JP2940930B2 - Method for producing hydrous alginate film - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a hydrous alginate film used as an external preparation for pharmaceuticals, cosmetics, and the like.

(Prior Art) It is known that soluble alginate easily gels when reacted with a divalent metal salt such as calcium ion in an aqueous solution. By utilizing this property, a hydrous alginate film can be produced. The hydrous alginate film can be applied to external preparations such as pharmaceuticals and cosmetics. These external preparations contain an active ingredient such as a medicinal ingredient, a humectant, a bactericide, a coloring agent, and other additives depending on the use. Such a water-containing alginate film is generally obtained by gelling a soluble alginate aqueous solution containing the active ingredient.

As a specific production method of a water-containing alginate film, for example, a method of extruding an aqueous solution of sodium alginate (hereinafter, referred to as Na alginate) into a solution (gelling solution) such as an aqueous solution of calcium chloride is disclosed in British Patent No. 552,770. Have been. The sodium alginate extruded into the gelling solution reacts with calcium ions and immediately gels to form a hydrous alginate film. However, in this method, when a medicinal ingredient, a humectant, and the like are blended in an aqueous sodium alginate solution, the active ingredient is eluted from the formed gel (hydrous alginate film) into the gelling solution. Therefore, the content of the active ingredient in the obtained hydrous alginate film is not constant. Therefore, the above method is not suitable for producing an external preparation for pharmaceuticals and cosmetics.

Another method for producing hydrous alginate films is described in Food Industry, Vol. 10, No. 4, (1967). In the method described in this document, gelation is achieved by adding a sparingly soluble calcium salt to an aqueous sodium alginate solution, forming the film, and allowing the film to stand. In this method, since a sparingly soluble calcium salt is used, the concentration of calcium ions formed in the aqueous sodium alginate solution is very low. Therefore, the reaction between the sodium alginate and the calcium ions is delayed, and as a result, it is possible to cast this solution before gelation to form a film. However, in this method, if the gelation rate is reduced by means such as adjusting the amount of calcium salt, the solution must be left for a long time until gelation after casting. Efficiency is reduced. Conversely, if the gelation rate is increased, the solution gels before casting and casting the solution. In other words,
The above method is difficult to set manufacturing conditions and is not suitable for continuous manufacturing.

In addition, in the case of a film formed by a conventional gelling method, when used as an external preparation, the required strength is not obtained stably, which may cause a problem when processed at the time of production, or when applied to skin or mucous membranes. was there.

(Problems to be Solved by the Invention) The present invention is to solve the above-mentioned conventional problems, and its object is to make it possible to produce easily and continuously, without variation in the active ingredient, and to provide a pharmaceutical and cosmetic product. An object of the present invention is to provide a method for producing a hydrous alginate film suitable for obtaining an external preparation.

(Means for Solving the Problems) The method for producing a hydrous alginate film of the present invention comprises the steps of forming a film of a soluble alginate aqueous solution, spraying a soluble calcium salt aqueous solution on the film of the aqueous solution, To obtain a gel-like film, and a step of further stretching the gel-like film, whereby the object is achieved.

The soluble alginate used in the present invention is an alkali metal salt of alginic acid such as Li, K and Na.

Examples of the soluble calcium salt used in the present invention include calcium halide (excluding calcium fluoride), calcium nitrate, and calcium acetate.

The hydrous alginate film of the present invention may contain various active ingredients and additives as needed. Examples include various medicinal ingredients, moisturizers, bactericides, antibacterial agents, coloring agents, thickeners, absorption promoters for medicinal ingredients, neutralizers / buffers, flavorings, flavors, surfactants, softeners Agents, organic and inorganic extenders, and the like.

In order to prepare the water-containing alginate film of the present invention, first, the alginate is dissolved in water to prepare an aqueous solution.
This aqueous solution is adjusted to have a viscosity of several hundreds to several tens of thousands cps so that a film can be formed by a normal coating method. If the viscosity is lower or higher than this range, film formation becomes difficult, which is not preferable.

Next, separately from this, an aqueous solution of the above-mentioned soluble calcium salt is prepared. The aqueous solution of a soluble calcium salt is prepared such that the amount of calcium ions contained is 0.15 to 0.4 mol, preferably 0.2 to 0.35 mol, per 1 mol of Na ions contained in the above-mentioned aqueous sodium alginate solution. When the amount is larger than this range, the obtained hydrous alginate film becomes hard, and when used as a patch for medicine, for example, the feeling of use becomes poor. When the amount is less than this range, gelling hardly occurs, and the strength of the film decreases. The concentration of the aqueous solution of the soluble calcium salt is usually 1 to 50% by weight, preferably 1 to 50% by weight.
20% by weight. If an aqueous solution having a concentration higher than this range is used, the film of the alginate aqueous solution sprayed with the aqueous solution shrinks, resulting in deformation of the resulting film and water separation. If the concentration is lower than this range, the gelation rate becomes slow, and the amount of the aqueous solution to be sprayed becomes large, so that the possibility of elution of the active ingredient appears.

Next, the aqueous solution of the soluble alginate is cast on a base film, for example, a polyethylene terephthalate film by a conventional method, for example, a casting method to form a film, and the aqueous solution of the soluble calcium salt is sprayed. Since the calcium ions in the sprayed aqueous solution of the soluble calcium salt quickly react with the alginate, the gelation occurs simultaneously with the spraying. Therefore, a water-containing alginate film can be efficiently and continuously produced. The obtained film is further subjected to a stretching treatment. This improves the strength, transparency and the like of the film. The produced hydrous alginic acid film is used by peeling it off from the base film as necessary. The thickness of the prepared hydrous alginate film varies depending on the purpose of use, but is usually 0.1 mm to 5 mm. This film does not lose the active ingredients and the required additives, since no hydrous alginate film is formed in solution as in the method of the British patent mentioned in the background section. Further, sufficient strength can be obtained during production and use.

(Examples) The present invention will be described below with reference to examples.

Reference Example 1 2 parts by weight of sodium alginate (IS grade, manufactured by Shimadzu Chemical Industries) was uniformly dissolved in 98 parts by weight of purified water of the Japanese Pharmacopoeia. This aqueous solution is placed on a polyethylene terephthalate film,
It was cast to a thickness of 1 mm. From above, an aqueous solution of calcium chloride (Hanai Chemical Co., Ltd., reagent special grade) was sprayed at the concentrations shown in Table 1. The total amount of the sprayed calcium ions is constant in each case, and is 0.2 mol per 1 mol of Na ions contained in the aqueous sodium alginate solution. After spraying the aqueous calcium chloride solution, the mixture was allowed to stand for 2 minutes, and the properties of the obtained hydrous alginate film were observed. Table 1 also shows the results.

From Table 1, the preferred concentration of the aqueous calcium chloride solution is:
1 to 50% by weight, more preferably 1 to 20% by weight
It is clear that

Reference Example 2 2 parts by weight of sodium alginate (IS grade, manufactured by Shimadzu Chemical Industries) was uniformly dissolved in 98 parts by weight of purified water of the Japanese Pharmacopoeia. This aqueous solution is placed on a polyethylene terephthalate film,
It was cast to a thickness of 1 mm. From above, a 5% by weight aqueous solution of calcium chloride (Hanai Chemical Co., Ltd., reagent grade) was sprayed. The total amount of calcium ions sprayed here is Na alginate
The aqueous solution was sprayed so as to have the amount shown in Table 2 with respect to 1 mol of Na ion contained in the aqueous solution. After spraying the aqueous calcium chloride solution, the mixture was allowed to stand for 2 minutes, and the strength and feeling of use of the obtained hydrous alginate film were examined. Table 2 also shows the results. Here, the strength and feeling of use of the film were examined by a sensory test.

From Table 2, the preferred amount of calcium ions sprayed is 0.15 to 1 mole of Na contained in Na alginate.
Obviously, the preferred amount is 0.2.35 mol.

Example 1 2 parts by weight of sodium alginate (IS grade, manufactured by Shimadzu Corporation) and 0.01 part by weight of copper chlorophyllin Na were uniformly dissolved in 97.99 parts by weight of purified water of the Japanese Pharmacopoeia. This aqueous solution was cast to a thickness of 2 mm on a polyethylene terephthalate film. From above, a 5% by weight aqueous solution of calcium chloride (reagent grade manufactured by Hanui Chemical Co., Ltd.) was sprayed. The total amount of calcium ions sprayed here is 0.2 mol per 1 mol of Na ions contained in the aqueous sodium alginate solution. After spraying the aqueous solution of calcium chloride, it was left for 2 minutes. The content of sodium copper chlorophyllin in the obtained hydrous alginate film was almost equal to that before the film formation. Both the strength and feeling of use of the film were good.

The obtained hydrous alginate film was stretched at 50 g / cm using a film stretching apparatus. The stretched film had higher film strength and better transparency than the unstretched film.

(Effect of the Invention) According to the production method of the present invention, a water-containing alginate film having no variation in the contained active ingredient is thus obtained.
It can be manufactured efficiently and continuously. If the method of the present invention is applied,
An external preparation based on alginic acid used in the fields of pharmaceuticals, cosmetics, and the like can be continuously produced at a constant quality, efficiently and continuously.

Claims (1)

(57) [Claims] 1. A step of forming a film of an aqueous solution of a soluble alginate, and spraying an aqueous solution of a soluble calcium salt on the film of the aqueous solution,
A method for producing a hydrous alginic acid film, comprising: a step of gelling the film of the aqueous solution to obtain a gel-like film; and a step of further stretching the gel-like film.