antiseptics and disinfectants
TRANSCRIPT
These are chemical substances which inhibit the growth or kill microorganism on living surfaces such as skin & mucous membrane.
ANTISEPTICS
These are chemical substances which inhibit the growth or kill microorganism on inanimate objects such as instruments.
DISINFECTANTS
Characteristics of an ideal antiseptics/disinfectants
• Chemically stable• Cheap• Nonstaining• Cidal, destroying spores as well.• Active against all pathogens• Require brief time of of exposure• Active even in presence of blood, pus, exudates
and excreta.
An antiseptics in addition
• Rapid in action & exert sustained protection.
• Nonirritating to tissues.
• Nonabsorbale , produce min. toxicity if absorbed.
• Nonsensitizing
• Earliest used , reference standard• Protoplasmic poison• Injures tissues & cells at high conc.
• Denauration of bacterial proteins• To disinfect urine , faeces , pus.
PHENOL
• Methyl derivative of phenol
• Less damaging to tissues than phenol.
• 3-10 times more active
• Use for disinfection of utensils , excreta & for washing hands.
CRESOL(Lysol)
• Phenol derivative• Doesnot coagulate proteins• Noncorrosive, nonirritating to skin• Commercial 4.8% solution used for surgical
antiseptics• Skin cream and soap 0.8%• Mouth wash 1%
CHLOROXYLENOL(Dettol)
Pot. permanganate• Purple crystals ,highly water soluble , liberates
oxygen
• Action is slow, high conc. cause burns
• Used for gargling ,irrigating cavities & wounds
• Also used to disinfect water in ponds
OXIDIZING AGENTS
• Liberates nascent oxygen which oxidizes necrotic matter & bacteria.
• Helps in loosening & removing slough, ear wax
HYDROGEN PEROXIDE
• Rapidly acting , broad-spectrum agent.• Acts by iodinating and oxidizing microbial
protoplasm• Use for cuts, degerming skin before surgery.• High conc. cause burns.
IODINE
• Soluble complexes of iodine. • Known as povidone iodine.• Nonirritating, nontoxic,nonstaining & exerts
prolonged grmicidal action.• Used on boils, furunculosis, burns ,ulcers ,
tinea,nonspecific vaginitis, disinfection of endoscope.
IODOPHORES
Chlorinated lime(bleaching powder)
• Obtained by action of chlorine on lime
• Use to disinfect drinking water, swimming pools
CHLOROPHORES
Sod. Hypochlorite :
• Powerful disinfectant used in dairies for milk cans.
• Too irritant to be used as anticeptics except in root canal therapy.
CHLORHEXIDINE• Acts by disrupting bacterial cell membrane &
denaturation of bacterial proteins.
• Nonirritant , more active against gram+ve bacteria
• Used in surgical scrub, neonatal bath, mouth wash & general skin anticeptics.
BIGUANIDES
CETRIMIDE:• Detergent action • Cidal to bacteria• Act by altering permeability of cell membrane.• Widely use as anticeptics & disinfectant for
surgical instruments.
QUATERNARY AMMONIUM ANTICEPTICS
ETHANOL:• Antiseptic ,cleansing agent at 40-90% conc.
• Acts by precipitating bacterial proteins.
• Irritant, should not be applied on mucous membrane, ulcers, open wounds.
ALCOHOL
• Use for fumigation• 37% aqueous solution is called formalin.• Protoplasmic poison , denatures protein.• Use for preserving dead tissues• Use as antiseptics is restricted due to bad
odour
FORMALDEHYDE
• Less pungent, less irritant
• Broad spectrum activity
• 2% solution (cidex) use to disinfect surgical instruments & endoscopes.
GLUTARALDEHYDE
BORIC ACIDS :• Weak antiseptics , bacteriostatic
• Use for mouth wash , irrigation of eyes , glossitis
• Vomiting , abdominal pain , diarrhoea on systemic absorption.
ACIDS
SILVER COMPOUNDS :
• Silver sulfadiazine is active against pseudomonas infection.
• Silver nitrate is highly active against gonococci
METTALIC SALTS
Gentian violet :• Active against gram +ve bacteria , fungi
• Use on chronic ulcers , bedsores , furunculosis, ring worm.
DYES
ACRIFLAVINE :
• Active against gram +ve bacteria, gonococci
• Store in amber colored bottle.
• Nonirritant
• Use chronic ulcers and wounds