Compositions and Related Methods

Abstract

The present disclosure relates to amine hydrofluorides and mixtures of these amine hydrofluorides, and to a process for the preparation of these amine hydrofluorides and their use in oral hygiene compositions.

Claims

1. A method of manufacturing an oral care or personal care composition, comprising the steps of: a. mixing a tertiary amine in water; and b. increasing the solubility of the tertiary amine via the addition of an effective amount of an alkali salt.

2. The method according to claim 1, wherein the step of mixing a tertiary amine in water further includes mixing an acid.

3. The method according to claim 2, wherein the acid is lactic acid, citric acid, tartaric acid, fumaric acid, malic acid or hydrochloric acid.

4. The method according to claim 3, wherein the acid is hydrochloric acid.

5. The method according to claim 1, wherein the step of mixing a tertiary amine in water further includes mixing a fluoride source.

6. The method according to claim 1, wherein the solubility of the tertiary amine is increased by at least 25%.

7. The method according to claim 1, wherein the solubility of the tertiary amine is increased by at least 40%.

8. The method according to claim 1, wherein the solubility of the tertiary amine is increased by at least 70%.

9. The method according to claim 1, wherein the tertiary amine comprises one or more of N′-octadecyltrimethylendiamine-N,N,N′-tris(2-ethanol), N′-octadecyltrimethylendiamine-N,N,N′-tris(2-ethanol)-dihydrofluoride (olaflur), N-octadeca-9-enylamine, and/or N-octadeca-9-enylamine hydrofluoride (dectaflur).

10. The method according to claim 1, wherein the tertiary amine comprises N′-octadecyltrimethylendiamine-N,N,N′-tris(2-ethanol) and/or N-octadeca-9-enylamine.

11. The method according to claim 1, wherein the tertiary amine is present in the resulting mixture in an amount of about 10 wt. % to about 80 wt. %, based on the total weight of the composition.

12. The method according to claim 1, wherein the alkali salt is sodium chloride, potassium chloride or trisodium citrate dihydrate.

13. The method according to claim 1, wherein the alkali salt is present in the resulting mixture in an amount of about 0.01 wt. % to about 15 wt. %, based on the total weight of the composition.

14. The method of claim 1, wherein the composition is an aqueous solution.

15. A composition obtained or obtainable by the method according to claim 1.

Description

EXAMPLES

Example 1—Effect of Alkali Salts on the Solubility of Amine Fluoride in Solution

[0180] Test solutions are created containing amine fluoride (N′-octadecyltrimethylendiamine-N,N,N′-tris(2-ethanol)-dihydrofluoride) and water. Amine fluoride is added in increasingly greater amounts to determine its saturation concentration, shown below in Table 1A. All values reported in the tables below are in weight percentages.

TABLE-US-00001 TABLE 1A Dissolution characteristics of Amine Fluoride in water without additional inorganic salts Amine Formulation Fluoride Water Solubility observation Composition 1 20.4 q.s. Clear yellow solution Composition 2 22.9 q.s. Clear yellow solution Composition 3 24.4 q.s. Clear yellow solution at the edge of solubility Composition 4 25.9 q.s. Clear yellow solution with some undissolved amine fluoride Composition 5 31.8 q.s Clear yellow semi solid mass

[0181] Thus, the maximum solubility of amine fluoride in water is established to be approximately 24% by weight, which corresponds to a concentration of about 440 mM tertiary amine once the amine fluoride is fully dissociated from hydrofluoride.

[0182] Similar formulations are created also containing one or more alkali salts, selected from sodium chloride, potassium chloride and trisodium citrate dihydrate to investigate the effect of the salts' presence on solubility of the amine fluoride. The results are summarized in Table 1B below.

TABLE-US-00002 TABLE 1B Dissolution characteristics of Amine Fluoride in water with addition of alkali salts Trisodium Amine Sodium Potassium Citrate Solubility Formulation Fluoride Chloride Chloride Dihydrate Water observation Composition 26.1 0.7 — — q.s. Clear yellowish 6 solution Composition 31.8 1.2 — — q.s. Clear yellowish 7 solution Composition 36.2 2.5 — — q.s. Slightly turbid 8 yellow solution with minimal sediment Composition 40.5 1.0 — — q.s. Clear yellowish 9 solution with some undissolved amine fluoride Composition 35.6 1.7 — — q.s. Clear yellowish 10 solution at the boundary of solubility Composition 32.9 1.6 — — q.s. Clear yellowish 11 solution Composition 32.9 0.5 — — q.s. Clear yellowish 12 solution with some undissolved amine fluoride Composition 32.9 — 1.6 — q.s. Clear yellowish 13 solution (dissolved slowly) Composition 32.9 — 2.0 — q.s. Clear yellowish 14 solution Composition 32.9 1.0 — 1.5 q.s. Clear yellowish 15 solution Composition 32.9 — — 2.5 Clear yellowish 16 solution

[0183] Addition of alkali salts were shown to increase the solubility of amine fluoride in water to slightly above 35% by weight (i.e., corresponding to a concentration of about 640 mM tertiary amine) when adding sodium chloride, as demonstrated with composition 10. Concentrations of sodium chloride as low as about 0.7% were shown to increase solubility of amine fluoride in water. Similar effects were observed with potassium chloride as well as trisodium citrate. On the other hand, a concentration of sodium chloride of 2.5% did not increase solubility of amine fluoride, as established in composition 8, which resulted in incomplete dissolution of recipe ingredients.

Example 2—Effect of Alkali Salts on the Solubility of a Tertiary Amine in Solution

[0184] Similar compositions were created as those listed in Table 1A, but instead of amine fluoride, a tertiary amine was used. Without adjustment of pH, the solubility of the tertiary amine in water was shown to be about 70% by weight (about 1520 mM tertiary amine). However, when adding hydrochloric acid to the solution (compositions 21-23) in concentrations calculated to correspond with the level of hydronium ions present in an equivalent amount of amine fluoride, then the solubility of tertiary amine is slightly above 24% corresponding to a concentration of about 530 mM. Results are summarized below in Table 2A.

TABLE-US-00003 TABLE 2A Dissolution characteristics of Tertiary Amine without addition of inorganic salts HCl (32% Tertiary solu- Formulation Amine tion) Water Solubility Observation Composition 17 40.0 — q.s. Clear yellow viscous solution Composition 18 50.0 — q.s. Clear yellow flowable gel Composition 19 60.0 — q.s. Clear yellow thick flowable gel Composition 20 70.0 — q.s. Clear yellow thick gel Composition 21 22.1 10.8 q.s. Clear yellow solution Composition 22 24.5 12.0 q.s. Clear yellow solution at the edge of solubility Composition 23 28.1 13.8 q.s Clear yellow undissolvable solid

[0185] Further compositions containing the tertiary amine and hydrochloric acid were created. To these solutions, various quantities of alkali salts were added to evaluate the effect on solubility of the tertiary amine. Results are summarized in Table 2B below

TABLE-US-00004 TABLE 2B Dissolution characteristics of Tertiary Amine with addition of inorganic salts HCl Trisodium Tertiary (32% Sodium Potassium Citrate Solubility Formulation Amine solution) Chloride Chloride Dihydrate Water observation Composition 34.3 16.8 0.5 — — q.s. Clear 24 yellow semi-solid mass Composition 34.3 16.8 1.0 — — q.s. Clear 25 yellowish solution Composition 34.3 16.8 1.9 — — q.s. Clear 26 yellowish solution Composition 34.3 16.8 2.5 — — q.s. Clear 27 yellowish solution Composition 34.3 16.8 5.0 — — q.s. Clear 28 yellowish solution Composition 34.3 16.8 7.5 — — q.s. Clear 29 yellowish viscous solution Composition 34.3 16.8 10.0 — — q.s. Clear 30 yellowish viscous solution Composition 34.3 16.8 — 2.5 — q.s. Clear 31 yellowish solution Composition 34.3 16.8 — — 3.0 q.s. Clear 32 yellowish solution Composition 36.8 18.9 2.5 — — q.s. Clear 33 yellowish viscous solution at the edge of solubility Composition 41.8 19.6 5.0 — — Clear 34 yellowish viscous solution

[0186] When adding hydrochloric acid to a tertiary amine solution in concentrations calculated to correspond with the level of hydronium ions present in an equivalent amount of amine fluoride and additionally adding an alkali salt, the solubility of tertiary amine in water is around increased to about 40% by weight (about 870 mM tertiary amine), which required addition of about 5% alkali salt to fully dissolve the tertiary amine (composition 34). The minimum addition of Sodium Chloride to fully dissolve 34% of tertiary amine was about 1%.

[0187] A new batch of solutions was created similar to those shown in Table 2B, but with the addition of sodium fluoride.

TABLE-US-00005 TABLE 2C Dissolution characteristics of Tertiary Amine without and with addition of inorganic salts and sodium fluoride HCl Tertiary (32% Sodium Sodium Solubility Formulation Amine solution) Chloride Fluoride Water observation Composition 17.2 8.4 — 3.1 q.s. Clear yellowish 35 solution Composition 19.6 9.6 — 3.5 q.s. Yellow turbid 36 solution with sediment Composition 22.1 10.8 1.0 4.0 q.s. Yellow turbid 37 solution with sediment Composition 34.3 16.8 1.0 6.2 q.s Yellow semi- 38 solid undissolvable mass

[0188] When adding hydrochloric acid and sodium fluoride to a solution containing a tertiary amine in concentrations calculated to correspond with the level of hydronium and fluoride ions present in an equivalent amount of amine fluoride, as well as additionally adding an alkali salt, the solubility of the tertiary amine was not increased any further compared to the solubility of the tertiary amine in absence of additional inorganic salts (composition 24). Without being bound by theory, this is likely due to the fact that hydrochloric acid and sodium fluoride contribute to a high load of additional ions in the solution preventing dissolution of additional tertiary amine.

[0189] While the present invention has been described with reference to embodiments, it will be understood by those skilled in the art that various modifications and variations may be made therein without departing from the scope of the present invention as defined by the appended claims.