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STERILIZATION

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STERILIZATION The complete destruction of all living organisms and their spores or their complete removal from the formulation. All parenterals, as well as otic ... – PowerPoint PPT presentation

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Title: STERILIZATION


1
STERILIZATION
  • The complete destruction of all living organisms
    and their spores or their complete removal from
    the formulation.
  • All parenterals, as well as otic, nasal,
    ophthalmic solutions, must be sterile,
  • includes packaging materials
  • methods
  • steam
  • dry-heat
  • filtration
  • gas
  • ionizing radiation

2
Viruses
3
Bacteria
4
Bacterial Endospores
5
Yeast and Mould
aspergillus
penicillium
6
Sterilization Methods
  • steam sterilization
  • conducted in an autoclave
  • method of choice
  • 121 ?C, 20 minutes
  • dry heat
  • less effective than moist heat
  • 170 ?C, gt 2 hours
  • used to sterilize equipment

7
Heat Resistances
  • method determined by nature of micro-organism and
    formulation ingredients
  • protocols are developed based on reference
    organisms of known sterilization resistance
  • micro-organisms possess different resistances to
    heat

8
Steam Sterilization
  • Determination of steam sterilization protocol
  • first select a reference organism
  • determine its D value under defined conditions
  • establish initial bioburden
  • calculate time of exposure at 121 ºC

9
Sterilization Methods
  • Filtration
  • used for heat sensitive solutions
  • pore sizes range from 14 to 0.025 mm
  • Gas sterilization
  • used in hospitals and industry for thermolabile
    materials
  • ethylene oxide, propylene oxide used
  • 500-1000 mg/L, 4 - 16 hours at 55 ºC, 50-60 RH
  • need to remove absorbed gas after sterilization
  • Ionization
  • use of gamma rays
  • limited application

10
Kinetics of Cell Inactivation
  • death rate follows first order kinetics

11
D value
  • decimal reduction time
  • time required for 90 reduction in cell count

12
Z value
degrees of temperature/dose change required to
achieve a tenfold decrease in D
13
Example
  • Using G. stearothermophilus as a reference
    organism (D121 1.5 min), and an initial
    bioburden of 1000 spores, determine the
    sterilization time required to achieve a 1 in
    1,000,000 chance of a spore surviving using a
    steam autoclave.

14
De-pyrogenation
  • Emphasis is placed on prevention of introduction
    of pyrogens
  • Removal
  • glassware, metals
  • 250 ºC for 45 minutes
  • water
  • oxidation to nonvolatile solvents using potassium
    permanganate, then distill
  • reverse osmosis
  • plastics
  • protect against contamination
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