Unit 3 lec

• Skin Cleansing:

  • Intended to remove dirt, makeup, environmental pollutants, germs, and other types of soilage from the skin
  • Serves as a foundation for healthy skin and contributes to its aesthetic appearance
  • Essential in maintaining healthy skin
  • Initial step in overall skin care
  • Maintains the barrier protection of the skin
• Effects of Skin Cleansing:

  • Cause changes in skin’s structure and barrier function
  • Solubilize lipids on the skin surface that provide protection and extract skin components
  • Damage skin proteins due to charge density of the surfactant aggregates
  • Anionic surfactants are soapy while nonionic surfactants are non-heavy foaming like cetaphil
  • Alkaline pH has a higher potential to irritate the skin
  • Irritation, itching, inflammatory responses may occur
  • Potentially flammable for alcohol content
• Desired Qualities of Skin Cleansers:

  • Neutral or pleasant odor and color
  • Easy to rub on with foaming property
  • Easy to spread
  • Pleasant feel during application
  • Non-oily/non-greasy feel
  • Leaves no residue
  • Moisturizes the skin
  • Non-comedogenic
  • Well tolerated and non-allergenic
  • Do not dry the skin but kill bacteria and viruses
• Classifications of Skin Cleansing:

  • Based on Chemical Nature and Mildness:
  • Soaps: pH 9.5-10, anionic surfactants
  • Synthetic Surfactants: pH 7, mild anionic surfactants
  • Solvents: Can be oil or alcohol-based
  • Based on Cleaning Principle:
  • Chemical Cleaning: Emulsifying and Dissolving
  • Physical Cleaning: Abrasion (friction)
  • Based on Foamability:
  • Foaming Cleansers
  • Low Foaming Cleansers
  • Non-Foaming Cleansers
  • Based on Product Types:
  • Solid: Soap bars, bath salts, cleansing wipes
  • Liquid: Surfactant solutions, toners
  • Semi-Solid: Creams, pastes, gels
• In single-celled organisms, substances can easily enter the cell due to a short distance, while in multicellular organisms, the distance is larger due to a higher surface area to volume ratio
• Multicellular organisms require specialised exchange surfaces for efficient gas exchange of carbon dioxide and oxygen due to their higher surface area to volume ratio
• Cleansing creams:

  • Have a lower irritation potential compared to soaps
• Toners:

  • Clear solution with various types of solvents containing a low amount of surfactants
  • Used on the face with a base of alcohol and glycol as sebum is soluble in these solvents
• Facial masks:

  • Rinse off with warm water after 15-30 mins application
  • Contain insoluble materials like clays, zinc oxide, kaolin, recommended for oily skin
  • Moisturizers and cleansing agents are beneficial for dry skin
  • Peel off masks are made of rubbery substances like polyvinyl alcohol or rubber-based substances, recommended for dry skin
• Cleansing wipes:

  • Beneficial when water is not available
  • Used for one-time only
  • More hygienic than bar soaps
  • Made from natural fibers like cotton or synthetic fibers like polypropylene
• Ingredients in bath and shower products include surfactants, thickeners, foam stabilizers, water, skin conditioning agents, abrasives, preservatives, and additional ingredients like colorants and fragrances
• Body skin cleansing products include soap bars, liquid cleaning products, bath oils and essences, bath salts, and bath bombs
• Hand skin cleansing products include bar soaps, liquid soaps, hand cleansing wipes, and common ingredients like water, surfactants, skin conditioning agents, thickeners, preservatives, natural components, antiseptics, and additional ingredients
• Topical antiseptic products are hand hygiene products with antimicrobial activity available for the general public, including healthcare antiseptics like hand washes, hand sanitizers, surgical hand scrubs, and patient preoperative skin preparation
• Antiseptic products can be categorized into healthcare antiseptics, consumer antiseptics, and food handler antiseptics
• Healthcare antiseptics include hand washes, hand sanitizers, surgical hand scrubs, and patient preoperative skin preparations, intended for use by healthcare professionals
• Consumer antiseptics, like antibacterial soaps and hand sanitizers, are marketed for use by the general public in various settings
• Food handler antiseptics, such as hand soaps and hand sanitizers, are marketed for use in food handling establishments
• Topical antiseptic products are marketed under the tentative final monograph for OTC healthcare antiseptic drug products
• Antimicrobial actives in antiseptic products are classified as Category I, Category II, or Category III
• Category I antimicrobial actives are Generally Recognized As Safe and Effective (GRASE) ingredients like ethanol and povidone-iodine
• Category II antimicrobial actives are generally not recognized as safe and effective, or have unacceptable indications
• Category III antimicrobial actives have insufficient evidence based on their effect, but the FDA does not object to selling products containing them
• Other ingredients in antiseptic products include benzalkonium chloride, triclocarban, and triclosan
• Antibacterial hand sanitizers can be alcohol-based or water-based formulations
• Alcohol-based hand sanitizers use ethanol or isopropyl alcohol as active ingredients, denaturing proteins and most effective at 60-95% alcohol concentration
• Alcohol-based hand sanitizers typically contain water, skin conditioners, preservatives, and other ingredients
• Water-based hand sanitizers are often labeled as "Alcohol-free formulations" and contain water, surfactants, antimicrobial ingredients, and emollients
• Water-based hand sanitizers are less drying, less harmful if ingested, not flammable, and offer immediate and persistent killing activity
• Quality problems of skin cleansers can include sticky bath salts, broken bath bombs, discoloration of bar soaps, poor foaming activity, and separation of emulsions
• Sticky bath salts can absorb water from the environment due to humidity and the hygroscopic property of the ingredients
• Broken bath bombs may result from inadequate compression force during manufacturing
• Discoloration of bar soaps can be caused by chemical changes like oxidation, incompatibility among components, and pH stability issues
• Poor foaming activity in cleansers can be influenced by the type and amount of surfactants and thickeners used
• Separation of emulsions can be reversible (creaming, sedimentation, flocculation) or irreversible (coalescence, phase inversion, Oswald ripening)
• Cloudy solutions in skin cleansers can result from inappropriate solubilizers or oil droplet size in the solution
• Microbiological contamination is a concern in water-based skin cleansers and can be addressed by adding preservatives
• Clumping in water-based formulations can occur due to hydrophilic thickeners aggregating and forming clumps
• Rancidification in skin cleansers can happen due to chemical decomposition of fats and oils, leading to unpleasant odors
• Quality parameters for skin cleansers include spreadability, extrudability, texture, firmness, foaming properties, viscosity, density, structure, and hardness