Methods for synthesizing stannous pyrophosphate
AssigneeColgate-Palmolive Company
InventorsZhigang Hao, Paul Thomson, Long Pan, Tatiana Brinzari, Guofeng Xu, Sergio Leite, Yu Wang
Life of this patent
Estimating the term…
Abstract
Disclosed herein are improved methods for the synthesis of stannous pyrophosphate, as well as improved methods for the manufacture of oral care compositions comprising stannous pyrophosphate.
Claims20
A method of making an oral care composition comprising stannous pyrophosphate, comprising the steps of (1) reacting stannous chloride with a tetrasodium pyrophosphate (TSPP) in a water or water/alcohol solvent mixture in a reactor tank, (2) precipitating the stannous pyrophosphate product, optionally (3) recovering the stannous pyrophosphate product by filtration, optionally (4) freeze-drying the stannous pyrophosphate product, and (5) transferring the stannous pyrophosphate product into a mixing tank containing at least one oral care ingredient and at least one orally acceptable solvent.
A method of making stannous pyrophosphate, comprising the steps of (1) reacting stannous chloride with tetrasodium pyrophosphate in a water or water/alcohol solvent mixture, (2) precipitating the stannous pyrophosphate product, (3) recovering the stannous pyrophosphate product by filtration, and (4) freeze-drying the stannous pyrophosphate product.
An oral care composition comprising stannous pyrophosphate and sodium chloride in a molar ratio of about 4 parts sodium chloride to one-part stannous pyrophosphate.
Dependencies are inferred from the claim text.