First of all, thank you to the moderators and many members of this community for always being so helpful and generous at providing your expertise and advice FOC. I have spent some time searching through this forum but I can't find any advice that specifically addresses my problem.
I have a moisturising lotion formula that is stable at room temperature for around 9 months. My goal is to make it stable for 1 year at least, preferably longer. I have also tried incubating at 45degC for 45 days at least, but some of the bottles will fail (I see phase separation) after 30+ days, while other bottles made in exactly the same way and within the same batch will pass (stay in emulsion).
My question is, if some replicate bottles fail, while the other replicate bottles pass, does that mean the whole formula fails?
My next question is, now the formula fails, what should I modify next to improve on the formula? I'm restricted to using only naturally-derived ingredients.
Below is the formula:
Rosemary leaf extract 0.04%
Vit E 0.75%
Olive Oil Unsaponifiable 1%
Capric Triglyceride 3%
jojoba oil 4%
sweet almond oil 4%
Potassium sorbet 0.1%
Sodium lactate 1%
Hydrolysed Oats 1%
Distilled water top up to 100%
Cool down phase
Leucidal SF 2%
Fragrance essential oil 1%
And here's how I make it:
Heat up the water bath to 77degC
Incubate the water phase and oil phase ingredients for 20 mins in separate beakers
Mix water phase ingredients into oil phase ingredients while stirring with a stick blender
After mixture reaches 45degC and below, add in cool down ingredients.