moodybalm Posted August 20, 2020 Share Posted August 20, 2020 Hi, y'all! I've been formulating lotion for the past few weeks (and it's been very fun), but I'm running into a consistent "problem". Quotations because I'm not sure it's even something that will occur in proper production: -My lotion sweats a very thin layer of oil on top! But only in the open bowl I use for excess/testing. The lotion in bottles doesn't (seem) to have the issue. I'll share the specifics of my recipe and a brief version of my process, but first I want to ask if this is just something lotion does when left to cool/thicken in open air? The room's been about 86f/30c, so heat might be a factor, as well. I haven't been in the game long enough to have that wisdom. My recipe, separated into phases: ----- Water Phase (75.5%): -14.7oz. distilled water (73.5%) (+ 2.6oz for evaporation AKA 17.3oz.) -0.4oz glycerin (2%) Oil Phase (15%): -1.8oz isopropyl myristate (9%) -0.8oz almond oil (4%) -0.4oz oat extract (2%) Emulsifiers (part of Oil Phase) (7%): -0.9oz of emulsifying wax (4.5%) -0.5oz of stearic acid (2.5%) Cooldown Phase (2.5%): -0.15oz high-concentration vitamin e-oil (0.75%) -0.2oz of Optiphen (1%) -0.15oz of Fragrance (0.75%) ----- My process, briefly: (0. Sanitize) 1. Get oil/water phase to 170f/77c and hold for 5 minutes. 2. Pour oil phase into water phase (on double boiler). 3. Stick blend while holding at 170f/77c for another 5 minutes. 4. Take off heat and stick blend until 140f/60c 5. Add cooldown phase 6. Stick blend 2 minutes 7. Spritz top bubble layer once with 91% isopropyl alcohol (test batches are shallow, so bubbles form) 8. Spatula-stir until rest of bubbles dissipate (It's usually 112f/44c, by this point) 9. Pour 10. Leave to cool, uncapped, overnight I've tried 3 other variations on this recipe, which involved more water/less oil and more/different emulsifiers, but they all have this slight separation issue (again, only in the bowl). TL;DR - If my lotion sweats a thin layer of oil on top as it cools/thickens, but only in an open bowl, do I need to worry about that for the seemingly-solid lotion in my bottles? Is my emulsion simply bad? Is even a single, fine spritz of 91% isopropyl alcohol to get rid of bubbles bad for it? Any help or wisdom offered would be greatly appreciated! -Moody Quote Link to comment Share on other sites More sharing options...
birdcharm Posted August 21, 2020 Share Posted August 21, 2020 I only dabble in creams, haven't progressed to lotions since I think they're a little more involved than I've been able to have the time to learn. So, all I can offer is that I'd try increasing the amount of emulsifier just a little bit. I don't know if that's the right thing though. Also, does it matter how you add the oil phase into the water phase? I know that with the creams I make, it has to be a slow stream of one to the other. 1 Quote Link to comment Share on other sites More sharing options...
moodybalm Posted August 22, 2020 Author Share Posted August 22, 2020 Someone else mentioned the same thing with the slow-pouring. The way I do it now, with the oil phase going into the water phase, I pour it all and scrape the bowl before blending. I should probably try the more common "water phase into oil phase" and pour it slowly. Thank you for the advice! Quote Link to comment Share on other sites More sharing options...
NightLight Posted August 23, 2020 Share Posted August 23, 2020 Can you take a photo and post. You shouldn’t have this happening. Have you tried sticking blending longer? and water phase into oil. Often when you formulate, it’s the technique that can make or break the end result. i would avoid spraying with alcohol. Let the lotion settle naturally overnight to let the bubble dissipate on their own. i stick blend longer than two minutes. Possible Optiphen could give you trouble - some of them need more emulsifier to incorporate. You might be seeing preservative floating! 1 Quote Link to comment Share on other sites More sharing options...
The Original Meekiecheese Posted August 23, 2020 Share Posted August 23, 2020 34 minutes ago, NightLight said: " some of them need more emulsifier to incorporate" I agree. I would up the emulsifier to 6% and adjust everything else from there. HTH 1 Quote Link to comment Share on other sites More sharing options...
moodybalm Posted August 23, 2020 Author Share Posted August 23, 2020 Sure yeah, here's a pic of the overflow/test bowl in question. It's separated a bit more, the last few days. 😬 You can see along the back of the bowl that there's a yellow-ish coloring coming through. The only yellowish thing I put in my lotion is one of the flavor oils I use, so I'm wondering if I'm just not stick-blending the cooldown phase long enough (as NightLight suggested). I'll also give upping the e-wax a try, though I want to avoid making it too thick (the bottles I'm using have disc-caps). Thanks for your advice! Quote Link to comment Share on other sites More sharing options...
TallTayl Posted August 23, 2020 Share Posted August 23, 2020 How are the samples in sealed containers? Open bowls are not really the best indicator of stability 🤗. Room humidity and other ambient conditions can change everything. stearic acid is not an emulsifier. It’s required HLB is 15, so stick that with the oil phase calculations. https://www.theherbarie.com/files/resource-center/formulating/Required_HLB_for_Oils_and_Lipids.pdf Ewax is typically minimally needed at about 25% of the oil phase. The measurement is little low in the above formula if you add all ingredients with a required HLB (vitamin e( tocopherol) stearic acid, IPM, almond oil) that seems like a high% of IPM. In lotions I’ve not seen more than 2-3% typically in most formularies. It can be used higher safely though. when making lotion, really blend those phases together with a high shear mixer. gently stir with a wide spatula as it cools to keep temps well distributed. 1 Quote Link to comment Share on other sites More sharing options...
moodybalm Posted August 24, 2020 Author Share Posted August 24, 2020 The sealed bottles have no visible separation, luckily. The undisturbed lotion in the bottle looks like it's got a bit of a skin on top, but that might just be normal for lotion? I didn't know that about stearic acid! Nor do I stir the lotion as it cools (usually, I just pour it after briefly blending in the cooldown phase and getting bubbles out). I suppose I'd have to switch to piping the lotion in via bag, if it gets really cool? Thanks so much for all your advice! Quote Link to comment Share on other sites More sharing options...
NightLight Posted August 24, 2020 Share Posted August 24, 2020 It doesn’t look emulsified to me. I would Switch the IPM and almond oil ratios and up the emulsifier start at added 1 percent, I agree with TT. Sometimes the switch in ingredients makes all the difference. Make sure you stick blend longer than what you have been doing. If this doesn’t help try changing preservative. Optiphen can break emulsions. 1 Quote Link to comment Share on other sites More sharing options...
moodybalm Posted August 24, 2020 Author Share Posted August 24, 2020 Cool thanks, will do! The more I learn about the chemistry behind it all, the more I feel like the more accessible tutorials out there are a bit irresponsible, hahaha 😂 I find it all very fun, though! I've got some lighter carrier oils (triglycerides and mango butter) and alternative co-emulsifiers (cetyl alcohol and cera bellina) on the way, along with a pH test kit. So hopefully, I can find a formula that will play nice. Quote Link to comment Share on other sites More sharing options...
NightLight Posted August 24, 2020 Share Posted August 24, 2020 I was going to suggest Cetyl alcohol for you. It has less thickening power than stearic and is also glide compared to stearic acid. Now you can also fine tune by doing 1 per cent stearic and .5 per cent Cetyl as an example. You could sub the IPM for fractionated coconut oil as it’s a drying oil. These are also cetyl esters which is one step down from Cetyl alcohol. Though I think you will find Cetyl alcohol very nice in lotion, and you won’t have to worry about too much viscosity. Cera Bellina will give another feel. It’s more waxy good for hand lotions. I would order another preservative to test with. Try and avoid spraying your emulsions with alcohol. Just let them sit and the bubbles do go away. Although you say you see no separation in lotions in bottles, but you see in bowl. Keep some of those bottle as stability test. They may separate in a month or two or less. I don’t know if you are testing this way but you should. They other thing you should get are samples of gums, you add a tiny tiny amount but the gums really help with stability in lotions. That throw another one into the pot with experimentation but worth it if you enjoy making lotions! 1 Quote Link to comment Share on other sites More sharing options...
moodybalm Posted August 24, 2020 Author Share Posted August 24, 2020 Yes, I'm looking forward to experimenting! Also, yeah I should probably just cut out the rubbing alcohol spray. 😄 I read citric acid can help cover Optiphen's gaps, but Germall Plus seems to be a better, full-spectrum preservative? I might order some of that. Oh, yeah! I'm definitely keeping the bottles around for longevity testing! I considered jumping into gums, but got scared by how people say proteins make formulating way more complicated. (At least, I think gums are proteins?) 😬 Quote Link to comment Share on other sites More sharing options...
TallTayl Posted August 24, 2020 Share Posted August 24, 2020 Cetearyl alcohol isn’t technically an emulsifier... it has a required HLB of around 15. It will thicken and add a nice cushiony feel though. cetearyl also comes in different proportions: 70:30, 50:50 and 30:70 Cetyl to stearyl 1 Quote Link to comment Share on other sites More sharing options...
moodybalm Posted August 24, 2020 Author Share Posted August 24, 2020 Ohhhh, I see! So if I get stearic acid and cetyl alcohol, can I just kinda make my own ratios? Or is stearic acid not the "stearyl" in "cetearyl"? Quote Link to comment Share on other sites More sharing options...
TallTayl Posted August 24, 2020 Share Posted August 24, 2020 19 minutes ago, moodybalm said: Ohhhh, I see! So if I get stearic acid and cetyl alcohol, can I just kinda make my own ratios? Or is stearic acid not the "stearyl" in "cetearyl"? Close... stearyl alcohol, not stearic acid. 🤗 1 Quote Link to comment Share on other sites More sharing options...
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