A film-forming composition comprising pullulan and a glucan

Abstract

The present invention is directed to aqueous film-forming compositions suitable for capsule films, capsule shells, as wells as methods for producing such capsule film, capsule shell and the use thereof.

Description

[0001] A FILM-FORMING COMPOSITION COMPRISING PULLULAN AND A GLUCAN

[0002] FIELD OF THE INVENTION

[0003] The present invention is directed to aqueous film-forming compositions suitable for capsule films, capsule shells, as wells as methods for producing such capsule film, capsule shell and the use thereof.

[0004] BACKGROUND OF THE INVENTION

[0005] Capsules are widely used in administration of pharmaceuticals and nutritional to humans and animals. Capsules also have divergent uses, such as serving as reservoirs of plant fertilizer for easy application, of colorants, of food materials or food supplements, and of cosmetic ingredients. Pullulan is a convenient material for the film part of the capsule because pullulan film can be formed on the capsule pins in the process of preparing the capsule with the aid of gelling agents.

[0006] Pullulan capsules are natural, clean label, potentially organic certifiable and have very low oxygen permeation. Pullulan capsules become a desirable alternative to gelatin capsules and HPMC capsules in today's consumer demands. The common gelling agent carrageenan used with pullulan capsules has a perception of being an unsafe material and consumers demand carrageenan-free products. Additionally, pullulan capsules with carrageenan as a setting system tend to dissolve differently when pH, salt concentration, protein concentration changes in the digestive tract. Another common gelling agent, gellan gum, tend to have more pH dependency than those of capsules made with carrageenan.

[0007] There is a continuous need for alternative capsule films and capsule shells of different materials providing for improved properties.

[0008] BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1. Synthesis of B-1,3 glucan using a three-enzyme system, Using sucrose phosphorylase, laminaribiose phosphorylase and laminaridextrin phosphorylase.

[0010] Figure 2. SEC chromatograms of SK-018 (red) and SK-019 (black).

[0011] Figure 3. A comparison of statistical analysis of normalized puncture force for pullulan film and the film made with blend of pullulan and p-1,3 glucan (Exp806 as shown in Table 4).

[0012] Figure 4. A comparison of statistical analysis of normalized puncture strength for pullulan film and the film made with blend of pullulan and p-1,3 glucan (Exp0122 as shown in Table 1).

[0013] SUMMARY OF THE INVENTION It is an object of embodiments of the invention to provide aqueous film-forming composition suitable for improved capsule coatings, films or capsule shells.

[0014] The present invention relates in a broad aspect to aqueous film-forming compositions suitable for improved or alternative capsule materials.

[0015] Accordingly, in a first aspect the present invention relates to an aqueous film-forming composition comprising a) one or more water-soluble, film forming polysaccharide(s) having a MW above about 15 kDA which polysaccharide(s) comprises units selected from the group consisting of glucose, fructose, and galactose units, which units are bound together by glycosidic bonds; and b) a 0-1,3-glucan having a MW in the range from about 1 to about 15 kDa.

[0016] In a second aspect the present invention relates to a capsule shell comprising an aqueous film-forming composition which composition comprises: a) one or more water-soluble, film forming polysaccharide(s) having a MW above about 15 kDA which polysaccharide(s) comprises units selected from the group consisting of glucose, fructose, and galactose units, which units are bound together by glycosidic bonds; and b) a -1,3-glucan having a MW in the range from about 1 to about 15 kDa.

[0017] In a third aspect the present invention relates to a capsule comprising a capsule shell prepared from the composition of the invention or a capsule shell according to the invention.

[0018] In a further aspect the present invention relates to a process for producing capsule film or capsule shells comprising the steps of providing the aqueous composition according to the invention, pre-heating moulding pins to a temperature at highest viscosity point ± 5 °C of the aqueous composition above the gelation temperature, dipping the pre-heated moulding pins into the aqueous composition at a temperature below gelation temperature, forming a film on said moulding pins by withdrawing said pins from said composition, and drying the film on the moulding pins above the gelation temperature.

[0019] In a further aspect the present invention relates to the use of a composition according to the invention for the manufacture of capsules in a dip moulding process, such as a hot dipping pins process.

[0020] DETAILED DESCRIPTION OF THE INVENTION

[0021] These present inventors have found a natural polymer, 0-1,3 glucan, that can serve as a setting system to facilitate gelation of film forming polysaccharide(s) having a MW above about 15 kDA which polysaccharide(s) comprising units of glucose, fructose, and galactose units, such as pullulan, which may be used for capsules. The same concept will apply for glucan based capsules potentially using a-1,6 glucan or enzymatically made pullulan-like materials (a-1,6 - a-1,4 glucan branched with majority of either a-1,6 or a- 1,4) and 0-1,3 glucan which will impart gelling properties that facilitate hard capsule manufacturing.

[0022] The commercial high MW 0-1,3 glucan (curdlan, ~ 2000 kDa) is not soluble in cold water due to the existence of extensive intra / intermolecular hydrogen bonds. However, the 0-1,3 glucan suitable for use in the compositions of the present invention is typically around 2 kDa with approximately 15 glucose units. The present inventors have identified three major components in 0-1,3 glucan. It was found that the component 2 preferably should be > 70%, wherein component 3 preferably should be < 30% to impart the optimal film performance.

[0023] As detailed above the present invention relates to an aqueous film-forming composition comprising a) one or more water-soluble, film forming polysaccharide(s) having a MW above about 15 kDA which polysaccharide(s) comprises units selected from the group consisting of glucose, fructose, and galactose units, which units are bound together by glycosidic bonds; and b) a 0-1,3-glucan having a MW in the range from about 1 to about 15 kDa.

[0024] In some embodiments the 0-1,3-glucan is thermo reversible in water.

[0025] In some embodiments the 0-1,3-glucan has a MW in the range from about 1 to about 14 kDa, such as from about 1 to about 12 kDa, preferably in the range of from about 1 to about 10 kDa, and more preferably in the range of from about 1 to about 5 kDa, and most preferably in the range of from about 2 to about 4 kDa.

[0026] In some embodiments the 0-1,3-glucan comprises glucose units in the range from about 5 to about 1000 glucose units such as glucose units in the range from about 5 to about 300 glucose units, preferably glucose units in the range from about 7 to about 100 glucose units, more preferably in the range of glucose units in the range from about 9 to about 50 glucose units, and most preferably in the range of from about 12 to about 20 glucose units.

[0027] In some embodiments the 0-1,3-glucan is unbranched.

[0028] In some embodiments the 0-1,3-glucan is prepared by an enzymatic reaction using a 0-1,3- glucan phosphorylase or a 0-1,3-glucan synthase. In some embodiments the -1,3-glucan is derived from algae, fungi, plants or bacteria.

[0029] In some embodiments the p-l,3-glucan is selected from the group consisting of callose, laminarin, and paramylon.

[0030] In some embodiments the >70% by weight of the total amount of p-l,3-glucan has a degree of polymerization (DP) above 9, more preferably >80% by weight of the total amount of 0-1,3-glucan has DP above 11, and most preferably >90% by weight of the total amount of 0-1,3-glucan has a DP above 12 .

[0031] In some embodiments the water-soluble film forming polysaccharide is selected from the group consisting of starch, pullulan, and glucan such as a-glucan.

[0032] In some embodiments the water-soluble film forming polysaccharide is an enzymatically produced polysaccharide.

[0033] In some embodiments the water-soluble film forming polysaccharide is derived from algae, fungi, plants or bacteria.

[0034] In some embodiments the water-soluble film forming polysaccharide is pullulan. In some embodiments the pullulan is enzymatically produced.

[0035] In some embodiments the water-soluble film forming polysaccharide is an a-glucan, preferably a-l,6-glucan with a-1,2 branches; a-l,6-glucan with a-1,3 branches or a-1,4 glucan with a-1,6 branches.

[0036] In some embodiments the water-soluble film forming polysaccharide has a solution viscosity in the range from about 500 cps to about 5000 cps at temperatures in the range of about 5 °C to about 80 °C with solution concentration within the range of about 10 wt% to about 40 wt% .

[0037] In some embodiments the composition according to invention is essentially free from cations such as mono- or divalent cations.

[0038] In some embodiments the final film composition comprises less than 5%, preferably less than 3%, most preferably less than 1% of sugar molecules (such as glucose, fructose, sucrose, and glucose-l-phosphate) by weight of dry film basis.

[0039] In some embodiments the concentration of the water-soluble film forming polysaccharide, such as pullulan is at least about 80%, such as at least about 82%, such as at least about 85%, such as at least about 87%, such as at least about 90% by weight of dry film basis. In some embodiments the concentration of the water-soluble film forming polysaccharide, such as pullulan is at least about 80-95%, such as in the range of 82-95%, such as 85-90, such as 87-90% by weight of dry film basis.

[0040] In some embodiments the concentration of 0-1,3-glucan is at least about 0.1%, such as at least about 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, or 9.0% by weight of dry film basis.

[0041] In some embodiments the concentration of 0-1,3-glucan is not more than about 9.0, such as not more than about 8.5, 8.0, 7.5, 7.0, 6.5, 6.0, 5.5, 5.0, 4.5, 4.0, 3.5, 3.0, 2.5, 2.0, 1.8, 1.6, 1.4, 1.2, 1.0, 0.8, 0.6, such as in the range of 0.1-10.0%, such as 0.2-8.0%, such as 0.4-6.0%, such as 0.6-4.0%, such as 0.8-4.0%, such as 1.0-4.0% by weight of dry film basis.

[0042] In some embodiments the composition according to invention is further comprising a plasticizer, wherein the plasticizer is a polyol, such as a sugar alcohol, such as sorbitol, mannitol, erythritol, xylitol, or glycerol (Propane-1, 2, 3-triol), or acetate esters of glycerol selected from the class consisting of the mono-, di-, and tri-acetates of glycerol, TEC (triethyl citrate), dibutyl sebacate, and dibutyl phthalate, or mixtures thereof.

[0043] In some embodiments the composition according to invention is additionally comprising at least one ingredient selected from the group consisting of surfactants, such as simethicone, sodium lauryl sulfate, lecithin, sorbitan esters; coloring agents, flavoring agents, or mixtures thereof.

[0044] 0-1,3-glucans consist of glucose polymers with variable molecular weight (MW). This present invention concerns aqueous compositions comprising a 0-1,3-glucan having a MW in the range from about 1 to about 15 kDa. A 0-1,3-glucan has a degree of polymerization (DP) and it is to be understood that when the 0-1,3-glucan is made enzymatically the distribution of components with different degree of polymerization can be "manipulated", e.g. by enzyme dose, temperature etc. The present inventors have identified three major components in 0-1,3 glucan, which components differ in DP and in MW. The ratio of the largest MW component of 0-1,3-glucan with a degree of polymerization (DP) above 9 to be used in an aqueous film-forming composition according to the present invention is preferably above 70%.

[0045] Film forming polysaccharide(s)

[0046] Any suitable film forming polysaccharide(s) having a MW above about 15 kDa which polysaccharide(s) comprises units selected from the group consisting of glucose, fructose, and galactose units, which units are bound together by glycosidic bonds may be used for the film of the present invention. The person skilled in the art will know these suitable polymers.

[0047] Suitable film forming polymer used according to the present invention includes starch, pullulan, and glucan such as o-glucan, such as an o-l,6-glucan with a-1,2 branches; an a- 1,6-glucan with a-1,3 branches or an a-1,4 glucan with a-1,6 branches.

[0048] Suitable film forming polymer used according to the present invention can be naturally derived (without chemical modification via chemical methods that involve additional chemicals that are not naturally derived, i.e., non-microbial or non-enzymatic methods) or enzymatic synthesized. Suitable film forming polymer used according to the present invention may be naturally derived and purified from a suitable species including from algae, fungi, plants or bacteria.

[0049] Plasticizer

[0050] Examples of the plasticizer include surfactants such as sucrose fatty acid ester, glycerin fatty acid ester, monoglycerin fatty acid ester, polyoxyethylene sorbitan fatty acid ester and the like, ester of citric acid such as triethyl citrate (TEC); polyhydric alcohol such as glycerin, propylene glycol, polyethylene glycol, etc., glucose , Sugar such as fructose and glucose liquid sugar, sugar such as sucrose, sugar alcohol such as sorbitol, maltitol, mannitol, erythritol, xylitol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, Higher alcohols such as hexadecyl alcohol, isostearyl alcohol, 2- octyldodecanol and the like (preferably having 6 to 22 carbon atoms), and oils and fats such as medium chain fatty acid esters (preferably having 6 to 12 carbon atoms) It is below. These may be used alone or in combination of two or more.

[0051] EXPERIMENTAL SECTION

[0052] EXAMPLE 1

[0053] Synthesis of |3-1,3 glucan used in the following examples are shown in figure 1.

[0054] Two large batches of beta-1,3 glucan (SK018 and SK019; Table 1) were made using a three-enzyme system (Fig.l). Reactions were conducted in one pot combining three enzymes together: Sucrose phosphorylase from Lactobacillus amylovorus GRL1118 (LEI2183 - W02020023278), laminaribiose phosphorylase from Paenibacillus sp. YM-1 [CRC12031](M . Kitaoka,, T. Sasaki, and H. Tamiguchi, Arch. Biochem. Biophys. (1993) DOI: 10.1006 / abbi.1993. 1383 doi: 10.1006 / abbi.1993. 1383) and lamiaridextrinphosphorylase from Clostridium grantti DSM 8605 [CRC12027 - WO2019209559A1], Enzymes were recombinantly expressed in Bacillus host (CBS 12-1).

[0055] Enzyme reactions were performed at 37 °C.

[0056] Table 1 : Composition of B-1,3 glucan batches produced, using LEI 2183, CRC 12031 and CRC 12027 in a one pot reaction.

[0057] The SEC analysis of the two -1,3 glucans are shown below.

[0058] The samples (SK-018 and SK-019) were dissolved in distilled water at 50 °C on a heater shaker for 2 hours. Each sample was prepared at two concentration levels, 1.5 and 1.8 mg / mL, respectively. The samples were filtered by 0.45 pm Nylon syringe filters prior to analyses.

[0059] The samples were analyzed by a chromatograph consisting of Agilent G7111B pump, G7129A autosampler, G7116A column oven, and G7162A refractive index detector (RI). The samples were injected to a column (Tosoh TSKgel G2500PW) maintained at 35 °C. The RI detector was set at 35 °C as well. The eluent was water with 0.05 wt% NaN3. The flow rate was at 0.5 mL / min. The injection volume was 0.1 mL. The chromatograms in Figure 2 were obtained by subtracting the blank (distilled water) chromatogram from sample chromatograms.

[0060] Three components are identified in the chromatograms as component 1, 2, and 3. The total peak area of the three components divided by the injected sample concentrations are similar between SK-018 and SK-019. The concentrations of individual components are calculated from the peak area of the components divided by the total peak area. The results are listed in Table 2. SK-018 has higher concentration of the major component (Component 2) than SK-019. Table 2. Concentrations of component 1, 2, and 3

[0061] The SEC elution time of component 2 of the two samples are compared in Table 3. The elution time of component 2 in SK-018 is slightly lower than that in SK-019 suggesting that the MW of the component is slightly higher in SK-018.

[0062] Table 3. Elution time of Component 2

[0063] Comparative example:

[0064] An example formulation with a (3-1,3 glucan (SK-019) is shown in Table 4.

[0065] Table 4. Formulation of pullulan with 0-1,3 glucan (SK-019).

[0066] As seen from Figure 3 the puncture strength of the film made from the blend of pullulan and 0-1,3 glucan (Exp806 as shown in Table 4), was lower than that of pullulan by itself. The puncture distance of the film made from the blend of pullulan and 0-1,3 glucan (Exp806 as shown in Table 3) was also lower to that of pullulan by itself.

[0067] EXAMPLE 2

[0068] An example formulation with a 0-1,3 glucan (SK-018) is shown in Table 5. Table 5. Formulation of pullulan with 0-1,3 glucan (SK-018).

[0069] A comparison of rheology curves demonstrated that the solution of pullulan and 0-1,3 glucan showed a synergistic effect with gel strength similar to that HPMC F5 solutions at temperatures above 45 °C during heating. This indicates that a cold / hot pin process can be used to gel the solution on capsule pins by adjusting solution bath processes and pin temperatures. The puncture strength of the film made from the blend of pullulan and 0-1,3 glucan (Exp0122 as shown in Table 5), was surprisingly better than that of pullulan by itself. The puncture distance of the film made from the blend of pullulan and 0-1,3 glucan (Exp0122 as shown in Table 5) was equivalent to that of pullulan by itself.

Claims

CLAIMS1 . An aqueous film-forming composition comprising a ) one or more water-soluble film forming polysaccharide(s) having a MW above about 15 kDa which polysaccharide(s) comprises units selected from the group consisting of glucose, fructose, and galactose units, which units are bound together by glycosidic bonds; and b ) a p-l,3-glucan having a MW in the range from about 1 to about 15 kDa.2 . The composition according to claim 1, which 0-1,3-glucan is thermo reversible in water.3 . The composition according to any one of claims 1-2, wherein the p-l,3-glucan has a MW in the range from about 1 to about 14 kDa, such as from about 1 to about 12 kDa, preferably in the range of from about 1 to about 10 kDa, and more preferably in the range of from about 1 to about 5 kDa, and most preferably in the range of from about 2 to about 4 kDa.4 . The composition according to any one of claims 1-3, wherein the |3-l,3-glucan comprises glucose units in the range from about 5 to about 1000 glucose units such as glucose units in the range from about 5 to about 300 glucose units, preferably glucose units in the range from about 7 to about 100 glucose units, more preferably in the range of glucose units in the range from about 9 to about 50 glucose units, and most preferably in the range of from about 12 to about 20 glucose units.5 . The composition according to any one of claims 1-4, wherein the p-l,3-glucan is unbranched.6 . The composition according to any one of claims 1-5, wherein the p-l,3-glucan is prepared by an enzymatic reaction using a p-l,3-glucan phosphorylase or a p-1, 3- glucan synthase.7 . The composition according to any one of claims 1-6, wherein the p-l,3-glucan is derived from algae, fungi, plants or bacteria.8 . The composition according to any one of claims 1-7, wherein the p-l,3-glucan is selected from the group consisting of callose, laminarin, and paramylon.9 . The composition according to any one of claims 1-8, wherein >70% by weight of the total amount of p-l,3-glucan has a degree of polymerization (DP) above 9, morepreferably >80% by weight of the total amount of |3-l,3-glucan has DP above 11, and most preferably >90% by weight of the total amount of -1,3-glucan has a DP above 12.10 . The composition according to any one of claims 1-9, wherein the water- soluble film forming polysaccharide is selected from the group consisting of starch, pullulan, and glucan such as o-glucan.11 . The composition according to any one of claims 1-10, wherein the water- soluble film forming polysaccharide is an enzymatically produced polysaccharide.12 . The composition according to any one of claims 1-11, wherein the water- soluble film forming polysaccharide is derived from algae, fungi, plants or bacteria.13 . The composition according to any one of claims 1-12, wherein the water- soluble film forming polysaccharide is pullulan.14 . The composition according to claim 13, wherein the pullulan is enzymatically produced.15 . The composition according to any one of claims 1-14, wherein the water- soluble film forming polysaccharide is an a-glucan, preferably o-l,6-glucan with a- 1,2 branches; a-l,6-glucan with o-l,3 branches or a-1,4 glucan with o-l,6 branches.16 . The composition according to any one of claims 1-15, wherein the water- soluble film forming polysaccharide has a solution viscosity in the range from about 500 cps to about 5000 cps at temperatures in the range of about 5 °C to about 80 °C with solution concentration within the range of about 10 wt% to about 40 wt%.17 . The composition according to any one of claims 1-16, which is essentially free from cations such as mono- or divalent cations.18 . The composition according to any one of claims 1-17, wherein the final film composition comprises less than 5%, preferably less than 3%, most preferably less than 1% of sugar molecules (such as glucose, fructose, sucrose, and glucose-1- phosphate) by weight of dry film basis.19 . The composition according to any one of claims 1-18, wherein the concentration of the water-soluble film forming polysaccharide, such as pullulan is at least about 80%, such as at least about 82%, such as at least about 85%, such asat least about 87%, such as at least about 90% by weight of dry film basis.20 . The composition according to any one of claims 1-19, wherein the concentration of the water-soluble film forming polysaccharide, such as pullulan is at least about 80-95%, such as in the range of 82-95%, such as 85-90, such as 87- 90% by weight of dry film basis.21 . The composition according to any one of claims 1-20, wherein the concentration of 0-1,3-glucan is at least about 0.1%, such as at least about 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, or 9.0% by weight of dry film basis.22 . The composition according to any one of claims 1-21, wherein the concentration of p-l,3-glucan is not more than about 9.0, such as not more than about 8.5, 8.0, 7.5, 7.0, 6.5, 6.0, 5.5, 5.0, 4.5, 4.0, 3.5, 3.0, 2.5, 2.0, 1.8, 1.6, 1.4, 1.2, 1.0, 0.8, 0.6, such as in the range of 0.1-10.0%, such as 0.2-8.0%, such as0.4-6.0%, such as 0.6-4.0%, such as 0.8-4.0%, such as 1.0-4.0% by weight of dry film basis.23 . The composition according to any one of claims 1-22, further comprising a plasticizer, wherein the plasticizer is a polyol, such as a sugar alcohol, such as sorbitol, mannitol, erythritol, xylitol, or glycerol (Propane-1, 2, 3-triol), or acetate esters of glycerol selected from the class consisting of the mono-, di-, and triacetates of glycerol, TEC (triethyl citrate), dibutyl sebacate, and dibutyl phthalate, or mixtures thereof.24 . The composition according to any one of claims 1-23 additionally comprising at least one ingredient selected from the group consisting of surfactants, such as simethicone, sodium lauryl sulfate, lecithin, sorbitan esters; coloring agents, flavoring agents, or mixtures thereof.25 . A capsule shell comprising an aqueous film-forming composition which composition comprises: a) one or more water-soluble, film forming polysaccharide(s) having a MW above about 15 kDA which polysaccharide(s) comprises units selected from the group consisting of glucose, fructose, and galactose units, which units are bound together by glycosidic bonds; and b) a p-l,3-glucan having a MW in the range from about 1 to about 15 kDa.

26. The capsule shell according to claim 25 which is a hard-capsule shell.27 . The capsule shell according to any one of claims 25-26 prepared from the composition according to any one of claims 1-24.28 . A capsule comprising a capsule shell prepared from the composition of any one of claims 1-23 or a capsule shell according to any one of claims 25-27.29 . The capsule of claim 28 further comprising a fill material comprising a pharmaceutically active ingredient, dietary supplement, flavouring agent, foodstuff, agrochemical or scent.30 . A process for producing capsule film or capsule shells comprising the steps of providing the aqueous composition according to any one of claims 1-24, pre-heating moulding pins to a temperature higher than 65 °C of the aqueous composition, dipping the pre-heated moulding pins into the aqueous composition at the temperature ranging from 53 to 65 °C, forming a film on said moulding pins by withdrawing said pins from said composition, and drying the film on the moulding pins at a temperature higher than 65 °C.

31. A process for producing capsule film or capsule shells comprising the steps of providing the aqueous composition according to any one of claims 1-24, pre-cooling moulding pins at the temperature ranging from 20-53 °C of the aqueous composition, dipping the pre-cooled moulding pins into the aqueous composition at a temperature higher than 65 °C, forming a film on said moulding pins by withdrawing said pins from said composition, and drying the film in a drying chamber.32 . Use of a composition according to any one of claims 1-24 for the manufacture of capsules in a dip moulding process, such as a hot dipping or cold dipping pins process.

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