Lesson 1Preservatives, fragrances, and potential irritants: parabens, isothiazolinones, fragrance allergens — relevance for sensitive skinE analyze preservatives, fragrances, and other potential irritants. E cover parabens, isothiazolinones, formaldehyde releasers, and fragrance allergens, with emphasis on patch testing, regulatory limits, and guidance for sensitive or atopic skin wey need care.
Common preservative classes and safety dataIsothiazolinones and formaldehyde releasersFragrance allergens and labeling rulesFormulating for sensitive and atopic skinPatch testing and counseling on avoidanceLesson 2Retinoids and retinoid alternatives: tretinoin, adapalene, retinol, retinaldehyde — mechanism, efficacy, irritation managementE explore topical retinoids and alternatives, including tretinoin, adapalene, retinol, and retinaldehyde. E discuss receptor binding, evidence in acne and photoaging, titration strategies, buffering, and managing irritation and purging wey happen.
Retinoid classes and receptor selectivityAcne vs photoaging: evidence and regimensRetinol and retinaldehyde: conversion stepsInitiation, titration, and buffering methodsManaging irritation, purging, and adherenceLesson 3Excipients and vehicles affecting delivery: pH, liposomes, esters, gels, creams, oil-in-water vs water-in-oil impact on actives and tolerabilityE examine how excipients and vehicles shape delivery, efficacy, and tolerability. E compare gels, creams, lotions, and ointments, pH effects, liposomes and esters, and how oil-in-water versus water-in-oil systems alter penetration for better use.
pH impact on ionization and irritationOil-in-water vs water-in-oil: key differencesLiposomes and encapsulation for activesRole of esters and solvents in penetrationSelecting vehicles for skin type and diseaseLesson 4Lightening pathway modulators: hydroquinone, azelaic acid, tranexamic acid — mechanisms and cautionsE cover hydroquinone, azelaic acid, and tranexamic acid as modulators of melanogenesis and vascular components. E detail mechanisms, dosing, treatment duration, rebound risk, and safety considerations in different skin phototypes wey differ.
Hydroquinone: mechanism and cycling regimensAzelaic acid for pigment and acne overlapTranexamic acid: topical and oral usePost-inflammatory hyperpigmentation strategiesSafety in darker phototypes and pregnancyLesson 5Photoprotection actives and filters: UVA/UVB chemical filters, mineral filters (zinc oxide, titanium dioxide), photostability, broad-spectrum requirementsE review organic and mineral UV filters, including zinc oxide and titanium dioxide. E explain UVA and UVB coverage, SPF and PPD concepts, photostability, filter combinations, and regulatory and labeling aspects of broad-spectrum claims wey protect.
UVA vs UVB: clinical and labeling relevanceOrganic filters: profiles and combinationsMineral filters: particle size and aestheticsPhotostability and use of stabilizing systemsBroad-spectrum, SPF, and PPD requirementsLesson 6Sunscreen adjuncts and enhancers: photostabilizers, antioxidants, intended claimsE focus on sunscreen adjuncts wey enhance protection, such as photostabilizers and antioxidants. E explore mechanisms, evidence for reduced photoaging, marketing claims, and how adjuncts influence texture and user adherence for daily use.
Photostabilizers for vulnerable UV filtersAntioxidants in sunscreens: added benefitsBlue light and infrared protection claimsImpact on cosmetic elegance and adherenceEvaluating evidence behind marketing claimsLesson 7Anti-inflammatory and barrier-supporting actives: ceramides, fatty acids, cholesterol, panthenol, colloidal oatmeal, allantoinE detail barrier-supporting and soothing actives such as ceramides, fatty acids, cholesterol, panthenol, colloidal oatmeal, and allantoin. E explain barrier repair ratios, anti-inflammatory actions, and roles in dermatitis and post-procedure care wey heal.
Ceramide, cholesterol, fatty acid ratiosPanthenol and allantoin: soothing mechanismsColloidal oatmeal: anti-itch and barrier effectsBarrier repair in eczema and irritant dermatitisPost-procedure recovery and product layeringLesson 8Antioxidants and brightening agents: vitamin C (ascorbic acid forms), niacinamide, alpha arbutin, kojic acid — stability, interactions, clinical indicationsE detail vitamin C forms, niacinamide, alpha arbutin, and kojic acid. E discuss antioxidant and brightening mechanisms, stability challenges, compatible pH ranges, layering with other actives, and evidence-based indications for dyschromia wey fix skin tone.
Ascorbic acid vs derivatives and pH needsNiacinamide: barrier, tone, and tolerabilityAlpha arbutin and kojic acid: pigment targetsFormulation and packaging for antioxidant stabilityCombining brighteners with retinoids and acidsLesson 9Keratolytics and comedolytics: salicylic acid, benzoyl peroxide, azelaic acid — concentrations, vehicles, side effectsE review keratolytics and comedolytics such as salicylic acid, benzoyl peroxide, and azelaic acid. E address mechanisms, optimal concentrations, vehicle selection, bleaching risk, irritation, and combining with retinoids or antibiotics wey work safe.
Salicylic acid: pH, strength, and vehiclesBenzoyl peroxide: efficacy and bleaching riskAzelaic acid: dual comedolytic and brighteningCombining with retinoids and topical antibioticsIrritation, dryness, and mitigation tacticsLesson 10Humectants and emollients: glycerin, hyaluronic acid, urea — function and formulation considerationsE explore humectants and emollients such as glycerin, hyaluronic acid, and urea. E cover mechanisms of water binding, barrier support, ideal concentrations, synergy with occlusives, and formulation choices for dry, sensitive, and aging skin wey need moisture.
Glycerin: mechanism, levels, and skin feelHyaluronic acid weights and crosslinkingUrea concentrations and indicationsCombining humectants, emollients, occlusivesFormulation tips for dry and sensitive skin
