Preparation and application of oil-dispersible titanium dioxide nano-sustained release microcapsules

Abstract

The present invention discloses a novel method for preparing a type of oil-dispersible nano titanium dioxide sustained-release microcapsule powder and its application. The first step is to prepare a dispersant consisting of a hydrophobic organosilicon Si-O-Si main chain and hydrophilic PEG segments at both ends, the second step is to configure an oil phase continuous phase mixture, the third step is to configure an aqueous phase dispersed phase mixture, and the fourth step is to prepare titanium dioxide nano sustained-release microcapsule powder by an oil-in-water emulsion method. This method has the advantages of simple process, non-toxic and pollution-free, controllable particle size <100nm, spherical morphology, good dispersibility in the oil phase, delicate hand feel, not only anti-ultraviolet properties of nano titanium oxide, but also a variety of active substances can be wrapped inside and slowly released, giving functions such as improving ultraviolet absorption capacity, moisturizing, whitening, sterilization, and disinfection, meeting different needs, and is particularly suitable for the cosmetics industry.

Description

Technical Field

[0001] The invention belongs to the field of nano titanium dioxide materials, and specifically relates to the preparation and application of oil-phase dispersible titanium dioxide nano sustained-release microcapsules. Background Art

[0002] Titanium dioxide, also known as titanium dioxide, is usually called nano titanium dioxide when the average particle size is at the nanoscale. Nano titanium dioxide is widely used in various fields such as coatings, paper, rubber, plastics, batteries, antibacterial, and cosmetics because of its non-toxic, odorless, non-irritating, good thermal stability, large specific surface area, UV resistance, photocatalytic properties, stable chemical properties, and excellent antibacterial properties.

[0003] At present, there are three main methods for preparing nano titanium dioxide: gas phase method, liquid phase method and solid phase method. Among them, the liquid phase method is the most widely used due to its simple operation and low cost. The liquid phase method refers to a method in which nanoparticles are uniformly precipitated by adding substances such as initiators or precipitants to the liquid, mainly including sol-gel method, hydrothermal method, liquid phase deposition method, microemulsion method, etc. For example, there is a Japanese patent (patent number: 2007-176753) that uses titanate, titanium salt, tetramethylammonium hydroxide (TMAH), diol or triol mixed solution hydrothermal treatment to prepare nano titanium dioxide. However, the raw material TMAH used is a toxic and hazardous chemical, which limits its production and application. In addition, a Chinese patent (patent number: CN 107074581B) prepares nano titanium dioxide by introducing a nitrogen-containing 5-membered ring compound to replace the toxic TMAH, and is used in dye-sensitized solar cells.

[0004] In a Chinese patent (patent number: CN 103917494 B), isopropyl titanium and carboxylic acid are reacted in a supercritical fluid to prepare spherical porous nano-titanium dioxide, and used as a carrier for a gene gun. However, this method requires supercritical methanol fluid and the addition of compounds such as benzamide and erbium acetate, resulting in a complex preparation process and high cost.

[0005] In the Chinese patent (patent number: CN 109112661 A), tetrabutyl phthalate is hydrolyzed into sol-gel, and then N-Au or / and N-Ag co-hyperbranched polymers are prepared, and finally the polymer is added to the sol-gel to prepare N-Au or / and N-Ag co-doped composite titanium dioxide, which has the advantages of antibacterial, UV resistance, high catalytic activity and environmental protection, and is used in the spinning process. In addition, Valan Arasu et al. (Renewable Energy, 2020, 152: 358-367.) used the sol-gel method to introduce nano-Ag in the process of generating nano-titanium dioxide, and prepared TiO2-Ag composite nanoparticles, which further improved the thermal conductivity of nano-titanium dioxide. However, these methods have many steps and the process is relatively complicated.

[0006] In a Chinese patent (patent number: CN 102015540 B), a polymer made from carboxylic acid and carboxylic acid derivatives is added to the acidic water dispersibility of titanium dioxide particles, and then neutralized with an alkali to obtain a titanium dioxide particle composite formed by a carboxylic acid monomer or polymer deposited on the surface of titanium dioxide. This titanium dioxide particle composite can be evenly dispersed in water, has high transparency and high stability, and can be used to prepare skin care products with ultraviolet protection. However, the nano titanium dioxide particles prepared in this method are water dispersible, have poor water resistance, and the added ultraviolet absorber and other compositions and nano titanium dioxide particles are simply physically mixed, so the retention effect is poor and the retention time is short.

[0007] Furthermore, there are literature reports that titanium dioxide is used as a shell material to encapsulate various active substances to form titanium dioxide microcapsules. For example, Cheng et al. (Powder Technology, 2021, 385: 546-556.) used formamide as the water phase and paraffin as the oil phase to construct an oil-in-water emulsion template system. In the process of forming a titanium dioxide shell by hydrolysis and condensation of tetrabutyl titanate, graphene oxide nanosheets were introduced to achieve the coating of paraffin, and TiO2 microcapsules with a particle size of about 5 μm were obtained. The thermal conductivity was increased by 100.69% relative to paraffin. There are also Li et al. (Energy Technology, 2020, 8 (12): 2000550.) who used the sol-gel method to hydrolyze tetrabutyl titanate to form a titanium dioxide shell material on the outer layer of the NaNO3 particle core material, thereby preparing a new type of TiO2 high-temperature phase change microcapsules, which were applied to latent heat functional fluids, heat recovery and other fields. However, the TiO2 microcapsules prepared by these methods have large particle sizes (5-15 μm), poor and irregular morphology, poor dispersibility in the oil phase, easy agglomeration, and difficulty in releasing the core material. These problems still need to be solved. Summary of the invention

[0008] The purpose of the present invention is to provide a method for preparing oil-dispersible titanium dioxide nano-sustained-release microcapsules in view of the deficiencies in the prior art, which includes preparing a dispersant consisting of a hydrophobic organosilicon Si-O-Si main chain and hydrophilic PEG segments at both ends. The method has a simple preparation process and low cost, and the prepared microcapsule powder has good oil dispersibility, no agglomeration and good stability.

[0009] The specific technical solutions are as follows:

[0010] A method for preparing oil-dispersible titanium dioxide nano-sustained-release microcapsules is prepared by the following four steps: (1) preparing a dispersant; (2) preparing an oil-phase continuous phase mixture; (3) preparing an aqueous dispersed phase mixture; (4) adding the aqueous dispersed phase mixture to the oil-phase continuous phase mixture, adding a titanium-containing dilution solution, and preparing titanium dioxide nano-sustained-release microcapsule powder by an oil-in-water emulsion method; the oil-phase continuous phase mixture is an oil-phase solvent in which a dispersant and an oil-phase surfactant are dissolved, and the dispersant is composed of a hydrophobic organosilicon Si-O-Si main chain and hydrophilic PEG segments at both ends.

[0011] The dispersant is prepared by the following reaction: 1) placing the same molar amount of polyethylene glycol monomethyl ether and isophorone diisocyanate in a solvent to react to obtain NCO-terminated PEG, and 2) then reacting with half the molar amount of amino-terminated silicone oil or aminopropyl-terminated silicone oil of the NCO-terminated PEG to obtain the dispersant PEG-(Si-O-Si)-PEG.

[0012] Specifically, the number of chain segments of the polyethylene glycol monomethyl ether is n=5-20; the number of chain segments of the amino-terminated silicone oil or amino-terminated propyl silicone oil is m=5-20.

[0013] The reaction formula is as follows:

[0014]

[0015] Specifically, the solvent is one or a mixture of ethyl acetate, butyl acetate and toluene. Preferably, the solvent is non-toxic and harmless ethyl acetate. The mass ratio of the solvent to the molar amount of polyethylene glycol monomethyl ether is (4-5) kg: 1 mol.

[0016] Specifically, in step 1), the mixture is first heated to 40-60° C., and then a catalyst is added to react for 6-8 hours.

[0017] Specifically, the catalyst is one or a mixture of organic tin, organic bismuth, organic zinc, and tertiary amine catalysts. Preferably, the catalyst is a non-toxic and harmless organic zinc catalyst. The molar ratio of the mass of the catalyst to the polyethylene glycol monoether is (10-50) g: 1 mol.

[0018] Specifically, after adding the amino-terminated silicone oil or the amino-terminated propyl silicone oil in step 2), the mixture is heated to 50-60° C. and reacted for 2-4 hours.

[0019] The oil phase surfactant is at least one of polyoxyethylene ether modified polysiloxane, sodium fatty acid, potassium lauryl sulfate, polyoxyethylene ether sodium lauryl phosphate, polyglycerol-4 isostearate or cetyl polyethylene glycol; the oil phase solvent is at least one of n-hexane, cyclohexane, octamethylcyclotetrasiloxane, hexamethyldisiloxane, cyclohexane, n-octane, benzene or toluene; the mass ratio of the dispersant to the oil phase solvent is 0.1-5%; the mass ratio of the oil phase surfactant to the oil phase solvent is 0.1-5%.

[0020] The aqueous dispersed phase mixture comprises a water-soluble active substance, an aqueous surfactant and a water-soluble acid.

[0021] The water-soluble active substance is at least one of glycerol, erythritol, polyethylene glycol, polypropylene glycol, retinoic acid, vitamin B6, PCA zinc, PCA sodium, L-valine, coated yeast fermentation product, sclerotium gum hydrogel, carnosine, blue copper peptide, acetyl tetrapeptide-2, snake venom peptide, L-carnitine, ergothioneine, dimethyl glycyrrhizinate or sodium hyaluronate, and the mass ratio of the water-soluble active substance to water is 1-20%.

[0022] The aqueous phase surfactant is at least one of sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, dodecyltrimethylammonium chloride or dodecyltrimethylammonium bromide, and the mass ratio of the aqueous phase surfactant to water is 0.5-10%.

[0023] The water-soluble acid is at least one of hydrochloric acid, citric acid, acetic acid or butyric acid, and the mass ratio of the water-soluble acid to water is 0-10%.

[0024] The specific steps of preparing oil-dispersible titanium dioxide nano sustained-release microcapsules by the water-in-oil emulsion method are as follows:

[0025] At 25-40°C, the aqueous dispersed phase mixture is added to the oil continuous phase mixture and stirred vigorously, and then the titanium-containing diluted solution is added dropwise. At this time, the titanium-containing active substance reacts with the small water droplets in the aqueous dispersed phase and aggregates on the surface of the droplets. After the addition is completed, it is heated to 70-80°C and reacted overnight. After centrifugation, washing, drying and other steps, titanium dioxide nano sustained-release microcapsule powder is obtained.

[0026] Among them, the titanium-containing active substance in the titanium-containing dilute solution is one or a mixture of tetrabutyl titanate, tetraethyl phthalate, titanium tetrachloride, titanyl sulfate, tetraisopropyl phthalate, and isopropyl tri(dioctyl pyrophosphate) titanate; preferably, the titanium source is tetraethyl phthalate, the solvent is octamethylcyclotetrasiloxane, and the mixing volume ratio is 1:4-1:10.

[0027] The present invention also provides oil-phase dispersible titanium dioxide nano sustained-release microcapsules prepared by the above preparation method.

[0028] The present invention also provides the application of the oil-phase dispersible titanium dioxide nano-sustained-release microcapsules, which are mixed in medical products or cosmetics for use, or used as a basic formula and prepared into medical products or cosmetics after adding auxiliary ingredients.

[0029] Compared with the prior art, the present invention has the following outstanding effects:

[0030] The dispersant designed by the present invention is composed of a hydrophobic organosilicon Si-O-Si main chain and hydrophilic PEG segments at both ends, resulting in the hydrophilic PEG segments at both ends of the dispersant being in the water droplets, and the middle organosilicon segment being dispersed in the continuous oil phase. When the titanate is hydrolyzed in the water droplets to form titanium oxide, part of the PEG segments at both ends of the dispersant are embedded in the titanium oxide powder, while the middle organosilicon segment is free on the outside, thereby improving the dispersibility in the oil phase. In addition, other emulsifiers added are also helpful in promoting the dispersibility in the oil phase.

[0031] The prior art is complex in the preparation of nano titanium oxide, and toxic and harmful substances are often required in the raw materials. The microcapsules of the inner core wrapped with substances have a large particle size (micrometer level), and the morphology is poor and irregular. The traditional method for preparing nano titanium oxide microcapsules is due to the water-in-oil preparation method and the large amount of hydrophilic Ti-OH in the nano titanium oxide, which leads to poor dispersibility in the oil phase, easy agglomeration, and difficult release of the core material; the preparation process in this technical solution is simple, low-cost and efficient, and the particle size can be controlled from less than 100nm to 300nm. The morphology is round and the powder is fine, so it is used for the skin without abrasive feeling, and it is non-toxic and harmless, with good oil dispersibility, not easy to agglomerate, and good stability. In addition, a variety of active substances can be wrapped inside and slowly released, which improves the efficacy of the active substances, reduces their toxicity, allergy and other risks, and gives higher ultraviolet absorption capacity, moisturizing, whitening, sterilization, disinfection and other functions to meet different needs, especially suitable for cosmetics, skin care products or pharmaceutical industries. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a scanning electron microscope image of the titanium dioxide nano-sustained-release microcapsule powder prepared in Example 4;

[0033] Figure 2 Schematic diagram of the oil dispersibility and sustained-release properties of the titanium dioxide nano-sustained-release microcapsule powder prepared in Example 4. DETAILED DESCRIPTION

[0034] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0035] Example 1

[0036] An oil-dispersible titanium dioxide nano-sustained-release microcapsule is prepared by the following method:

[0037] The above-mentioned object of the present invention is achieved by the following technical scheme, comprising the following steps:

[0038] (1) Preparation of dispersant

[0039] 10.0g (0.01mol) of polyethylene glycol monomethyl ether 1000 and 0.22g (0.01mol) of isophorone diisocyanate (IPDI) were placed in a three-necked flask containing 50g of ethyl acetate and stirred evenly. After heating to 40°C, 0.1g of organic zinc catalyst was added and stirred for 6h to obtain the reaction product IPDI-PEG. Subsequently, 5.0g (0.005mol) of amino-terminated silicone oil 1000 was added, and after heating to 60°C for 2h, the solvent was removed by rotary evaporation to obtain the dispersant PEG-Si-PEG.

[0040] (2) Preparation of oil phase continuous phase mixture

[0041] Add 0.1g of dispersant and 0.5g of oil phase surfactant into cyclohexane and stir evenly to obtain the oil phase continuous phase.

[0042] (3) Preparation of aqueous dispersed phase mixture

[0043] Add 0.5 g of glycerol, 0.5 g of sodium dodecyl sulfate and 0.5 g of acetic acid into 5.0 g of ultrapure water and stir evenly to obtain the aqueous dispersed phase.

[0044] (4) Preparation of oil-dispersible titanium dioxide nano-sustained-release microcapsules by water-in-oil emulsion method

[0045] At 25°C, the aqueous dispersed phase mixture was added to the oil continuous phase mixture and stirred vigorously at a rotation speed of 1000 rpm, and then an octamethylcyclotetrasiloxane solution containing 10% tetraethyl phthalate was added dropwise. After the addition was completed, the mixture was heated to 70°C and reacted overnight. After centrifugation, washing, drying and other steps, titanium dioxide nano sustained-release microcapsule powder was obtained.

[0046] Example 2

[0047] An oil-dispersible titanium dioxide nano-sustained-release microcapsule is prepared by the following method:

[0048] The above-mentioned object of the present invention is achieved by the following technical scheme, comprising the following steps:

[0049] (1) Preparation of dispersant

[0050] 6.0g (0.01mol) of polyethylene glycol monomethyl ether 600 and 0.22g (0.01mol) of isophorone diisocyanate (IPDI) were placed in a three-necked flask containing 40g of butyl acetate and stirred evenly. After heating to 45°C, 0.05g of organic zinc catalyst and 0.05g of organic bismuth catalyst were added and stirred for 8h to obtain the reaction product IPDI-PEG. Subsequently, 10.0g (0.005mol) of amino-terminated silicone oil 2000 was added, and after heating to 60°C for 2h, the solvent was removed by rotary evaporation to obtain the dispersant PEG-Si-PEG.

[0051] (2) Preparation of oil phase continuous phase mixture

[0052] Add 0.2g of dispersant and 0.8g of oil phase surfactant into toluene and stir evenly to obtain the oil phase continuous phase.

[0053] (3) Preparation of aqueous dispersed phase mixture

[0054] Add 1.0 g of erythritol, 1.0 g of sodium dodecyl sulfate and 0.1 g of acetic acid into 5.0 g of ultrapure water and stir evenly to obtain the aqueous dispersed phase.

[0055] (4) Preparation of titanium dioxide nano-sustained release microcapsule powder by water-in-oil emulsion method

[0056] At 30°C, the aqueous dispersed phase mixture was added to the oil continuous phase mixture and stirred vigorously at a rotation speed of 1200 rpm, and then a cyclohexane solution containing 20% ​​tetrabutyl phthalate was added dropwise. After the addition was completed, the mixture was heated to 80°C and reacted overnight. After centrifugation, washing, drying and other steps, titanium dioxide nano sustained-release microcapsule powder was obtained.

[0057] Example 3

[0058] An oil-dispersible titanium dioxide nano-sustained-release microcapsule is prepared by the following method:

[0059] The above-mentioned object of the present invention is achieved by the following technical scheme, comprising the following steps:

[0060] (1) Preparation of dispersant

[0061] 4.0g (0.01mol) of polyethylene glycol monomethyl ether 400 and 0.22g (0.01mol) of isophorone diisocyanate (IPDI) were placed in a three-necked flask containing 40g of butyl acetate and stirred evenly. After heating to 50°C, 0.05g of organic bismuth catalyst was added and stirred for 7h to obtain the reaction product IPDI-PEG. Subsequently, 7.5g (0.005mol) of amino-terminated silicone oil 1500 was added, and after heating to 55°C for 4h, the solvent was removed by rotary evaporation to obtain the dispersant PEG-Si-PEG.

[0062] (2) Preparation of oil phase continuous phase mixture

[0063] Add 0.1g of dispersant and 0.4g of oil phase surfactant into cyclotetrasiloxane and stir evenly to obtain the oil phase continuous phase.

[0064] (3) Preparation of aqueous dispersed phase mixture

[0065] Add 1.0g vitamin B6, 1.0g sodium dodecyl sulfate and 0.1g acetic acid to 5.0g ultrapure water and stir evenly to obtain the aqueous dispersed phase.

[0066] (4) Preparation of titanium dioxide nano-sustained release microcapsule powder by water-in-oil emulsion method

[0067] At 35°C, the aqueous dispersed phase mixture was added to the oil continuous phase mixture and stirred vigorously at a rotation speed of 1500 rpm, and then a hexamethyldisiloxane solution containing 15% tetrabutyl phthalate was added dropwise. After the addition was completed, the mixture was heated to 75°C and reacted overnight. After centrifugation, washing, drying and other steps, titanium dioxide nano sustained-release microcapsule powder was obtained.

[0068] Example 4

[0069] An oil-dispersible titanium dioxide nano-sustained-release microcapsule is prepared by the following method:

[0070] The above-mentioned object of the present invention is achieved by the following technical scheme, comprising the following steps:

[0071] (1) Preparation of dispersant

[0072] 10.0g (0.01mol) of polyethylene glycol monomethyl ether 1000 and 0.22g (0.01mol) of isophorone diisocyanate (IPDI) were placed in a three-necked flask containing 40g of ethyl acetate and stirred evenly. After heating to 60°C, 0.10g of organic zinc catalyst was added and stirred for 8h to obtain the reaction product IPDI-PEG. Subsequently, 5.0g (0.005mol) of amino-terminated silicone oil 1000 was added, and after heating to 55°C for 4h, the solvent was removed by rotary evaporation to obtain the dispersant PEG-Si-PEG.

[0073] (2) Preparation of oil phase continuous phase mixture

[0074] Add 0.2g of dispersant and 0.6g of oil phase surfactant into cyclotetrasiloxane and stir evenly to obtain the oil phase continuous phase.

[0075] (3) Preparation of aqueous dispersed phase mixture

[0076] Add 0.1 g of retinoic acid, 1.0 g of sodium dodecyl sulfate and 0.01 g of acetic acid into 5.0 g of ultrapure water and stir evenly to obtain the aqueous dispersed phase.

[0077] (4) Preparation of titanium dioxide sustained-release microcapsule powder by water-in-oil emulsion method

[0078] At 35°C, the aqueous dispersed phase mixture was added to the oil continuous phase mixture and stirred vigorously at a rotation speed of 1100 rpm, and then a hexamethyldisiloxane solution containing 20% ​​tetrabutyl phthalate was added dropwise. After the addition was completed, the mixture was heated to 80°C and reacted overnight. After centrifugation, washing, drying and other steps, titanium dioxide nano sustained-release microcapsule powder was obtained.

Claims

1. A method for preparing oil-dispersible titanium dioxide nano-sustained-release microcapsules, characterized in that: The method is prepared by the following four steps: (1) preparing a dispersant; (2) preparing an oil-phase continuous phase mixture; (3) preparing an aqueous dispersed phase mixture; (4) adding the aqueous dispersed phase mixture to the oil-phase continuous phase mixture, adding a titanium-containing dilution solution, and preparing titanium dioxide nano-sustained-release microcapsule powder by an oil-in-water emulsion method; the oil-phase continuous phase mixture is an oil-phase solvent in which a dispersant and an oil-phase surfactant are dissolved, and the dispersant is composed of a hydrophobic organosilicon Si-O-Si main chain and a hydrophilic PEG chain segment at both ends; The dispersant is prepared by the following reaction: 1) placing the same molar amount of polyethylene glycol monomethyl ether and isophorone diisocyanate in a solvent to react to obtain NCO-terminated PEG, 2) then reacting with half the molar amount of amino-terminated silicone oil or aminopropyl-terminated silicone oil of the NCO-terminated PEG to obtain the dispersant PEG-(Si-O-Si)-PEG; The aqueous dispersed phase mixture includes a water-soluble active substance, an aqueous surfactant and a water-soluble acid; The water-soluble active substance is at least one of glycerol, erythritol, polyethylene glycol, polypropylene glycol, retinoic acid, vitamin B6, PCA zinc, PCA sodium, L-valine, coated yeast fermentation product, sclerotium gum hydrogel, carnosine, blue copper peptide, acetyl tetrapeptide-2, snake venom peptide, L-carnitine, ergothioneine, dipotassium glycyrrhizate or sodium hyaluronate, and the mass ratio of the water-soluble active substance to water is 1-20%.

2. The method for preparing the oil-dispersible titanium dioxide nano-sustained-release microcapsules according to claim 1, characterized in that: The number of chain segments of the polyethylene glycol monomethyl ether is n=5-20; the number of chain segments of the amino-terminated silicone oil or amino-terminated propyl silicone oil is m=5-20.

3. The method for preparing the oil-dispersible titanium dioxide nano-sustained-release microcapsules according to claim 1, characterized in that: The oil phase surfactant is at least one of polyoxyethylene ether modified polysiloxane, sodium fatty acid, potassium lauryl sulfate, polyoxyethylene ether sodium lauryl phosphate, polyglycerol-4 isostearate or cetyl polyethylene glycol; the oil phase solvent is at least one of n-hexane, cyclohexane, octamethylcyclotetrasiloxane, hexamethyldisiloxane, n-octane, benzene or toluene; the mass ratio of the dispersant to the oil phase solvent is 0.1-5%; the mass ratio of the oil phase surfactant to the oil phase solvent is 0.1-5%.

4. The method for preparing the oil-dispersible titanium dioxide nano-sustained-release microcapsules according to claim 1, characterized in that: The aqueous phase surfactant is at least one of sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, dodecyltrimethylammonium chloride or dodecyltrimethylammonium bromide, and the mass ratio of the aqueous phase surfactant to water is 0.5-10%.

5. The method for preparing the oil-dispersible titanium dioxide nano-sustained-release microcapsules according to claim 1, characterized in that: The water-soluble acid is at least one of hydrochloric acid, citric acid, acetic acid or butyric acid, and the mass ratio of the water-soluble acid to water is 0-10%.

6. An oil-dispersible titanium dioxide nano-sustained-release microcapsule prepared by the preparation method according to any one of claims 1 to 5.

7. An application of the oil-dispersible titanium dioxide nano-sustained-release microcapsules according to claim 6, characterized in that: The oil-dispersible titanium dioxide nano-sustained-release microcapsules are used as a basic formula, and auxiliary ingredients are added to prepare medical products or cosmetics.

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