Lesson 1Soothing and barrier-repair actives: panthenol, niacinamide, ceramides, cholesterol, fatty acids, oat extract (Avena), and use-level guidanceExplore calming and barrier-fixing ingredients good for sensitive, dry skin. Understand how they work and right amounts for panthenol, niacinamide, ceramides, cholesterol, fatty acids, and oat extracts 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 chance of irritation, supporting the barrier. Learn to cut down on extras, avoid repeats, and mix humectants with emollients in a basic 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 humectants, occlusives, and emollients team up to moisten sensitive, dry skin. Check out glycerin, hyaluronic acid, propanediol, squalane, esters, and fatty alcohols with useful amount ranges for your mixes.
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 set up buffer systems that guard both skin and mix. Deal with how actives, cleaners, and preservatives fit together, and watch pH changes as time goes on.
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 managementLook at ways to preserve suitable for sensitive mixes. Compare allowed types, usual amounts, and helpers, and know the dangers and controls when going without preservatives.
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 plan for scents and allergens good for sensitive skin. Weigh no-scent, essential oils, and low-allergen mixes, follow IFRA rules, and handle allergen labelling like in the EU to meet 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 cleaning agents for washes aimed at sensitive, dry skin. Compare nonionic, amine oxide, and zwitterionic types, set safe amounts, and make 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 activesCreate a way to choose ingredients that puts safety, proof, and multi-use first. Learn to read safety info, balance live and lab tests, and pick items that give many benefits in one go.
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 good at flow and feel design for simple systems. Compare oil-in-water creams, water-serums, and gel-creams, choose thickeners, and adjust smoothness, time on skin, and finish for delicate skin that overloads easily.
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 into how weak barriers, water loss, and overactive nerves mark sensitive, dry skin. Learn main triggers, the difference between dehydration and dryness, 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
