Lab

• Hand sanitizers


  Applied to dry hands followed by rubbing to remove microorganisms and prevent infections/reduce spread of infectious diseases
• Types of hand sanitizer formulations

  • Gel
  • Foam
  • Cleanser
  • Cream
  • Spray
  • Wipes
• Before the 1980s, there were no hand sanitizers, with proper handwashing being the gold standard for preventing infection
• Healthcare workers and the food industry need constant handwashing, leading to dry hands and the development of WHO hand sanitizing gel formulations
• Gel formulations


  Deal with different gelling agents, with factors like other ingredients affecting the choice of gelling agent. Focus is on aesthetics and consumer acceptability.
• Foam hand sanitizer formulations are not common in the Philippines, but more common in soap
• Cream hand sanitizer formulations are a current trend due to their additional moisturizing effect
• Alcohol-based hand sanitizers


  Contain at least 62% alcohol (60-95% most effective), either ethanol or isopropyl alcohol. Provide immediate benefit but no residual activity.
• Alcohol-based hand sanitizers


  • Safety concerns: ingestion (especially by children), flammability, drying effect
• Alcohol-based hand sanitizers are the most common classification in the Philippines
• Mechanism of action of alcohol as a disinfectant

  Denatures the proteins of microorganisms, killing them and some viruses
• Alcohol-based hand sanitizers with 40% alcohol were previously sold but phased out due to ineffectiveness
• US data shows a high percentage of alcohol sanitizers being ingested by alcoholics
• Alcohol-based, supplemented hand sanitizers

  Contain at least 62% alcohol plus an antimicrobial agent like triclosan or benzalkonium chloride, providing more persistent activity
• Water-based hand sanitizers


  Alcohol-free, contain water, surfactant, and antimicrobial ingredients like benzalkonium chloride and triclosan. Advantage is no drying effect and less safety concerns.
• WHO-recommended hand sanitizer formulations

  • Formulation 1: Ethanol 80% v/v, Hydrogen peroxide 0.125% v/v, Glycerol 1.45% v/v, Sterile distilled or boiled cold water
  • Formulation 2: Isopropyl alcohol 75% v/v, Hydrogen peroxide 0.125% v/v, Glycerol 1.45% v/v, Sterile distilled or boiled cold water
• Glycerin is water-soluble and not used in the WHO hand sanitizer formulations, which use glycerol instead
• Gels


  A dispersion system composed of small or large molecules dispersed throughout a liquid vehicle, with increased water content resulting in faster evaporation and a cooling effect. Commonly used for burns.
• Classification of gels


  • Colloidal phases (single- or two-phase system)
  • Nature of solvent used (hydrogel or organogel, xerogel)
  • Physical nature (elastic or rigid)
  • Rheological properties (plastic, pseudoplastic, or thixotropic)
• Antimicrobial agent classifications


  • Category I: Ingredients Generally Recognized As Safe and Effective (GRASE)
  • Category II: Ingredients generally not recognized as safe and effective or have unaccepted indications (not GRASE)
  • Category III: Insufficient data available to permit final classification
• Antimicrobial agents in alcohol-based hand sanitizers

  • Ethanol
  • Isopropyl alcohol
  • N-propanol
  • Hydrogen peroxide
• Antimicrobial agents in water-based hand sanitizers

  • Benzalkonium chloride
  • Triclosan
• Alcohol-based hand rubs


  • Antiseptic agents: Ethanol, Isopropanol
• Alcohol-free hand rubs


  • Antiseptic agents: Chlorhexidine, Chloroxylenol, Triclosan, Iodine/Iodophors, Quaternary ammonium compounds
• Gelling agents in hydrogels

  • Synthetic polymers: Carbomers, Polyacrylates
  • Natural polymers: Cellulose derivatives, Guar derivatives
• Iodine/iodophors were phased out as ingredients for hand sanitizing gels because iodine stains the hands
• Gelling/thickening agents


  Used to enhance viscosity and stabilize the product, added in concentrations usually less than 10%
• Antimicrobial agents


  • Triclosan
  • Iodine/Iodophors
  • Quaternary ammonium compounds
• Gelling agents


  • Hydrogels
  • Synthetic polymers
  • Carbomers
  • Polyacrylates
  • Natural polymers
  • Cellulose derivatives
  • Guar derivatives
• Iodine/Iodophors were phased out as ingredients for hand sanitizing gels because iodine stains on the hands
• Gelling agents


  • Also known as thickening agents
  • Used to enhance the viscosity of the product and stabilizers
  • Added in concentrations mostly less than 10% (usually 0.3%՞2%)
• Natural polymer gelling agents

  • Carrageenan
  • Chitosan
  • Collagen
  • Guar gum
  • Xanthan gum
  • dextran
• Synthetic polymer gelling agents

  • Carbomer
  • Poloxamer
  • Polyvinyl alcohol
• Semi-synthetic polymer gelling agents

  • CMC (carboxymethyl cellulose)
  • HPMC (hydroxypropyl methyl cellulose)
  • EC (ethyl cellulose)
  • HEC (hydroxyethyl cellulose)
  • HPC (hydroxypropyl cellulose)
  • MC (methyl cellulose)
  • Sodium alginate
• Carbomer (brand name: Carbopol) is the most potent and cheapest gelling agent
• Cellulose derivatives have a greater gelling properties when they have more carbons in their structure
• Skin conditioning agents


  • Added to reduce dryness brought by alcohol in alcohol-based formulation
  • Retains the natural moisture of the skin
• Common skin conditioning agents

  • Aloe vera
  • Glycerol
  • Propylene glycol
  • Isopropyl myristate
  • Vitamin E
• pH modifying agents


  • Added to avoid skin irritation
  • For water-based formulations, a low-pH matrix is used
• Common pH modifying agents

  • Citric acid
  • Triethanolamine (TEA)