What are the methods of sterilization?

The following methods are used of sterilization:-

1. Physical method of sterilization

2. Chemical method

3. Mechanical method of sterilization

1. Physical method: -

a.Dry heat sterilization:

1.Flaming: in this method the articles should be sterilized on the hot flame of Bunsen burner.

2. Hot air oven: - It is also called dry heat sterilizer. The articles should be sterilized at the temperature 150c-170c for 1hour.

Glass wear like test tube, pipette, flask and glass syringes etc. can be sterilized by this method. Fixed oil glycerin, liquid paraffin, propylene glycol and zinc oxide etc also can be sterilized by this method.

b.Moist heat sterilization: -

 Moist heat sterilization is also known as steam sterilization. It is done is an auto clave but on small scale of pressure cooker can be used.

1. Auto clave: - Auto cleaving is the process of moist heating in an autoclave, in which destroys the micro-organism at the process of moist heating in an autoclave, in which destroys the micro-organism at the temperature of 120c on 1510 pressure for 20 minutes. Time is recorded from the temperature at 121c. the sterilization is done by steam heat under pressure.

Use: - Glass wear, surgical dressing, rubber, gloves, gurgical instrument are sterilized by this method (Autoclaved)

Solution packed in sealed container or seated ampoules are sterilized by this method. If the solution is below 100ml auto calved for 30minute. More than 100ml on hour period is needed.

2. Horizontal harge scale autoclave: - It is used pharmaceutical industry ad big hospital.

3.Sterilization by boiling water: - The boiling water bath or electric boiling sterilizer is useful for sterilizing instruments like syringe, needles, knives blades, scissor, scalpel and other surgical instrument. Temperature at the 100c (boiling point) for 20 minutes.

4. Other method of sterilization: -

Pasteurization.

 a. Holding method: 62.8c and held the temperature for 30min.

 b. Flash method or high temperature short time: in this method at the temperature 161F for 25 second.

 c. Sterilization by radiation: - Sterilization by radiation is also known as cold sterilization by radiation is also known as cold sterilization. Ultra-violate ray, Gamma-ray can be used for sterilizing antibiotics, injection, Benzylpenicllin, streptomycin, vitamin like ascorbic acid, vaccine can be sterilized by this method.

2. Chemical method: -

   a. Gaseous sterilization: - It is especial type of chemical sterilization in which chemical reused as gas or vapor and not the liquid but solid dissolved in a solution many gas like sulfur dioxide, chlorine formaldehyde, ozone, ethylene oxide, have bactericidal effect. Now day ethylene oxide widely used as gaseous sterilizing agent.

           

b. Sterilization by disinfectant: - Disinfectant are mainly used for sterilizing the surfeit for aseptic wash. In emergency. They may be used for sterilizing for the sugars instrument, iodine, chloride, caracole soap solution, phenol an formaldehyde are commonly used disinfectant.

3. Mechanical method of sterilization: -

In this method of sterilization the solution to the sterilized the solution is passed through mechanical device known bacteria, peon fitter whit include.

     1. Seitz filter

     2. Sintered glass filter

     3. Millipore filter

     4. Berkefild / mangle filter

    5. Pasteur chamber filter

    6. Membrane filter

Pharmaceutical solution can be sterilized in this method the micro-organism are physically remove absorption on the filter medium or by mechanism. All process filtration filling and sealing are the under a septic condition. Sterilize test must be done.