ShmmonAhmad
 Department of Pharmaceutics
 Glocal School of Pharmacy
    Definition :
     Sterilization is a process that eliminates (removes) or kills all forms of 
      life, including transmissible agents (such as fungi, bacteria ,viruses, spore 
      forms, etc.) present on a surface, contained in a fluid, in medication, or in a 
      compound such as biological culture media. 
     Sterilization can be achieved by applying the proper combinations of heat, 
      chemicals, irradiation, high pressure, and filtration.
    A . Physical methods:
    1.Heat sterilization:
     a . Dry heat sterilization
     b . Moist heat sterilization
    2 . Sterilization by radiation
      a . Use of ultra violet rays 
      b . Ionising radiation
    B . Chemical methods:
      a . Sterilization by  Gases
    C . Mechanical methods
      a . Ceramic filters 
      b . Seitz filter
      c . Sintered glass filters
      d . Sintered meta filters
      e . Membrane filters
   A . PHYSICAL(THERMAL ) METHODS :
     The lethal effectiveness of heat on microorganism depends on
   ❖   Degree of heat
   ❖   Exposure period
   ❖   Moisture present
    Within the range of sterilizing temperatures,  the time required to produce  a 
     lethal effect is inversely proportional to temperature employed.
   Eg.,
      Dry heat  at 170°C   - 1 hour
            at 140°C  - 3 hour
   Mechanism:
     Coagulation of the protein of the living cell