Sterilisation techniques

• What is the definition of sterilization?

  Destruction or removal of microorganisms
• What are the pharmacopoeia recommended processes for sterilization?

  Terminal sterilization processes
• What types of injections require sterility?

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

  Irrigation solutions and dialysis solutions
• What types of ophthalmic preparations require sterility?

  Eye drops and ophthalmic ointments
• What medical devices require sterility?

  Syringes, needles, and pacemakers
• What are the main sterilization techniques?

  • Heat sterilization: moist and dry
  • Radiation sterilization
  • Gaseous sterilization
  • Filtration
• How does an autoclave sterilize products?

  Uses steam, temperature, pressure, and time
• What is the role of steam in autoclave sterilization?

  Delivers heat to the product
• Why is steam at the phase boundary effective in sterilization?

  It holds more latent heat than boiling water
• How does steam transfer heat during sterilization?

  By condensation onto a cooler surface
• What effect does condensed water have on microorganisms?

  Hydrates them and makes them more sensitive
• How does steam penetrate porous items?

  It penetrates through cell membranes of microorganisms
• What is the temperature required to kill bacterial spores?

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

  50-60 °C
• What is the temperature range for vegetative forms of yeasts and moulds?

  50-60 °C
• What is the temperature range for cysts of amoebae?

  55 °C to 60 °C
• How do viruses compare to bacterial spores in terms of resistance?

  Viruses are less resistant than bacterial spores
• What is the effect of heat sterilization on microorganisms?

  Degrades membranes, proteins, and nucleic acids
• What is the mechanism of hydrolysis in steam sterilization?

  It involves the breakdown of molecules by water
• What is the mechanism of oxidation in dry heat sterilization?

  It involves the breakdown of molecules by oxygen
• Why is dry heat sterilization less effective than steam?

  It is a longer procedure and less effective
• What types of products are sensitive to water/moisture?

  Metallic medical devices and oily injections
• What is the mechanism of cold sterilization?

  Uses non-ionizing radiation for heat-sensitive products
• Why is non-ionizing radiation not used for pharmaceutical products?

  It has low penetration and absorption by containers
• What is an example of ionizing radiation used for sterilization?

  Gamma radiation
• What is the effect of alkylating gases in gaseous sterilization?

  They alkylate essential macromolecules in microorganisms
• What is the role of hydrogen peroxide gas in sterilization?

  Effective against spores at near-saturation levels
• What is the limitation of chlorine dioxide in sterilization?

  It has limited applications despite being broad-spectrum
• What is the purpose of filter sterilization?

  Complete removal of microorganisms from liquids or gases
• What is a requirement for filter sterilization?

  Aseptic techniques are required
• What is a limitation of filter sterilization?

  Viruses are not removed by filtration
• What types of products are suitable for filter sterilization?

  Heat-sensitive products and biological products
• What is the purpose of filter sterilization in aseptic areas?

  To supply air and other gases