Antiseptic and Disinfectant-Introduction, Classification
- 1. 2. Antiseptic and Disinfectant Presented By- Mr. Dattatraya B Thorat M. Pharm. Head of Department PRES, Institute of Pharmacy, Loni
- 2. -Disinfectants are strong chemical agents that inhibit or kill microorganisms. -Antiseptics are disinfecting agents with sufficiently low toxicity for host cells can be used directly on skin, mucous membranes, or wounds. -Sterilants kill both vegetative cells and spores when applied to materials for appropriate times and temperatures. -Antiseptic, disinfectant and sterilant users should be aware of their short-term and long-term toxicity since they may have general biocidal activity and may accumulate in the environment or in the patient’s or caregiver’s body.
- 3. Disinfection -DISINFECTANTS are chemical agents that inhibit or kill microorganisms (surgical apparatus, periphery of the patient, and the objects used by the patient). OR -Disinfection It is the application of chemicals to destroy most pathogenic organisms on inanimate surfaces, Can be accomplished by application of chemical agents, use of physical agents (ionizing radiation) dry or moist heat, superheated steam(autoclave, 120̊ C). IDEAL DISINFECTANT •Effective at room temperature, •Non-corrosive and nontoxic, •Inexpensive, •Capable of killing the vegetative form of all pathogenic organisms, •Require limited time of exposure
- 4. PROCESS OF DISINFECTION Prevents infection by reducing the number of potentially infective organisms either by killing, removing or diluting them. •Application of chemical agent. •Use of ionizing irradiation, dry or moist heat or superheated steam (autoclave, 120◦ C). ANTISEPTICS are disinfecting agents with sufficiently low toxicity for host cells that they can be used directly on skin, mucous membranes or wounds. ANTISEPSIS It is the use of chemicals to destroy most pathogenic organisms on animate surfaces. The ideal antiseptic has to have similar properties as an ideal disinfectant. But the primary importance for antiseptics is the selective toxicity which means toxicity to microorganisms but not to human cells. The degree of selectivity of the antiseptic agents can change depending on the tissues they contact.
- 5. Antiseptic drugs are used in: •The treatment of skin infections. •Prevention of infections in cuts and wounds. •Cleaning the skin area of surgery from microorganisms. •Prophylaxis and treatment of infections in mucosal areas such as mouth, nose and vagina that are open to environment. •As a scrub for surgeons and the medical personnel. CLASSIFICATIONS OF ANTISEPTICS AND DISINFECTANTS 1.Those that denature proteins. 2.Those that cause osmotic disruption of the cell. 3.Those that interfere with specific metabolic processes. •The first and second classifications are tend to kill the organisms. •The third one affects cell growth and reproduction without killing the cell.
- 6. MECHANISM OF ACTION Phenols, iodine, alcohols, aldehydes and metallic compounds denature proteins and DNA bases. Cationic detergents interfere with plasma membrane’s permeability and cause leakage of enzyme, coenzyme and metabolites. Oxidizing compouns oxidize functional molecules in the microorganisms. EXAMPLES OF HALOGENS •The halogens and halogen – releasing compounds include some of the most effective antimicrobial compounds used for disinfection and antisepsis. •Iodine and chlorine are the most effective halogens with bromine and fluorine being less active. •Because of the irritating nature of the products of sodium hypochlorite, it is currently used primarily as a disinfectant.
- 7. IODINE -Tincture of iodine (2g I, 2.5 g NaI and 50% ethanol to 100 mL). -Powerful antiseptic for intact skin, should avoid contact with mucosas. Can cause serious hypersensitivity reactions, staining of skin and dressing can happen and this limits its use. -Povidon iodine (A complex of I with polivinyl pyrrolidone- surface active agent-). Can be used as antiseptics or disinfectants.Kill vegetative bacteria, mycobacteria, fungi, lipid containing viruses. They kill spores as well on prolonged use. Iodine and other free halogens oxidize the –SH groups of proteins and enzymes and produce -S-S- bonds and disrupts the structure and function of these M.O. CHLORINE Chlorine is a strong oxidizing agent. Hypochloric acid and sodium hypochlorite (household bleach 5.25%) are bactericidal and effective disinfectants can kill bacteria, fungi ,inactivate viruses.
- 8. ALCOHOLS -Ethyl alcohol (70% )and isopropyl alcohol are effective antiseptic and disinfectant agents. They reduce the number of bacteria 90% when applied to the skin. They rapidly kill vegetative bacteria, M tuberculosis, many fungi and inactivate lipophilic viruses. They denature proteins and disturb the membrane permeability of bacteria. -They are not effective as sterilizing agents because of their inefficient antibacterial spectrum -They can damage corneal tissue if directly applied, therefore instruments that will be used in the eye must be free of alcohol before use.
- 9. ALDEHYDES -2-8% of formaldehyde can be used as a sterilizing agent for surgical instruments. -Not corrosive for metal, plastic or rubber. -Broad spectrum of activity against microorganisms and viruses. -Alkylate chemical groups in proteins and nucleic acids. -It is especially useful for instruments that can not be autoclaved. (hemodialyzers, dental handpieces, respiratory therapy equipment). -Formaldehyde has a pungent odor and is highly irritating to respiratory mucous membranes and eyes at conc 2-5 ppm is rarely used because of its toxicity and tendency to cause sensitization with repeated contact. The relative risk of formaldehyde as a human carcinogen when used as a disinfectant is significant.
- 10. Sterilization It is the way for killing of all forms of microorganisms. •Dry heat •Steam •Chemical vapor •Ethylene oxide gases •Formaldehyde gases •Ultraviolet radiation •Gamma radiation OXIDIZING AGENTS -Hydrogen peroxide is the most common of a number of oxidizing compounds that have been used as antiseptics. It is also effective in injured skin due to its bubbling effect. 3% solution is effective. -Disinfection of respirators, acrylic resin implants, plastic eating utensils, soft contact lenses, cartons for milk or juice 10-25% conc is sporicidal.
- 11. Thank You….