Electric Co., Ltd., droplet size 5-15 μm)
Cooling tower temperature: inlet 230-250 ° C, outlet 100-120 ° C
Collection method: Cyclone recovery Mixed liquid flow rate: Control so that the cooling tower temperature is within the setting

<How to check the generation status>
The prepared core-shell structure spherical composite powder was observed with a scanning electron microscope (SEM). Observation is the appearance image of the composite powder, the cleaved image obtained by mixing and solidifying the composite powder and the epoxy resin, and the powder extracted by immersing the composite powder once in water and then filtering and drying. Was performed on the cleaved image (check the elution of APM and the state of the outer shell) (see SEM observation sample preparation flow in FIG. 1).

  In the appearance, a spherical shape as shown in FIG. 2 is obtained (appearance image of Production Example 6), and in the cleaving, an image in which APM is densely packed inside can be observed as shown in FIG. In the cleaving after the immersion, the APM and the synthetic stevensite eluted as shown in FIG. 4 and the outer shell was confirmed not to collapse (the cleaved image after the water immersion in Production Example 6) is good. Δ. Poor x indicates that a powder with a dent as shown in FIG. 5 (appearance image of Comparative Example 2), a powder with a umeboshi-like dent as shown in FIG. 6 (appearance image of Comparative Example 1), etc. (Approx. X when the number of dents in the field of view was confirmed to be about half the number at a low magnification of about 2000 times), and the appearance was a beautiful sphere, but completely disintegrated by water immersion Etc. In addition, the presence of silica-coated fine particle titanium oxide in the outer shell part is connected to an SEM with an energy dispersive X-ray analyzer, and APM and synthetic stevensite are eluted by water immersion, and the composition analysis of the part where the outer shell part remains. It confirmed from the result of (surface analysis) that titanium and silicon were identified.

<Particle size of generated powder>
The particle size of the produced spherical composite powder having a core-shell structure was classified as 5 μm or less, 10 μm or less, 20 μm or less, less than 50 μm, or 50 μm or more based on the maximum particle size in the field of view from the SEM image.

<Confirmation of APM elution from the spherical composite powder with core-shell structure>
In order to confirm that even a small amount of water is eluted from the produced spherical composite powder having a core-shell structure, the following examination was conducted.
(1) About 0.1 g of the composite powder is added to and dispersed in an ethanol / 1,3-butylene glycol mixture (volume ratio 3/1), and subjected to membrane suction filtration (inner diameter 35 mm filter holder) to obtain a membrane filter (cellulose Acetate, pore diameter 0.8 μm, outer diameter 47 mm).
(2) 7 g of purified water per sheet, which was an amount adjusted so that water did not bleed out by lightly pressing the cosmetic cotton, was moistened.
(3) A new piece of cosmetic cotton was placed on the petri dish, the wetted cotton piece was placed thereon, and the membrane filter of (1) was placed on it and lightly pressed to adhere. A test was started in which APM was eluted from the spherical-shell composite powder having a core-shell structure attached to the membrane filter by the cover of the petri dish and transferred to the lower cotton.
(4) After a certain period of time (10 minutes, 30 minutes, 60 minutes), the membrane filter was removed, two cottons were collected, and APM transferred to both cottons was quantified by high performance liquid chromatography. The test was repeated every time, and the average value of 3 points with little difference was calculated, and the elution rate of APM was calculated.

<Result>
From the knowledge of the solubility of APM and the results of Production Example 1 and Comparative Example 1, when a mixed liquid of APM and silica-coated fine particle titanium oxide dissolved in an aqueous dispersion of synthetic stevensite is spray-dried, a spherical composite with a core-shell structure Although it was possible to make a powder, it became clear that when APM dissolved in tripotassium citrate was used, it did not become spherical. That is, in order to form a spherical composite powder having a core-shell structure, APM is dissolved in a synthetic stevensite aqueous dispersion .

From the results of the state change of the aqueous dispersion depending on the concentration of the synthetic stevensite and the results of the production example and the comparative example , the concentration of the aqueous dispersion of the synthetic stevensite prepared in advance is 1.9 to 2.2% by weight.

  From the results of Comparative Example 3, the core-shell structure could not be formed without the silica-coated fine particle titanium oxide, and even when immersed in water, the core-shell structure was completely disintegrated. Further, as in Comparative Example 6, finely divided titanium oxide having no silica coating layer obtained spherical composite particles in appearance, but when immersed in water, it completely disintegrated and no outer shell portion remained. Accordingly, it was shown that silica-coated fine particle titanium oxide is essential for forming the core-shell structure spherical composite powder of the present invention.

From the results of Production Example 1 and Production Example 4, MT-100HP coated with about 6% by weight of aluminum hydroxide was used compared to Production Example 1 using Maxlite TS-04, which is a silica-only coating. in this case, since the non-uniformity of the shape looks like powder with a recess exists little is concerned, the fine particles of titanium dioxide of the silica-coated only in order to obtain a spherical composite powder of good yield a core-shell structure Use . Moreover, when SEM observation of the fractured surface after immersion in water as shown in FIG. 4 was conducted with respect to Production Example 1 with an energy dispersive X-ray analyzer connected, titanium and silicon were identified. Silica-coated fine particle titanium oxide was confirmed.

In the manufacturing process according to the present invention, it is considered important to mix and spray more uniformly both in the preparation of the mixed liquid and in the spraying of the droplets. Therefore, the solid content concentration that affects the viscosity of the mixed liquid is important. In the invention of this application, the synthetic state finally obtained as a solid content from the mixed liquid is confirmed as the solid content of the synthetic shell site , APM, silica-coated fine particle titanium oxide, and the production state of the core-shell structure spherical composite powder is confirmed using this solid content concentration as a guide. did. From the results of Production Examples 1 to 8, Comparative Example 4 and Comparative Example 5, it was determined that 15 to 30% by weight of the solid content concentration was appropriate (the actual calculated value was rounded off to the nearest decimal place).

  About the spherical composite powder having the core-shell structure obtained in Production Example 6, elution confirmation of APM was performed. As a result, it was confirmed that 58% by weight of APM was eluted in 10 minutes, 88% by weight in 30 minutes, and 98% by weight in 60 minutes. In contrast, the composite powder obtained in Comparative Example 3 without using the silica-coated fine particle titanium oxide as the outer shell portion showed a value of 98% by weight in 10 minutes. Further, even in the composite powder having a dent shape as in Comparative Example 2, most APM flowed out in 10 minutes as in Comparative Example 3. Therefore, it was shown that the spherical composite powder having the core-shell structure of the present invention has sustained release characteristics. That is, the core-shell structured spherical composite powder of the present invention is a novel drug capsule material that can be expected to be continuously dissolved and penetrated when APM is gradually dissolved in a small amount of skin moisture when actually using cosmetics. It can be said that there is.

  As Example 2, a core-shell structured spherical composite powder was prepared by changing the working medium of the bead mill to 50 μm yttrium-stabilized zirconia beads in Production Example 6 of Table 3.

  When the obtained spherical composite powder having a core-shell structure was confirmed by SEM, a slightly larger number of hollow spherical powder was observed than when 30 μm medium was used in appearance (APM elution is a fractured surface after water immersion). Good observation). A similar tendency was confirmed with 100 μm yttrium-stabilized zirconia beads, and many dents were observed. Therefore, the particle diameter of the beads used is preferably 30 μm or less.

  As Example 3, in the manufacturing example 6 of Table 3, spraying is performed in the spray drying process. The four-fluid nozzle of Fujisaki Electric Co., Ltd., the twin jet nozzle of Okawahara Chemical Co., Ltd., the rotary atomizer of Fujisaki Electric Co., Ltd., and the Okawara Chemical Machine Co., Ltd. A spherical composite powder having a core-shell structure was prepared by changing to an M-type disk of Co., Ltd.

  As a result, in the SEM observation and the APM elution test, when the four-fluid nozzle of Fujisaki Electric Co., Ltd. and the twin jet nozzle of Okawara Chemical Industries Co., Ltd. were used, the same particle size as in Production Example 6 in Example 1 was obtained. The particles were confirmed and confirmed to release APM at a similar rate.

  On the other hand, when sprayed with a rotary atomizer manufactured by Fujisaki Electric Co., Ltd. or an M-type disk manufactured by Okawara Chemical Industries Co., Ltd., particles with a particle size of 50 μm or more were obtained, and the elution of APM was halved to about 30% by weight in 10 minutes. . Therefore, in order to obtain a composite powder having a particle size of 10 μm or less that can be easily dissolved on the skin, which is considered to have a lower water content, and can be used smoothly when blended into a powder cosmetic (at the time of application) In order to increase the smoothness of the powder, a spherical powder of 5 to 10 μm is generally used in the powder foundation.) A three-fluid nozzle, a four-fluid nozzle, and a twin jet nozzle that can spray droplets of 30 μm or less are used. A nozzle system that uses and sprays is preferred.

The core-shell structure spherical composite powder obtained in the present invention has a sustained release property by enclosing a drug such as APM inside. For this reason, it is possible to stably mix water-soluble drugs that have deliquescence into powdered drugs, and when you want to release internal drugs, you can release them by touching a little water. It is most suitable for the formulation of

Claims (3)

A method for producing a spherical composite powder having a core-shell structure for a solid powder cosmetic, in which a synthetic stevensite is previously dispersed in water in a concentration range of 1.9 to 2.2% by weight, phosphoric acid L - a step of Ru dissolved magnesium ascorbyl, after the liquid mixture was prepared as further comprising alumina and silica-coated fine particles of titanium oxide were dispersed finally solids concentration of 15 to 30 wt%, which did not contain aluminum hydroxide, The manufacturing method characterized by including the process of spray-drying the liquid mixture . 2. The method for producing a spherical composite powder having a core-shell structure according to claim 1, wherein the dispersion of the silica-coated fine particle titanium oxide in the mixed liquid is performed by a bead mill . 3. The method for producing a spherical composite powder having a core-shell structure according to claim 1 or 2, wherein spraying is performed with droplets of 100 [mu] m or less in the spray drying step .