Lesson 1Humectants: examples (glycerin, propanediol, sodium PCA), mechanism and suitability for sensitive skinThis section breaks down humectants like glycerin, propanediol, and sodium PCA, explaining water-holding actions, blend synergies, skin feel effects, and customising for sensitive or weak skin barriers.
Glycerin: benchmark humectant behaviorPropanediol and alternative glycolsSodium PCA and NMF-mimicking blendsTack reduction and sensory balancingHumectants in barrier-impaired skinLesson 2Antioxidants and chelators: examples (tocopherol, EDTA), role in oxidative stability and preservationThis section shows how antioxidants and chelators like tocopherol and EDTA guard oils and actives from oxidation, boost preservatives, and lengthen shelf life without harming skin comfort or clear look.
Lipid-phase antioxidants for oilsWater-phase antioxidants and synergyChelators to control trace metalsImpact on color and odor stabilityDesigning antioxidant systems in O/WLesson 3Occlusives: examples (dimethicone, hydrogenated polyisobutene), balancing occlusion and light feelThis section discusses barrier agents like dimethicone and hydrogenated polyisobutene, balancing skin protection, water loss cut, and a light, airy feel for everyday sensitive skin care.
Dimethicone grades and skin feelHydrogenated polyisobutene in creamsTEWL reduction and barrier metricsAvoiding heaviness and pore occlusionOcclusive levels for day versus nightLesson 4Soothing/anti-irritant actives: examples (niacinamide, panthenol, dipotassium glycyrrhizate), evidence and typical use rangesThis section reviews calming actives like niacinamide, panthenol, and dipotassium glycyrrhizate, covering actions, proof, compatibility, and common levels in sensitive skin creams.
Niacinamide: barrier and redness benefitsPanthenol: hydration and repair rolesDipotassium glycyrrhizate: calming actionUse levels and pH compatibilityCombining soothing actives safelyLesson 5Core functional groups for O/W moisturizer: role of solvent, humectant, emollient, occlusive, emulsifierThis section outlines key roles in O/W creams—solvents, humectants, emollients, barriers, emulsifiers—showing contributions to feel, moisture, stability, and tolerance for sensitive skin.
Water phase and co-solvent selectionHumectant blend design and levelsEmollient phase structure and feelOcclusive agents and barrier supportEmulsifier system and phase balanceLesson 6Preservative systems for mild formulas: examples (phenoxyethanol+ethylexylglycerin, sodium benzoate+potassium sorbate), rationale for sensitive skinThis section checks preservative blends for gentle O/W creams, like phenoxyethanol with ethylhexylglycerin and acid salts, focusing on coverage, pH fit, limits, and skin tolerance.
Phenoxyethanol and boosters in blendsSodium benzoate and potassium sorbatepH windows for organic acid systemsPreservative efficacy versus mildnessMinimizing sting and sensitization riskLesson 7Emollients: examples (caprylic/capric triglyceride, C12-15 alkyl benzoate), sensory and absorption considerationsThis section explores softening agents like caprylic/capric triglyceride and C12-15 alkyl benzoate, tying structure to spread, uptake speed, leftover feel, and fit for light, non-oily sensitive creams.
Medium-spreading esters and triglyceridesFast-absorbing versus rich emollientsPolarity and pigment or filter wettingTack, gloss, and afterfeel controlEmollient choices for acne-prone skinLesson 8Solubilizers, pH adjusters, and texture modifiers: examples and impact on performanceThis section covers solubilizers, pH tuners, and texture adjusters in O/W creams, explaining effects on clarity, thickness, spread, and performance while keeping sensitive skin happy.
Nonionic solubilizers for fragrance and oilspH adjustment for skin compatibilityBuffers and pH drift controlRheology modifiers and viscosity tuningSlip, spread, and pick-up optimizationLesson 9Common incompatibilities and ingredient substitution strategiesThis section tackles usual clashes in O/W creams like pH, charge, oxidation, and offers swap plans to keep stability, gentleness, and performance when suppliers or actives change.
pH-driven instability and hydrolysisCationic–anionic charge conflictsOxidation-prone oils and activesPreservative and polymer conflictsDesigning robust substitution plansLesson 10Emulsifiers and co-emulsifiers: examples (polyglyceryl esters, glyceryl stearate SE), HLB considerations and mildnessThis section details emulsifiers like polyglyceryl esters and glyceryl stearate SE, covering HLB ideas, oil phase needs, and building mild, stable systems for sensitive skin creams.
Required HLB of the oil phaseNonionic emulsifiers for mildnessPolyglyceryl esters in O/W systemsFatty alcohols as co-emulsifiersOptimizing droplet size and stability
