USE OF DESTRUCTURIZED STARCH AS A THICKENING AGENT AND COMPOSITIONS CONTAINING IT

Abstract

This invention relates to the use of destructurized starch as a thickening agent in cosmetic, dermatological and pharmaceutical compositions, paints, phytosanitary products and detergents.

Claims

1. A method of thickening a composition selected from the group of cosmetic, dermatological and pharmaceutical compositions, paints, phytosanitary products and detergents, which comprises including 1% to 30% by weight in the composition, with respect to the total weight of the composition, of a destructurized starch as a thickening agent, wherein said destructurized starch is obtained from a starch in the presence of from 1% to 40% by weight, with respect to the weight of said starch, of one or more plasticizers.

2. The method according to claim 1, in which the said destructurized starch is obtained from a starch selected from the group consisting of native starch, oxidized starch, dextrinized starch, starch ethers, starch esters and mixtures thereof.

3. A composition selected from the group of cosmetic, dermatological and pharmaceutical compositions, paints, phytosanitary products and detergents comprising destructurized starch as a thickening agent comprising from 1% to 30% by weight, with respect to the total weight of the respective compositions, of said destructurized starch, wherein said destructurized starch is obtained from a starch in the presence of from 1% to 40% by weight, with respect to the weight of said starch, of one or more plasticizers.

4. The composition according to claim 3, in which the said destructurized starch is obtained from a starch selected from the group consisting of native starch, oxidized starch, dextrinized starch, starch ethers, starch esters, and mixtures thereof.

5. The composition according to claim 3, characterised by viscosities within the range 10-2000 Pa.Math.s measured by means of a plate-plate geometry rotational rheometer at constant shear rate (time sweep test) at 25 C.

6. The composition according to claim 3, characterised by stress threshold values in the range 1-90 Pa using plate-plate geometry rotational rheometer with decreasing stress rate (stress rate test) at 25 C.

7. The composition according to claim 3, in the form of a fluid, gel, foam, spray, lotion or cream.

8. The composition according to claim 3, having aqueous or lipophilic nature.

9. The composition according to claim 8, in the form of emulsions, solutions or dispersions.

10. The composition according to claim 4, characterised by viscosities within the range 10-2000 Pa.Math.s measured by means of a plate-plate geometry rotational rheometer at constant shear rate (time sweep test) at 25 C.

11. The composition according to claim 10, characterised by stress threshold values in the range 1-90 Pa using plate-plate geometry rotational rheometer with decreasing stress rate (stress rate test) at 25 C.

12. The composition according to claim 4, characterised by stress threshold values in the range 1-90 Pa using plate-plate geometry rotational rheometer with decreasing stress rate (stress rate test) at 25 C.

13. The composition according to claim 5, characterised by stress threshold values in the range 1-90 Pa using plate-plate geometry rotational rheometer with decreasing stress rate (stress rate test) at 25 C.

14. The composition according to claim 4, in the form of a fluid, gel, foam, spray, lotion or cream.

15. The composition according to claim 5, in the form of a fluid, gel, foam, spray, lotion or cream.

16. The composition according to claim 6, in the form of a fluid, gel, foam, spray, lotion or cream.

17. The composition according to claim 4, having an aqueous or lipophilic nature.

18. The composition according to claim 5, having an aqueous or lipophilic nature.

19. The composition according to claim 6, having an aqueous or lipophilic nature.

20. The composition according to claim 7, having an aqueous or lipophilic nature.

Description

EXAMPLE 1PREPARATION OF DESTRUCTURIZED STARCH FROM NATIVE MAIZE STARCH

[0064] A mixture comprising 75 parts by weight of Cargill C*Gel 03401 (12% water) native maize starch and 25 parts of water was fed to a TSA EM 21-40 co-rotating twin-screw extruder (diameter=21 mm, L/D=40) operating under the following conditions: [0065] rpm (min.sup.1)=100; [0066] thermal profile ( C.): 60-80-140-170-160-140-120-110; [0067] throughput (kg/h): 1.5; [0068] degassing: closed; [0069] head temperature ( C.): 110; [0070] head pressure (bar): 5-6.

[0071] The destructurized starch so obtained was analysed using phase contrast optical microscopy and this showed that structures which could be attributed to the native granular structure of starch were completely absent.

EXAMPLE 2PREPARATION OF DESTRUCTURIZED STARCH FROM STARCH HYDROXYPROPYLATE

[0072] A mixture comprising 75 parts by weight of Ingredion Beneform 3750 starch hydroxypropylate (13% of water) and 25 parts of water was fed to a TSA EM 21-40 co-rotating twin-screw extruder (diameter=21 mm, L/D=40) operating under the following conditions: [0073] rpm (min.sup.1)=100; [0074] thermal profile ( C.): 60-80-140-170-160-140-110-90; [0075] throughput (kg/h): 2.2; [0076] degassing: closed; [0077] head temperature ( C.): 90; [0078] head pressure (bar): 7-25.

[0079] The destructurized starch so obtained was analysed by phase contrast optical microscopy and showed that structures which could be attributed to the native granular structure of starch were completely absent.

EXAMPLE 3PREPARATION OF STARCH DESTRUCTURIZED FROM NATIVE MAIZE STARCH

[0080] A mixture comprising 75 parts by weight of Cargill C*Gel 03401 (12% water) native maize starch, 15 parts of water and 10 parts of glycerol was fed to a TSA EM 21-40 co-rotating twin-screw extruder (diameter=21 mm, L/D=40) operating under the following conditions: [0081] rpm (min.sup.1)=100; [0082] thermal profile ( C.): 60-80-140-170-160-140-120-110; [0083] throughput (kg/h): 1.5; [0084] degassing: closed; [0085] head temperature ( C.): 110; [0086] head pressure (bar): 5-6.

[0087] The destructurized starch so obtained was analysed using phase contrast optical microscopy and this showed that structures which could be attributed to the native granular structure of starch were completely absent.

EXAMPLES 4-7 AND 8 (COMPARATIVE)PREPARATION OF COSMETIC COMPOSITIONS

[0088] Five cosmetic compositions were prepared using the destructurized starch prepared in Examples 1 and 2 as thickening agent, and as a comparison, native potato starch (compositions in Table 1).

TABLE-US-00001 TABLE 1 Composition (g) Example Example Example Example Example 8 Component 4 5 6 7 (comparative) Plantasens HP30 natural 3 3 3 3 3 emulsifier (Clariant) Myritol 318 softener (Clariant) 12 12 12 12 12 Aqueous solution of glycerine 3 3 3 3 3 (85% wt) Phenonip ME preservative 1 1 1 1 1 (Clariant) Destructurized starch according 11 12 to Example 1 Destructurized starch according 7 10 to Example 2 Maize native starch (Cargill) 11 Water 70 69 74 71 70

[0089] Said compositions were prepared using the following preparation protocol: [0090] A. Plantasens HP30 natural emulsifier (Clariant) and Myritol 318 softener (Clariant) were mixed in a 50 cc flask and heated to approximately 80 C. until they melted/dissolved and were set aside; [0091] B. Then an aqueous solution of 85% by weight glycerine and water were mixed at 25 C. and these too were set aside; [0092] C. The quantities of thickening agent shown in Table 1 were added to the mixture prepared in paragraph A in a polyethylene flask, stirring provided by an Ika Ultra-Turrax T 25 mixer set at 400 rpm; [0093] D. The mixture containing the thickening agent obtained in paragraph C was then added to the mixture obtained in paragraph B with stirring provided by an Ika Ultra-Turrax T 25 (set at 13000 rpm), then keeping the whole stirred for 2 minutes. Subsequently stirring was reduced to 400 rpm, and the mixture so obtained was allowed to cool to 40 C. [0094] E. When the mixture in paragraph D had reached a temperature below 40 C., Phenonip ME preservative (Clariant) was added, again with stirring (400 rpm), and the whole was allowed to cool to 25 C. [0095] F. The pH was then measured and if outside the range 6.0-6.5, citric acid or NaOH was added as necessary in order to bring it within this range. [0096] G. The composition so obtained was allowed to rest for 24 hours and then characterised by determining its viscosity and stress threshold (Table 2).

TABLE-US-00002 TABLE 2 Example Viscosity (Pa .Math. s) Stress Threshold(Pa) 4 506 31 5 631 36 6 282 13 7 567 14 8 (comparative) 40 nd

[0097] wherein, nd stands for not determinable.

EXAMPLES 9, 10 AND 11 (COMPARATIVE)ASSESSMENT OF THE EFFECT OF ELECTROLYTES CONTENT ON THE PERFORMANCE OF THICKENING AGENTS

[0098] In order to test the ability of the thickening agents according to the invention to maintain their properties as the electrolytes content changed, some cosmetic compositions were prepared following the protocol shown in Examples 4-7 and 8 (comparative) above, also adding 3 g of NaCl in paragraph B. Table 3 shows the quantities of thickening agent used to prepare the compositions and the viscosity and stress threshold values obtained.

TABLE-US-00003 TABLE 3 Stress Grams Viscosity Threshold Example Thickening agent added (Pa .Math. s) (Pa) 9 Destructurized 11 356 13 starch according to Example 1 10 Destructurized 7 153 1 starch according to Example 2 11 (com- Maize native 11 25 nd parative) starch

[0099] wherein, nd stands for not determinable.

[0100] Despite the addition of the electrolytes, the compositions according to Examples 9 and 10 appeared to maintain good performance, as shown by the small change in the viscosity and stress threshold values in comparison with Examples 4 and 6.

EXAMPLES 12-17ASSESSMENT OF THE EFFECT OF PH AND THE PERFORMANCE OF THICKENING AGENTS

[0101] In order to test the ability of thickening agents according to the invention to maintain their properties as the pH of the compositions varied, some cosmetic compositions were prepared following the protocol shown above in Examples 4-7 and 8 (comparative), modifying the pH of the compositions to values of 1, 6-6.5 and 12 in paragraph F through the addition of HCl, citric acid or NaOH as required. Table 4 shows the quantities of thickening agents used to prepare the compositions and the viscosity and stress threshold values obtained.

TABLE-US-00004 TABLE 4 Stress Grams Viscosity Threshold Example Thickening agent added pH (Pa .Math. s) (Pa) 12 Destructurized 11 1 744 65 starch according to Example 1 4 Destructurized 11 6-6.5 506 31 starch according to Example 1 13 Destructurized 11 12 718 38 starch according to Example 1 14 Destructurized 7 1 343 15 starch according to Example 2 6 Destructurized 7 6-6.5 282 13 starch according to Example 2 15 Destructurized 7 12 418 27 starch according to Example 2 16 (com- Maize native 11 1 45 nd parative) starch 8 (com- Maize native 11 6-6.5 40 nd parative) starch 17 (com- Maize native 11 12 48 nd parative) starch

[0102] Despite the wide variation of pH, the compositions comprising destructurized starch according to the present invention appeared to maintain good performance, as shown by the small change in the viscosity and stress threshold values throughout the pH range investigated.