Lesson 1Humectants: examples (glycerin, propanediol, sodium PCA), mechanism and suitability for sensitive skinThis part looks at moisture keepers like glycerin, propanediol, and sodium PCA, explaining how they hold water, work together, affect skin feel, and fit for sensitive or weak skin.
Glycerin as main moisture keeperPropanediol and other optionsSodium PCA and natural blendsReducing stickiness and balancing feelMoisture keepers for weak skinLesson 2Antioxidants and chelators: examples (tocopherol, EDTA), role in oxidative stability and preservationThis part explains how fighters against oxidation and metal binders like tocopherol and EDTA protect oils and ingredients from going bad, help preservatives, and keep shelf life without hurting skin comfort.
Oil phase oxidation fightersWater phase fighters and teamsBinders for small metalsEffect on color and smell stabilityBuilding oxidation systems in oil-waterLesson 3Occlusives: examples (dimethicone, hydrogenated polyisobutene), balancing occlusion and light feelThis part talks about barriers like dimethicone and hydrogenated polyisobutene, showing how to balance skin protection, less water loss, and light feel for daily sensitive skin care.
Dimethicone types and skin feelHydrogenated polyisobutene in creamsWater loss reduction measuresAvoiding heavy feel and blocked poresBarrier levels for day and nightLesson 4Soothing/anti-irritant actives: examples (niacinamide, panthenol, dipotassium glycyrrhizate), evidence and typical use rangesThis part checks calming and anti-irritant ingredients like niacinamide, panthenol, and dipotassium glycyrrhizate, summing ways they work, proof, fit, and common amounts in sensitive creams.
Niacinamide for protection and less redPanthenol for moisture and fixDipotassium glycyrrhizate for calmAmounts and pH fitMixing calming ingredients safelyLesson 5Core functional groups for O/W moisturizer: role of solvent, humectant, emollient, occlusive, emulsifierThis part maps main groups in oil-water creams—solvents, moisture keepers, softeners, barriers, and mixers—showing how each adds to feel, moisture, stability, and fit for sensitive skin.
Water phase and extra solvent pickMoisture blend design and amountsSoftener phase build and feelBarrier agents and protectionMixer system and phase balanceLesson 6Preservative systems for mild formulas: examples (phenoxyethanol+ethylexylglycerin, sodium benzoate+potassium sorbate), rationale for sensitive skinThis part reviews keeper systems for gentle oil-water creams, like phenoxyethanol with ethylhexylglycerin and acid salts, focusing on coverage, pH needs, rule limits, and fit for sensitive skin.
Phenoxyethanol and helpers in mixesSodium benzoate and potassium sorbatepH ranges for acid systemsKeeper strength vs gentlenessReducing sting and allergy riskLesson 7Emollients: examples (caprylic/capric triglyceride, C12-15 alkyl benzoate), sensory and absorption considerationsThis part explores softeners like caprylic/capric triglyceride and C12-15 alkyl benzoate, linking build to spread, soak speed, leftover, and fit for light, non-oily sensitive creams.
Medium spread esters and fatsQuick soak vs rich softenersPull and color or filter wettingStick, shine, and afterfeel controlSofteners for spot-prone skinLesson 8Solubilizers, pH adjusters, and texture modifiers: examples and impact on performanceThis part reviews key dissolvers, pH changers, and texture changers in oil-water creams, explaining how they affect clearness, thickness, spread, and work while keeping sensitive skin comfortable.
Non-pull dissolvers for smell and oilspH change for skin fitBuffers and pH steady controlFlow changers and thickness tuneSmooth, spread, and pick-up bestLesson 9Common incompatibilities and ingredient substitution strategiesThis part covers usual mismatches in oil-water creams, like pH, charge, and oxidation problems, and gives real swap plans to keep stability, gentleness, and work when changing sellers or ingredients.
pH caused unsteadiness and breakPull-charge clashesOxidation easy oils and ingredientsKeeper and plastic clashesBuilding strong swap plansLesson 10Emulsifiers and co-emulsifiers: examples (polyglyceryl esters, glyceryl stearate SE), HLB considerations and mildnessThis part details mixers and helper mixers, like polyglyceryl esters and glyceryl stearate SE, explaining HLB ideas, needed HLB of oil parts, and how to make gentle, steady systems for sensitive creams.
Needed HLB of oil partNon-pull mixers for gentlenessPolyglyceryl esters in oil-waterFat alcohols as helper mixersBest drop size and steadiness
