Lesson 1Preservatives, fragrances, and potential irritants: parabens, isothiazolinones, fragrance allergens — relevance for sensitive skinThis lesson scrutinises preservatives, fragrances, and common irritants like parabens, isothiazolinones, formaldehyde releasers, and scent allergens. It stresses patch testing, legal limits, and advice for sensitive or eczema-prone skin in everyday use.
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 substitutes like tretinoin, adapalene, retinol, and retinaldehyde. It discusses cell receptor interactions, proof in acne and sun-aging, gradual introduction, buffering, and handling irritation or initial breakouts.
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 looks at how excipients and bases affect ingredient delivery, effectiveness, and skin tolerance. It compares gels, creams, lotions, ointments, pH influences, liposomes, esters, and oil-in-water versus water-in-oil systems on absorption.
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 addresses hydroquinone, azelaic acid, and tranexamic acid as controllers of melanin and blood vessel factors. It outlines actions, dosages, treatment lengths, rebound risks, and safety notes for various skin tones and conditions.
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 reviews chemical and mineral UV blockers, including zinc oxide and titanium dioxide. It explains UVA/UVB protection, SPF/PPD ideas, light stability, filter mixes, and rules for broad-spectrum product labels in sunny regions.
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: photostabilizers, antioxidants, intended claimsThis lesson focuses on sunscreen add-ons like photostabilizers and antioxidants that boost protection. It explores their workings, evidence against sun-aging, promotional claims, and effects on product feel and consistent 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, allantoinThis lesson details soothing and barrier-boosting actives like ceramides, fatty acids, cholesterol, panthenol, colloidal oatmeal, and allantoin. It explains repair ratios, anti-inflammatory effects, and uses in eczema or after treatments.
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, suitable pH levels, combining with other actives, and proven uses 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 skin-shedding and pore-clearing agents like salicylic acid, benzoyl peroxide, and azelaic acid. It covers mechanisms, best strengths, base choices, bleaching risks, irritation, and pairing 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 water-attracting and softening agents like glycerin, hyaluronic acid, and urea. It covers water-binding mechanisms, barrier aid, ideal levels, pairing with sealants, and choices for dry, sensitive, or mature skin.
Glycerin: mechanism, levels, and skin feelHyaluronic acid weights and crosslinkingUrea concentrations and indicationsCombining humectants, emollients, occlusivesFormulation tips for dry and sensitive skin