Which of the following are examples of viscosity-inducing agents?

• A. Acacia, Methylcellulose, Carbomer
• B. Glycerin, Propylene Glycol
• C. Water, Ethanol
• D. Sodium Chloride, Potassium Sorbate

Answer: (A)

Viscosity-inducing agents, or thickeners, work by building a network within the liquid that restricts flow. Natural gums like acacia hydrate and swell to form a viscous solution, while cellulose derivatives such as methylcellulose swell and gel to raise viscosity. Carbomers are synthetic thickening polymers that, when neutralized, swell and trap water to create a gel. These are classic examples of substances added specifically to increase thickness in suspensions and gels.

Glycerin and propylene glycol are primarily humectants and solvents; they can influence viscosity to some extent, but their main role is not thickening. Water and ethanol are solvents and do not inherently act as thickeners. Sodium chloride and potassium sorbate are salts and preservatives, which do not function as thickeners. Therefore, the group containing acacia, methylcellulose, and carbomer best represents viscosity-inducing agents.