Lotion Formulation Instability: Loss of Viscosity and Stringy Texture

Thank you for your question. Regarding the issue with your lotion formulation becoming less viscous and stringy after 7 days, this suggests a stability problem.

As the previous staff reply mentioned, some key ingredients in your formula, such as Sodium Polyacrylate, Dicaprylyl ether, น้ำมันบัว (Coconut/Palm kernel oil), Eumulgin SG, and Glydant, are not sold by our company.

The stability of a lotion, especially its texture and viscosity, heavily relies on the interaction between the thickeners (like Sodium Polyacrylate) and emulsifiers (like Eumulgin SG) with other ingredients, including active ingredients like AHA and Vitamin C. Acidic ingredients like AHA and Vitamin C can significantly affect the performance of many thickeners and emulsifiers, particularly those sensitive to pH, potentially leading to a loss of viscosity, changes in texture (like stringiness), and color fading over time.

Therefore, the most accurate advice regarding troubleshooting this specific formulation, especially concerning the ingredients not supplied by us, would come directly from the manufacturers or suppliers of those specific ingredients. They can provide detailed information on compatibility, optimal usage conditions (including pH range), and potential interactions with other common cosmetic ingredients. We recommend reaching out to them for the best guidance on stabilizing your formulation.

Checking the pH of your final product might also provide some insight, as pH plays a critical role in the stability of many cosmetic ingredients and formulations.