Understanding DPHP Recrystallization in Oil

Hello! Thank you for reaching out. It sounds like you're trying to create a simple face oil using Dipalmitoyl Hydroxyproline (DPHP) and Fractionated Coconut Oil, and you've observed that the DPHP recrystallizes after cooling, even though it dissolved when heated.

You are correct that Dipalmitoyl Hydroxyproline (DPHP) is an oil-soluble ingredient and does not require an emulsifier to mix with oils like Fractionated Coconut Oil. An emulsifier is typically used to combine oil and water phases, which is not the case in your formulation.

The reason you are seeing recrystallization is related to the solubility of DPHP in Fractionated Coconut Oil at different temperatures. According to the product information, DPHP requires heating to 80-85°C to fully dissolve in oil. While it dissolves at this high temperature, its solubility in Fractionated Coconut Oil decreases significantly as the mixture cools down to room temperature. When the concentration of DPHP (2% in your case) exceeds its solubility limit in Fractionated Coconut Oil at room temperature, the excess DPHP will come out of solution and form crystals, which is what you are observing.

Fractionated Coconut Oil is a relatively light oil, and it may not have sufficient solvency to keep 2% DPHP dissolved stably at room temperature.

To create a stable, crystal-free oil serum with DPHP, you would typically need to use an oil or a blend of oils that has better solvency for DPHP at room temperature, or incorporate a compatible oil-soluble ingredient that can help maintain the DPHP in a dissolved or dispersed state upon cooling.

Given your goal of a simple formulation using only DPHP and natural oil, achieving a completely stable, crystal-free solution with 2% DPHP solely in Fractionated Coconut Oil might be challenging due to the inherent solubility characteristics of DPHP. You might need to consider adjusting the oil phase or slightly modifying the formula to improve stability if you want to avoid recrystallization.