Sterilization of Aseptic techniques

There have many methods of sterilization.,there have also sterilization with aseptic techniques for help to education. Easy to learn about of sterilization, and how to sterile easy to learn way. So i hope you'll enjoy and learn easily and to read about this slide.

1. Aseptic Techniques Prepared by Apu

2. Overview To prevent contamination during the preparation and testing of pharmaceutical products. Prevent contamination of the specific microorganism we are working with. Prevent contamination of the room and personnel with the microorganism we are working with. What is the Aim of Aseptic Technique? Aseptic technique refers to a procedure that is performed under sterile conditions. This includes medical and laboratory techniques which deal with cultures and human cells and tissue for transplantation, etc. It is a procedure that does not allow the access of micro-organisms from possible sources such as ingredients, solvents, mixing equipment , final containers , working area, the operators hand and other contact parts.

3. Sources of Contamination The Atmosphere The Breath The Hands Clothing The Hair The Working Surface Equipment

4. Some Basic Terms Sterilization: It is the process by which article, surface or medium is made free from all microorganisms either in the vegetative or spore state. Spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. of the lifecycles of many bacteria, plants, algae , fungi and some protozoa. Sterile/Sterile products: A products is said to be sterile when it is free from all living microorganisms. Disinfection : It is the process by which an article, surface or medium is made free from all pathogenic microorganisms (that is organisms that are capable of giving rise to infection ). Antisepsis : It is the process by which the growth of bacteria is inhibited but they are not killed (chemicals or disinfectants that can be safely applied on skin or mucous membrane) Decontamination: It is the process of rendering an article or area free of contaminants, including microbial, chemical, radioactive and other hazards.

5. Other Terms Used in Relation to Sterilization Bactericides : These are the substance used to kill bacteria. Bacteriostatic agents : These are the agents which inhibit the growth of bacteria ( only prevent multiplication of bacteria, but they remain alive) Fungicides : These are the agents which kill fungi. Germicides: These are the substance which kill germs. Mycocides : These are the agents which kill molds. Viricides : These are the agents which kill viruses.

6. What need to be sterilized in the process of aseptic technique? Culture media Fluids used in the labs Reagents Laboratory containers Laboratory equipment Medical and surgical instruments Vaccine and biological products Parental pharmaceutical products Certain foods

7. Methods of Sterilization

8. Methods of Sterilization

9. Sterilization by Dry Heat All microorganisms including bacterial spores can be destroyed by heat. Sterilization by dry heat is usually carried out in a apparatus known as hot air oven. Heat is transferred from its source to the load by radiation, convention and to a lesser extent conduction. During this process the microorganisms are killed by oxidation. It is a function of time temperature combination. It is the simplest and most economical method of sterilization. It is less effective than moist heat because higher temperature and longer periods of exposure are required. Therefore, The economy must be considered during the time temperature relationship.

10. Design of Hot Air Oven Hot air oven or dry heat sterilizer consists of a metallic chamber of aluminium or stainless steel, which is electrically heated and thermostatically controlled. The chamber of the oven has double walls which are separated from each other by thick layer of glass- fibre insulation. The hollow flanged door is also filled with glass fibre insulation . The inner side of the door is fitted with asbestos gasket that provides a tight seal to prevent heat loss.

11. Design of Hot Air Oven Depending on the size of the oven 3-4 perforated salves are provided in the chamber which can be removed as and when desired . A good quality of thermometer is fitted in front of the chamber for noting the temperature the process . A fan is provided for air circulation in the oven. A vent is fitted at the top of the oven . A on-off switch is provided along with green and red indicators. The heating elements are fitted on the lower side of chamber.

12. Method of Use Articles are to be arranged in a manner to allow free circulation of air. (For getting good results the oven should be properly loaded so that all the articles are exposed to uniform heat for required time .) Care should be taken that the oven is not opened in between the sterilization operation. Generally, the oven can be operated fron 50⁰ to 300⁰ C (122 to 572 F) Precautions : Glass wares should be dry. Oven should not be over loaded Door of oven should be opened after it cools down (2 hr.) Applications Glassware, eg . Volumetric flask , Pipette, All- glass syringes Other instruments, eg . Forceps, Scissors, Scalpels Oil and Similar Anhydrous Material, eg . Liquid paraffin Powders, eg . Dusting powder

13. Advantages and Disadvantages Advantages 1. It is the most suitable method of sterilization for moisture sensitive material. Example : Oily substance and dry powders 2. It is suitable for assembled equipment providing sufficient time for penetration. Example : All glass, syringes, test tube etc. 3. It is less damaging to glass and metal equipment than moist heat. 4. The method is economically safe . Disadvantages 1 . It requires high temperature and long exposure time. 2. Most medicaments ,rubber and plastic articles which are thermolabile get destroyed by this method. 3. Preparations containing H2O, alcohol, other volatile substances cannot be sterlized , sterilized by this method because the liquid may evaporate at high temperature. 4. It is unsuitable for surgical dressing because the natural moisture of the fibers quickly vaporizes which leads to deterioration and ultimately charring may take place. 5 . Drastic nature may appear in high temperature, eg . A tube cannot be sterilized after filling because, if closed it many burst from expansion of contents.

14. Sterilization by Moist Heat Moist heat sterilization: Moist heat sterilization is also known as steam sterilization. Microorganism can be exposed to moist heat by using • Hot water • Boiling water • Steam at atmospheric pressure • Steam under pressure Moist heat is believed to destroy microorganisms by causing protein coagulation or denaturation. It can kill microorganisms at lower temperature and in shorter times than dry heat. For example, all vegetable bacteria are destroyed by 1 hour at 80⁰C and very few will survive 10 minutes at this temperature. The spores of pathogens, however require 30 minute at 115⁰C will also destroy easily the vegetative forms of molds, yeasts and yeast spores.

15. Factors affecting sterilization by moist heat pH Inhibitory medicaments Protective substances Initial number of organisms Inactivation factor of the process

16. Principle of sterilization by stem under pressure Steam under pressure is allowed to penetrate through the materials. Pressure itself has no sterilizing power. S team is under pressure to obtain temperatures high enough to destroy micro- organisms quickly. Greater the pressure applied Higher the temperature obtained Lesser the time required. Steam for Sterilization can be obtained in two ways: Wet Saturated Steam Dry Saturated Steam

17. Principle of sterilization by stem under pressure The apparatus for sterilization by steam under pressure is called an autoclave or steam sterilizer. Autoclaving is the process of heating in an autoclave in which saturated steam under pressure is allowed to penetrate through the materials for at least 15 minutes at a minimum temperature of 121 C. The amount of time begins when the temperature of the material being sterilized reaches at 121 C . Autoclaves mainly are of two types: Portable Large Sterilizes

18. Key Features of Portable Autoclave A portable or bench autoclave is quite similar to pressure cooker. It is a hollow cylindrical vessel of about 15 liters capacity. Made of aluminum or stainless steel, fitted with a lid which can be firmly secured. In one type of autoclave the lid is fitted with eight screw clamps, a pressure gauge an air vent and adjustable safety valve . The externally fitted lid has the advantage that whole capacity of the vessel can be used but at the same time. It has disadvantage also that even if one clamp is damaged or left loose, the pressure imposed on others may lead to explosion. Therefore it is essential that all the clamps should be secured and carefully maintained. T he autoclave is electrically heated, the electric elements are fitted at the bottom of the autoclave. It is provided with a perforated metallic basket fitted with legs, in which the material to be sterilized is placed.

19. Operation of Portable Autoclave The perforated metallic basket is taken out of the vessel. A bucket full of water is put in the vessel so that the heating elements get completely immersed in water. The material to be sterilized is loosely packed in the basket which is then kept in autoclave. Care should be taken that the basket should not touch the water. After sometimes the water in autoclave starts boiling and steam generated in the body of autoclave. When the steam is passed freely through the autoclave the vent for minute, close the vent. As the pressure inside the autoclave increases the temperature also increases and reaches to the sterilization point controlled by thermostat which is generally, 10 pounds per square inch at 115 C for 30 minutes 15 pounds per square inch at 121 C for 20 minutes.

20. Advantages and Disadvantages Advantages 1 . The penetrating power of steam is much more than that of dry heat. So microorganisms are killed more efficiently in lesser time at lower temperature than dry heat. 2 . In large size autoclaves large quantities of materials can be sterilized in one batch. 3 . Solutions packed in sealed containers as ampoules are readily sterilized by this method. 4 . Bulk solutions, glassware, surgical dressings, rubber gloves and surgical instruments are effectively sterilized by this method. Disadvantages 1 . This method is unsuitable for materials which cannot withstand the heating at 115 C or more. 2 . This method is not useful for oils, fats, ointments, powder , oily injections and other preparations through which steam cannot penetrate

21. References Test Book: COOPER and GUNN’S “Dispensing for Pharmaceutical Students”; Twelfth Edition; Edited by S J Carter Web resources

22. Thank you