CONSIDERATIONS IN CONSIDERATIONS IN SELECTION OF SELECTION OF

ANTISEPTICS AND ANTISEPTICS AND DISINFECTANTS DISINFECTANTS FOR VETERINARY FOR VETERINARY

DISPENSARIESDISPENSARIES

IntroductionIntroduction Antiseptics are used in surgery for antisepsis Antiseptics are used in surgery for antisepsis

of the surgical site, surgeon’s hands of the surgical site, surgeon’s hands disinfect surgical instruments, apparel, and disinfect surgical instruments, apparel, and

hospital premises. hospital premises. Other common uses are as disinfectants for Other common uses are as disinfectants for

home and farm premises, food processing home and farm premises, food processing facilities, in water treatment, in public health facilities, in water treatment, in public health sanitationsanitation

As antiseptics in soaps, teat dips, dairy As antiseptics in soaps, teat dips, dairy sanitizers, sanitizers,

The same compound -AS or DIS, dep.on conc., The same compound -AS or DIS, dep.on conc., conditions of exposure, number of organisms, conditions of exposure, number of organisms, etc.etc.

Maximal efficiency- proper concentration of the Maximal efficiency- proper concentration of the agents for the purpose intended agents for the purpose intended

Selecting Selecting antiseptics/disinfectantsantiseptics/disinfectants

Three factors are to be consideredThree factors are to be considered the type of microorganism the agent the type of microorganism the agent

has to eliminate(bacteria, virus, fungi has to eliminate(bacteria, virus, fungi or vegetative or spore forms)or vegetative or spore forms)

the environment in which the agent the environment in which the agent will be used (living tissue/inanimate, will be used (living tissue/inanimate, presence or absence of dirt/debris)presence or absence of dirt/debris)

the characteristics of the characteristics of agent(corrosiveness, cost and agent(corrosiveness, cost and antimicrobial spectrum)antimicrobial spectrum)

ClassificationClassification

Physical agentsPhysical agents Moist Heat-Moist Heat- –Boiling water & –Boiling water &

autoclaving autoclaving Pasteurization Pasteurization Dry heat-Dry heat- –Flaming,, Incineration,, –Flaming,, Incineration,,

Baking in oven Baking in oven Filtration Filtration RadiationRadiation - Ionizing –X-rays and gamma - Ionizing –X-rays and gamma

rays; Non-ionizing –UV and infrared light rays; Non-ionizing –UV and infrared light Ultrasonic VibrationsUltrasonic Vibrations

Chemical Agents Chemical Agents 1.1. Acids and alkaliesAcids and alkalies

boric acid, benzoic acid, NaOH Na2CO3 quick boric acid, benzoic acid, NaOH Na2CO3 quick lime(CaO) lime(CaO)

2. 2. HalogensHalogens- iodine Iodophores Chlorine, bromine - iodine Iodophores Chlorine, bromine

3. 3. AlcoholsAlcohols- ethyl alcohol(70%), isopropyl alcohol - ethyl alcohol(70%), isopropyl alcohol (50%), benzyl alcohol (50%), benzyl alcohol

4. 4. Phenols and PhenolicsPhenols and Phenolics

phenol, cresol, lysol, hexyl resorcinol, phenol, cresol, lysol, hexyl resorcinol, hexachlorophene, chloroxylenol hexachlorophene, chloroxylenol

5. 5. Heavy Metals and their compoundsHeavy Metals and their compounds

mercuric chloride, merchurochrome, AgNO3, ZnO, mercuric chloride, merchurochrome, AgNO3, ZnO, CuSO4 CuSO4

6. 6. Oxidizing agentsOxidizing agents

H2O2, KMnO4, Zn permanganate, sodium H2O2, KMnO4, Zn permanganate, sodium perborate, benzyl peroxideperborate, benzyl peroxide

7. 7. Reducing agents/ Alkylating agents-Reducing agents/ Alkylating agents- fformaldehyde, ethylene oxide(gas), ormaldehyde, ethylene oxide(gas), glutaraldehyde glutaraldehyde

8.8. DyesDyes acriflavine, euflavine, proflavine, gentian acriflavine, euflavine, proflavine, gentian

violet, crystal violet, methylene blue, brilliant violet, crystal violet, methylene blue, brilliant green, fluorescein dye, aminocrine green, fluorescein dye, aminocrine

9. 9. Detergents/surfactants/ Wetting Detergents/surfactants/ Wetting agents/Cleansersagents/Cleansers

cationic(Quaternary ammonium cationic(Quaternary ammonium compoumnds- benzalkonium chloride, compoumnds- benzalkonium chloride, benzethonium chloride, cetrimide, acertyl benzethonium chloride, cetrimide, acertyl pyridinium chloride)pyridinium chloride)

anionic (soaps)anionic (soaps) nonionic ( amphoteric) nonionic ( amphoteric) 10. 10. Miscellaneous /Miscellaneous /BiguanidesBiguanides- chlorhexidine - chlorhexidine

HClHCl

AlcoholsAlcohols Ethyl alcohol (70% ethanol) Ethyl alcohol (70% ethanol) isopropyl alcohol (50% isopropanol) isopropyl alcohol (50% isopropanol) Isopropanol is slightly more potent than Isopropanol is slightly more potent than

ethanolethanol As a skin disinfectant and rubefacient.As a skin disinfectant and rubefacient. Alcohol-based hand rinses have rapid-Alcohol-based hand rinses have rapid-

acting antiseptic effectsacting antiseptic effects Wide germicidal activity,non corrosive, but-Wide germicidal activity,non corrosive, but-

fire hazardous riskfire hazardous risk Limited residual activity due to evaporation Limited residual activity due to evaporation Limited activity in the presence of organic Limited activity in the presence of organic

matter and not effective against bacterial matter and not effective against bacterial or fungal sporesor fungal spores

Acids and AlkaliesAcids and Alkalies Strong mineral acids (HCl, H2SO4, etc) in Strong mineral acids (HCl, H2SO4, etc) in

concentrations of 0.1-1 N concentrations of 0.1-1 N Corrosive action limits their usefulnessCorrosive action limits their usefulness Acids as food preservatives-, benzoic acid, Acids as food preservatives-, benzoic acid,

antiseptics (eg, boric acid, acetic acid), antiseptics (eg, boric acid, acetic acid), fungicides (eg, salicyclic acid, benzoic acidfungicides (eg, salicyclic acid, benzoic acid))

Acetic acid, 1%, used in surgical dressings, Acetic acid, 1%, used in surgical dressings, and 0.25% acetic acid is a useful antibacterial and 0.25% acetic acid is a useful antibacterial agent for irrigation of the urinary tract.agent for irrigation of the urinary tract.

At 5%, it is bactericidal to many bacteria and At 5%, it is bactericidal to many bacteria and has been used to treat otitis externa produced has been used to treat otitis externa produced by by PseudomonasPseudomonas , , CandidaCandida , , MalasseziaMalassezia , or , or AspergillusAspergillus spp. spp.

Acids and Alkalies…contdAcids and Alkalies…contd Hydroxides of sodium and calcium Hydroxides of sodium and calcium

used as disinfectantsused as disinfectants their caustic property usually limits their caustic property usually limits

their application on tissues. their application on tissues. A 2% solution of soda lye (contains A 2% solution of soda lye (contains

94% sodium hydroxide in hot water) 94% sodium hydroxide in hot water) used is a potent causticused is a potent caustic

Calcium oxide , ie, lime (hydrated or Calcium oxide , ie, lime (hydrated or air-slaked lime), soaked in water air-slaked lime), soaked in water produces Ca(OH)2. are used to produces Ca(OH)2. are used to disinfect premises disinfect premises

ChlorhexidineChlorhexidine

potent activity against gram-positive, some gram-potent activity against gram-positive, some gram-negative bacteria but not against sporesnegative bacteria but not against spores

activity is enhanced by alcohols, quaternary activity is enhanced by alcohols, quaternary ammonium compounds, and alkaline pH, ammonium compounds, and alkaline pH,

depressed by high concentrations of organic matter depressed by high concentrations of organic matter (pus, blood, etc), hard water, and contact with cork(pus, blood, etc), hard water, and contact with cork..

incompatible with anionic compounds, including soapincompatible with anionic compounds, including soap 4% emulsion of chlorhexidine gluconate is used as a 4% emulsion of chlorhexidine gluconate is used as a

skin cleanser, skin cleanser, 0.5% (w/v) solution in 70% isopropanol as a general 0.5% (w/v) solution in 70% isopropanol as a general

antisepticantiseptic 0.5% solution in 70% isopropanol with emollients as 0.5% solution in 70% isopropanol with emollients as

a hand rinse.a hand rinse. Chlorhexidine-alcohol mixtures are particularly Chlorhexidine-alcohol mixtures are particularly

effective in that they combine the antiseptic rapidity effective in that they combine the antiseptic rapidity of alcohol with the persistence of chlorhexidine.of alcohol with the persistence of chlorhexidine.

low potential for systemic/ dermal toxicity --low potential for systemic/ dermal toxicity --shampoos, ointments, skin and wound cleansers, teat shampoos, ointments, skin and wound cleansers, teat dips etcdips etc

Hydrogen peroxide: Hydrogen peroxide: (3%) (3%) Effervescent action (liberates oxygen when in Effervescent action (liberates oxygen when in

contact with catalase present on wound contact with catalase present on wound surfaces) helps to remove pus and cellular surfaces) helps to remove pus and cellular debris from woundsdebris from wounds

cleaning and deodorizing infected tissue. cleaning and deodorizing infected tissue. action is of short duration and is limited to the action is of short duration and is limited to the

superficial layer of the applied surface, no superficial layer of the applied surface, no penetration of the tissue. penetration of the tissue.

Benzoyl peroxideBenzoyl peroxide cause skin irritationcause skin irritation keratolytic and antiseborrheic activitykeratolytic and antiseborrheic activity treating pyoderma in dogs treating pyoderma in dogs

Potassium permanganatePotassium permanganate is an effective algicide (0.01%) and is an effective algicide (0.01%) and

virucide (1%) for disinfectionvirucide (1%) for disinfection concentrations >1:10,000 tend to concentrations >1:10,000 tend to

irritate tissues. irritate tissues. Staining of tissues is disadvantage.Staining of tissues is disadvantage. Chocolate brown coloured old Chocolate brown coloured old

solutions indicate the loss of solutions indicate the loss of activity activity

IodineIodine Elemental iodine is a potent germicide Elemental iodine is a potent germicide

with a wide spectrum of activity and with a wide spectrum of activity and low toxicity to tissues.low toxicity to tissues.

Poorly soluble in water but readily Poorly soluble in water but readily dissolves in ethanol, which enhances dissolves in ethanol, which enhances its antibacterial activityits antibacterial activity

Tincture iodine (strong/weakTincture iodine (strong/weak)) Wide germicidal activity including fungi Wide germicidal activity including fungi

and bacterial spores, characteristic and bacterial spores, characteristic odor odor

corrosive and has limited activity in corrosive and has limited activity in the presence off organic matter the presence off organic matter

IodophoresIodophores povidone-iodinepovidone-iodine slowly release iodine as an antimicrobial slowly release iodine as an antimicrobial

agentagent do not sting ,stain. nontoxic to tissues but do not sting ,stain. nontoxic to tissues but

may be corrosive to metals. may be corrosive to metals. Effective against bacteria, viruses, and fungi Effective against bacteria, viruses, and fungi

but less so against spores. but less so against spores. Good antibacterial activity even in the Good antibacterial activity even in the

presence of organic matterpresence of organic matter Change color when the activity is lost. Change color when the activity is lost. Phosphoric acid is often mixed with Phosphoric acid is often mixed with

iodophores to maintain an acidic medium. iodophores to maintain an acidic medium. Used in teat dips, dairy sanitizers and for Used in teat dips, dairy sanitizers and for

various dermal and mucosal infectionsvarious dermal and mucosal infections

Chlorine Chlorine potent germicidal effect against most bacteria, potent germicidal effect against most bacteria,

viruses, protozoa, and fungi ( 0.1 ppm)viruses, protozoa, and fungi ( 0.1 ppm) Much higher conc. in presence of organic Much higher conc. in presence of organic

matter.matter. strong acid smell, is irritant to the skin and strong acid smell, is irritant to the skin and

mucous membranes. mucous membranes. Used to disinfect water supplies ,inanimate Used to disinfect water supplies ,inanimate

objects (eg, utensils, bottles, pipelines) in objects (eg, utensils, bottles, pipelines) in dairiesdairies. .

Inorganic chlorides include sodium hypochlorite Inorganic chlorides include sodium hypochlorite (Dakin's solution) solutions (bleach)and calcium (Dakin's solution) solutions (bleach)and calcium hypochlorite.hypochlorite.

Chlorinated lime (bleaching powder): mixture of Chlorinated lime (bleaching powder): mixture of calcium hypochlorite and calcium chloridecalcium hypochlorite and calcium chloride; for ; for disinfection of water, livestock premises, disinfection of water, livestock premises, destruction and disposal of destruction and disposal of carcasses ,elimination of pathogens from carcasses ,elimination of pathogens from organic matter organic matter

PhenolPhenol (carbolic acid) (carbolic acid) bacteriostatic at 0.1-1%;s bacteriostatic at 0.1-1%;s

bactericidal/fungicidal at 1-2%. Tbactericidal/fungicidal at 1-2%. T Activity enhanced by warm temperaturesActivity enhanced by warm temperatures Decreased by alkaline medium, lipids, Decreased by alkaline medium, lipids,

soaps, and cold temperatures.soaps, and cold temperatures. 5% solution - strongly irritating, corrosive to 5% solution - strongly irritating, corrosive to

tissues. tissues. Oral ingestion/ excess application to skin Oral ingestion/ excess application to skin

can cause systemic toxicity. can cause systemic toxicity.

CresolCresol : : 2% solution of either pure or 2% solution of either pure or saponated cresol (Lysol) in hot water is a saponated cresol (Lysol) in hot water is a disinfectant for inanimate objectsdisinfectant for inanimate objects

FormaldehydeFormaldehyde 1-10% solution used as a 1-10% solution used as a

disinfectantdisinfectant

GlutaraldehydeGlutaraldehyde 1-2% alkaline solution (pH 7.5-8.5) 1-2% alkaline solution (pH 7.5-8.5)

in 70% isopropanol is a more potent in 70% isopropanol is a more potent germicide than 4% formaldehyde.germicide than 4% formaldehyde.

used to sterilize surgical and used to sterilize surgical and endoscopic instruments and plastic endoscopic instruments and plastic and rubber apparatus and rubber apparatus

Teat dipsTeat dips

SoapsSoaps Anionic detergents which emulsify Anionic detergents which emulsify

lipoidal secretions of the skin lipoidal secretions of the skin Remove, along with most of the Remove, along with most of the

accompanying dirt, desquamated accompanying dirt, desquamated epithelium and bacteria, which are then epithelium and bacteria, which are then rinsed away with the lather. rinsed away with the lather.

The antibacterial potency: enhanced by The antibacterial potency: enhanced by inclusion of certain antiseptics, eg, inclusion of certain antiseptics, eg, hexachlorophene, phenols, carbanilides, hexachlorophene, phenols, carbanilides, or potassium iodide.or potassium iodide.

They are incompatible with cationic They are incompatible with cationic surfactantssurfactants

Cationic detergentsCationic detergents Quaternary ammonium compounds (eg, benzalkonium Quaternary ammonium compounds (eg, benzalkonium

chloride, benzathonium chloride, cetylpyridinium chloride, benzathonium chloride, cetylpyridinium chloride, cetyl pyridinium bromide/cetrimide)chloride, cetyl pyridinium bromide/cetrimide)

Activity is reduced by porous or fibrous materials (eg, Activity is reduced by porous or fibrous materials (eg, fabrics, cellulose sponges) that adsorb themfabrics, cellulose sponges) that adsorb them

Inactivated by anionic substances (eg, soaps, proteins, Inactivated by anionic substances (eg, soaps, proteins, fatty acids, phosphates).fatty acids, phosphates).

Limited value in presence of blood and tissue debris. Limited value in presence of blood and tissue debris. Effective against most bacteria, some fungi , protozoa Effective against most bacteria, some fungi , protozoa

but not against viruses and sporesbut not against viruses and spores. . Aqueous solutions of 1:1,000 to 1:5,000 have good Aqueous solutions of 1:1,000 to 1:5,000 have good

antimicrobial activity, especially at slightly alkaline pH.antimicrobial activity, especially at slightly alkaline pH. When applied to skin, they may form a film under When applied to skin, they may form a film under

which microorganisms can survive, which limits their which microorganisms can survive, which limits their reliability as antisepticsreliability as antiseptics. .

Concentrations >1% are injurious to mucous Concentrations >1% are injurious to mucous membranes membranes

ChloroxylenolsChloroxylenols Parachlorometaxylenol ,dichlorometaxylenParachlorometaxylenol ,dichlorometaxylen

olol broad-spectrum with more activity against broad-spectrum with more activity against

gram-positive than gram-negative bacteria.gram-positive than gram-negative bacteria. Active in alkaline pH; however, contact Active in alkaline pH; however, contact

with organic matter diminishes their with organic matter diminishes their activity. activity.

5% chloroxylenol solution (in α-terpineol, 5% chloroxylenol solution (in α-terpineol, soap, alcohol, and water) is diluted with soap, alcohol, and water) is diluted with water (1:4) for skin sterilizationwater (1:4) for skin sterilization

1:25 to 1:50 for wound cleansing and 1:25 to 1:50 for wound cleansing and irrigation of the uterus and vagina irrigation of the uterus and vagina

Preferred antisepticsPreferred antiseptics

with antifungal activitywith antifungal activity

phenols, chlorhexidine , iodine, phenols, chlorhexidine , iodine, povidoneiodine,hypochlorite,cetrimidepovidoneiodine,hypochlorite,cetrimide

withwith antviralantviral activity activity

isopropanol,ethanol,formaldehydeisopropanol,ethanol,formaldehyde

glutaraldehyde,sodium glutaraldehyde,sodium hyopochlorite,phenol,hyopochlorite,phenol,

potassiumpermanganate,hydrogen potassiumpermanganate,hydrogen peroxide, iodophorsperoxide, iodophors

Recommended antiseptics/disinfectants Recommended antiseptics/disinfectants for hospital situations for hospital situations

All the instruments have to be immersed for 30 mins and rinsed All the instruments have to be immersed for 30 mins and rinsed and autoclaved.and autoclaved.

2% sodium hypochlorite:2% sodium hypochlorite: for gloves, syrienges, needles , blood for gloves, syrienges, needles , blood spills on floor, floor washing. lab glasswares spills on floor, floor washing. lab glasswares

2% benzalkonium chloride2% benzalkonium chloride: foreceps, thermometer : foreceps, thermometer 2% glutaraldehyde2% glutaraldehyde: Instruments-catheters, laryngoscope, : Instruments-catheters, laryngoscope,

endotracheal tubes endotracheal tubes 6% hydrogen peroxide6% hydrogen peroxide: removal of blood clots from : removal of blood clots from

tubes,catheters, dressing wounds tubes,catheters, dressing wounds Benzalkonium chlorideBenzalkonium chloride: hand wash, foreceps, catheters , : hand wash, foreceps, catheters ,

instruments instruments Phenol:Phenol: disinfecting toilets disinfecting toilets Povidone iodine:Povidone iodine: surgical scrub, painting skin, dressing, hand surgical scrub, painting skin, dressing, hand

wash wash Ethyl alcoholEthyl alcohol: antiseptic at injection site, furniture disinfection: antiseptic at injection site, furniture disinfection