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level: METHODS OF STERILIZATION

Questions and Answers List

level questions: METHODS OF STERILIZATION

Question	Answer
destruction of all living organisms and their spores or their complete removal from the preparation.	Sterilization
TYPES OF STERILIZATION	1. Steam 2. Dry heat 3. Filtration 4. Gas 5. Ionizing radiation
- autoclave and employs steam under pressure - microbial destruction is caused by denaturation & coagulation of bacterial proteins by moist heat - Bacillus stearothermophilus: biological indicator - applicable to pharmaceutical preparations and materials: withstand the required temperatures penetrated but not adversely affected by moisture * It is not useful for oils, fats, oleaginous preparations, and other preparations not penetrated by moisture or for exposed powders that may	Steam Sterilization
STEAM PRESSURES:	1) 10-lb pressure (115.5°C, or 240°F) for 30 minutes 2) 15-lb pressure (121.5°C, or 250°F) for 20 minutes 3) 20-lb pressure (126.5°C, or 260°F) for 15 minute
- carried out in ovens, heated by gas or electricity and are generally thermostatically controlled - 150°C to 170°C, not <2 hrs - Bacillus subtilis: biological indicator - use: for substances not effectively sterilized by moist heat: fixed oils, glycerin, petrolatum - method of choice when dry apparatus or dry containers are required, as in the handling of packaging of dry chemicals or nonaqueous solutions.	Dry Heat Sterilization
- depends on the physical removal of microorganisms by adsorption on the filter medium or by a sieving mechanism - use: for heat-sensitive solutions	Sterilization by Filtration
- thin plastic membrane of cellulosic esters with millions of pores per square inch -14 to 0.025 um	Millipore filter
Bacterial Filtration ADVANTAGE AND DISADVANTAGE	1 speed in filtration of small quantities of sol'n 2 sterilize thermolabile materials 3 inexpensive equipment 4 complete removal of living and dead m.o and particulate matter Disadvantage: 1 membrane tends to be FRAGILE 2 essential to determine that the ASSEMBLY WAS PROPERLY MADE (membrane not ruptured/flawed during assembly, sterilization, or use). 3 Large volume of liquids requires more time
- requires specialized equipment resembling an autoclave, and many combination steam autoclaves and ethylene oxide ( 4 to 16 hrs) or propylene oxide sterilizers -Bacillus stearothermophilus: biological indicator - for sterilizing heat sensitive & moisture sensitive products	Gas Sterilization
- sterilization by gamma rays and by cathode rays, but application of such techniques is limited because of the highly specialized equipment required and the effects of irradiation on products and their containers - biological indicator: Bacillus pumilus	Sterilization by Ionization Radiation
- best used to validate sterility for steam sterilization - a characterized preparation of specific microorganisms resistant to a particular sterilization process - use: to monitor a sterilization cycle and/or periodically to revalidate the process	Biologic Indicator
- time required to kill a particular organism under specified conditions	Thermal Death Time
subset of pyrogens that come from GRAM-NEGATIVE BACTERIA CAUSATIVE MATERIAL OF PYROGENS a lipopolysaccharide from the outer cell wall of the bacteria potent, toxic and very stable material is thermostable and water soluble (remain in water even after sterilization by autoclaving or by bacterial filtration (0.2-um). insoluble in organic solvents	Endotoxin
Endotoxin units/ EU 1 Parenterals 2 Intrathecal	. 1) 5.0 EU/kg 2) 0.2 EU/kg
USP 35- NF 30: 1 Contains not more than 0.5 USP EU/mL for injections containing less than 5% dextrose and not more than 10.0 USP EU/mL for injections containing between 5% and 70% dextrose. 2 Contains not more than 200.0 USP EU/mg of digoxin. 3 Contains not more than 0.71 USP EU/mg of gentamicin	. 1 Dextrose Injection 2 Digoxin Injection 3 Gentamicin Injection
KMnO4 + BaOH > Ba salts Uses: HEALTHY RABBITS properly maintained in terms of environment and diet before the test Normal, or control, temperatures are taken for each animal - used as the base for the determination of any temperature increase resulting from injection of a test solution - rabbits used: temperatures do not differ by more than 1ºC from each other	Pyrogen Test, USP
To measure the concentration of endotoxins of gram negative bacterial origin REAGENT: Amoebocyte lysate from horseshoe crab, Limulus polyphemus	LAL TEST (Limulus amebocyte lysate test)