In the dry gum method, how is the final volume adjusted?

In the dry gum method, how is the final volume adjusted?

• A. with oil
• B. with water
• C. with alcohol
• D. with glycerin

Answer: (B)

In the dry gum method, the final volume is adjusted with water. The process forms an emulsion by first making a mucilage of gum arabic with water, then gradually adding oil to create the emulsion. Once the oil is well dispersed and a stable emulsion is achieved, the remaining water is added to bring the preparation up to the desired final volume. Using oil to adjust volume would disturb the emulsion balance, while alcohol or glycerin aren’t used for this purpose in this method because they would alter the emulsion stability and the final vehicle composition.

In the dry gum method, the final volume is adjusted with water. The process forms an emulsion by first making a mucilage of gum arabic with water, then gradually adding oil to create the emulsion. Once the oil is well dispersed and a stable emulsion is achieved, the remaining water is added to bring the preparation up to the desired final volume. Using oil to adjust volume would disturb the emulsion balance, while alcohol or glycerin aren’t used for this purpose in this method because they would alter the emulsion stability and the final vehicle composition.