| CPC A61L 27/20 (2013.01) [A61F 9/0017 (2013.01); A61F 9/00754 (2013.01); A61L 27/025 (2013.01); A61L 27/12 (2013.01); A61L 27/3637 (2013.01); A61L 31/042 (2013.01); A61L 31/143 (2013.01); A61K 47/02 (2013.01); A61K 47/18 (2013.01); A61K 47/36 (2013.01); A61L 2400/06 (2013.01); A61L 2400/16 (2013.01); A61L 2430/16 (2013.01)] | 29 Claims |
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1. A viscoelastic composition comprising:
(a) about 0.001 to about 1 wt. %, based on the total weight of the viscoelastic composition, of tris(hydroxymethyl)aminomethane or a salt thereof;
(b) about 0.001 to about 2 wt. %, based on the total weight of the viscoelastic composition, of a phosphate buffer agent, wherein the phosphate buffer agent comprises one or more of sodium hydrogen phosphate monobasic, sodium hydrogen phosphate dibasic, potassium hydrogen phosphate monobasic and potassium hydrogen phosphate dibasic; and
(c) about 0.001 to about 10 wt. %, based on the total weight of the viscoelastic composition, of a viscoelastic agent having an average molecular weight of about 500,000 to about 5,000,000;
wherein the viscoelastic composition is one of a dispersive viscoelastic composition and a cohesive viscoelastic composition, the dispersive viscoelastic composition having a low-shear viscosity from about 20,000 centipoise (cPs) to about 80,000 cPs, and the cohesive viscoelastic composition having a low-shear viscosity of from about 75,000 cPs to about 475,000 cPs; and
wherein the viscoelastic composition has a pH of about 6 to 7.8.
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