Lesson 1Soothing and barrier-repair actives: panthenol, niacinamide, ceramides, cholesterol, fatty acids, oat extract (Avena), and use-level guidanceGet into calming and barrier-fixing actives good for sensitive, dry skin. Learn how they work and amounts to use for panthenol, niacinamide, ceramides, cholesterol, fatty acids, and oat parts in simple formulas.
Panthenol for soothing and barrier recoveryNiacinamide at low, tolerable inclusion levelsCeramide, cholesterol, fatty acid ratiosColloidal oatmeal and oat-derived activesCombining actives without overloading skinLesson 2Design principles for sensitive-dehydrated skin: minimalism, low-irritancy, barrier-supporting, humectant-emollient balanceSet main design ideas for sensitive, dry skin: keeping it simple, low-sting, and barrier-helping. Learn to cut down actives, skip repeats, and mix water-holders with softeners in a smooth routine.
Minimalist INCI lists and formula focusAvoiding common irritant and sensitizer groupsHumectant–emollient–occlusive balancingLayering strategy across a simple routinePatch testing and gradual introductionLesson 3Humectants, occlusives, and emollients: glycerin, hyaluronic acid, propanediol, squalane, esters, and fatty alcohols with suggested use-level rangesSee how water-holders, sealers, and softeners team up to water sensitive, dry skin. Check glycerin, hyaluronic acid, propanediol, squalane, esters, and fatty alcohols with real amount suggestions.
Water-binding humectants and optimal levelsHyaluronic acid types and molecular weightsLight emollients: squalane and estersFatty alcohols for structure and mildnessBalancing humectant load to avoid tightnessLesson 4pH targeting and buffer systems: safe pH ranges for skin, stability considerations, and ingredient compatibilityLearn to aim for skin-friendly pH levels and make buffer setups that guard skin and formula. Handle matches with actives, cleaners, and keepers, and watch pH changes over time on shelf.
Physiological pH range and barrier impactpH needs of surfactants and preservativesSelecting acids, bases, and buffersManaging pH drift during stability testspH considerations for exfoliating activesLesson 5Preservative approaches suitable for sensitive skin: approved preservative families, typical levels, synergists, and preservative-free risk managementCheck keeper systems fit for sensitive mixes. Compare allowed groups, usual amounts, and helpers, and know risks and controls when going for no-keeper claims.
Regulatory status of key preservative groupsOrganic acids and mild preservative blendsChelators and humectants as boostersChallenge testing and PET requirementsRisk of under-preservation and recallsLesson 6Fragrance and allergen strategy: fragrance-free vs masked scents, IFRA considerations, and EU/allergen declarationBuild a scent and allergen plan good for sensitive skin. Compare no-scent, essential oils, and low-allergen mixes, use IFRA limits, and handle EU-style allergen labels and what buyers expect.
Fragrance-free versus low-scent approachesEssential oils and sensitization riskUsing IFRA categories and maximum levelsLabelling listed fragrance allergensMasking base odors without overloadingLesson 7Gentle surfactants and mild cleansing systems: non-ionic/amine oxide/zwitterionic options and concentration guidanceLearn to pick very mild cleaner systems for washes aimed at sensitive, dry skin. Compare nonionic, amine oxide, and zwitterionic choices, set safe amounts, and make low-bubble, low-sting bases.
Irritation mechanisms of common surfactantsNonionic surfactants for sensitive skinAmine oxides and zwitterionic co-surfactantsDesigning low-foam, creamy cleanser basesActive surfactant level and dilution guidanceLesson 8Ingredient selection framework: prioritizing safety, evidence, and multifunctional activesMake an ingredient pick setup that puts safety, proof, and multi-use first. Learn to read safety info, weigh live and lab support, and choose items that give many gains at once.
Reading safety assessments and CIR opinionsEvaluating clinical and instrumental dataChoosing multifunctional emollient-humectantsSupplier documentation and quality checksDecision trees for go or no-go ingredientsLesson 9Formulation rheology and sensorial design: emulsion types (O/W, water-serum, gel-cream), viscosity modifiers, and sensory targets for a minimalist lineGet skilled in flow and feel design for simple systems. Compare O/W creams, water-serums, and gel-creams, pick thickness changers, and adjust smoothness, play time, and after-touch for weak, easy-overload skin.
Choosing emulsion type for skin conditionPolymeric versus natural thickenersSlip, playtime, and afterfeel optimizationLightweight gel-creams for dehydrationStability checks for low-oil systemsLesson 10Skin physiology and pathophysiology: barrier function, TEWL, sensitive skin triggers, and dehydration vs drynessLook at how weak barriers, water loss, and overactive nerves mark sensitive, dry skin. Learn main triggers, how dry from lack of water differs from true dry, and what it means for picking feels, actives, and cleaners.
Stratum corneum structure and lipid organizationTEWL, corneometry, and hydration assessmentNeurosensory hyperreactivity and stingingTriggers: surfactants, pH, fragrance, alcoholsDehydration versus true lipid dryness
