The present invention relates to an edible film and a method for manufacturing the edible film.
Known edible films include film pharmaceuticals and film confectionery. For example, Patent Literature 1 describes an edible film formed from an orally soluble base material containing medicines and additives.
Known edible films as described above are manufactured with a coating method. The coating method includes dissolving an edible base material and other ingredients in a liquid and applying the solution onto a carrier film to form a thin coating. The coating is then dried to be an edible film.
However, when the solution used in manufacturing an edible film with the coating method has a high viscosity, the solution may flow less smoothly and cause difficulty in achieving uniform coating.
When the solution has a low viscosity, convection currents (Benard convection) can occur during the drying process and may cause nonuniform distribution of the ingredients contained in the edible film.
In response to the above issues, one or more aspects of the present invention are directed to an edible film that is easy to manufacture with a coating method and contains ingredients in a uniformly distributed manner.
An edible film according to a first aspect of the present invention includes a base material, and at least one ingredient including microcrystalline cellulose. A content of the microcrystalline cellulose is 5 to 50 wt %.
A solution with the above composition is less viscous and more flowable during the coating process in which the solution is sheared. Thus, the coating process in manufacturing the edible film is easy.
When the solution is not sheared after coating, the solution is more viscous and less flowable. This reduces convection during the drying process and allows uniform distribution of the ingredients in the edible film.
An edible film according to a second aspect of the present invention is the edible film according to the first aspect in which the at least one ingredient further includes maltitol.
The above composition reduces aggregation of the microcrystalline cellulose and reduces nonuniform distribution of the ingredients in the edible film.
An edible film according to a third aspect of the present invention is the edible film according to the second aspect in which the base material is polyvinyl alcohol, and a ratio of a content of the microcrystalline cellulose to a content of the maltitol is 0.5 to 3.3.
Polyvinyl alcohol used as the base material further reduces aggregation of the microcrystalline cellulose, more effectively reducing nonuniform distribution of the ingredients in the edible film.
An edible film according to a fourth aspect of the present invention is the edible film according to the second aspect in which the base material is polyethylene oxide, and a ratio of a content of the microcrystalline cellulose to a content of the maltitol is 0.5 to 7.5.
The above composition containing polyethylene oxide as a base material further reduces aggregation of the microcrystalline cellulose, more effectively reducing nonuniform distribution of the ingredients in the edible film.
An edible film according to a fifth aspect of the present invention is the edible film according to the second aspect in which the base material is polyvinylpyrrolidone, and a ratio of a content of the microcrystalline cellulose to a content of the maltitol is 0.67 to 7.5.
The above composition containing polyvinylpyrrolidone as the base material further reduces aggregation of the microcrystalline cellulose, thus reducing nonuniform distribution of the ingredients in the edible film.
An edible film according to a sixth aspect of the present invention includes a dried solution containing a base material and an ingredient. The ingredient includes microcrystalline cellulose, and η0/η100 is 1.5 to 10, where η0/η100 is a ratio of a zero shear viscosity no of the solution at a temperature of 25° C. to a viscosity η100 of the solution measured at a temperature of 25° C. and a shear rate of 100/s.
A method for manufacturing an edible film according to a seventh aspect of the present invention includes preparing a solution containing a base material and an ingredient with η0/η100 of 1.5 to 10, where η0/η100 is a ratio of a zero shear viscosity no of the solution at a temperature of 25° C. to a viscosity η100 of the solution measured at a temperature of 25° C. and a shear rate of 100/s, coating a carrier film with the solution, drying the solution after the coating, and cutting the dried solution into pieces.
The solution in the sixth aspect and the seventh aspect is less viscous and more flowable during the coating process in which the solution is sheared. Thus, the coating process in manufacturing the edible film is easy.
When the solution is not sheared after coating, the solution is more viscous and less flowable. This reduces convection during the drying process and allows uniform distribution of the ingredients in the edible film.
The edible film according to the above aspects of the present invention is easy to manufacture with a coating method and contains the ingredients in a uniformly distributed manner.
One or more embodiments of the present invention will now be described with reference to the drawings.
An edible film 10 according to an embodiment of the present invention is, for example, a rectangular thin film in a plan view with a thickness of 10 to 300 μm, or more specifically, 30 to 200 μm. The edible film 10 is formed mainly from a base material and ingredients blended with the base material. Examples of the edible film 10 include those that dissolve or disintegrate in the oral cavity to release ingredients and those that are swallowable and digestible in the stomach or intestines to allow ingredients to be absorbed.
Examples of typical ingredients blended with the base material include microcrystalline cellulose and maltitol. In addition to these ingredients, the edible film 10 may contain various other materials as ingredients as appropriate for the purpose. Examples of the other materials include medicinal ingredients to provide medicinal efficacy with the edible film 10, flavor ingredients to add flavors to the edible film 10, coloring ingredients to color the edible film 10, nutritional ingredients (including supplements) to add nutrition to the edible film 10, aromatic ingredients to add aroma to the edible film 10, and additives to adjust the physical properties of the edible film 10.
Examples of additives include binders, excipients, disintegrants, flavoring agents, wetting agents, coloring agents, and emulsifiers.
The base material is the main material for forming the edible film 10.
The base material may be, for example, an edible organic compound or an edible inorganic compound. Examples of edible organic compounds include edible carbohydrates, edible proteins, and edible fats. Examples of edible carbohydrates include edible disaccharides, edible polysaccharides, edible sugar alcohols, and edible dietary fiber. Examples of edible polysaccharides include alginic acid, sodium alginate, pregelatinized starch, carrageenan, agar, xanthan gum, potato starch, cellulose, and pullulan. Examples of edible dietary fiber include pectin and cellulose. Examples of edible disaccharides include sucrose. Examples of edible sugar alcohols include sorbitol. Examples of edible proteins include gelatin. Examples of edible organic compounds other than carbohydrates, proteins, and fats include polyvinyl alcohol (PVA), polyethylene oxide (PEO), polyvinylpyrrolidone (PVP or povidone), and macrogol (polyethylene glycol). Examples of their edible derivatives include, for example, sugar derivatives, cellulose derivatives, PVA derivatives, and sorbitol derivatives. Examples of sugar derivatives include, for example, sucrose fatty acid esters. Examples of cellulose derivatives include ethylcellulose, carmellose (CMC), carmellose sodium, and hypromellose (HPMC). Derivatives of sorbitol include sorbitan and sorbitan fatty acid esters (polysorbate). Among these, PVA, PEO, or PVP may particularly be used. PVA, PEO, or PVP may be used as a base material to form strong and flexible edible films.
Microcrystalline cellulose is used to improve the thixotropy of a solution 32 that is a raw material of the edible film 10. Thixotropy is a property of the solution 32 to be less viscous when the solution 32 is sheared and to be more viscous when the solution 32 is not sheared. When having high thixotropy, the solution 32 is sheared and is less viscous and more flowable during the coating process. The solution 32 is thus applied easily in the coating process. After the coating process, the solution 32 is not sheared and is more viscous and less flowable. This reduces convection (Benard convection) particularly in the process of drying the solution 32, reducing nonuniform distribution of ingredients.
Thixotropy is higher when the microcrystalline cellulose content is higher, but the microcrystalline cellulose content is not to be too high when an ingredient other than microcrystalline cellulose is to be contained at a high level. The microcrystalline cellulose content may be, for example, 5 to 50 wt %, specifically 7.5 to 45 wt %, or more specifically 10 to 40 wt %. The edible film 10 can have high thixotropy with a microcrystalline cellulose content of 5 wt % or more, 7.5 wt % or more, or more specifically, 10 wt % or more. The microcrystalline cellulose content of 50 wt % or less, 45 wt % or less, or 40 wt % or less is low enough to allow other ingredients to be sufficiently contained. In this embodiment, the microcrystalline cellulose content refers to the amount of microcrystalline cellulose contained in the edible film 10 in a solid state obtained by drying the solution 32.
Maltitol may be used as appropriate to reduce aggregation of microcrystalline cellulose. Maltitol may or may not be used when microcrystalline cellulose is less likely to aggregate or when aggregation is not an issue. Although microcrystalline cellulose reduces nonuniform distribution of ingredients resulting from convection by alleviating convection in the solution 32 in the drying process, microcrystalline cellulose can aggregate in the edible film 10 and cause nonuniform distribution of ingredients including the microcrystalline cellulose. However, maltitol blended with the base material can reduce aggregation of microcrystalline cellulose.
The maltitol content may be, for example, 1 to 35 wt %, specifically 2 to 25 wt %, or more specifically 3 to 15 wt %, although being largely affected by its ratio to the microcrystalline cellulose content. With a maltitol content of 1 wt % or more, 2 wt % or more, or more specifically 3 wt % or more, the ratio of maltitol to microcrystalline cellulose is likely to be higher, expectedly reducing aggregation of microcrystalline cellulose. With a maltitol content of 35 wt % or less, 25 wt % or less, or more specifically 15 wt % or less, the drying speed of the solution 32 is less likely to be slow and the edible film 10 is less likely to be sticky. In this embodiment, the maltitol content refers to the amount of maltitol contained in the edible film 10 in a solid state obtained by drying the solution 32.
A binder increases the strength of the edible film 10. Examples of binder materials include amylopectin, sodium alginate, pregelatinized starch, carmellose, carmellose sodium, agar, glycerin, crystalline cellulose, polymer polyvinylpyrrolidone, wheat starch, rice starch, sucrose fatty acid esters, purified gelatin, purified shellac, sucrose, gelatin, soy lecithin, low substituted hydroxypropyl cellulose, dextrin, concentrated glycerin, crystalline cellulose, hydroxyethyl cellulose, hypromellose, pullulan, pectin, polysorbate, macrogol, D-mannitol, and methylcellulose.
An excipient increases the volume of the edible film 10 to a size that is easy to handle. Examples of excipient materials include alginic acid, sodium alginate, pregelatinized starch, ethylcellulose, carrageenan, carmellose, carmellose sodium, agar, glycerin, croscarmellose sodium, crospovidone, magnesium silicate, crystalline cellulose, wheat flour, wheat starch, rice flour, rice starch, titanium dioxide, sucrose fatty acid esters, sucrose, gelatin, skimmed milk powder, talc, dextran, dextrin, potato starch, hypromellose, pullulan, pectin, polysorbate, macrogol, maltose, and methylcellulose.
A disintegrant provides disintegratability to the edible film 10. Examples of disintegrant materials include alginic acid, pregelatinized starch, carmellose, carmellose sodium, agar, croscarmellose sodium, crospovidone, crystalline cellulose, wheat starch, rice starch, sucrose fatty acid esters, gelatin, dextrin, corn starch, potato starch, hydroxypropyl cellulose, hypromellose, polysorbate, macrogol, magnesium aluminometasilicate, methylcellulose, and sodium lauryl sulfate.
A flavoring agent adjusts the flavor of the edible film 10. Examples of flavoring agent materials include aspartame, DL-alanine, erythritol, reduced maltose syrup, xylitol, citric acid hydrate, sodium citrate hydrate, glycerin, succinic acid, sodium succinate, acetic acid, saccharin, tartaric acid, sodium tartrate, sucralose, thaumatin, sodium bicarbonate, capsicum, trehalose, white soft sugar, honey, povidone, D-mannitol, and menthol.
A wetting agent prevents the edible film 10 from drying and increases the flexibility of the edible film 10. Examples of wetting agent materials include reduced syrup, glycerin, sucrose fatty acid esters, D-sorbitol, propylene glycol, polysorbate, macrogol, and methylcellulose.
A coloring agent colors the edible film 10. Examples of coloring agent materials include titanium dioxide, food dyes, and talc.
An emulsifier facilitates mixing of ingredients. Examples of emulsifier materials include polysorbate, purified soybean lecithin, medium-chain triglycerides, and sodium lauryl sulfate.
A method for manufacturing the edible film 10 according to an embodiment of the present invention will now be described briefly with reference to the drawings.
As shown in
Each of the steps shown in
The weighing process will be described.
In the weighing process, the base material, the ingredients, and the liquid are weighed. The liquid may be an edible liquid. Examples of edible liquids include water, edible alcohols, edible glycols, glycerin, and edible fats. Examples of edible alcohols include ethyl alcohol. Examples of edible glycols include propylene glycol.
The mixing and de-bubbling process will be described.
As shown in
The coating process will be described.
As shown in
The drying process will be described.
As shown in
The slitting process will be described.
A wound-up roll of the carrier film 31 is cut into multiple rolls by a slitter machine (not shown). For example, this step may be performed in a roll-to-roll system. As shown in
The cutting and packaging process will be described.
The coating layer of the solution 32 on the carrier film 31 on each cut roll is cut into pieces by a cutting and packaging machine (not shown) to obtain pieces of edible film 10. For example, this step may be performed in a roll-to-roll system. As shown in
The advantages and effects of using microcrystalline cellulose as one of the ingredients will now be described. Edible films in examples 1 to 3 and comparative examples 1 to 6 were prepared as shown in Table 1. Although Table 1 shows the contents of the base materials and microcrystalline cellulose, the edible films also contained small amounts of additives. Maltitol, acesulfame potassium, and lactose were used as additives. In example 3 and comparative examples 5 and 6, corn starch was further used. In Table 1, the base material contents in the solution and the microcrystalline cellulose contents in the solution are each shown as weight percent of the base material and the microcrystalline cellulose dissolved in a water-ethanol mixture solution. The base material content in the solid content and the microcrystalline cellulose content in the solid content are shown as weight percent of the base material or the microcrystalline cellulose contained in the edible film obtained by drying the solution. Viscosity no is the zero shear viscosity at a temperature of 25° C. Viscosity η100 is the viscosity of the solution measured at a temperature of 25° C. and a shear rate of 100/s. Microcrystalline cellulose was contained as an ingredient in examples 1 to 3, but not in comparative examples 1 to 6.
The viscosity of the solution was measured at a temperature of 25° C. over a range of shear rates from 10 to 200/s with the continuous ramp method, using a rotational rheometer (AR-G2 manufactured by TA Instruments, Ltd.) and a steel parallel plate with a diameter of 40 mm. The viscosity data in the shear rate range of 10 to 20/s was approximated linearly by the least-squares method, and extrapolated to the zero shear rate point to estimate the zero shear viscosity no.
Typically, a solution with a higher base material content has higher thixotropy. However, higher base material content in the solution decreases the solubility and disintegrability of the edible film obtained by drying the solution, causing slower release of the ingredients from the edible film. Thus, thixotropy of the solution is to be improved at lower base material content levels.
The base material content in the solution was 14.5 wt % in example 1, 24.0 wt % in comparative example 1, and 18.2 wt % in comparative example 2. The solution in example 1 had a base material content lower than the solutions in comparative examples 1 and 2, but had high thixotropy with η0/η100 of 2.83. Comparative example 1 had the highest thixotropy with η0/η100 of 3.68, but had a high base material content of 24.0 wt % in the solution, possibly causing poor solubility and disintegrability in the resulting edible film. In comparative example 2, the curve showing the relationship between the shear rate and the viscosity does not decline rightward, but is substantially horizontal, with η0/η100 being 1.48 indicating low thixotropy.
As described above, the use of microcrystalline cellulose as an ingredient improves thixotropy while reducing the base material content. When an edible film is manufactured by preparing a solution containing microcrystalline cellulose with η0/η100 of 1.5 to 10, or more specifically 2 to 10, the high thixotropy of the solution allows the coating process using the solution to be easier and allows the edible film obtained by drying after coating to have uniform distribution of ingredients.
The advantages and effects of using maltitol as one of the ingredients will now be described.
As described above, maltitol reduces aggregation of microcrystalline cellulose.
The optimum maltitol content for each type of base material will now be described. The maltitol content is determined based on the microcrystalline cellulose content to have the ratio of the microcrystalline cellulose content to the maltitol content within the optimal range. In this embodiment, the microcrystalline cellulose content and the maltitol content refer to the amounts of microcrystalline cellulose and maltitol contained in the edible film in a solid state obtained by drying the solution.
Edible films using PVA as the base material were prepared by adjusting the ratio of microcrystalline cellulose content to maltitol content (the ratio of microcrystalline cellulose to maltitol), as shown in Table 2 (examples 4 to 7 and comparative examples 7 to 9). In the examples, the microcrystalline cellulose content and the maltitol content refer respectively to the amount of microcrystalline cellulose and the amount of maltitol contained in the edible film in a solid state obtained by drying the solution. Observations were performed with a microscope on examples 4 to 7 and comparative examples 7 to 9 for any ingredient aggregation. The results showed that no ingredient aggregation was observed in examples 4 to 7 in which the ratio of microcrystalline cellulose to maltitol was within a range of 0.5 and 3.3. In contrast, ingredient aggregation was observed in comparative examples 7 to 9 in which the ratio of microcrystalline cellulose to maltitol was outside the range of 0.5 and 3.3.
As described above, a solution containing PVA as the base material is unlikely to have ingredient aggregation at a ratio of microcrystalline cellulose to maltitol between 0.5 and 3.3 when the total content of the base material (PVA) and all other ingredients in the edible film is 100 wt %, allowing uniform distribution of ingredients in the resulting edible film.
Edible films using PEO as the base material were prepared by adjusting the ratio of microcrystalline cellulose content to maltitol content (ratio of microcrystalline cellulose to maltitol), as shown in Table 3 (examples 8 to 11 and comparative examples 10 to 12). Observations were performed with a microscope on examples 8 to 11 and comparative examples 10 to 12 for any ingredient aggregation. The results showed that no ingredient aggregation was observed in examples 8 to 11 in which the ratio of microcrystalline cellulose to maltitol was within a range of 0.5 to 7.5. In contrast, ingredient aggregation was observed in comparative examples 10 to 12 in which the ratio of microcrystalline cellulose to maltitol was outside the range of 0.5 and 7.5.
As described above, a solution containing PEO as the base material is unlikely to have ingredient aggregation at a ratio of microcrystalline cellulose to maltitol between 0.5 and 7.5 when the total content of the base material (PEO) and all other ingredients in the edible film is 100 wt %, allowing uniform distribution of ingredients in the resulting edible film.
Edible films using PVP as the base material were prepared by adjusting the ratio of microcrystalline cellulose content to maltitol content (the ratio of microcrystalline cellulose to maltitol), as shown in Table 4 (examples 12 to 16 and comparative examples 13 and 14). Observations were performed with a microscope on examples 12 to 16 and comparative examples 13 and 14 for any ingredient aggregation. The results showed that no ingredient aggregation was observed in examples 12 to 16 in which the ratio of microcrystalline cellulose to maltitol was within a range from 0.67 to 7.5. In contrast, ingredient aggregation was observed in comparative examples 13 and 14 in which the ratio of microcrystalline cellulose to maltitol was outside the range of 0.67 and 7.5.
As described above, a solution containing PVP as the base material is unlikely to have ingredient aggregation at a ratio of microcrystalline cellulose to maltitol between 0.67 and 7.5 when the total content of the base material (PVP) and all other ingredients in the edible film is 100 wt %, allowing uniform distribution of ingredients in the resulting edible film.
With the method for manufacturing the edible film according to the above embodiment, slits were formed in both the carrier film and the layer of the solution on the carrier film, but the slits may be formed in the layer of the solution as a coating alone without being formed in the carrier film.
With the method for manufacturing the edible film according to the above embodiment, the layer of the solution on the carrier film alone is cut in a half-cutting process without the carrier film being cut, but the carrier film may be cut together with the layer of the solution. In this case, the edible film may be packaged together with the carrier film without the carrier film being peeled from the pieces of edible film obtained by cutting the solution layer into pieces.
Additionally, with the method for manufacturing the edible film according to the above embodiment, slitting and cutting are separate processes, but slitting and cutting may be performed as one process in which the dried solution layer is cut into pieces.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-119027 | Jul 2022 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2023/015521 | 4/18/2023 | WO |