Lesson 1Soothing and barrier-repair actives: panthenol, niacinamide, ceramides, cholesterol, fatty acids, oat extract (Avena), and use-level guidanceGo deep into calming and barrier-fixing ingredients good for sensitive, dry skin. Find out 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 out main design ideas for sensitive, dry skin: keeping it simple, low on irritation, supporting the barrier. 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 moisten sensitive, dry skin. Check glycerin, hyaluronic acid, propanediol, squalane, esters, and fatty alcohols with useful amount ranges for practice.
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-kind pH levels and make buffer setups that guard skin and formula. Handle fits with actives, cleaners, and keepers, and watch pH changes over time on the 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 preservative setups right for sensitive formulas. Compare allowed groups, usual amounts, and helpers, and know risks and controls for going without preservatives safely.
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 declarationMake a scent and allergen plan good for sensitive skin. Compare no-scent, natural oils, and low-allergy mixes, use IFRA rules, and handle EU-type allergen labels and what users expect.
Fragrance-free versus low-scent approachesEssential oils and sensitization riskUsing IFRA categories and maximum levelsLabeling listed fragrance allergensMasking base odors without overloadingLesson 7Gentle surfactants and mild cleansing systems: non-ionic/amine oxide/zwitterionic options and concentration guidanceFind out how to pick very mild cleaner systems for washes aimed at sensitive, dry skin. Compare nonionic, amine oxide, and zwitterionic choices, set safe amounts, and build low-bubble, low-irritation 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 activesSet up a picking framework for ingredients that puts safety, proof, and multi-use first. Learn to read safety info, balance live and lab support, and choose items that give many benefits together.
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 oil-in-water creams, water-serums, and gel-creams, pick thickness changers, and adjust smoothness, time on skin, and feel after for delicate 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 lack of water differs from rough skin, 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
