Hi guys, i want to ask about maintaining pH in a surfactant formula. Actually this is for avoiding changing of color like what I have posted in previous discussion. But i decided to post a new one, because this is different topic.
I looked in the internet, that one of the cause color changing in surfactant is due to pH drifting. I learned from IPCS (institute personal care of science), and they said too acidic will turn into pink, and too alkaline will turn into greenish. And during 2-3 years of product life span, the pH can drift +/- 10% from its origin.
I have questions as below:
1. Is there any way to keep the pH of the product stable?
2. What cause the pH drift much? (is there any relation with storage keeping, temperature, humidity?)
3. IPCS mentioned very little about something called "buffer" to keep the pH steady. But I did not get any good explanation and detail about this. Do we really need to make buffer solution for a simple shampoo/bodywash product? How do we make this buffer solution?
Thank you guys, and sorry for the many questions I have. Really hope to hear your insight about this matter.