Anti-viral tissue product with visual efficacy indicator
Anti-viral tissues are provided with a pH indicator which can communicate to a tissue user by means of visual indicia, via color changes, that the tissue has active ingredients. Furthermore, the pH indicators can be used to illustrate neutralization of the pH of infected nasal discharge, which has a higher pH than healthy nasal discharge, giving the user a reason to believe that the product is working to deactivate virus.
1. An anti-viral tissue product comprising one or more tissue sheets containing an anti-viral component and a pH indicator, wherein the color of the pH indicator in one or more of the tissue sheets changes when contacted with mucus having a pH of 7.2 to 8.3, wherein the pH indicator is topically applied to one or more of the tissue sheets by means of an ink composition with the following ranges: pH indicator 0.01-10 wt. %; ink carrier medium 20-95 wt. %; surfactant 0-25 wt. %; immobilizer 2-25 wt. %; pH adjuster 0-25 wt. %; and solvent 20-90 wt. %.
2. The product of claim 1 , wherein the anti-viral component is acidic.
3. The product of claim 1 , wherein the anti-viral component comprises citric acid.
4. The product of claim 1 , wherein the color of the pH indicator in one or more of the tissue sheets changes from an initial color to a first color when contacted with mucus having a pH of 7.2 to 8.3 and changes to a second color or reverts to the initial color as the pH of the mucus is changed by the anti-viral component.
5. The product of claim 1 , comprising two outer tissue sheets and one or more inner tissue sheets, wherein an inner sheet contains an acidic anti-viral component and the outer sheets contain a pH indicator, wherein the color of the pH indicator in the outer tissue sheets changes when contacted with mucus having a pH of 7.2 to 8.3.
6. The product of claim 1 , wherein the pH indicator is 4-anilino-3″-azobenzene, or 4-anilino-3′-azobenzene.