Film-forming composition comprising a surfactant or a surfactant and a salt as a whitening agent

Abstract

In order to provide a whitened capsule or film without using a white pigment such as titanium dioxide, a film, capsule and film-forming composition are provided, characterized in that they contain a film-forming polymer component and a whitening agent, the whitening agent comprising: a surfactant or a surfactant and a salt. The surfactant is characterized in that it is selected from polyol fatty acid esters, polyethylene glycol, polypropylene glycol, polyalkylene oxide derivatives, alkyl sulfate ester salts and saponins.

Description

Technical Field

[0001] The present invention relates to a film-forming composition for the purpose of preparing a pharmaceutical preparation, etc., and whitening is performed by a surfactant or by both a surfactant and a salt during the film-forming process. The present invention also relates to the use of the film-forming composition in the following fields: capsules and orodispersible films made using the film-forming composition; pharmaceutical preparations such as tablets and granules coated with the film-forming composition; film products, printing inks and other products.

[0002] In addition, the present invention relates to a sunscreen capsule made of a film-forming composition with a higher whitening level to provide a sunscreen effect against various lights including UV, thereby maintaining the stability of the active ingredient and the quality of the capsule for a long time, while the sunscreen capsule enables the active ingredient to dissolve quickly. Background Art

[0003] Various colors have been given to various preparations, including pharmaceutical products and health foods. Among others, some of the purposes of this coloring are: to make the preparation highly recognizable; to make the preparation beautiful in appearance; and to provide light-shielding ability to maintain quality. In particular, in the case of preparations containing light-sensitive ingredients, it is common practice to add a light-shielding agent to the capsule film or coating film so that a white light-shielding film can be made. In addition, as needed, various food colorants (blue No. 1, yellow No. 5, red No. 3, etc.) or various pigments such as ferric oxide, aluminum lake, etc. are added to freely give the desired color to the light-shielding film.

[0004] Various whitening agents are known for imparting light-shielding properties to target materials. Among such whitening agents, titanium dioxide is the most commonly used one. Titanium dioxide is a white pigment characterized by excellent whiteness, opacity and coloring power as well as extremely high chemical stability. Therefore, titanium dioxide has long been used in the field of pharmaceutical products and in the field of cosmetics.

[0005] The contents of some pharmaceuticals and cosmetics are destroyed by titanium dioxide, or their decomposition is accelerated by free radicals generated by titanium oxide due to ultraviolet rays. Quality maintenance of such products has always been a problem. In addition, irradiation with light may cause the film of the preparation coated with a film containing titanium dioxide to peel off and / or become powdery over time, making it difficult to keep the preparation in a coated state. As a result, the appearance of such preparations may be impaired. Another issue of concern is that light, oxygen and / or moisture may cause decomposition of the ingredients contained in the preparation.

[0006] So far, various coating materials for pharmaceutical preparations have been studied. One example of such a coating material is a coating material containing titanium dioxide mixed with a free radical scavenger (Patent Document 1: JP11-147819A). Other examples include titanium dioxide-free coating materials, such as opaque or translucent hard capsules made of gelatin containing natural calcium powder having an average particle size of 3 μm or less (Patent Document 2: JPH7-124462A) and a coating agent containing talc and / or barium sulfate (Patent Document 3: JP2002-212104A).

[0007] The above-mentioned inorganic pigments such as titanium dioxide are not soluble in water or organic solvents, which makes the preparation of the coating liquid more troublesome. The use of such inorganic pigments also has other problems, such as irregular surface of tablets and reduced film strength, both of which are caused by spraying of the suspension; problems may occur in the coating step of the manufacturing process (e.g., clogging of the nozzle, liquid dripping caused by solids accumulated at the nozzle tip, etc.).

[0008] Consideration of the above problems has led to research on light-shielding film compositions that do not contain titanium dioxide, such as compositions containing one or more substances selected from water-soluble calcium salts and a water-soluble cellulose-based polymer film base (Patent Document 4: WO2004 / 054619A).

[0009] [Prior art documents]

[0010] [Patent Document]

[0011] [Patent Document 1] JP11-147819A

[0012] [Patent Document 2] JPH7-124462A

[0013] [Patent Document 3] JP2002-212104A

[0014] [Patent Document 4] WO2004 / 054619A Summary of the invention

[0015] [Problems to be Solved by the Invention]

[0016] To date, although various alternative technologies that can replace the above titanium dioxide have been studied, titanium dioxide powder is still widely used as a sunscreen in various industrial fields including the food industry and the pharmaceutical industry. This is because the extremely fine particles and unparalleled opacity of titanium dioxide can provide sufficient shading ability even in small doses.

[0017] The International Agency for Research on Cancer (IARC) changed the carcinogenicity classification of titanium dioxide from Group 3 (not classifiable as carcinogenic to humans) to Group 2B (possibly carcinogenic to humans) in June 2006, concluding that the results of animal experiments conducted by inhalation and intratracheal injection of pigment-grade and ultrafine TiO2 provide sufficient evidence that TiO2 is carcinogenic to animals (Baan R, Staif K, Grosse Y, Secretan B, Ghissassi F, Cogliano V. On behalf of the World Health Organization International Agency for Research on Cancer Monograph Working Group (2006). Carcinogenicity of carbon black, titanium dioxide and talc [cited June 22, 2009], available at: http: / / oncology.thelancet.com.)

[0018] Therefore, the health food industry in particular has begun to avoid capsules containing titanium dioxide, and there is an increasing demand for the development of alternative sunscreens to titanium dioxide. As mentioned above, it is difficult to find any alternative to the excellent titanium dioxide sunscreen. At present, there is still no supply of any sunscreen capsules that do not contain titanium dioxide, and the health food industry has a high demand for this.

[0019] [Solution to the problem]

[0020] The inventors of the present invention have attempted to solve the above technical problems to develop an alternative shading method that can replace the use of titanium dioxide, especially what the health food industry desires. After several years of screening and experiments, the inventors found that, according to the type of film-forming polymer, the addition of a colorless surfactant or a combination of a colorless surfactant and a colorless salt can whiten the film during film formation and provide a beautiful appearance and shading ability comparable to the appearance and shading ability obtained by titanium dioxide dispersion. It is also found that the film formed in the above manner will not fade or change its color even in a hot and humid environment. In the case of using natural extract saponin as a surfactant, even saponin with colors such as light brown can be used, because the film may turn white in a state with this color. In addition, according to the whitening technology, the whitening level and the shading level can be adjusted by changing the amount of the added surfactant and / or the amount of the added salt. In addition, the whitening technology can be used in combination with other coloring materials, so that a variety of different colors can be provided as needed.

[0021] A variety of surfactants are registered as food additives and drug additives. Surfactants as food additives are used for the following purposes: emulsification, wetting / dispersion, viscosity control, lubrication, taste improvement, antibacterial, prevention of frozen food denaturation, prevention of chocolate fat blooming, inhibition of starch aging, foaming / defoaming, etc. Surfactants as drug additives are widely used as stabilizers, lubricants, solubilizers, alkalis, adhesives, suspending agents, coating agents, wetting agents, defoamers, emulsifiers, fillers, etc.

[0022] Likewise, salts (malates, succinates, citrates, phosphates, carbonates, acetates, etc.) can also be used as food additives, such as seasonings, pH adjusters, acidulants, anti-acidifiers, thickeners, stabilizers, chelating agents, dispersants, buffers, etc. Salts are also widely used as pharmaceutical additives, such as flavoring agents, stabilizers, buffers, binders, suspending agents, isotonic agents, pH adjusters, foaming agents, disintegrants, disintegration aids, soothing agents, solubilizers, solubilizing aids, etc.

[0023] These substances are usually colorless and transparent ingredients. As mentioned above, some naturally extracted saponins are colored and transparent ingredients with light brown or similar colors. The whitening of film-forming polymers during film formation by using surfactants alone or in combination with salts is a phenomenon that the inventors of the present invention have discovered for the first time ever, which is indeed a surprising discovery.

[0024] The present invention can provide a film or capsule with light-shielding properties in beautiful white or different colors. In particular, for the health food market, a safe and beautifully colored light-shielding capsule can be provided by combining with a colorant of natural origin such as Gardenia.

[0025] The technology of the present invention can be used for compositions containing hydroxypropyl methylcellulose (hydroxypropyl methylcellulose), gelatin and / or pullulan, which are conventional raw materials for capsule films. In addition, the technology of the present invention can also be used to color products other than capsule films, for example, coloring the band sealing of capsules, oral dispersible film preparations, coating materials for tablets and granules, edible film products, food inks, etc. In addition, the technology of the present invention can be used for films made by adding the technology of the present invention to a film-forming polymer solution other than those described above and then drying the resulting solution.

[0026] The whitening level can be adjusted according to the type and amount of the surfactant used and the type of salt used in combination with the surfactant. Thus, the whitening level can be adjusted from a white color that imparts excellent light-shielding properties to a white color that allows the user to see a dim, blurred image through the film.

[0027] The mechanism of whitening has not been revealed, but the inventors have found through the use of microscope observation that during the drying step, microcrystals are produced in the base agent film (base agent film), and white crystals grow from the microcrystals used as its seeds. Based on this observation, the inventors estimate that the whitening phenomenon is caused by the generation of microcrystals of surfactants in the base agent film, and salts contribute to the generation or growth of crystals. Another estimate is that the whitening phenomenon is caused by microcrystals of salts continuously generated in the substrate film during the drying step. Whether salt is needed for the whitening phenomenon to occur seems to depend on the physical properties or the type of the film base agent.

[0028] Even though the film can be whitened using sodium chloride or potassium chloride, microcrystals of these substances are generated on the surface of the film. Therefore, the microcrystals are easily scraped off the film, depriving the film of its whiteness. In this sense, the whitening caused by the use of sodium chloride or potassium chloride does not match the present invention, in which the microcrystals appear in the film and are not easily scraped off the film, thereby causing no color loss and maintaining the film white.

[0029] The polymer base material from which the aqueous solution to be used in the present invention can be produced can be the base material for capsules that can be used for pharmaceutical products and foods. Alternatively, the base material for coatings for pharmaceutical and food preparations can be used for the same purpose. Cellulose derivatives, gelatin and pullulan are some examples of such ingredients.

[0030] Various types of hydroxypropyl methylcellulose (hydroxypropyl methylcellulose = HPMC) are some preferred cellulose derivatives. Specifically, HPMC2910 (containing about 29% methoxyl groups and about 10% hydroxypropoxyl groups), HPMC2906 (containing about 29% methoxyl groups and about 6% hydroxypropoxyl groups) and HPMC2208 (containing about 22% methoxyl groups and about 8% hydroxypropoxyl groups) are some preferred HPMCs.

[0031] Each of these components may be used alone or in combination.

[0032] The surfactant used in the present invention is selected from fatty acid esters of polyols, polyethylene glycol, polypropylene glycol, polyalkylene oxide derivatives, alkyl sulfate ester salts, saponin and the like.

[0033] Some examples of the fatty acid esters of the above-mentioned polyhydric alcohols are sucrose fatty acid esters, sorbitan fatty acid esters, glycerol fatty acid esters, polyoxysorbitan fatty acid esters (e.g., sucrose monolaurate, sucrose palmitate, sorbitan monolaurate and polysorbate 80 (polyoxyethylene sorbitan monooleate). An example of the above-mentioned polyethylene glycol is polyethylene glycol 4000 (macrogol 4000). Some examples of the above-mentioned polyalkylene oxide derivatives are polyoxyethylene polyoxypropylene glycol, and polyoxyethylene alkyl ethers, polyoxyethylene fatty acid esters (e.g., polyoxyethylene (105) polyoxypropylene (5) glycol and polyoxyethylene (160) polyoxypropylene (30) glycol). An example of the alkyl sulfate ester salt is sodium lauryl sulfate.

[0034] The term "saponin" is a common name for glycosides of steroids or triterpenes (terpenoid saponins or steroid saponins). Although triterpenoid saponins are widely distributed in the plant kingdom, they are found not only in plants but also in echinoderms such as sea cucumbers and star fish. The saponins used as surfactants in the present invention are saponins of any kind, regardless of where their raw materials come from, i.e., whether the raw material of a particular saponin is of animal or plant origin, or which animal / plant origin. Some examples of preferred saponins are quillaja saponin, ginsenosides, soybean saponins, sophora saponins, tea seed saponins, beet saponins, yucca saponin and glycyrrhizin.

[0035] Each of these surfactants can be used alone or in combination. Changing the amount of surfactant added can change the whiteness.

[0036] Typically, for a total of 100 parts by weight (on a dry weight basis) of a film-forming polymer (e.g., a polymer selected from a cellulose derivative, gelatin, pullulan, etc.), the total amount of surfactant to be added can be 0.5 to 30 parts by weight, 0.7 to 30 parts by weight, or 1.0 to 30 parts by weight. Preferably, the total amount of surfactant to be added can be 0.5 to 15 parts by weight, 0.7 to 15 parts by weight, or 1.0 to 15 parts by weight. The amount of surfactant within the above range can be used to change the whiteness. The use of more than 30 parts by weight of a surfactant produces a film that is more brittle and more easily broken. On the contrary, the use of a surfactant in an amount less than 0.5 parts by weight may result in no whitening phenomenon, or may result in a whitening phenomenon of a very light color, which makes the shading effect less than expected.

[0037] The salt used in the present invention is a sodium salt and / or a potassium salt and / or an ammonium salt. Specifically, sodium malate, sodium succinate, sodium citrate, sodium polyphosphate, sodium bicarbonate (baking soda), potassium acetate, potassium carbonate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, disodium hydrogen phosphate, sodium dihydrogen phosphate, dehydrated sodium pyrophosphate and ammonium chloride are some examples of salts used in the present invention. Each of these salts can be used alone or in combination with the others. Changing the amount of salt added can change the whiteness.

[0038] Typically, a total amount of 0.5 to 30 parts by weight of salt can modify whiteness for a total of 100 parts by weight (on a dry weight basis) of film-forming polymer (eg, a polymer selected from cellulose derivatives, gelatin, pullulan, etc.).

[0039] In the case of using the film-forming composition of the present invention to make hard capsules, a gelling agent is used to prepare an impregnation solution (capsule impregnation solution), examples of which include carrageenan, gellan gum, agar, pectin, gelatin, xanthan gum, locust bean gum, Curdlan, alginic acid, sodium alginate, guar gum, gum arabic, glucomannan, tamarind seed gum, furcellan, tara gum and karaya gum. However, these are not the only possible gelling agents available in this case. In addition to the additives mentioned so far, some other substances may also be added if necessary. Some examples of such other substances include gelling aids, plasticizers, pH regulators, sweeteners, acidulants, preservatives and flavoring agents. The amount of the gelling agent can be 0-10%, preferably 0-5%.

[0040] Some examples of plasticizers include triethyl citrate, glycerol, propylene glycol, D-mannitol, D-sorbitol, trehalose, polyethylene glycol, triacetin and phthalate. Some examples of pH adjusters include phosphoric acid, hydrochloric acid, citric acid, glycine, gluconic acid, succinic acid, acetic acid, tartaric acid, lactic acid, fumaric acid, boric acid, maleic acid, sulfuric acid, malic acid, ammonia, hydroxides, amines and their salts.

[0041] The film-forming composition of the present invention may contain a colorant other than white. For example, a black or colored colorant may be mixed into the film-forming composition of the present invention. The above-mentioned colored colors are all colors except black, white and gray.

[0042] In the case where coloring agents are used for coating purposes in pharmaceutical preparations or health food preparations, any colored coloring agents can be used as long as these coloring agents can be used in the field of medicine and food. Some examples of such coloring agents include tar colorant lakes, water-soluble tar colorants and natural colorants.

[0043] Some specific examples of tar-based colorant lakes include: Food Blue No. 1 aluminum lake, Food Blue 2 aluminum lake, Food Red 2 aluminum lake, Food Red 3 aluminum lake, Food Red 40 aluminum lake, Food Yellow 4 aluminum lake, Food Yellow 5 aluminum lake, and Food Green 3 aluminum lake. Some specific examples of water-soluble tar-based colorants include Food Blue 1, Food Blue 2, Food Yellow 4, Food Yellow 5, Food Red 2, Food Red 3, Food Red 40, Food Red 102, Food Red 104, Food Red 105, Food Red 106, and Food Green 3. Some specific examples of natural colorants include caramel colorant, gardenia colorant, safflower colorant, turmeric colorant, monuscus colorant, carotene, beet red, tomato colorant, carmine colorant, shellac colorant, perilla colorant, red cabbage colorant, red carrot colorant, red rice colorant, red bean colorant, purple potato colorant, purple yam colorant, purple corn colorant, grape peel colorant, various berry colorants, grape juice colorant, Haematococcus pluvialis colorant, red pepper colorant, Annatto colorant, spirulina colorant, cocoa colorant, persimmon colorant, sorghum colorant, onion colorant, tamarind colorant, green tea powder, squid ink, Phaffia colorant, pecan kernel colorant, rutin, logwood colorant, saffron colorant, Lonicera gracilipes Colorant), colorant of various teas, laver colorant, hibiscus colorant, paprika, plum colorant, cherry colorant, chicory colorant, fruit juice, vegetable juice, red currant colorant, marigold colorant, chlorella powder, sodium norannatto, sodium iron chlorophyllin, sodium copper chlorophyllin, copper chlorophyllin, naked barley green leaf extract powder, naked barley green leaf juice dry powder and naked barley green leaf extract. Some specific examples of other color colorants include methylrosanilinniumchloride, carmine, photosensitizer 201, permanent violet RL (Permanent violet-R-special), methylene blue, riboflavin tetrabutyrate, riboflavin, riboflavin sodium phosphate, sesquioxide, sesquioxide yellow iron and black iron oxide. Pearlescent pigments made of pigments such as fine powder of fish scale guanine, pearl layer of shellfish, mica, silica, etc. can be used in an appropriate amount to give pearl luster.

[0044] Some specific examples of plasticizers for use in the film-forming composition of the present invention include triethyl citrate, glycerin, sesame oil, D-sorbitol / sorbitan liquid, vegetable oil, medium chain fatty acid triglyceride, triacetin, castor oil, dioctyl phthalate, phytosterol, propylene glycol, polysorbate and polyethylene glycol. Some specific examples of sweeteners include aspartame, acesulfame potassium, sweet hydrangea leaf powder, liquid sugar, fructose, glucose, reduced maltose syrup, glycyrrhizin, xylitol, glycine, glycerin, glycyrrhizate, brown sugar, saccharin, sucralose, stevia extract, purified sucrose, purified honey, D-sorbitol, maltitol, maltose and D-mannitol.

[0045] In addition, some specific examples of acidulants include adipic acid, itaconic acid, citric acid, trisodium citrate, glucono delta lactone, gluconic acid, potassium gluconate, sodium gluconate, succinic acid, monosodium succinate, disodium succinate, sodium acetate, tartaric acid, lactic acid, sodium lactate, acetic acid, phytic acid, fumaric acid, malic acid and phosphoric acid. Some specific examples of preservatives include benzoic acid, sodium benzoate, paraoxybenzoic acid esters, sodium sulfite, sodium thiosulfate, sodium pyrosulfite, potassium pyrosulfite, propionic acid, calcium propionate, sodium propionate, Styrax japonica extract, Artemisia capillaris extract, protamine extract, sorbic acid compounds, sodium dehydroacetate, nisin, sulfur dioxide, pectin degradation products and ε-polylysine.

[0046] In addition, some specific examples of flavoring agents include various essences, spices, peppermint, menthol, Japanese mint, cinnamon, anise and camphor.

[0047] The hard capsule according to the present invention can be manufactured by the method for manufacturing ordinary capsules. As an example, the situation of manufacturing gelatin capsules will be described below. First, 20 to 40 parts by weight of gelatin are uniformly dissolved in hot water to prepare a light yellow transparent impregnation solution derived from the color of gelatin. At this stage, the surfactant (and salt) of the present invention used as a whitening agent is added to the impregnation solution. After adjusting the viscosity of the resulting impregnation solution, a stainless steel molding pin is immersed in the impregnation solution. The pin is lifted out of the impregnation solution, and the impregnation solution on the lifted pin is immediately cooled to become a gel with a certain thickness, which is suitable for capsule use. Then, the gel thus obtained is dried, and its unnecessary parts are cut off to produce a main body and a lid. Then, a capsule is manufactured by assembling a pair of main bodies and lids together.

[0048] It is preferred to select the most suitable surfactant or the most suitable combination of surfactant and salt according to the type of polymer that can be dissolved to form the aqueous solution. For HPMC, some examples of combinations that produce particularly high whitening levels and particularly excellent light-shielding ability include the following combinations: polyoxyethylene (105) polyoxypropylene (5) glycol and sodium malate; polyoxyethylene (105) polyoxypropylene (5) glycol and sodium citrate; polyoxyethylene (105) polyoxypropylene (5) glycol and sodium succinate; polyoxyethylene (105) polyoxypropylene (5) glycol and sodium bicarbonate (baking soda); sucrose monolaurate and sodium malate; sucrose monolaurate and potassium carbonate; sucrose monolaurate and dipotassium hydrogen phosphate; sucrose monolaurate and potassium dihydrogen phosphate; sucrose monolaurate Ester and disodium hydrogen phosphate; sucrose monolaurate and sodium dihydrogen phosphate; sucrose monolaurate and sodium bicarbonate (baking soda); sucrose monolaurate and sodium citrate; sucrose monolaurate and sodium succinate; polyoxyethylene (160) polyoxypropylene (30) glycol and sodium malate; polyoxyethylene (160) polyoxypropylene (30) glycol and sodium succinate; polyoxyethylene (160) polyoxypropylene (30) glycol and sodium citrate; sucrose palmitate and sodium malate; sucrose palmitate and sodium succinate; polyethylene glycol 4000 and sodium malate; polysorbate 80 and sodium malate; and quila saponin and sodium succinate. For gelatin, some examples of such combinations include the following combinations: sucrose monolaurate and sodium polyphosphate; sucrose monolaurate and disodium hydrogen phosphate; sucrose monolaurate and dehydrated sodium pyrophosphate; polyoxyethylene (105) polyoxypropylene (5) glycol and sodium polyphosphate; quila saponin and sodium polyphosphate; and quila saponin and dehydrated sodium pyrophosphate. Some examples of pullulan include: polyoxyethylene (105) polyoxypropylene (5) glycol alone, and a combination of polyoxyethylene (105) polyoxypropylene (5) glycol and sodium bicarbonate (baking soda), etc.

[0049] Among those mentioned above, particularly preferred combinations for HPMC include: polyoxyethylene (105) polyoxypropylene (5) glycol and sodium malate; polyoxyethylene (105) polyoxypropylene (5) glycol and sodium citrate; sucrose monolaurate and sodium malate; sucrose monolaurate and sodium citrate; sucrose monolaurate and dipotassium hydrogen phosphate; sucrose monolaurate and disodium hydrogen phosphate; sucrose monolaurate and sodium dihydrogen phosphate; sucrose monolaurate and potassium carbonate; sucrose monolaurate and potassium dihydrogen phosphate; Sucrose monolaurate and sodium bicarbonate (baking soda); sucrose monolaurate and sodium succinate; polyoxyethylene (160) polyoxypropylene (30) glycol and sodium malate; polyoxyethylene (160) polyoxypropylene (30) glycol and sodium succinate; polyoxyethylene (160) polyoxypropylene (30) glycol and sodium citrate; sucrose palmitate and sodium malate; sucrose palmitate and sodium succinate; polyethylene glycol 4000 and sodium malate; polysorbate 80 and sodium malate; and quila saponin and sodium succinate. In the case of gelatin, particularly preferred combinations include: sucrose monolaurate and sodium polyphosphate; sucrose monolaurate and disodium hydrogen phosphate; sucrose monolaurate and dehydrated sodium pyrophosphate; polyoxyethylene (105) polyoxypropylene (5) glycol and sodium polyphosphate; quila saponin and sodium polyphosphate; and quila saponin and dehydrated sodium pyrophosphate. In the case of pullulan, it is particularly preferred to use polyoxyethylene (105) polyoxypropylene (5) glycol alone.

[0050] The film is formed by the following steps: first dissolving a specific film base agent in hot or cold water suitable for dissolving the specific film base agent; then adding the selected surfactant and (if necessary) the selected salt to the solution, optionally adding necessary additives according to the specific purpose, thereby obtaining the target aqueous solution; then drying the solution by heating or natural drying. The temperature conditions during drying may affect the whitening level. Therefore, it is desirable to select drying conditions suitable for the specific combination of base material, surfactant and salt.

[0051] Some examples of drying conditions include high temperature drying at a temperature of 60° C. for 15 minutes in an oven, and natural drying at room temperature.

[0052] Beneficial effects of the present invention

[0053] The present invention provides a technology for whitening a film without using titanium dioxide, which is involved in possible carcinogenicity. Instead, the technology uses ingredients that are harmless to the human body, in particular surfactants, or a combination of surfactants and salts, which have been used in the field of pharmaceutical products and foods to date. The degree of whitening is adjustable, ranging from a level where the whitened film still allows a blurred image to be seen through the film to a level where the light-shielding effect of the whitening is comparable to that obtained using titanium dioxide. Therefore, the technology can be preferably used for general coloring purposes and for the preparation of pharmaceutical products and foods that are unstable to light.

[0054] In addition, the film produced by using the film-forming composition of the present invention does not suffer from the removal of its white color, which would otherwise be caused by rubbing the film. The film produced by using the film-forming composition of the present invention has excellent solubility and can form a white film that is stable for a long time. In addition, if used together with a colorant of a different color, the film-forming composition of the present invention can provide a colored opaque film.

[0055] Therefore, the film-forming composition of the present invention, if used in combination with a naturally derived colorant, such as a gardenia colorant, can provide safe and aesthetically pleasing colored light-blocking capsules and films, particularly for the health food market.

[0056] [Brief Description of the Drawings]

[0057] Figure 1 A shows the light-shielding effect of a white film produced by using a whitening agent comprising 2.5 parts by weight of sodium malate and 2.5 parts by weight of polyoxyethylene (105) polyoxypropylene (5) glycol and 100 parts by weight of hydroxypropyl methylcellulose; and the light-shielding effect of a film produced without using a whitening agent. Figure 1 B shows the Y-axis scale with different Figure 1 A's curve graph.

[0058] Figure 2 A shows the light-shielding effect of a white film produced using a whitening agent containing 2.5 parts by weight of sodium malate and 2.5 parts by weight of sucrose monolaurate and 100 parts by weight of hydroxypropylmethylcellulose; and the light-shielding effect of a film produced without using a whitening agent. Figure 2 B shows the Y-axis scale with different Figure 1 A's curve graph.

[0059] Figure 3The dissolution rate of a white film made using a whitening agent containing 1.25 parts by weight of sodium malate and 1.25 parts by weight of polyoxyethylene (105) polyoxypropylene (5) glycol and 100 parts by weight of hydroxypropyl methylcellulose is shown, as well as the dissolution rate of a film without a whitening agent. The dissolution rate of each film measured after 9 minutes and 15 minutes is shown.

[0060] [Test Example]

[0061] Whitening during film formation was tested by preparing test samples containing various film-forming polymers and surfactant alone or preparing test samples containing various film-forming polymers and surfactants and salts.

[0062] In the table, the numerical values ​​of the respective salts and surfactants are their respective parts by weight, based on 100 parts by weight of the membrane base material (dry weight).

[0063] The white ratio and white depth are determined by visual observation using the following criteria. Note that the term "white ratio" is the ratio of the white area independent of the "white depth". The term "white depth" indicates the white depth of each portion that appears white.

[0064] White ratio: α = 100% to 90%, β = 90% to 80%, γ = 80% to 70%, δ = 70%

[0065] or lower, ε=0%

[0066] White depth: α = pure white, β = white, γ = translucent, δ = dark white, ε = transparent

[0067] The stability of the films was evaluated by observing the whiteness level after storage for 6 weeks at a temperature of 40°C and a relative humidity of 75%.

[0068] The membranes were produced by methods A, B and C below.

[0069] Method A: Pour the room temperature gel onto a glass plate heated in an oven at 105°C (pour the glass plate immediately after taking it out of the 105°C oven). Immediately dry the gel and the glass plate in an oven at 60°C for 15 minutes.

[0070] Method B: Pour the room temperature gel onto a glass plate heated in an oven at 105°C (note that the gel was poured onto the glass plate after the glass plate had cooled to about 70°C (temperature measured with a radiation thermometer)). Immediately dry the gel and the glass plate in an oven at 60°C for 15 minutes.

[0071] Method C: The gel is dried naturally indoors.

[0072] [Form 1]

[0073] Table 1

[0074] Example using HPMC2910 and PEP101

[0075] prescription 1-1 1-2 1-3 1-4 1-5 1-6 1-7 1-8 1-9 1-10 1-11 HPMC2910 100 100 100 100 100 100 100 100 100 100 100 Sodium Malate 2.5 3.75 1.25 10 10 1.25 Disodium succinate 2.5 Trisodium Citrate 2.5 Sodium Polyphosphate 2.5 Sodium bicarbonate 2.5 PEP101 2.5 2.5 2.5 2.5 2.5 2.5 1.25 3.75 10 10 1.25 Additive dosage 5 5 5 5 5 2.5 5 5 20 20 2.5 White ratio α α α α β δ α β α α α White Depth α β α γ β γ α β α γ β stability No change No change No change No change White Deepen - No change No change No change - - Manufacturing method A A A A A A A A A C A

[0076] HPMC used in the tests of this table is a product of Shin-Etsu Chemical Co., Ltd.

[0077] Table 1 shows the test results by using HPMC2910 as a film base material and using polyoxyethylene (105) polyoxypropylene (5) glycol (PEP101) as a surfactant.

[0078] Even when polyoxyethylene (105) polyoxypropylene (5) glycol is used alone, some whitening effect is observed, but a greater whitening effect is more likely to be obtained in the presence of salt. In addition, the film produced by method A has a darker white color than the corresponding film produced by method C.

[0079] [Table 2]

[0080] Table 2. Examples of using HPMC2910 and sucrose monolaurate

[0081]

[0082] Table 2 shows the test results by using HPMC2910 as a membrane base material and sucrose monolaurate as a surfactant.

[0083] Sucrose monolaurate alone did not result in whitening. A greater whitening effect was obtained in the presence of salt. In addition, the films made by method A had a wider white area and a darker white color than the corresponding films made by method C.

[0084] [Table 3]

[0085] Table 3. Examples of using HPMC2910 and quillaja saponin

[0086] prescription 3-1 3-2 3-3 3-4 3-5 HPMC2910 100 100 100 100 100 Sodium Malate 5 Trisodium Citrate 2.5 Disodium hydrogen phosphate 2.5 Disodium succinate 2.5 Sodium bicarbonate 2.5 Quilaea saponins 2.5 2.5 2.5 2.5 2.5 Additive dosage 5 7.5 5 5 5 White ratio δ γ δ α γ White Depth δ β γ α β Manufacturing method A A A A A

[0087] Table 3 shows the test results by using HPMC2910 as the membrane base material and Quilae saponin as the surfactant.

[0088] Quila saponin is a natural extract, and its solution is a transparent solution with a light brown or similar color. The use of Quila saponin can produce a light brownish white color. The use of 2.5 parts by weight of Quila saponin and 2.5 parts by weight of disodium succinate makes the film have an excellent white ratio and an excellent white depth.

[0089] [Table 4]

[0090] Table 4. Examples using HPMC2208 or mixed HPMC (HPMC2906+HPMC2910) together with sucrose monolaurate or PEP-101

[0091]

[0092] Table 4 shows the test results by using HPMC2208 or a mixture of HPMC2910 and HPMC2906 as the membrane base material together with sucrose monolaurate or polyoxyethylene (105) polyoxypropylene (5) glycol (PEP101) as the surfactant and the corresponding salt.

[0093] For both base materials, the films formed by Method A exhibited a wider white area and a darker white color than the corresponding films formed by Method C.

[0094] [Table 5]

[0095] Table 5 Examples of using HPMC2910 and various brighteners and drying method A

[0096] prescription 5-1 5-2 5-3 5-4 5-5 5-6 5-7 5-8 5-9 5-10 HPMC2910 100 100 100 100 100 100 100 100 100 100 Sodium malate 2.5 2.5 2.5 2.5 Disodium succinate 2.5 2.5 Trisodium Citrate 2.5 Sodium Polyphosphate 2.5 Sucrose Palmitate 2.5 2.5 2.5 Polysorbate 80 2.5 PLONON 188P 2.5 2.5 2.5 2.5 Polyethylene glycol 4000 2.5 2.5 Additive dosage 5 5 5 5 5 5 5 2.5 2.5 5 White ratio α α α γ α α α ε ε α White Depth α α α β α α α ε ε α Manufacturing method A A A A A A A A A A

[0097] Table 5 shows the test results of using HPMC2910 as the membrane base material together with ingredients selected from sucrose palmitate, polyoxyethylene sorbitan monooleate (polysorbate 80), polyoxyethylene (160) polyoxypropylene (30) glycol (PLONON188P) and polyethylene glycol 4000 (macrogol4000) as surfactants.

[0098] [Table 6]

[0099] Table 6. Examples using HPMC2910 and sucrose monolaurate or PEP101 and drying method B

[0100] prescription 6-1 6-2 6-3 6-4 6-5 6-6 6-7 6-8 6-9 6-10 HPMC2910 100 100 100 100 100 100 100 100 100 100 Sodium Malate 2.5 1.25 2.5 1.25 1.25 0.625 1.25 0.625 0 0 Sucrose Monolaurate 2.5 3.75 1.25 1.875 1 25 PEP101 2.5 3.75 1.25 1.875 1.25 Additive dosage 5 5 5 5 2.5 2.5 2.5 2.5 1.25 1.25 White ratio β γ β δ δ δ δ δ ε ε White Depth α β α δ γ δ δ δ ε ε Manufacturing method B B B B B B B B B B

[0101] Table 6 shows the test results by using HPMC2910 as the film base material and using sucrose monolaurate or polyoxyethylene (105) polyoxypropylene (5) glycol (PEP101) as the surfactant and using the film forming method B. When the film formed by the method B and its corresponding film formed by the method A are compared (see Tables 1 and 2), the method A tends to make the whitening level of the film higher than that of the method B.

[0102] [Table 7]

[0103] Table 7. Examples using HPMC2910 and sodium lauryl sulfate or sorbitan monolaurate

[0104]

[0105] Table 7 shows the test results by using various HPMCs as the film base material and using alkyl sulfate ester salt (sodium lauryl sulfate or sorbitan monolaurate) as the surfactant and the film forming method A.

[0106] [Table 8]

[0107] Table 8. Examples using HPMC2208 or mixed HPMC (HPMC2910+HPMC2208) and sucrose monolaurate and drying method B

[0108]

[0109] Table 8 shows the test results by using HPMC2208 alone or a mixture of HPMC2910 and HPMC2208 as a film base material and sucrose monolaurate as a surfactant and film formation method B. The use of a mixture of HPMC2910 and HPMC2208, 5 parts by weight of sodium malate and 1.25 parts by weight of sucrose monolaurate resulted in a film having an excellent white ratio and excellent white depth.

[0110] [Table 9]

[0111] Table 9. Examples using pullulan

[0112]

[0113] Table 9 shows the test results by using pullulan as the membrane base material and using polyoxyethylene (105) polyoxypropylene (5) glycol (PEP101) or sucrose monolaurate as the surfactant. In the case of this base, the embodiment using polyoxyethylene (105) polyoxypropylene (5) glycol (PEP101) alone and without adding salt at all can allow the whitening phenomenon to occur. The use of salt even tends to reduce rather than increase the whitening level. It has been found that the use of sucrose monolaurate darkens the whitening, whether it is used alone or in combination with any salt.

[0114] [Table 10]

[0115] Table 10 Examples using gelatin

[0116]

[0117] Table 10 shows the results of testing by using gelatin as a film base material, together with polyoxyethylene (105) polyoxypropylene (5) glycol (PEP101), sucrose monolaurate or quila saponin as a surfactant. In the case of this base agent, it is observed that whitening is allowed to occur when polyoxyethylene (105) polyoxypropylene (5) glycol (PEP101) or sucrose monolaurate is used alone without adding salt (see prescriptions 92 and 93). Any combination of sucrose monolaurate and polyoxyethylene (105) polyoxypropylene (5) glycol (PEP101) with any one of sodium polyphosphate, disodium hydrogen phosphate and dehydrated sodium pyrophosphate tends to enhance whiteness. The table also shows that the use of potassium salt also has a whitening effect. In the case of using 7.3 parts by weight of quila saponin and 5 parts by weight of sodium polyphosphate or 5 parts by weight of dehydrated sodium pyrophosphate, the film has an excellent white ratio and an excellent white depth.

[0118] [Example]

[0119] Some embodiments of the present invention will be provided below to specifically describe the present invention, but the following embodiments are not the only possible forms of the present invention.

[0120] Example 1: Example 1 using hydroxypropyl methylcellulose as a membrane base material

[0121] A film-forming aqueous solution was prepared by adding an aqueous solution containing 2.5 parts by weight of sodium malate and 2.5 parts by weight of polyoxyethylene (105) polyoxypropylene (5) glycol (wherein the amount of hydroxypropyl methylcellulose was 100 parts by weight) to an approximately 20% hydroxypropyl methylcellulose solution. The resulting solution was poured onto a glass plate heated to approximately 105° C., and then the glass plate and the solution thereon were heated at 60° C. for 15 minutes. Thus, a white film was formed.

[0122] Example 2: Example 2 using hydroxypropyl methylcellulose as a membrane base material

[0123] A film-forming aqueous solution was prepared by adding an aqueous solution containing 2.5 parts by weight of dipotassium hydrogen phosphate and 2.5 parts by weight of sucrose monolaurate to a solution of about 20% hydroxypropyl methylcellulose (mixed HPMC of HPMC2906 and HPMC2910) (wherein the amount of hydroxypropyl methylcellulose was 100 parts by weight). The resulting solution was poured onto a glass plate heated to about 105° C., and then the glass plate and the solution thereon were heated at 60° C. for 15 minutes. Thus, a white film was formed.

[0124] Similar films were formed by replacing the salts added in the above method with disodium hydrogen phosphate, sodium dihydrogen phosphate, potassium carbonate, potassium dihydrogen phosphate, and sodium bicarbonate.

[0125] Each of these films received an "alpha" rating on white scale and white depth.

[0126] Example 3: Example using pullulan as a membrane base material

[0127] A film-forming aqueous solution was prepared by adding an aqueous solution containing 2.5 parts by weight of polyoxyethylene (105) polyoxypropylene (5) glycol (wherein the amount of pullulan was 100 parts by weight) to an approximately 22% pullulan solution. The resulting solution was poured onto a glass plate to which a release agent was applied and heated to approximately 60° C., and then dried at room temperature. A white film was thereby formed.

[0128] Example 4: Example using gelatin as a membrane base material

[0129] A film-forming aqueous solution was prepared by adding an aqueous solution containing 5 parts by weight of sodium polyphosphate and 5 parts by weight of sucrose monolaurate to an approximately 34% gelatin solution (wherein the amount of gelatin was 100 parts by weight). The resulting solution was poured onto a glass plate to which a release agent was applied and heated to approximately 60° C., and then dried at room temperature. Thus, a white film was formed.

[0130] Example 5: Light blocking property (film transmittance)

[0131] With respect to the white film produced according to the method of Example 1, the light shielding effect was evaluated.

[0132] Each test sample is a film having a thickness of 100±10 μm, and the transmittance of each test sample for light having a wavelength in the range of 1100 nm to 190 nm is measured using a spectrophotometer. The test results confirm that the transmittance is reduced by forming a white film, and that the white film has a light shielding effect.

[0133] Figure 1A and 1B show the measured transmittance of a film formed by: adding an aqueous solution containing 2.5 parts by weight of sodium malate and 2.5 parts by weight of polyoxyethylene (105) polyoxypropylene (5) glycol (wherein the amount of hydroxypropyl methylcellulose is 100 parts by weight) to an approximately 20% hydroxypropyl methylcellulose solution, then pouring the resulting solution onto a glass plate heated to approximately 105°C, and heating the plate solution at 60°C for 15 minutes to form a white film; the measured transmittance of a film formed by pouring an approximately 20% hydroxypropyl methylcellulose solution onto a glass plate heated to approximately 105°C and heating the glass plate and the solution thereon at 60°C for 15 minutes; and the measured transmittance of a film manufactured by the above manufacturing method except that no whitening agent is used at all. A white film as a general control product using titanium dioxide as a sunscreen was formed by adding a suspension containing 2 parts by weight of titanium dioxide to an approximately 20% hydroxypropyl methylcellulose solution (wherein the amount of hydroxypropyl methylcellulose was 100 parts by weight), then pouring the resulting solution onto a glass plate heated to approximately 105° C., and heating the glass plate and the solution thereon at 60° C. for 15 minutes.

[0134] Figure 2 A and 2B show the measured transmittance of a film formed by adding an aqueous solution containing 2.5 parts by weight of sodium malate and 2.5 parts by weight of sucrose monolaurate to an approximately 20% hydroxypropyl methylcellulose solution (wherein the amount of hydroxypropyl methylcellulose is 100 parts by weight), then pouring the resulting solution onto a glass plate heated to approximately 105°C, and heating the glass plate and the solution thereon at 60°C for 15 minutes; and the measured transmittance of a film manufactured by the above manufacturing method except that no whitening agent is used at all. A white film as a general control product using titanium dioxide as a sunscreen is formed by adding a suspension containing 2 parts by weight of titanium dioxide to an approximately 20% hydroxypropyl methylcellulose solution (wherein the amount of hydroxypropyl methylcellulose is 100 parts by weight), then pouring the resulting solution onto a glass plate heated to approximately 105°C, and heating the glass plate and the solution thereon at 60°C for 15 minutes.

[0135] Example 6: Film solubility

[0136] A film-forming aqueous solution was prepared by adding an aqueous solution containing 1.25 parts by weight of sodium malate and 1.25 parts by weight of polyoxyethylene (105) polyoxypropylene (5) glycol to an approximately 20% solution of hydroxypropyl methylcellulose (the amount of hydroxypropyl methylcellulose being 100 parts by weight). The resulting solution was poured onto a glass plate heated to approximately 105°C, and the glass plate and the solution thereon were then heated at 60°C for 15 minutes. A white film was thereby formed. The solubility of the white film in water was evaluated. Each test sample was a film having a thickness of 100±10 μm, and the test method employed was a paddle method selected from the solubility test methods specified in the Japanese Pharmacopoeia. The solubility of hydroxypropyl methylcellulose was evaluated under the following conditions.

[0137] Test solution: deionized water, test solution volume: 400mL,

[0138] Test solution temperature: 37±0.5℃

[0139] Paddle speed: 50rpm

[0140] The test results confirmed that dissolution improved after the solubility test was initiated (see Figure 3 A and 3B).

[0141] Example 7: Film colorability

[0142] A film-forming aqueous solution is prepared by adding an aqueous solution containing 1.25 parts by weight of sodium malate, 5 parts by weight of sucrose monolaurate and 1 part by weight of Yellow No. 5 to a solution of about 20% hydroxypropyl methylcellulose (a mixture of HPMC2910 and HPMC2208) (the amount of hydroxypropyl methylcellulose is 100 parts by weight). The resulting solution is poured onto a glass plate heated to about 105°C (note that the solution is poured onto the glass plate when the glass plate is cooled to 70°C (the temperature is measured by using a radiation thermometer), and the glass plate and the solution thereon are heated at 60°C for 15 minutes. A colored film is thus manufactured. A film-forming aqueous solution is prepared by adding an aqueous solution containing 5 parts by weight of sodium polyphosphate, 5 parts by weight of sucrose monolaurate and 1 part by weight of a gardenia red colorant to a gelatin solution of about 34% (the amount of gelatin is 100 parts by weight). The resulting solution is poured onto a glass plate to which a release agent is applied and heated to about 60°C, and then dried at room temperature. The film thus produced is a colored film. A film-forming aqueous solution is prepared by adding an aqueous solution (the amount of gelatin is 100 parts by weight) containing 5 parts by weight of sodium polyphosphate, 5 parts by weight of sucrose monolaurate and 1 part by weight of a gardenia blue colorant to a gelatin solution of about 34%. The resulting solution is poured on a glass plate to which a release agent is applied and heated to about 60°C, and then dried at room temperature. The film thus produced is a colored film. A film-forming aqueous solution is prepared by adding an aqueous solution (the amount of gelatin is 100 parts by weight) containing 5 parts by weight of sodium polyphosphate, 5 parts by weight of sucrose monolaurate and 1 part by weight of a green colorant (a mixed colorant of a gardenia blue colorant and a safflower colorant) to a gelatin solution of about 34%. The resulting solution is poured on a glass plate to which a release agent is applied and heated to about 60°C, and then dried at room temperature. The film thus produced is a colored film.

[0143] Separately, a film-forming aqueous solution was prepared by adding an aqueous solution containing 2.5 parts by weight of polyoxyethylene (105) polyoxypropylene (5) glycol and 1 part by weight of a gardenia red colorant to an approximately 22% pullulan solution (the amount of pullulan being 100 parts by weight). The resulting solution was poured onto a glass plate to which a release agent had been applied and heated to approximately 60° C., and then dried at room temperature. Thus, a colored film was produced. All test results confirmed that an opaque colored film was produced in each of the above cases.

[0144] [Industrial Applicability]

[0145] The film-forming composition of the present invention contains a polymer dissolved in water and a whitening agent containing a surfactant alone or a whitening agent containing a combination of a surfactant and a salt, and the resulting film can be whitened and opaque by a surfactant without using titanium dioxide, which has been reported to be carcinogenic. Therefore, the film of the present invention can be given light-shielding properties. The film-forming composition has excellent solubility. Even if the film is wiped, the white color of the film cannot be removed. The white film thus formed is stable for a long time. When used with a colorant, the film-forming composition of the present invention can provide an opaque colored film. Therefore, the film of the present invention is very useful, especially as a material for capsules containing contents such as medicines, pesticides, cosmetics and health foods for humans and animals. The film can also be used very advantageously as a coating material for tablets and granules, an edible film, and ink for food.

Claims

1. A white film without white pigment, comprising: a film-forming polymer, which is gelatin or pullulan; and a whitening agent comprising a surfactant, or comprising both a surfactant and a salt, wherein when the film-forming polymer is gelatin, the whitening agent is both a surfactant and a salt, wherein the surfactant is selected from sucrose fatty acid esters, sorbitan fatty acid esters, glycerol fatty acid esters or polyoxysorbitan fatty acid esters, polypropylene glycol, polyalkylene oxide derivatives, alkyl sulfate ester salts and saponins, wherein the polyalkylene oxide derivatives are selected from polyoxyethylene polyoxypropylene glycol, polyoxyethylene alkyl ethers and polyoxyethylene fatty acid esters, and the saponins are selected from triterpenoid saponins and steroid saponins, The whiteness is adjusted by a total amount of 0.5 to 30 parts by weight of the surfactant, while the dry weight of the film-forming polymer is defined as 100 parts by weight, wherein the salt to be added to the film-forming polymer is one or more salts selected from the group consisting of sodium malate, sodium succinate, sodium citrate, sodium polyphosphate, sodium bicarbonate, dipotassium hydrogen phosphate, disodium hydrogen phosphate, sodium dihydrogen phosphate, potassium carbonate, potassium dihydrogen phosphate and sodium pyrophosphate dehydrate, and The whiteness varies with the total amount of the salt, wherein the range is from 0.5 parts by weight to 30 parts by weight, and the dry weight of the film-forming polymer is defined as 100 parts by weight.

2. The film according to claim 1, The surfactant is selected from polyoxyethylene (105) polyoxypropylene (5) glycol, polyoxyethylene (160) polyoxypropylene (30) glycol, sucrose monolaurate, sucrose palmitate, sorbitan monolaurate, polysorbate 80, sodium lauryl sulfate, quila saponin, ginsenoside, soybean saponin, sophora saponin, tea seed saponin, beet saponin, yucca saponin and glycyrrhizin.

3. The film according to any one of claims 1 to 2, in, The whiteness is adjusted by the total amount of 0.7 to 30 parts by weight of the surfactant, while the dry weight of the film-forming polymer is defined as 100 parts by weight.

4. The film according to any one of claims 1 to 2, The whiteness is adjusted by the total amount of 1.0 to 30 parts by weight of the surfactant, and the dry weight of the film-forming polymer is defined as 100 parts by weight. 5 . The film according to claim 1 , wherein the whiteness is adjusted by a total amount of 0.5 to 15 parts by weight of the surfactant, with the dry weight of the film-forming polymer being defined as 100 parts by weight.

6. The film according to any one of claims 1 to 2, The film may be given a color other than white by adding dyes or pigments.

7. A capsule made from the film according to any one of claims 1 to 6 and suitable for oral delivery. The capsule according to claim 7 , wherein the capsule is filled with medicine or health food.

9. The capsule according to claim 7 or 8, in, The combination of the film-forming polymer and the surfactant is a combination of pullulan and polyoxyethylene (105) polyoxypropylene (5) glycol.

10. A film-forming composition for forming a film according to any one of claims 1 to 6, the film-forming composition comprising a gelatin or pullulan film-forming polymer soluble in water, and Brightening agents, including: a surfactant; or both a surfactant and a salt, wherein when the film-forming polymer is gelatin, the whitening agent is both a surfactant and a salt.

11. A method of making a film according to any one of claims 1 to 6 or a capsule suitable for oral delivery according to any one of claims 7 to 9, the method comprising: Use of gelatin or pullulan film-forming polymers; and A surfactant is used as the whitening agent, or both a surfactant and a salt are used as the whitening agent, wherein when the film-forming polymer is gelatin, the whitening agent is both a surfactant and a salt.

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