TOPICAL COMPOSITIONS

Abstract

The present invention is concerned with the use of a PEG-emulsifier, optionally in combination with hyaluronic acid or a salt thereof for suppressing discoloration in topical compositions comprising vitamin B6 or a derivative thereof. Furthermore, the invention relates to a method for reducing discoloration of topical compositions containing vitamin B6 or a derivative thereof, comprising preparing a topical composition comprising vitamin B6, a PEG-emulsifiers and optionally hyaluronic acid and a cosmetically acceptable carrier.

Claims

1. Use of a PEG-emulsifier, optionally in combination with hyaluronic acid or a salt thereof for suppressing discoloration of topical compositions comprising Vitamin B6 or a derivative thereof.

2. The use according to claim 1, wherein the Vitamin B6 or derivative thereof is pyridoxine hydrochloride.

3. The use according to claim 1, wherein the PEG emulsifier is PEG-100 stearate, optionally in combination with glyceryl stearate, PEG-20 Cocoate and/or Steareth-21.

4. The use according to claim 1, wherein a hyaluronic acid or a salt thereof is present and wherein the hyaluronic acid or a salt thereof is sodium hyaluronate.

5. The use according to claim 1, wherein the amount of the Vitamin B6 or a derivative thereof in the topical compositions is selected in the range of 0.02 to 6 wt. %, preferably in the range of 0.05 to 4 wt. %, most preferably in the range of 0.1 to 3 wt. %, based on the total weight of the composition.

6. The use according to claim 1, wherein the amount of the PEG-emulsifier is selected in the range of 0.02 to 6-wt. %, preferably in the range of 0.05 to 4 wt.-%, most preferably in the range of 0.1 to 3 wt.-%, based on the total weight of the composition.

7. The use according to claim 1, wherein the amount of the hyaluronic acid or a salt thereof is selected in the range of 0.01 to 5 wt.-%, preferably in the range of 0.02 to 3 wt.-%, most preferably in the range of 0.05 to 2 wt.-%, based on the total weight of the composition.

8. The use according to claim 1, wherein the topical composition is an O/W emulsion comprising an oily phase dispersed in an aqueous phase in the presence of the PEG-emulsifier.

9. Method for reducing discoloration of topical compositions containing Vitamin B6 or a derivative thereof, comprising preparing a topical composition comprising Vitamin B6 or a derivative thereof, a PEG-emulsifier and optionally hyaluronic acid or a salt thereof and a cosmetically acceptable carrier.

10. The method according to claim 9 wherein the Vitamin B6 or derivative thereof is pyridoxine hydrochloride.

11. The method according to claim 9, wherein the PEG-emulsifier is PEG-100 stearate used in combination with glyceryl stearate.

12. The method according to claim 9, wherein a hyaluronic acid or a salt thereof is present and wherein the hyaluronic acid or a salt thereof is sodium hyaluronate.

13. The method according to claim 9, wherein the amount of the Vitamin B6 or a derivative thereof in the topical compositions is selected in the range of 0.02 to 6 wt.-%, preferably in the range of 0.05 to 4 wt.-%, most preferably in the range of 0.1 to 3 wt.-%, based on the total weight of the composition.

14. The method according to claim 9, wherein the amount of the PEG-emulsifier is selected in the range of 0.02 to 6 wt.-%, preferably in the range of 0.05 to 4 wt.-%, most preferably in the range of 0.1 to 3 wt.-%, based on the total weight of the composition.

15. The method according to claim 9, wherein the amount of the hyaluronic acid or a salt thereof is selected in the range of 0.01 to 5 wt.-%, preferably in the range of 0.02 to 3 wt.-%, most preferably in the range of 0.05 to 2 wt.-%, based on the total weight of the composition.

Description

EXAMPLE 1

[0050] The formulations as outlined in table 1 have been prepared and stored for 3 months at 40° C. As reference the same composition comprising a cetyl phosphate emulsifier has been prepared. The colour stability was assessed by measuring the b values (L* a* b* values/CIELAB system) at t0 and after 3 months storage, which is an indicator of the discoloration of the sample (the higher the b-value, the higher the discoloration).

TABLE-US-00001 TABLE 1 Ref. 1 Inv. 1 Inv. 2 INCI Wt % Wt % Wt % PEG-100 Stearate, Glyceryl Stearate 2.0 2.0 (Arlacel 165) Potassium Cetyl Phosphate (Amphisol K) 2.0 Cetyl Alcohol 3.0 3.0 3.0 Cetearyl Alcohol 2.0 2.0 2.0 Dimethicone 3.0 3.0 3.0 Caprylic/Capric Triglyceride 10.0 10.0 10.0 Glycerin 3.0 3.0 3.0 Xanthan Gum 0.3 0.3 0.3 Phenoxyethanol, Ethylhexylglycerin 1.0 1.0 1.0 Pyridoxin HCI 1.0 1.0 1.0 Hyaluronic Acid (Hyasol PF) 3.0 Aqua Ad 100 Ad 100 Ad 100 b-value initial −0.90 −0.70 −0.72 b-value after 3 months/40° C. +0.46 −0.40 −0.37

[0051] Surprisingly, the use of a PEG-emulsifier solved the problem of discoloration, while the addition of sodium hyaluronate even ameliorated the effect. The color of the formulation stayed cream-white over the whole storage time while the formulation comprising a cetyl phosphate emulsifier turned yellow.

EXAMPLE 2

[0052] The formulations as outlined in table 2 and 3 have been prepared and stored for 6 weeks on a window board. The reference comprised a cetyl phosphate emulsifier instead of a PEG-emulsifier. Table 2 outline examples with 2 wt.-% of emulsifiers and 0.5 wt.-% Vitamin B6 whereas table 3 outline examples with 2 wt.-% of emulsifiers and 0.1 wt.-% of vitamin B6.

[0053] The colour stability was assessed by measuring the L* a* b* values at tO and after 6 weeks storage. Then the ΔE values after 6 weeks storage versus tO have been calculated.

[0054] The L* a* b* measurement determines a possible color change of formulations. The L* a* b* system is also referred to as the CIELAB system. It can be visualized as a cylindrical coordinate system in which the axis of the cylinder is the lightness variable L*, ranging from 0% to 100%, and the radii are the chromaticity variables a* and b*. Variable a* is the green (negative) to red (positive) axis, and variable b* is the blue (negative) to yellow (positive) axis. Based on these values, the ΔE values can be calculated. The ΔE value reflects the difference of the overall color of a formulation over storage time. The higher the ΔE value the stronger the difference of color.

TABLE-US-00002 TABLE 2 Ref. 1 Inv. 1 Inv. 2 Inv. 3 Inv. 4 Inv. 5 Inv. 6 INCI Wt % Wt % Wt % Wt % Wt % Wt % Wt % Potassium Cetyl Phosphate 2.0 (Amphisol K) PEG-100 Stearate, Glyceryl 2.0 2.0 Stearate (Arlacel 165) Steareth-21 (Eumulgin S21) 2.0 2.0 PEG-20 Cocoate (Hydriol KP 10) 2.0 2.0 Cetyl Alcohol 3.0 3.0 3.0 3.0 3.0 3.0 3.0 Cetearyl Alcohol 2.0 2.0 2.0 2.0 2.0 2.0 2.0 Dimethicone 3.0 3.0 3.0 3.0 3.0 3.0 3.0 Caprylic/Capric Triglyceride 10.0 10.0 10.0 10.0 10.0 10.0 10.0 Glycerin 3.0 3.0 3.0 3.0 3.0 3.0 3.0 Xanthan Gum 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Phenoxyethanol, Ethylhexylglycerin 1.0 1.0 1.0 1.0 1.0 1.0 1.0 Pyridoxin HCl 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Hyaluronic Acid (Hyasol PF) 3.0 3.0 3.0 Aqua Ad 100 ΔE values after 6 versus t0 6.77 4.53 4.91 5.28 5.89 4.84 4.17

TABLE-US-00003 TABLE 3 Ref. 1 Inv. 1 Inv. 2 Inv. 3 Inv. 4 Inv. 5 Inv. 6 INCI Wt % Wt % Wt % Wt % Wt % Wt % Wt % Potassium Cetyl Phosphate 2.0 (Amphisol K) PEG-100 Stearate, Glyceryl 2.0 2.0 Stearate (Arlacel 165) Steareth-21 (Eumulgin S21) 2.0 2.0 PEG-20 Cocoate (Hydriol KP 10) 2.0 2.0 Cetyl Alcohol 3.0 3.0 3.0 3.0 3.0 3.0 3.0 Cetearyl Alcohol 2.0 2.0 2.0 2.0 2.0 2.0 2.0 Dimethicone 3.0 3.0 3.0 3.0 3.0 3.0 3.0 Caprylic/Capric Triglyceride 10.0 10.0 10.0 10.0 10.0 10.0 10.0 Glycerin 3.0 3.0 3.0 3.0 3.0 3.0 3.0 Xanthan Gum 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Phenoxyethanol, Ethylhexylglycerin 1.0 1.0 1.0 1.0 1.0 1.0 1.0 Pyridoxin HCl 0.1 0.1 0.1 0.1 0.1 0.1 0.1 Hyaluronic Acid (Hyasol PF) 3.0 3.0 3.0 Aqua Ad 100 ΔE values after 6 weeks 3.34 2.40 2.21 2.69 1.94 1.82 1.63 storage versus t0

[0055] Surprisingly, formulas containing PEG-emulsifiers showed lower ΔE values, corresponding to a lower discoloration of the formulations, compared to formulations containing a cetyl phosphate as emulsifier.