Non-gelatinous capsule film compositions containing as the base a starch hydrolyzate having an average DE of less than 10 and an average molecular weight of not more than 30,000. These non-gelatinous capsule film compositions have stable moisture absorbing/releasing properties and strength to such extent as sufficiently withstanding the production and storage as products and yet achieve excellent disintegration properties in vivo. Also, capsules produced by using the non-gelatinous capsule film compositions as described above are provided.

DISCLOSURE OF INVENTION

(Subject that the Invention is to Solve)

A main object of the present invention is to provide a non-gelatinous capsule shell composition having a strength durable to production and storage as the product of the capsule, stable moisture absorbing/releasing properties and excellent disintegrability in the body, and a capsule formed from the non-gelatinous capsule shell composition.

(Means of Solving the Subject)

In order to accomplish the object, the present inventors have studied the capsule shell composition. As a result, they have found that it is suitable for producing a capsule having easy disintegrability to use easily-water-soluble base at high content in a capsule shell composition. Moreover, they have studied vegetable materials that can retain sufficiently low viscosity to easily form a capsule by using at high content even if the solid content is high, and that have stable moisture absorbing/releasing properties. As a result, they have found to accomplish the object by using a starch hydrolyzate having low molecular weight as a base and optimizing the DE (dextrose equivalent) thereof.

The present invention provides a non-gelatinous capsule shell composition comprising a starch hydrolyzate as a base. Particularly, the present invention provides a non-gelatinous capsule shell composition comprising a starch hydrolyzate as a base and a gelling agent. In the present invention, the starch hydrolyzate having an average DE of less than 10 and an average molecular weight of not more than 30,000 is suitably used. The non-gelatinous capsule shell composition comprises the gelling agent and a gelation aid, and optionally a shell reinforcer and a plasticizer.

In addition, the present invention provides a capsule formed from the non-gelatinous capsule shell composition.

(Effect of the Invention)

According to the non-gelatinous capsule shell composition of the present invention using easily-water-soluble starch hydrolyzate, which is vegetable substance, as a base, the problem by using a gelatin can not be only solved, but a capsule having high strength, easy disintegrability in the body and excellent storage stability by stable moisture absorbing/releasing, which can not accomplished by the conventional non-gelatinous capsule, can be provided.

In present invention, the non-gelatinous capsule shell composition can comprise various additives, such as an enteric material, sweetening material and colorant, in order to impart the desired properties to the resulting capsule as the same as the conventional gelatinous capsule, and in the production of the capsule, the apparatus for the conventional gelatinous capsule can be used.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic cross section illustrating one embodiment of the apparatus for making the capsule of the present invention (the apparatus for making the seamless capsule with doublet nozzle used for dripping process in Examples).

FIG. 2 is a graph illustrating the correlation of the humidity with the decrement of moisture (weight loss on drying) of the shell in the capsule of the present invention comprising as a base two starch hydrolyzates having different DE.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will explain briefly as follows.

Non-gelatinous Capsule Shell Composition

(1) Base

The capsule shell composition of the present invention comprises a starch hydrolyzate, which is easily water-soluble, as a base.

The starch hydrolyzate suitably used as the base is water-soluble, and has an average molecular weight of not more than 30,000, preferably 100 to 30,000.

In the capsule shell composition of the present invention, the starch hydrolyzate as a base is contained in an amount of not less than 50% by weight, preferably 55 to 65% by weight, based on total weight of the solid content in the capsule shell composition. In order to produce a capsule easily disintegrated, it is desired for the starch hydrolyzate to maintain low viscosity when used as an aqueous solution having high content.

Therefore, the starch hydrolyzate used preferably has a viscosity of 40% aqueous solution of not more than 300 mPas at 80.degree. C.

Examples of the starch hydrolyzates suitably used as the base include, for example, soluble starch, dextrin and mixture thereof (such as "Stabilose", "Pinedex" (trade name); molecular weight Mw=100 to 40,000, which are commercially available from Matsutani Chemical Industry Co., Ltd.).

In the present invention, it was attempted to optimize a dextrose equivalent DE of starch hydrolyzate used as the base in order to provide a capsule having storage stability by stable moisture absorption and release. Capsule shell compositions were prepared by using two starch hydrolyzates having different DE (one has DE of less than 10, and the other has DE of not less than 10) and the moisture content of the capsule shell at different humidity conditions was determined by measuring a decrement of moisture (weight loss on drying) of the shell in absolute drying condition at 120.degree. C. for 24 hours. As the result, when using the starch hydrolyzate having DE of not less than 10, the weight loss was not less than 25% at a humidity of 20 to 80% RH. On the other hand, when using the starch hydrolyzate having DE of less than 10, the weight loss was not more than 15% (as shown in FIG. 2). That is, when using the starch hydrolyzate having DE of less than 10 as a base, the moisture absorption and release of the capsule shell composition is stabilized. As the result, it was possible to prevent the capsule shell from cracking by brittleness at low humidity and from degrading the product quality by softening and stickiness at high humidity.

Therefore, in the present invention, it is desired for the starch hydrolyzate used for the base to have a DE of less than 10. The starch hydrolyzate having the DE of less than 10 may be used alone or optionally in combination with the starch hydrolyzate having DE of not less than 10, that is, high hydrolyzability. If using the combination, it is desired to select the starch hydrolyzate having high hydrolyzability and the starch hydrolyzate having low hydrolyzability such that the mixture of the starch hydrolyzates has an average DE of less than 10, the average molecular weight of not more than 30,000 and the viscosity of 40% aqueous solution of not more than 300 mPas at 80.degree. C. Examples of the starch hydrolyzates having high hydrolyzability include, for example, maltodextrin, which is commercially available from Matsutani Chemical Industry Co., Ltd. under the trade name "TK-16", and the like. The amount of the maltodextrin as the starch hydrolyzates having high hydrolyzability is preferably not more than 35% by weight, more preferably not more than 25% by weight, based on the total weight of the solid content in the capsule shell composition.

The capsule shell composition of the present invention may optionally comprise a shell reinforcer in order to improve the disintegrability of the capsule itself in the body and the capsule shell strength, in addition to the gelling agent and gelation aid used together with the base.

(2) Gelling Agent and Gelation Aid

As the gelling agent, polysaccharides derived from plant, which melts at a temperature not more than 80.degree. C., are suitably used, and examples thereof include one or combination of two or more selected from the group consisting of furcellan, carrageenan, pectin, curdlan, psyllium seed gum, xanthan gum, locust bean gum, guar gum and gelled starch. In the gelling agent, a weight ratio of one or combination of two or more selected from the group consisting of furcellan, LM pectin, curdlan, psyllium seed gum, mixture of xanthan gum and locust bean gum, mixture of xanthan gum and guar gum, mixture of xanthan gum and guar gum hydrolyzate, and gelled starch to the carrageenan may be within the range of 6:4 to 9:1. As the gelling agent, one or mixture of two or more gelled starches selected from the group consisting of acid hydrolyzed starch and white dextrin may be used.

The gelling agent is contained in an amount of 0.5 to 30% by weight, preferably 1 to 15% by weight, based on total weight of the solid content in the capsule shell composition.

In the capsule shell composition of the present invention, it is desired to use the gelation aid consisting of monovalent ion or divalent ion, preferably one or combination of two or more selected from the group consisting of a potassium ion, a sodium ion, a calcium ion and an ammonium ion, together with the gelling agent in order to improve the formability of the capsule shell. The gelation aid is contained in an amount of 0.1 to 10% by weight, preferably 0.5 to 5% by weight, based on total weight of the solid content in the capsule shell composition.

(3) Shell Reinforcer

Examples of the suitable shell reinforcer include monosaccharides, such as dextrose, fructose, glucose, galactose; oligosaccharide, and disaccharides, such as sucrose, maltose, trehalose, coupling suger; polysaccharides, such as pullulan, gum arabic, arabinogaractan, cellulose and derivatives thereof; and sugar alcohol, such as sorbitol, maltitol (reduced maltose syrup), lactitol, palatinit, xylitol, mannitol, galactitol. The shell reinforcer may be used alone or in combination with two or more thereof. The shell reinforcer is contained in an amount of 0.1 to 50% by weight, preferably 0.5 to 30% by weight, based on total weight of the solid content in the capsule shell composition.

(4) Plasticizer

In the present invention, the capsule shell composition may optionally contain the plasticizer in addition to the above components. Examples of the plasticizers suitably used include one or combination of two or more selected from the group consisting of polyhydric alcohols, such as glycerin, polyethylene glycol, propylene glycol, polypropylene glycol. The plasticizer is contained in an amount of 10 to 40% by weight, preferably 15 to 30% by weight, based on total weight of the solid content in the capsule shell composition.

(5) Enteric Material and Additives

In the present invention, the capsule shell composition may optionally contain the enteric material as the same as the conventional capsule shell composition in order to form the enteric capsule. Examples of the enteric materials include pectin, alginic acid salt, methacrylic acid copolymer, hydroxypropylmethylcellulose phthalate, hydroxypropylmethylcelluloseacetate succinate, carboxyl methylethylcellulose, celluloseacetate phthalate and the like. The enteric material may be used alone or in combination with two or more thereof. The enteric material is contained in an amount of 0.5 to 20% by weight, preferably 1 to 20% by weight, based on total weight of the solid content in the capsule shell composition.

The capsule shell composition of the present invention may contain various additives, such as aromatic, sweetening material, colorant, antiseptic including paraben, which have been conventionally used in the art, in addition to the above components. The additives are contained in total amount of 0.01 to 10% by weight, preferably 0.1 to 5% by weight, based on total weight of the solid content in the capsule shell composition.

Capsule

By using the non-gelatinous capsule shell composition of the present invention, capsules having easy disintegrability in any form of hard capsule, soft capsule or micro-capsule can be provided. As non-limited examples of methods of producing the capsule include a method of producing a capsule having a particle diameter of 50.mu. to 10 mm described in Japanese Patent Kokai Publication No. 49154/1981, of which the content used is oily substance, such as purified vegetable oil, aromatic, oily vitamin, oil-soluble medicinal substance, unsaturated fatty acid or a derivative thereof; a method of producing a capsule, of which the content contains a hydrophilic substance, described in Japanese Patent Kokai Publication Nos. 52639/1991 and 31352/1993; and a method of producing a capsule, of which the content contains bifidus (Lactobacillus bijidus), described in Japanese Patent Kokai Publication Nos. 151127/1986 and 69867/1995.

The capsule of the present invention may be a seamless capsule. The seamless capsule can be produce by a method of continuously producing seamless capsule by a dripping process using a multiple nozzle, for example, described in Japanese Patent Kokai Publication Nos. 22062/1983, 131355/1984, 52639/1991, 31352/1993, 69867/1995 and the like, but is not limited thereto. In the dripping process using a multiple nozzle, after a concentric multiple nozzle, which is doublet or more, is inserted into liquid oil flowing down at a constant rate, the content substance is ejected through an innermost nozzle and the non-gelatinous capsule shell composition is ejected through an outermost nozzle, simultaneously, at a constant rate to continuously produce spherical seamless capsule by interfacial tension applied between the liquid oil and shell substance.

The capsule of the present invention has a particle diameter after drying of 0.1 to 10 mm, preferably 0.3 to 8 mm. The capsule of the present invention has a shell thickness of 30 to 300 .mu.m.

The capsule after producing may be used without drying the moisture in the capsule shell, or after drying the moisture by a conventional drying process or vacuum drying process, depending to purpose thereof.
 

Claim 1 of 10 Claims

1. A non-gelatinous seamless capsule comprising a content and a capsule shell encapsulating the content, wherein the capsule shell comprises (a) a soluble starch or dextrin having an average dextrose equivalent DE of less than 10 and an average molecular weight of not more than 30,000 and (b) a gelling agent being a polysaccharide which melts at a temperature of not more than 80.degree. C., and the seamless capsule is obtained by a dripping process using a multiple nozzle.

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