A storage clarity-stable aqueous or aqueous/alcoholic mouthwash solution of zinc ions in the presence of bicarbonate ions which results from providing, in a single solution, a combination consisting essentially of:
- (a) a zinc ion source which is a zinc salt of a first anion which salt is selected from the group consisting of
- (i) salts of zinc with one or more of said first anion, including mixed first anion salts thereof, said first anion being selected from the group consisting of
- (1) chloride, sulfate, monophosphate, pyrophosphate, metaphosphate, tripolyphosphate, tetrametaphosphate, orthophosphate, and
- (2) organic carboxylic acid anions selected from the group consisting of gluconate, tartrate, fumarate, maleate, malonate, malate, lactate, citrate, EDTA, citraconate, citramalate, stearate, oleate, laurate, octoate ascorbate, picolinate, and orotate, and
- (ii) salts of mixed alkali metal/zinc or mixed magnesium/zinc with said first anion;
- (b) a source of a stabilizing anion which stabilizes solutions of zinc ions in the presence of bicarbonate ions, which source is a salt of a first metal and a second anion, said first metal being selected from the group consisting of sodium and potassium and said second anion being selected from the group consisting of (i) carboxylic acids selected from the group consisting of tartrate, fumarate, maleate, malonate, malate, citraconate, citramalate, lactate, citrate, and EDTA, and (ii) phosphates selected from the group consisting of pyrophosphate and tripolyphosphate;
- (c) a bicarbonate ion source selected from the group consisting of sodium bicarbonate and potassium bicarbonate;
- (d) a solvent therefor, said solvent comprising:
- (i) a major proportion of water;
- (ii) optionally a minor amount of a lower all monohydric alcohol;
- and
- (iii), optionally a minor amount of a humectant having at least 3 hydroxy groups;
- (e) optionally one or more mouthwash acceptable antibacterial agents;
- (f) optionally one or more mouthwash acceptable viscosity enhancers;
- (g) optionally one or more sweeteners;
- (h) optionally one of more flavors;
- and
- (i) optionally one or more colors;
- said zinc salt being present in an amount A sufficient to yield a zinc ion concentration of from about 0.01 to about 1 weight %;
- said salt of said second anion present in an amount B, which in combination with any of said second anion present from other components of said solution, is sufficient to provide a total second anion concentration of at least 1.2 equivalents per equivalent of zinc ion;
- said bicarbonate source being present in an amount of C equivalents, which is no greater than the sum of
- (a) (6).times.(the number of equivalents of said pyrophosphate and tripolyphosphate);
- and
- (b) {(3.sup.(n-1))/(2.sup.m)}.times.(the number of equivalents of said second anions which are carboxylic acids), where n is the number of carboxyl groups and m is the number of basic nitrogens
- whereby said storage clarity-stable aqueous or aqueous/alcoholic single phase mouthwash solution remains clear and free of cloudiness or insoluble crystals or basic salts of zinc and carbonate during storage, said zinc ions and said bicarbonate ions being provided in amounts which are effective for the prevention and counteraction of oral malodors, said bicarbonate ions providing a clean mouthfeel and a refreshing aftertaste in the oral cavity, and said zinc ions combating oral malodor.