Lesson 1Preservatives, fragrances, and potential irritants: parabens, isothiazolinones, fragrance allergens — relevance for sensitive skinThis lesson evaluates preservatives, fragrances, and common irritants like parabens, isothiazolinones, formaldehyde releasers, and fragrance allergens. It stresses patch testing, regulatory standards, and recommendations for sensitive or atopic skin.
Common preservative classes and safety dataIsothiazolinones and formaldehyde releasersFragrance allergens and labelling rulesFormulating for sensitive and atopic skinPatch testing and counselling on avoidanceLesson 2Retinoids and retinoid alternatives: tretinoin, adapalene, retinol, retinaldehyde — mechanism, efficacy, irritation managementThis lesson covers topical retinoids and alternatives including tretinoin, adapalene, retinol, and retinaldehyde. It discusses receptor interactions, evidence for acne and photoaging, gradual introduction methods, buffering techniques, and irritation control.
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 tolerabilityThis lesson explores how excipients and vehicles influence delivery, efficacy, and skin tolerance. It compares gels, creams, lotions, ointments, pH influences, liposomes, esters, and the effects of oil-in-water versus water-in-oil emulsions on penetration.
pH impact on ionisation 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 cautionsThis lesson reviews hydroquinone, azelaic acid, and tranexamic acid as modulators of melanogenesis and vascular factors. It covers mechanisms, dosing guidelines, treatment durations, rebound risks, and safety for various skin phototypes.
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 requirementsThis lesson surveys organic and mineral UV filters, including zinc oxide and titanium dioxide. It explains UVA/UVB protection, SPF and PPD metrics, photostability, filter synergies, and regulatory requirements for broad-spectrum labelling.
UVA vs UVB: clinical and labelling relevanceOrganic filters: profiles and combinationsMineral filters: particle size and aestheticsPhotostability and use of stabilising systemsBroad-spectrum, SPF, and PPD requirementsLesson 6Sunscreen adjuncts and enhancers: photostabilisers, antioxidants, intended claimsThis lesson focuses on sunscreen enhancers like photostabilisers and antioxidants that boost protection. It examines mechanisms, evidence against photoaging, permissible claims, and their effects on product texture and user compliance.
Photostabilisers 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, allantoinThis lesson details soothing and barrier-repair actives such as ceramides, fatty acids, cholesterol, panthenol, colloidal oatmeal, and allantoin. It explains repair ratios, anti-inflammatory effects, and applications in dermatitis and post-procedure recovery.
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 indicationsThis lesson covers vitamin C variants, niacinamide, alpha arbutin, and kojic acid. It discusses antioxidant and brightening actions, stability issues, compatible pH levels, combinations with other actives, and indications for uneven 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 effectsThis lesson reviews keratolytics and comedolytics including salicylic acid, benzoyl peroxide, and azelaic acid. It addresses mechanisms, ideal concentrations, vehicle choices, bleaching risks, irritation, and pairings with retinoids or antibiotics.
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 considerationsThis lesson explores humectants and emollients like glycerin, hyaluronic acid, and urea. It covers water-binding mechanisms, barrier support, optimal levels, synergies with occlusives, and formulations for dry, sensitive, or aging skin.
Glycerin: mechanism, levels, and skin feelHyaluronic acid weights and crosslinkingUrea concentrations and indicationsCombining humectants, emollients, occlusivesFormulation tips for dry and sensitive skin