Guest guest Posted October 23, 2000 Report Share Posted October 23, 2000 Maurice posted the following to the list a week or so ago and it seems to have been lost in the shuffle. I think Maurice was looking for feedback to determine if he is to follow up with other installments. I don't recall anyone responding to this post and am left wondering if I am the only one on the list that needs help with lotions and creams:-) -------- Donna, First I would like to thank you for letting me share your question to the Cosmeticinfo list group. I will open up the discussion by trying to respond simply to a simple question about a very complex subject. It will take a few installments. I expect my posts to elicit more questions. I will do my best to answer those questions where I know the answer or solution(s). And hopefully, and others will feel free to respond to some of these questions and kindly correct me about the science and to let me know when their practice of the art differs from mine. Let's start with some basic understandings about creams and lotions. Basically, when you formulate/create a lotion or cream, you are combining two things, oil and water, that don't like one another. Water is a polar material. Things that " like " water are also polar materials. Polar bears like water, but that not quite what I had in mind. Polar materials are also called hydrophilic. The prefix " hydro- " means water and the suffix, " -philic " means loving. So a hydrophilic material is water-loving. A non-polar material, like Canola Oil, is hydrophobic. The suffix -phobic means hating. So hydrophobic materials hate water. Sometimes oils like Canola Oil are called lipophilic. In this case the prefix, " lipo- " means fatty. So a lipophilic material loves fatty materials. So when we are making an emulsion, a cream or lotion, we are attempting to combine water with oil or a hydrophilic material with a hydrophobic material or a hydrophilic material with a lipophilic material. Different ways of saying the same thing. If we were to pour some Canola Oil into a bowl of water, the Canola Oil would float to the top rather quickly. If we stirred the Canola Oil & Water mixture with a whisk, the Canola Oil would breakup into small droplets or globules but on standing, the smaller globules would come together and becomes one larger globule. The smaller globules are coalescing to form larger globules. This process will continue until we are left with two layers. In order to bring these two incompatible materials, like Canola Oil and water, together, we need is something that will make the water like the oil and will also make the oil like the water. Going right to the point, what we need is an emulsifier or two or three. The group of emulsifiers that I will address for the purposes of answering your question is the group called nonionic emulsifiers. The word " nonionic " mean no charge. The nonionic emulsifier has no positive or negative charge. But nonionic emulsifiers have a unique property that is of special value to the formation of emulsions. Each nonionic emulsifier has a hydrophilic portion and a separate lipophilic portion. So you could say that a nonionic emulsifier has two tails. One tail loves water and the other tale loves oil. To help the formulator of emulsions pick the right emulsifier(s) for the job and bring a little science to the art, the HLB system was developed. This is a tool. The HLB System is a rule of thumb. It is not a chemical law; it has limitations but it does provide an excellent framework to help use formulate creams and lotions. Quoting from: http://www.paddocklabs.com/publications/secundum/secart41.html The HLB (Hydrophile-Lipophile Balance) system is used for describing the characteristics of a surface-active agent. It consists of an arbitrary scale to which HLB values are experimentally determined and assigned. If the HLB value is low, there is a low number of hydrophilic groups on the surfactant and it is more lipophilic (oil soluble) than hydrophilic (water soluble). For example, Span 80 has an HLB value of 4.3, from Table 2, and is oil soluble. If the HLB value is high, there is a large number of hydrophilic groups on the surfactant and it is more hydrophilic (water soluble) than oil soluble. For example, Tween 20 has an HLB value of 16.7 and is water soluble. Some general applications of materials with various HLB values are as follows: 1-3 Antifoaming agents 3-6 Emulsifying agents (w/o emulsions) 7-9 Wetting agents 8-18 Emulsifying agents (o/w emulsions) 13-16 Detergents 16-18 Solubilizing agents Below are two lists of commonly used nonionic emulsifiers: One is sorted by HLB and the other is sorted by INCI name. NONIONIC EMULSIFIERS SORT BY HLB INCI Nomenclature = HLB Gycol Distearate = 1 Sorbitan Trioleate = 1.8 Glycol Stearate = 2 Glyceryl Stearate = 3.6 Sorbitan Sesquioleate = 3.7 Sorbitan Oleate = 4.3 Methyl Glucose Dioleate = 4.4 Sorbitan Stearate = 4.7 Oleth-2 = 4.9 Steareth-2 = 4.9 Ceteth-2 = 5.3 Glyceryl Stearate SE = 5.8 PEG-4 Dilaurate = 6 Methyl Glucose Sesquistearate = 6.6 Sorbitan te = 8.6 PEG-40 Sorbitan Peroleate = 9 Laureth-4 = 9.7 Glyceryl Stearate (and) PEG-100 Stearate = 11 Polysorbate 85 = 11 Oleth-10 = 12.4 Oleth-20 = 12.4 Ceteth-10 = 12.9 PEG-8 te = 13 Polysorbate 60 = 14.9 Isosteareth-20 = 15 PEG-20 Methyl Glucose Sequistearate = 15 Polysorbate 80 = 15 Ceteareth-20 = 15.2 Steareth-20 = 15.3 Steareth-21 = 15.5 Ceteth-20 = 15.7 Isoceteth-20 = 15.7 Polysorbate 20 = 16.7 Laureth-23 = 16.9 PEG-100 Stearate = 18.8 NONIONIC EMULSIFIERS SORT BY INCI NAME INCI Nomenclature = HLB Ceteareth-20 = 15.2 Ceteth-10 = 12.9 Ceteth-2 = 5.3 Ceteth-20 = 15.7 Glyceryl Stearate = 3.6 Glyceryl Stearate (and) PEG-100 Stearate = 11 Glyceryl Stearate SE = 5.8 Glycol Stearate = 2 Gycol Distearate = 1 Isoceteth-20 = 15.7 Isosteareth-20 = 15 Laureth-23 = 16.9 Laureth-4 = 9.7 Methyl Glucose Dioleate = 4.4 Methyl Glucose Sesquistearate = 6.6 Oleth-10 = 12.4 Oleth-2 = 4.9 Oleth-20 = 12.4 PEG-100 Stearate = 18.8 PEG-20 Methyl Glucose Sequistearate = 15 PEG-4 Dilaurate = 6 PEG-40 Sorbitan Peroleate = 9 PEG-8 te = 13 Polysorbate 20 = 16.7 Polysorbate 60 = 14.9 Polysorbate 80 = 15 Polysorbate 85 = 11 Sorbitan te = 8.6 Sorbitan Oleate = 4.3 Sorbitan Sesquioleate = 3.7 Sorbitan Stearate = 4.7 Sorbitan Trioleate = 1.8 Steareth-2 = 4.9 Steareth-20 = 15.3 Steareth-21 = 15.5 Quite conveniently, many oils and other lipophilic materials have been assigned " Required HLB " values. The Required HLB of an oil tells us, in theory, that oil in question requires a certain HLB emulsifier(s) to form an emulsion. Again, quoting from: http://www.paddocklabs.com/publications/secundum/secart41.html Below are some lipophilic materials and their respective " Required HLB " values. Material = Required HLB Beeswax = 12 Cetyl alcohol = 15 Cottonseed oil = 10 Lanolin, anhydrous = 10 Mineral oil, light/heavy = 12 Paraffin wax = 11 Petrolatum = 12 Stearic acid = 15 Stearyl alcohol = 14 As I recall, vegetable oils have Required HLB values that range from 6 to 9. In the next installment, we discuss some of the factors that come into play when choosing nonionic emulsifiers for your cream or lotion. Pat. Peace, Joy, Serenity House of Scents tm. Body Oils, Fragrance Oils, Incense, Candles, Soap, Etc. achil@... http://houseofscents.safeshopper.com/ www.yourhealthandbody.com Quote Link to comment Share on other sites More sharing options...
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