Sterilisation techniques

• What is the meaning of sterilization?

  Destruction or removal of microorganisms
• What are the different products that require sterility?

  Injections, sterile fluids, ophthalmic preparations
• What are the different sterilization techniques?

  Heat, radiation, gaseous, filtration
• What are the indications for using different sterilization techniques?

  Depends on product type and heat sensitivity

  
• What is the recommended process for terminal sterilization?

  Preparation sterilized in final container

  
• What are examples of injectable sterile fluids?

  Small-volume injections, IV infusions, TPN fluids
• What are examples of non-injectable sterile fluids?

  Irrigation solutions, dialysis solutions, nebulizer solutions
• What are examples of ophthalmic preparations?

  Eye drops, ointments, contact lens solutions
• What are examples of medical devices that require sterilization?

  Syringes, needles, pacemakers, heart valves
• What is the mechanism of heat sterilization?

  Degradation of membranes, proteins, nucleic acids
• What is the difference between moist heat and dry heat sterilization?

  Moist heat uses steam; dry heat uses hot air

  
• What is the temperature required for bacterial spores to be killed?

  Greater than 100 °C
• What is the temperature range for nonsporulating bacteria to be killed?

  50-60 °C
• What is the mechanism of dry heat sterilization?

  Damage to DNA, RNA, enzymes, cell membranes
• What is cold sterilization used for?

  Heat-sensitive products
• What is an example of non-ionizing radiation used for disinfection?

  Ultraviolet (UV) radiation
• What is the purpose of ionizing irradiation?

  Sterilizing syringes, needles, etc.
• What is the role of ethylene oxide in gaseous sterilization?

  Good penetration, kills various microorganisms
• What is the effect of hydrogen peroxide gas in sterilization?

  Effective against spores at various temperatures
• What is the purpose of filter sterilization?

  Complete removal of microorganisms from liquids
• What is a limitation of filter sterilization?

  Viruses are not removed
• What are the main sterilization techniques and their mechanisms?

  1. Heat sterilization:

  • Moist heat: Degrades membranes, proteins, nucleic acids
  • Dry heat: Damages DNA, RNA, enzymes

  1. Radiation sterilization:

  • Non-ionizing: UV for surfaces
  • Ionizing: Gamma for syringes, needles

  1. Gaseous sterilization:

  • Ethylene oxide: Good penetration, kills microorganisms
  • Hydrogen peroxide gas: Effective against spores

  1. Filtration: Removes microorganisms from liquids
• What are the strengths and weaknesses of different sterilization methods?

  Strengths:

  • Effective against a wide range of microorganisms
  • Suitable for various products

  Weaknesses:

  • Some methods are expensive
  • Certain methods have limitations (e.g., penetration)