BACKGROUND

Zinc and basic amino acids are known to have several benefits and are currently used as active materials in oral care compositions. Zinc has been shown to have antibacterial properties in plaque and caries studies. Arginine and other basic amino acids have benefits in combating cavity formation and tooth sensitivity. Arginine was initially introduced as an additive to oral care compositions for the treatment of tooth sensitivity. When combined with calcium, arginine has been clinically proven to be effective in treating dentinal sensitivity by plugging and sealing dentinal tubules. Basic amino acids are also known to have significant anti-caries benefits.

Zinc-amino acid complex forms a soluble cationic moiety, which in turn may form a salt with a halide or other anion. A zinc-lysine complex (“ZLC”) having the chemical structure [Zn(C6H14N2O2)2Cl]+Cl−has been described in prior art (e.g., WO 2014/098813). When placed in an oral care formulation, this complex provides an effective concentration of zinc ions to the enamel, thereby protecting against erosion, reducing bacterial colonization and biofilm development, and providing enhanced shine to the teeth (WO 2014/098824). Moreover, upon use, the formulation provides a precipitate that can plug the dentinal tubules, thereby reducing the sensitivity of the teeth.

In oral care formulations containing zinc and amino acids, other ingredients present in the formulations can potentially interact with zinc and amino acids to form new species in the final product and affect their performance. The present invention relates to the identification of new complexes formed by the interaction of zinc-amino acid complexes and sodium lauryl sulfate.

BRIEF SUMMARY

The present invention describes zinc-amino acid-lauryl sulfate complexes. In some embodiments, the amino acid in the complex is a basic amino acid. In a preferred embodiment, the zinc-basic amino acid-lauryl sulfate complex is a zinc-arginine (Arg)-lauryl sulfate (LS) or zinc-lysine (Lys)-lauryl sulfate having the chemical structure [Zn(Arg)2](LS)2or [Zn(Lys)2](LS)2. In an embodiment, the zinc-amino acid-lauryl sulfate complex is in powder form.

The present invention also provides methods of producing a zinc-basic amino acid-lauryl sulfate complex by combining sodium lauryl sulfate and a zinc-amino acid complex in an aqueous solution, e.g., an aqueous solution having pH of from 6 to 9, e.g., from 6.5-8.5, or from 7 to 8. In some embodiments, the method further comprises a step of filtering and drying the zinc-amino acid-lauryl sulfate complex.

The present invention also provides oral care compositions comprising a zinc-amino acid-lauryl sulfate complex, e.g., zinc-basic amino acid-lauryl sulfate complex, e.g., zinc-arginine-lauryl sulfate or zinc-lysine-lauryl sulfate. In some embodiments, the zinc-amino acid-lauryl sulfate complex is added to the composition as a preformed complex. In some embodiments, the zinc-amino acid-lauryl sulfate complex may be present in an amount of 0.1-10% by weight of the composition.

The present invention also provides use of a zinc-amino acid-lauryl sulfate complex in powder form for the manufacture of an oral care composition for reducing and inhibiting acid erosion of the enamel, cleaning the teeth, reducing bacterially-generated biofilm and plaque, reducing gingivitis, inhibiting tooth decay and formation of cavities, and reducing dentinal hypersensitivity.

Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the disclosure, are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.

