Personal Lubricant Composition

Abstract

The present invention provides a personal lubricant composition comprising a humectant and a thixotropic agent, wherein the thixotropic agent comprises a combination of: i) one or more celluloses; and ii) one or more alkali metal carboxyalkylcelluloses. The composition may be sprayable and provided in a pump spray device or squeeze-type spray bottle. The invention further provides a method of providing personal lubrication, comprising dispensing the composition to a target area, as well as the use of the composition to provide lubrication during sexual activity.

Claims

1. A personal lubricant composition comprising: a humectant; and a thixotropic agent; wherein the thixotropic agent comprises a combination of: one or more celluloses; and one or more alkali metal carboxyalkylcelluloses.

2. The personal lubricant composition according to claim 1, wherein the humectant is propylene glycol, glycerine or a combination thereof.

3. The personal lubricant composition according to claim 1, wherein the composition is sprayable.

4. The personal lubricant composition according to claim 1, wherein the composition has an osmolality of less than 1200 mOsm/kg.

5. The personal lubricant composition according to claim 1, wherein the thixotropic agent comprises a combination of microcrystalline cellulose and sodium carboxymethylcellulose.

6. The personal lubricant composition according to claim 1, wherein the thixotropic agent is present in an amount of from 1 to 10 wt % by weight of the composition.

7. The personal lubricant composition according to claim 1, wherein the humectant is present in an amount of less than 25 wt % by weight of the composition.

8. The personal lubricant composition according to claim 2, wherein the humectant is a combination of glycerine and propylene glycol.

9. The personal lubricant composition according to claim 8, wherein the glycerine and propylene glycol are present in a weight ratio of from 3:2 to 2:3.

10. The personal lubricant composition according to claim 1, wherein the composition has a viscosity of at least 800 mPa.Math.s at a temperature of 25° C. and a shear rate of 10 s.sup.−1.

11. The personal lubricant composition according to claim 1, wherein the composition has a pH of from 4.0 to 5.0.

12. A personal lubricant composition comprising: glycerine and propylene glycol, in a total amount of 5 to 15 wt %; and one or more celluloses, and one or more alkali metal carboxyalkylcelluloses, in a total amount of 2 to 5 wt %; wherein the glycerine and propylene glycol are present in a weight ratio of 3:2 to 2:3; and wherein the composition has an osmolality of less than 1200 mOsm/kg and a pH of from 4.0 to 5.0.

13. An apparatus comprising the personal lubricant composition according to claim 1; wherein the apparatus is selected from the group consisting of a pump spray device and squeeze-type spray bottle.

14. A method of providing personal lubrication comprising: dispensing a personal lubricant composition according to claim 1 to a target area.

15. Use of a personal lubricant composition according to claim 1 to provide lubrication during sexual activity.

16. The method of providing personal lubrication according to claim 14, wherein the dispensing is from an apparatus selected from the group consisting of a pump spray device and squeeze-type spray bottle.

Description

[0053] An embodiment of the present invention will now be described in relation to the following non-limiting figures, in which:

[0054] FIG. 1 is a graph showing the measured viscosity of a personal lubricant of the present invention as a function of shear rate in accordance with Examples 1 and 2. The y-axis represents viscosity in Pa.Math.s and the x-axis represents shear rate in s.sup.−1. The solid lines represent the viscosity of the lubricant before spraying (the unfilled and filled circles represent first and second measurements respectively). The dashed lines represent the viscosity of the lubricant after spraying (the unfilled and filled diamonds represent first and second measurements respectively).

[0055] FIG. 2 is a graph showing the measured coefficient of friction of a personal lubricant of the present invention as a function of sliding speed in accordance with Examples 1 and 3. The y-axis represents coefficient of friction and the x-axis represents sliding speed in μm. The dashed lines represent the coefficient of friction of the lubricant before spraying (the filled circles, squares and diamonds represent first, second and third measurements respectively). The solid lines represent the coefficient of friction of the lubricant after spraying (the unfilled circles, squares and diamonds represent first, second and third measurements respectively).

[0056] The present invention will now be described in relation to the following non-limiting Examples.

EXAMPLE 1

[0057] A personal lubricant was prepared having the following composition:

TABLE-US-00002 Substance % w/w Benzoic Acid 0.10-0.30 Glycerine 3.5-4.5 Propylene Glycol 3.5-4.5 DI Water qs. Microcrystalline cellulose 3.1-3.3 Sodium 0.3-0.5 carboxymethylcellulose NaOH (30%) 0.01-0.03

[0058] The composition was prepared by dispersing the thickener in de-ionized water with low shear force. High shear was then applied to activate the thickener (colloidal mill at max rpm. 3-10 min: homogenizer min 150 bar). After activation, the mixture was left to stand for 15 minutes. The propylene glycol, glycerine and perseverative were then dissolved in the liquid phase and mixed with medium stirring. Finally, the NaOH was added and the pH was measured.

[0059] The pH was 4.2 and the osmolality was measured as 1045.9 mOsm/kg in accordance with the reference standard 785 of USP43-NF38. The product had a desirable texture and skin-feel, without feeling sticky, giving a very pleasurable sensation during sexual activity.

EXAMPLE 2

[0060] The viscosity of the composition of Example 1 was determined at a temperature of 25° C. before and after spraying on a research rheometer (DHR2, TA Instruments) fitted with a 40 mm 1° cone measuring system. A solvent trap cover was employed to minimise drying of the sample at the exposed edges. Following a 30 s equilibration time at 25° C. the samples were exposed to a 30 s pre-shear at 10 s.sup.−1 shear rate sweep, 10 s.sup.−1 to 15000 s.sup.−1, logarithmically scaled, 8 points per decade of shear rate, shear applied for 30 s at each rate with viscosity calculated over the final 5 seconds of each step.

[0061] The results are shown in FIG. 1 and summarised in the following table:

TABLE-US-00003 TABLE 1 Viscosity Metrics Viscosity at 10 s.sup.−1 Viscosity at 1000 s.sup.−1 Sample Run 1 Run 2 Mean Run 1 Run 2 Mean Example 1 (before spraying) 1.23 1.20 1.22 0.02 0.02 0.02 Example 1 (after spraying) 0.70 0.56 0.63 0.02 0.02 0.02

EXAMPLE 3

[0062] The tribology profile of the composition of Example 1 was determined before and after spraying using the same rheometer used in Example 2 (DHR-2, TA Instruments) fitted with a custom 3 balls on plate measuring system. Specifically, the tribology profile of the composition of Example 1 was determined as follows. A tribology assembly was employed that comprised a geometry of 3 glass hemispheres that slid against a lower silicone substrate, under a defined load of IN, onto which the sample had been spread. The rotational angular velocity is ramped from 0.05 rad/s to 20 rad/s, 8 points per decade, each point held for 20 s with the coefficient of friction averaged over the final 15 s. The lower substrate was held at 32° C. throughout. This test was performed in triplicate.

[0063] The results are shown in FIG. 2 and summarised in the following table:

TABLE-US-00004 Coefficient of Friction at 10,000 μm/s Sample Run 1 Run 2 Run 3 Mean Example 1 (before spraying) 0.08 0.08 0.08 0.08 Example 1 (after spraying) 0.08 0.09 0.09 0.09

[0064] Surprisingly, the inclusion of the thixotropic thickener described herein allows the lubricity of the composition to be retained over a broad range of sliding speeds, both before and after spraying. This cannot simply be explained by viscosity, since the viscosity of the composition has been shown in Example 2 to decrease after spraying when measured at low shear rates.

EXAMPLE 4

[0065] The tribology profile of the composition of Example 1 was compared with two existing commercial products (K-Y Liquid and K-Y Jelly). The coefficient of friction at 10000 μm/s was determined without spraying using the method described in Example 3. The results are shown in the following table:

TABLE-US-00005 Sample Coefficient of friction (μ) at 10000 μm/s Example 1 0.08 K-Y Liquid 0.08 K-Y Jelly 0.09

[0066] The lubricity of the composition of Example 1 is comparable to that of existing commercial personal lubricants, even though it can be sprayed as a fine mist.

[0067] The foregoing detailed description has been provided by way of explanation and illustration, and is not intended to limit the scope of the appended claims. Many variations in the presently preferred embodiments illustrated herein will be apparent to one of ordinary skill in the art, and remain within the scope of the appended claims and their equivalents.