Preparation of phytate-salt free gel dentifrice

Claim 2

The process of preparing a phytate-salt free gel dentifrice consisting essentially of forming a preblend of a liquid vehicle containing humectant and a gelling agent, mixing therewith an antinucleating agent containing at least one phosphonic group and adding thereto a polishing agent comprising a synthetic precipitated, amorphous silica gel having an average particle size of 1 to 30 microns and (a) a surface area of 1 to 600 m 2 /g, (b) a pore volume of 0.05 to 0.5 cm 3 /g, (c) a product of surface area (in m 2 /g)×pore volume (in cm 3 /g) less than or equal to 240, (d) a calculated pore diameter of 1.5 to 2.5 nm and said dentifrice consisting essentially of said liquid vehicle in amount of about 20-90% by weight and including water in amount of about 1-10% by weight, about 0.2-5% by weight of said gelling agent, about 10-50% by weight of said polishing agent and about 1-15% by weight of said antinucleating agent.

Claim 3

The process of preparing a gel dentifrice claimed in claim 1 wherein said antinucleating agent is ethylene diamine tetramethylene phosphonic acid or non-toxic pharmaceutically acceptable salt thereof.

Claim 4

The process of preparing a gel dentifrice claimed in claim 2 wherein said antinucleating agent is a neutralised ethylene diamine tetramethylene phosphonic acid.

Claim 5

The process of preparing a gel dentifrice claimed in claim 1 wherein said synthetic amorphous silica gel is selected from the group having characteristics consisting of: ______________________________________ a b c ______________________________________ Average particle size 4 7 4 (according to Coulter) μm Wet screen residue 0.02 0.02 0.02 (42 μm) % pH (5% suspension in 3 6 6-8 water) Surface area (B.E.T.) m.sup.2 /g 7 4 7 Loss in drying % 7 4 7 SiO.sub.2 content (on 96 99 96 ignited substance) Refractive index 1.46 1.46 1.46 and (d) mixtures thereof ______________________________________