Pharmaceutical Microbiology Lecture PDF

24/10/2023 Pharmaceutical Microbiology 1 1  24/10/2023 Sterilization& Disinfection-1 3 2  24/10/2023 Sterilization & Disinfection-...

24/10/2023 Pharmaceutical Microbiology 1 1  24/10/2023 Sterilization& Disinfection-1 3 2  24/10/2023 Sterilization & Disinfection-1 Fight bacteria Inside Outside the body the body Sterilization & Antibiotics Disinfection 5 3  24/10/2023 Sterilization Sterilization: Complete destruction or total kill of ALL living micro-organisms (pathogenic and non-pathogenic including bacteria and their spores, fungi and their spores and viruses) Using physical or chemical methods. 6 4  24/10/2023 7 5  24/10/2023 I) Sterilization ❑ Need for what Inhibition ❑ Surgical instruments 8 6  24/10/2023 I) Sterilization Inhibition ❑ Syringes, Gloves & catheters 9 7  24/10/2023 I) Sterilization Inhibition ❑ Culture media 10 8  24/10/2023 Disinfection: Destruction of most pathogenic m.o. on non-living objects such as instruments, bed pans, toilets and bed clothes. The main purposes of disinfection are: 1. Decontamination of microorganisms on equipment before disposal or reuse. 2. Decrease the level of contamination to decrease cross infection (mainly in hospitals). 11 9  24/10/2023 ❑ Disinfectant TOXIC Substances that used to achieve disinfection 12 10  24/10/2023 Antiseptics: Agents used TOPICALLY on living tissues to kill or inhibit the growth of pathogenic m.o. substance that kills or inhibits the growth of infectious microorganisms, but its mild toxicity allows its superficial application to living tissues. Non-TOXIC 14 11  24/10/2023 I) Sterilization Inhibition Physical methods Chemical methods a) Heat a) Gaseous b) Radiation b) Liquids c) Filtration 16 12  24/10/2023 Sterilization Physical method : 18 13  24/10/2023 Sterilization Physical method : I-HEAT 23 14  24/10/2023 1. DRY HEAT 24 15  24/10/2023 b. Hot air oven: a double walled metal chamber provided with perforated shelves and a temperature regulator, that is heated by electricity and has a thermostat that maintains the chamber air constantly at the chosen temp Temp: 160 for 1 hour usually sufficient to kill bacteria and spores. 25 16  24/10/2023 b. Hot air oven: Uses of Hot air oven: 1. Glass wares: such as (test tubes, beakers, flasks, dishes and pipettes). 2. Metal objects: such as throat swabs, scissors scalpels 3. Materials as dry powders (as talk powder), fats, wax and oils and sulfa drugs. 26 17  24/10/2023 b. Hot air oven: Advantages Disadvantages ✓ Non-toxic ❖Slow heat penetration ✓ Inexpensive ❖Time consuming ✓ Not corrosive ❖Not suitable for any thing affected with heat 27 18  24/10/2023 b. Hot air oven: 28 19  24/10/2023 C. Infra-red (IR) radiation: It is of limited use due to carcinogenic effect. It is used for sterilizing surgical instruments. 29 20  24/10/2023 (so it is a method of disinfection not a method of sterilization). 30 21  24/10/2023 b. Moist heat at 100°C: i. Boiling for 5-10 minutes: It is sufficient to kill vegetative forms of microorganisms (but not spores so it is a method of disinfection). This method is used before disposal of syringes, needles, catheters…etc. and before reuse of surgical instruments when no other methods are available. ii. Boiling with bactericidal agent: It is used for sterilization of injections that decompose above 100°C. 31 22  24/10/2023 iii. Steaming at 100°C in Koch steamer: (open autoclave) This apparatus is the same as autoclave but without pressure it is opened so temperature does not rise above 100°C (open autoclave). This apparatus is used to sterilize sugar media and gelatin which might be destroyed by exposure to higher temperature. a method which is known as intermittent steaming or tyndallization. 32 23  24/10/2023 C. Moist heat above 100°C: It is done by an apparatus called the autoclave. Principle: the boiling point of water raises as the pressure is elevated. E.g. at double atmospheric pressure the boiling point of water reaches 121°C. Steam condenses on the object to be sterilized releasing its latent heat 33 24  24/10/2023 36 25  24/10/2023 37 26  24/10/2023 39 27  24/10/2023 III. 41 28  24/10/2023 B) Chemical methods of sterilization 1. Gases: Ethylene oxide: for sterilization of plastic, rubber. Formaldehyde: for silk, room, books, furniture. Ozone: for water and meat preservation. Sulfur dioxide: used as room disinfectant. 43 29  24/10/2023 2. Liquids: Chloroform: at conc. of 0.5% to preserve serum. Ethyl alcohol 70%: as disinfectant for thermometers and antiseptic for skin wounds. Phenol: at conc. of 0.5% to preserve vaccine and at conc. of 5% for floors. Halogens: Iodine for skin and chlore for water. Salts of heavy metals: Mercurochrome for wounds. Gluteraldhyde (Cidex 2%): for endoscopes. 44 30  24/10/2023 45 31