DE102024111019A1 - Gel mass for the production of soft capsules or films, their use and production process - Google Patents

Abstract

The invention relates to a gel mass for producing soft capsules or films. The gel mass comprises agarose, gellan with a high degree of acylation, one or more fillers, one or more plasticizers, and water. The invention further relates to a process for producing soft capsules, comprising the steps of: providing a gel mass according to the invention at a temperature between 80 and 100°C, forming a film from the gel mass by cooling to a temperature below 30°C, providing a capsule filling, producing the soft capsules by enclosing the capsule filling with the film formed from the gel mass to form the capsule shell, and drying the capsule shell to a water content of approximately 20% by weight or less.

Description

The present invention relates to a gel mass for the production of soft capsules or films.

The invention further relates to the use of such a gel mass for producing soft capsules or films, as well as to processes for producing soft capsules or films using such a gel mass.

Soft capsules have long been a well-known dosage form for pharmaceutical active ingredients or dietary supplements. The vast majority of soft capsules on the market have a capsule shell based on gelatin as a gel-forming hydrocolloid. These soft gelatin capsules are manufactured using the so-called Scherer process, in which the filling is encapsulated fully automatically using counter-rotating forming rollers (hence the synonymous term "rotary die process"). Two gel ribbons made of a gel mass, typically containing approximately 40 to 50 wt.% gelatin, a plasticizer (e.g., glycerin), and water, are passed between the forming rollers at a temperature of approximately 55 to 70°C and sealed around the filling. Upon cooling, the gel mass acquires its required strength through gelation (so-called cold-set gelation) and is then dried.

Due to the desire of a growing segment of the population to largely or completely avoid the use of animal products, there is a growing demand for vegan soft capsules, i.e., soft capsules in which gelatin, an animal product, has been replaced by plant or microbial biopolymers. Various biopolymers, particularly polysaccharides and proteins, are known to be used as hydrocolloids to produce gels with properties more or less similar to those of gelatin gels. However, in detail, the rheological properties differ from those of a gelatin-based gel mass, which are required for reliable performance of the Scherer process. This particularly applies to the viscosity, strength, and seam-forming properties of the gel mass required for the process.

The invention is therefore based on the object of proposing a vegan gel mass from which soft capsules can be produced using the established Scherer process.

This object is achieved according to the invention in the gel mass of the type mentioned at the outset in that the gel mass comprises agarose, gellan with a high degree of acylation, one or more fillers, one or more plasticizers and water.

It has surprisingly been shown that the combination of agarose and gellan with a high degree of acylation, in particular, enables the production of a gel mass whose rheological properties are highly suitable for the production of soft capsules using the Scherer process. In particular, the gel mass according to the invention can be processed using the same equipment used to produce soft gelatin capsules. The agarose, in particular, provides the required gel strength, while the gellan with a high degree of acylation is responsible for the required elasticity of the gel mass. The respective advantageous properties of the two polymers, and in particular their gel formation, are surprisingly not negatively affected by this combination.

Agarose is a polysaccharide composed of D-galactose and 3,6-anhydro-L-galactose. Agarose is the main component of agar, in which it, along with agaropectin, makes up approximately 70% by weight. Agar is obtained from various algae species, primarily from the red algae of the genera Gelidium and Gracilaria.

As a component of agar, which is traditionally used as a food in Asia, agarose is completely safe. This represents a significant advantage over carrageenan, a hydrocolloid also derived from algae, which, however, has been suspected for some time of causing allergenic effects in humans. The European Food Safety Authority has set a permissible daily intake of 75 mg/kg body weight for carrageenan, whereas there are no such restrictions for agarose or agar.

Preferably, the agarose is present as a component of agar in the gel mass according to the invention. Agar is relatively inexpensive. Alternatively, pure agarose, which is obtained by removing the agaropectin from agar, can also be used for the gel mass.

In addition to agarose, the gel composition according to the invention contains gellan with a high degree of acylation as another gel-forming hydrocolloid. It has been shown that, in combination with agarose, this leads to significantly better rheological properties of the gel composition than gellan with a low degree of acylation.

The required proportion of agarose and gellan in the gel mass according to the invention is, as explained in detail below, significantly lower than for gelatin. Particularly against this background, the gel mass according to the invention also contains one or more fillers. The filler(s) are preferably selected from fructans, especially inulin, and from modified and/or hydrolyzed starches, especially maltodextrin. However, unmodified starch is not suitable as a filler because it prevents the agarose from gelling.

The gel mass according to the invention further contains one or more plasticizers to ensure the required flexibility of the produced soft capsules. The plasticizer(s) are preferably selected from sugar alcohols and non-reducing sugars, in particular from glycerol, sorbitol, sorbitan, mannitol, maltitol, isomalt, isomaltulose, and trehalose.

Advantageously, the gel mass further comprises one or more complexing agents for divalent metal ions. Complexing these metal ions, particularly calcium and magnesium ions, lowers the setting temperature of the gel mass. The complexing agent(s) are preferably selected from alkali metal salts of polybasic carboxylic acids, particularly sodium or potassium citrate.

• - ca. 0,7 bis ca. 2,1 Gew.% Agarose oder ca. 1,0 bis ca. 3,0 Gew.% Agar, bevorzugt ca. 1,5 bis ca. 2,5 Gew.% Agar,
• - ca. 1,0 bis ca. 3,0 Gew.%, bevorzugt ca. 1,5 bis ca. 2,5 Gew.%, Gellan mit hohem Acylierungsgrad,
• - ca. 10 bis ca. 25 Gew.%, bevorzugt 12 bis 20 Gew.%, eines oder mehrerer Füllstoffe,
• - ca. 10 bis ca. 30 Gew.%, bevorzugt 20 bis 25 Gew.%, eines oder mehrerer Weichmacher,
• - ca. 0,5 bis 2,0 Gew.% eines oder mehrerer Komplexbildner für zweiwertige Metallionen, und
• - ca. 37 bis ca. 78 Gew.% Wasser.

As already mentioned, the gel mass according to the invention preferably comprises a significantly lower proportion of agarose and gellan with a high degree of acylation, typically approximately 5% by weight or less, than the gelatin content of a gel mass for soft gelatin capsules (approximately 40 to 50% by weight). The quantitative composition of the gel mass according to the invention is preferably as follows:

• - approx. 0.7 to approx. 2.1 wt.% agarose or approx. 1.0 to approx. 3.0 wt.% agar, preferably approx. 1.5 to approx. 2.5 wt.% agar,
• - approx. 1.0 to approx. 3.0 wt.%, preferably approx. 1.5 to approx. 2.5 wt.%, gellan with a high degree of acylation,
• - approximately 10 to approximately 25% by weight, preferably 12 to 20% by weight, of one or more fillers,
• - about 10 to about 30% by weight, preferably 20 to 25% by weight, of one or more plasticizers,
• - approximately 0.5 to 2.0 wt.% of one or more complexing agents for divalent metal ions, and
• - approx. 37 to approx. 78 wt.% water.

• - ca. 1,5 bis ca. 2,5 Gew.% Agar,
• - ca. 2,0 bis ca. 3,0 Gew.% Gellan mit hohem Acylierungsgrad,
• - ca. 12 bis ca. 20 Gew.% Maltodextrin,
• - ca. 8,0 bis ca. 15 Gew.% Glycerin,
• - ca. 2,0 bis ca. 3,0 Gew.% Isomalt,
• - ca. 0,5 bis 1,5 Gew.% Natriumcitrat-Dihydrat, und
• - ca. 55,0 bis ca. 74,0 Gew.% Wasser.

According to a first preferred embodiment of the invention, the concrete composition of the gel mass is as follows:

• - approx. 1.5 to approx. 2.5% by weight of agar,
• - approx. 2.0 to approx. 3.0 wt.% gellan with a high degree of acylation,
• - approx. 12 to approx. 20 wt.% maltodextrin,
• - approx. 8.0 to approx. 15 wt.% glycerol,
• - approx. 2.0 to approx. 3.0 wt.% isomalt,
• - approx. 0.5 to 1.5 wt.% sodium citrate dihydrate, and
• - approx. 55.0 to approx. 74.0 wt.% water.

• - ca. 1,5 bis ca. 2,5 Gew.% Agar,
• - ca. 1,5 bis ca. 2,5 Gew.% Gellan mit hohem Acylierungsgrad,
• - ca. 12 bis ca. 20 Gew.% Maltodextrin,
• - ca. 12 bis ca. 20 Gew.% Glycerin,
• - ca. 8 bis ca. 15 Gew.% Isomalt,
• - ca. 0,5 bis 1,5 Gew.% Natriumcitrat-Dihydrat, und
• - ca. 38,5 bis ca. 64,5 Gew.% Wasser.

According to a second preferred embodiment of the invention, with a tendency towards a higher dry mass compared to the first preferred embodiment, the concrete composition of the gel mass is as follows:

• - approx. 1.5 to approx. 2.5% by weight of agar,
• - approx. 1.5 to approx. 2.5 wt.% gellan with a high degree of acylation,
• - approx. 12 to approx. 20 wt.% maltodextrin,
• - approx. 12 to approx. 20 wt.% glycerol,
• - approx. 8 to approx. 15 wt.% isomalt,
• - approx. 0.5 to 1.5 wt.% sodium citrate dihydrate, and
• - approx. 38.5 to approx. 64.5 wt% water.

• - ca. 2 bis ca. 3 Gew.% Agar,
• - ca. 2 bis ca. 3 Gew.% Gellan mit hohem Acylierungsgrad,
• - ca. 12 bis ca. 20 Gew.% Maltodextrin,
• - ca. 12 bis ca. 20 Gew.% Glycerin,
• - ca. 8 bis ca. 15 Gew.% Isomalt,
• - ca. 0,5 bis 1,5 Gew.% Natriumcitrat-Dihydrat, und
• - ca. 37,5 bis ca. 63,5 Gew.% Wasser.

According to a third preferred embodiment of the invention, with a higher proportion of agar and gellan compared to the second preferred embodiment, the concrete composition of the gel mass is as follows:

• - approx. 2 to approx. 3 wt.% agar,
• - approx. 2 to approx. 3 wt.% gellan with a high degree of acylation,
• - approx. 12 to approx. 20 wt.% maltodextrin,
• - approx. 12 to approx. 20 wt.% glycerol,
• - approx. 8 to approx. 15 wt.% isomalt,
• - approx. 0.5 to 1.5 wt.% sodium citrate dihydrate, and
• - approx. 37.5 to approx. 63.5 wt% water.

A higher proportion of agar and gellan typically results in increased elasticity and strength of the soft capsules or films produced from the gel mass.

The gelling point of the gel mass according to the invention is, depending on the specific recipe, typically in the range of 50 to 70 °C.

Since the gel mass according to the invention is intended in particular for the production of vegan soft capsules, it preferably does not comprise any components obtained from animal raw materials, in particular no gelatin, collagen or collagen hydrolysate.

The present invention further relates to the use of the gel mass according to the invention for the production of soft capsules, in particular by means of the rotary die process (Scherer process). As already explained, the gel mass according to the invention is particularly distinguished by the fact that, due to its rheological properties, it can be used for the production of vegan soft capsules on the same systems used for the production of gelatin soft capsules. Thus, no additional costs arise due to the necessary adaptation of the rotary die systems.

• - Bereitstellen einer erfindungsgemäßen Gelmasse bei einer Temperatur zwischen 80 und 100 °C,
• - Bildung eines Films aus der Gelmasse durch Abkühlen auf eine Temperatur von unter 30 °C,
• - Bereitstellen einer Kapselfüllung,
• - Herstellen der Weichkapseln durch Umschließen der Kapselfüllung mit dem aus der Gelmasse gebildeten Film unter Ausbildung einer Kapselhülle, und
• - Trocknen der Kapselhülle bis zu einem Wassergehalt von ca. 20 Gew.% oder weniger.

The present invention further relates to a process for producing soft capsules, comprising the steps

• - Providing a gel mass according to the invention at a temperature between 80 and 100 °C,
• - Formation of a film from the gel mass by cooling to a temperature below 30 °C,
• - Providing a capsule filling,
• - producing the soft capsules by enclosing the capsule filling with the film formed from the gel mass to form a capsule shell, and
• - Drying the capsule shell to a water content of approximately 20% by weight or less.

The process according to the invention corresponds in its basic features to the known rotary die process for the production of soft gelatin capsules and, as mentioned, can be carried out on the same rotary die systems.

However, one difference from the production of gelatin capsules is that the aging process required for gelatin capsules, which involves tempering the gel mass over a period of 6 to 18 hours, is not required for the agarose and gellan-based gel mass according to the invention. By eliminating the aging process, the process according to the invention offers significant time savings.

In rotary die systems, the gel mass is typically provided at a temperature between 80 and 100 °C via a so-called spreader box. From this box, the gel mass is transferred to a rotating cooling drum to form the film. Cooling to a temperature below 30 °C can be achieved either passively or by means of active cooling.

The capsule filling is preferably enclosed by welding two film strips together at a temperature of approximately 95 °C or more. Accordingly, the system typically includes two spreader boxes, cooling drums, etc. The capsule filling is metered between the two opposing strips via a so-called wedge. The film strips are welded around the filling using a rotating forming roller, the actual rotary die, and the capsules are formed.

The present invention further relates to a soft capsule produced from a gel composition according to the invention and/or by the process according to the invention. Preferred embodiments and advantages of the soft capsules according to the invention have already been described in connection with the gel composition according to the invention.

The soft capsule according to the invention preferably comprises a capsule shell with a thickness in the range of approximately 200 to approximately 1,000 µm, these values referring to the thickness of the capsule shell after drying the soft capsule. By adjusting the thickness of the film strips formed from the gel mass in the rotary die process, the resulting thickness of the capsule shell can be varied over a relatively wide range. Depending on the composition of the gel mass and the specific intended use of the soft capsules, thinner or thicker capsule shells may be preferred, for example in the range of approximately 200 to approximately 400 µm, in the range of approximately 400 to approximately 700 µm, or in the range of approximately 700 to approximately 1,000 µm.

In addition to the production of soft capsules, the gel mass according to the invention is in principle also suitable for other applications, e.g. in the food sector or for technical applications.

The invention therefore also relates to the use of a gel mass according to the invention for producing a film, as well as to a film produced from a gel mass according to the invention. Such films can be used, for example, for the production of foodstuffs or as a biodegradable film (e.g., as packaging material).

The film according to the invention preferably has a thickness in the range of approximately 200 to approximately 1,000 µm. To produce the film, the gel mass according to the invention can be applied, in particular with an appropriate thickness, to a carrier, e.g., by means of a doctor blade, and then cooled and dried to gel. As in the case of the capsule shell, the thickness of the film according to the invention can be varied over a relatively wide range, in particular depending on the intended use. For example, the film can have a thickness in the range of approximately 200 to approximately 400 µm, in the range of approximately 400 to approximately 700 µm, or in the range of approximately 700 to approximately 1,000 µm.

A special feature of the film according to the invention is that it is transparent after drying, unlike comparable films based on other hydrocolloids. The transparency of the film represents a significant advantage for many applications.

These and other advantages of the invention are explained in more detail using the following embodiments.

Production of gel masses according to the invention

The components used for the production of gel masses according to the invention are listed in Table 1 below. Table 1 Example 1 Example 2 Example 3 agar 200 g 200 g 250g Gellan with high degree of acylation 250g 200 g 250g Maltodextrin 1,500 g 1,500 g 1,500 g Glycerin 1,030 g 1,500 g 1,500 g Isomalt 250g 1,000 g 1,000 g Sodium citrate dihydrate 100 g 100 g 100 g Water 6,670 g 5,500 g 5,400 g

To prepare the gel mass, the agar and sodium citrate are first boiled in water while stirring until a clear solution is obtained. Then, the filler maltodextrin and the plasticizer isomalt are mixed and added to the solution while stirring until a clear solution is obtained. The highly acylated gellan is mixed with the plasticizer glycerin and gradually added to the hot solution. The mixture is stirred at 95 °C until a homogeneous gel mass is obtained.

In this procedure, crystallization of the isomalt can be prevented by mixing the isomalt with the maltodextrin before adding it to the solution.

The gel masses according to Examples 1 to 3 have a gel point of approximately 57 °C, approximately 62 °C and approximately 66 °C, respectively.

Production of films according to the invention

A film was produced from the gel mass according to Example 1 by pouring the gel mass from the spreader box of a rotary die system onto the cooling drum at approximately 80 °C.

The film has a thickness of approximately 1,000 µm before drying. After drying to a water content of approximately 16 wt.%, the film thickness is approximately 850 µm.

The produced film is transparent.

Claims (19)

Gel mass for the production of soft capsules or films, characterized in that the gel mass comprises agarose, gellan with a high degree of acylation, one or more fillers, one or more plasticizers and water. Gel mass after Claim 1 , where agarose is contained in the gel mass as a component of agar. Gel mass according to one of the preceding claims, wherein the filler(s) are selected from fructans, in particular inulin, and from modified and/or hydrolyzed starches, in particular maltodextrin. Gel mass according to one of the preceding claims, wherein the plasticizer(s) are selected from sugar alcohols and non-reducing sugars, in particular from glycerol, sorbitol, sorbitan, mannitol, maltitol, isomalt, isomaltulose and trehalose. Gel mass according to one of the preceding claims, further comprising one or more complexing agents for divalent metal ions, which are preferably selected from alkali metal salts of polybasic carboxylic acids, in particular sodium or potassium citrate. Gel mass according to one of the preceding claims, comprising - about 0.7 to about 2.1% by weight of agarose or about 1.0 to about 3.0% by weight of agar, preferably about 1.5 to about 2.5% by weight of agar, - about 1.0 to about 3.0% by weight, preferably about 1.5 to about 2.5% by weight of gellan with a high degree of acylation, - about 10 to about 25% by weight, preferably 12 to 20% by weight, of one or more fillers, - about 10 to about 30% by weight, preferably 20 to 25% by weight, of one or more plasticizers, - about 0.5 to 2.0% by weight of one or more complexing agents for divalent metal ions, and - about 37 to about 78% by weight of water. Gel mass after Claim 6 , comprising - approx. 1.5 to approx. 2.5 wt.% agar, - approx. 2.0 to approx. 3.0 wt.% gellan with a high degree of acylation, - approx. 12 to approx. 20 wt.% maltodextrin, - approx. 8.0 to approx. 15 wt.% glycerol, - approx. 2.0 to approx. 3.0 wt.% isomalt, - approx. 0.5 to 1.5 wt.% sodium citrate dihydrate, and - approx. 55.0 to approx. 74.0 wt.% water. Gel mass after Claim 6 , comprising - approx. 1.5 to approx. 2.5 wt.% agar, - approx. 1.5 to approx. 2.5 wt.% gellan with a high degree of acylation, - approx. 12 to approx. 20 wt.% maltodextrin, - approx. 12 to approx. 20 wt.% glycerol, - approx. 8 to approx. 15 wt.% isomalt, - approx. 0.5 to 1.5 wt.% sodium citrate dihydrate, and - approx. 38.5 to approx. 64.5 wt.% water. Gel mass after Claim 6 , comprising - approx. 2 to approx. 3 wt.% agar, - approx. 2 to approx. 3 wt.% gellan with a high degree of acylation, - approx. 12 to approx. 20 wt.% maltodextrin, - approx. 12 to approx. 20 wt.% glycerol, - approx. 8 to approx. 15 wt.% isomalt, - approx. 0.5 to 1.5 wt.% sodium citrate dihydrate, and - approx. 37.5 to approx. 63.5 wt.% water. Gel mass according to one of the preceding claims, wherein the gel mass does not comprise any components obtained from animal raw materials, in particular no gelatin, collagen or collagen hydrolysate. Gel mass according to one of the preceding claims, wherein the gel mass does not contain carrageenan. Use of a gel mass according to one of the preceding claims for the production of soft capsules, in particular by means of the rotary die process. A process for producing soft capsules, comprising the steps of - providing a gel mass according to one of the Claims 1 until 11 at a temperature between 80 and 100 °C, - forming a film from the gel mass by cooling to a temperature below 30 °C, - providing a capsule filling, - producing the soft capsules by enclosing the capsule filling with the film formed from the gel mass to form the capsule shell, and - drying the capsule shell to a water content of approximately 20% by weight or less. Procedure according to Claim 13 , wherein the capsule filling is enclosed by welding two strips of film at a temperature of approximately 95 °C or more. Soft capsule, made from a gel mass according to one of the Claims 1 until 11 and/or in accordance with the procedure Claim 13 or 14 . Soft capsule after Claim 15 , comprising a capsule shell having a thickness in the range of approximately 200 to approximately 1,000 µm, preferably in the range of approximately 200 to approximately 400 µm, in the range of approximately 400 to approximately 700 µm or in the range of approximately 700 to approximately 1,000 µm. Use of a gel mass according to one of the Claims 1 until 11 to make a film. Film made from a gel mass according to one of the Claims 1 until 11 . Film after Claim 18 , wherein the film has a thickness in the range of about 200 to about 1,000 µm, preferably in the range of about 200 to about 400 µm, in the range of about 400 to about 700 µm or in the range of about 700 to about 1,000 µm.