This document discusses various antiseptics and disinfectants. It defines antiseptics as chemical substances used to destroy or inhibit bacteria on living surfaces, while disinfectants destroy bacteria on inanimate surfaces. It then categorizes and describes common antiseptics and disinfectants such as phenol derivatives, iodine, alcohols, chlorhexidine and provides their mechanisms of action and uses. Ideal antiseptics are described as having broad-spectrum activity, rapid onset, durability and low toxicity. Factors affecting the action of antiseptics and disinfectants and their general uses are also summarized.

1. Antiseptics
&
Disinfectants
1

2. -:Introduction:-
Antimicrobial:- the substances derived from natural or
synthetic sources that kills or inhibit the growth of micro-
organism such as bacteria, fungi, protozoas
Germicides:- a group of drugs that are able to inhibit the
growth, development or leads to death of microorganisms in
the environment surrounding the patient or on the surface
of the body.
 Specially agents which inhibits or kills microbes on
contact
 They have low margin of safety
 Non-systemic use
 Non selective Antimicrobial agents
2

3. Germicides
ANTISEPTICS DISINFECTANTS
ANTISEPTICS:- (Anti= against; septicas – emitting a fetid
smell)
Chemical substances which are used to destroy, inhibit
pathogenic bacteria (not the spores) on animate (living)
surface such as skin, eye, mucous membranes(as in mouth
washes).
1879- Lister- Father of ‘Antiseptic surgery’
They falls under “ Drug Control Agency of the Government”

4. DISINFECTANTS
• Chemical substances or germicides which are use to destroy
or inhibit the growth of pathogenic vegetative bacteria (not
their spores) on inanimate(non-living) surface such as
glassware's or surgical instruments.
e.g.- Formaldehyde, phenol, ethyl alcohol, soaps.
 They falls under “Control of Environmental protection
agency of the Government”
 They process “concentration dependent killing”
 Antiseptics & Disinfectant are often added to easily
available every day utilities like soaps,toothpastes,mouth
wash, after saving lotion.
4

5. -:Some ancillary terms:-
1. Sterilization:-
Definition:- freeing an article, a surface or a medium by
removing or killing all micro-organisms including
vegetative bacteria, Spores, fungi & viruses
 usually sterilization is affected by autoclaving at 15lb
pressure of stream at 120oC for atleast 30 min
[It is the ultimate goal of any infection control protocol]
Other methods also include-
o Infra-red(IR)-radiation,
o Ultraviolet(UV)-radiation
o γ-radiation

6. 2. Decontamination:-
Marketed destruction of viable pathogenic organisms to a
level that will allow a healthy person’s natural defenses
to prevent any infection.
e.g.- Decontamination of water
3.Sanitisation:- reduction In microbial load from an
inanimate surface to a level set forth by public health
Department of Environmental Agency
 These levels are considered acceptable for the health of
the population

7. 4. Pasteurisation:-
Process of heating milk or other liquids or semisolids for
about 30 min at 60-80oC which kills the non-
sporulating microorganism and prevents the growth of
food-borne pathogens for a specific period of time.
5.Preservation:-
To preserve the efficacy & to prevent the deterioration of
the drug formulation up to its expiry period.
A Preservatives may protect the drug from oxidation.
e.g.-Benzyl Alcohol(2%),Benzoic Acid & its salts (0.2%)
7

8. -:IDEAL Antiseptics/Disinfectant:-
• High Efficacy:
– Broad spectrum / sporicidal / kill all forms
– Rapid onset / long duration action
– Cidal not static
– Active in presence of blood, pus,exudates and
excreta
– No Resistance
• Non Toxic:
– Non-irritating to tissues,should not delay healing.
– Non absorbable / No hypersensitivity
– Chemically stable.
8

9. IDEAL ANTISEPTICS :
• Added Advantage:-
– Non-staining with agreeable color and odour
– Could be added to soaps
– Non corrosive.
9

10. MECHANISM OF ACTION:
1. Oxidation of Bacterial protoplasm.
e.g.- KMn04, H202, Halogens
2.Denaturation of Bacterial Proteins & Enzyme
e.g.-Phenols, Chlorhexidine, Alcohol, Aldehyde
3.Detergent like action increasing permeability
of bacterial membrane
e.g.- Soaps,Cetrimide
10

11. FACTORS MODIFYING ACTION
• TEMPERATURE AND pH.
• PERIOD OF CONTACT WITH MICROBES.
• NATURE OF MICROBES INVOLVED.
• SIZE OF INNOCULUM
• PRESENCE OF BLOOD,PUS,OR ORGANIC
MATTER.
11

12. General Uses of Antiseptics/ Disinfectants
• Asepsis before injections:-
• Surgical Uses:-
– Asepsis before surgery
– Scrubbing
– Sterilization of the surgical instruments
• Cuts, wounds & Lacerations
• Disinfection of Hospital premises
• Water purification & domestic disinfection
12

13. CLASSIFICATION :-‘PHAARMA GOD’
• PHENOL DERIVATIVES:-
Phenol,Cresol,Hexylresorcinol,Hexachlorophene
• HALOGENS:-Iodine, Iodophores, Chlorine, Chlorophores
• ALCOHOLS:-ethanol , Isopropanol.
• ALDEHYDES:- Formaldehyde, Glutaraldehyde
• SURFACE ACTIVE AGENTS:-
• QUATERNARY AMMONIUM (CATIONIC):-
Cetrimide, Benzalkonium chloride, Dequalinium chloride.
BIGUANIDE:- Chlorhexidine
• SOAPS:- OF sodium & Potassium
13

14. • METALLIC SALTS:- Silver nitrate, Silver
sulfadiazine, Mild silver protein, Zinc sulfate,
Calamine, Zinc oxide.
• ACIDS:- Boric acid, Acetic acid
• GASES:- Ethylene oxide
• OXIDIZING AGENTS:- KMno4,Hydrogen peroxide,
Benzoyl peroxide
• DYES:- GENTIAN VIOLET, METHYLENE BLUE
BRILIANT GREEN, ACRIFLAVIN AND PROFLAVIN
• MISCELLANEOUS:- NITROFURAZONE
14

15. PHENOL DERIVATIVES:
• PHENOL (CARBOLIC ACID):-
• One of the earliest used Antiseptics & still the standard for
comparing other germicides.
• Weak agents Static at- 0.2% Bactericidal at >1%,
• Poor action bacterial spore
• Protoplasmic poison
MOA:- Denatured bacterial protein (irritant/toxic to tissues)
-Mild LA action- use as Antipruritic Preparation
USES: Disinfectant of Urine,faeces pus,sputum,antipruritic
preparation mouth wash.
Side effect:-Buccal, esophageal, gastric burns, scars/strictures
15

16. CRESOL (METHYL PHENOL):-
• X3 potent than Phenol / less damage to tissues
• USES:- Disinfecting of utensils, Excreta, for washing
hands, irrigation of root canals.
CHLOROXYLENOL(DETTOL):-
• Non-corrosive, Non-irritating to intact skin, No stain,
 4.8% commercial use “Dettol”(9% terpinol+13% Alcohol)
 6.25%- Instruments
 Cream & Soap,
 Lubricating obstetric cream (1.4% ).
• USES:-
Surgical Antiseptics , skin cream, mouth wash, soaps, wounds
& cuts

17. • HEXACHLOROPHENE:
• POTENT CHLORINATED PHENOL
• Odourless, non staining, non irritant (+soaps)
• Sustained action
• Good- Gm+ve/ Poor- Gm-ve & spores
• USES:- ANTISEPTICS FOR SURGICAL SCRUB,
TOILET PRODUCTS & DEODRANTS, Skin infections
(Furunculosis/ Carbuncle), baby bath products (<2%).
• Side effect:- Neurotoxicity (Neonates)->2%- BAN.
17

18. Phenol Derivatives (contd.)
• Triclosan:-uses- Liquid soaps, Dentifrices, mouth wash
• Thymol:-
– Antiseptic / mild LA effect
– Uses- cough drops / Dentifrices / Acne / mouth wash
• Resorcinol- less potent than Phenol
• Uses- Antiseptic (ringworm, acne, ), keratolytic &
antipruritic effect (Seborrhoeic dermatitis, Eczema,
Psoriasis
• Hexylresorcinol- mouthwash
18

19. 19
Contains are
menthol,
thymol,
methyl salicylate, and
eucalyptol

20. OXIDIZING AGENTS:-
• POTASSIUM PERMAGNATE:-
• HIGHLY WATER SOLUBLE.
• Nascent [O]-OXIDIZES BACTERIAL PROTOPLASM.
USES:- 1:4000-1:10,000 SOLN (CONDY’S LOTION)-
– Antiseptic(Mouthwash/GARGLING/DOUCHING, IRRIGATING
CAVITIES/ wounds/ Atheletes foot (1%)
– Domestic use-DISINFECTION OF utensils/ vegetables/ fruits/
purification of WATER (ponds/ wells)
– GASTRIC LAVAGE (in alkaloidal poisoning)
– Styptic (5%)
• Side effect:- BURNS,BLISTERING /stain / Rusting /
sensitve to light.
20

21. OXIDIZING AGENTS:
H2O2 – Adv.-
– Non-toxic/ colorless/ odourless
– Effective against anaerobic bacteria
• Demerits-
– Weak antiseptic
– To be kept in dark bottles
• Uses-
– Dental use- Mouthwash (3%)- dilute with water- stomatitis/ cavity
preparation
– Bleaching agent (for teeth stains)- 30% H2O2 + glycerine+ pumice
– Surgical use (3-6%)- wound cleaning / slough remove
– Removal of ear wax
– Deodorant
– Styptic (25-30%)

22. • BENZOYL PEROXIDE:-
• Liberate 02,killsAnerobic,microaerophilic bacteria
Keratolytic & comedolytic properties-(To remove
warts and other lesions in which the epidermis
produces excess skin)
• USES:-ACNE (2.5-10% cream), ANTISEPTICS.
ADVERSE EFFECTS:-
Burning,
stinging sensation,
localized erythmia,
dryness of skin,
SCALING EDEMA.
22

23. HALOGENS:-
IODINE & I- releasing
agents:
• Rapid action
• Broad spectrum
• Not readily inactivated
by organic matter
• MICROBICIDAL
AGENT, IODINATES
AND OXIDIZES
MICROBIAL
PROTOPLASM
Chlorine & Cl-
releasing agents:
• Rapid action
• Broad spectrum
• readily inactivated by
organic matter
• MICROBICIDAL
AGENT,
CHLORINATES AND
OXIDIZES
MICROBIAL
PROTOPLASM

24. HALOGENS:-
• IODINE:
USES: (1:20,000 , SOLN KILL VEGETATIVE FORM- ANTISEPTIC
USES)
1.TINCTURE IODINE (2.5% IN ALCOHOL)
2.MANDL’S THROAT PAINT (1.25% IN POT .IODIDE) FOR SORE
THROAT.
3.COUNTER IRRITANT
4. WATER PURIFICATION.
ADRs: CORROSIVE,BURNS,BLISTERS, RASHES, stain,
irritant, less duration of action
• To be kept in dark colored bottles.
24

25. IODOPHORES:-
• SOLUBLE COMPLEX OF IODINE.
• Slow RELEASE of FREE IODINE
• NON-IRRITATING,NONTOXIC,Non staining
• USES:- POVIDONE IODINE (POLYVINYL
PYRROLIDONE Iodine)-
– FOR BOILS,FURUNCULOSIS,BURNS,OTITIS
EXTERNA, ULCER,VAGINITIS,SURGICAL
SCRUBBING,DISINFECTION OF ENDOSCOPIC
INSTRUMENTS, Tinea infections (5%- cream, solution,
Ointment
– Dental uses- Mouth wash/ Gargle (2%)
– Analgesic (Iodine (4%) creams- analgesics}
25

26. • CHLORINE:-
• HIGHLY REACTIVE
• POTENT GERMICIDE
• USES: DISINFECTION OF URBAN WATER SUPPLIES
(Cl2 gas- 0.2- 0.4ppm)
• CHLOROPHORES:-
• COMPOUND RELEASES hypochlorous.
• TYPES:-1.CHLORONATED LIME (BLEACHING
POWDER)
• USES:
• Disinfection of drinking water,
• Swimming pool
• Sanitizer
• Tooth stains removal 26

27. 2.SODIUM HYPOCHLORITE SOLN:-
USES:(4-6%) DISINFECTANT IN DAIRIES FOR MILK CANS, Lab
disinfectant, Biohazard Spill management,
EQUIPMENTS,ANTISEPTIC,ROOT CANAL THERAPY, also used
as Bleaching agent in dentistry
• 3.DAKIN SOLN: DILUTE SOD. HYPOCHLORITE BUFFERED
WITH BORIC ACID.
• 4.EUSOL: (chlorinated lime 1.25%+Boric acid).
• USES:-
Dissolving pus,
Blood clots,
Necrotic matter,
Clean infected wound,
27

28. -:QUATERNARY AMMONIUM
(CATIONIC ANTISEPTICS):-
• Detergents,Cidal to bacteria, Fungal &viruses, non
irritating, mild keratolytic.
• USES:- Sanitizer, Antiseptics, Disinfectant for surgical
instrument, gloves.
• CETRIMIDE:-
• soapy powder with faint ,fishy odors
• wound clearing from dirt ,skin disinfectant,
• Anti-plaque agent,
• As antiseptics, Surgical instruments, utensil
28

29. • Cetyl pyridinium Chloride- mouth wash, antiplaque agent,
Lozenges
• Benzalkonium Chloride- storage of sterile surgical
instruments
• SOAPS:-
• Anionic detergents, weak Antiseptics
• Sod. Or Pot. Salts of large chain fatty acids
• Emulsifying agents.
• Affective against-gm+Ve
• USED FOR CLEANSING ACTION
• Sodium Lauryl sulphate.
29

30. -:CHLOROHEXIDINE:-
• Cationic biguanide which highly Powerful, on-irritating, colorless,
odorless antiseptics
• Spectrum of activity:-
Active against gm+ve bacteria
Moderately active against –gm-ve bacteria
MOA:- Disrupt bacterial membrane.
• Effective in the presence of pus, blood, organic matter.
• Exhibits residual activity after repeated use
• Savlon liquid antiseptics:- Chlorhexidine gluconate 1.5% +
cetrimide 3% exhibits enhanced efficacy
• Formulation available:- lotion,
Cream,
Washes, Aqueous solution 30

31. 31
(Savlon is a combination
of Chlorhexidine gluconate
& cetrimide)

32. USES:-
 Bath, Neonatal bath, surgical scrub,
 Dental use-
 mouthwash including candidiasis (0.1-0.2% mouth wash)
 Aqueous solution In mouth wash-↓dental plaque accumulation
 Obstetrics (1% cream) & skin antiseptics & clearing of
wounds(0.05% aqueous solution)
 Preoperative clearing of skin(0.5% solution in 70% alcohol)
 Anti-plaque agent(prevent periodic disease)
 In catheterisation & cystoscopy- gel (0.25%
chlorhexidine+xylocaine)
 Disinfection of hydrophilic contact lenses-0.002-0.005%
chlorhexidine
Side effects:- Yellow brown stain, Altered taste, mucosal soreness

33. -:ALCOHOLS:-
MOA- ppts bacterial proteins /cidal
• ETHANOL:
• EFFECTIVE ANTISEPTIC on skin (not on muc.
Membrane) / rapid action
• CLEANSING AGENT AT 40-90% CONC.
• ADRs: BURNING SENSATION,INJURY, irritant on
Muc. membranes.
• Uses- wounds/ cuts, degerming of skin before injections
(Isopropyl alcohol)
33

34. ALDEHYDES:
• MOA- DENATURES BACTERIAL PROTEINS.
• PROTOPLASMIC POISON.
• FORMALDEHYDE (Formalin): slow antiseptic,
broad spectrum, sporicidal
• USES:
Disinfection of surgical instruments (2-8%),
Preservation of dead tissue samples (4% aqueous
Solution),
fumigation, urinary antiseptic (Methenamine)
• ADRs: ECZEMATOID REACTIONS, irritates,No oral
use.
34

35. ALDEHYDES:
• GLUTARALDEHYDE:
 Sterilizing agents
 Less irritating
 Less pungent ,
 Broad spectrum ,not inactivated by Bio fluids,
 Activated at alkaline pH.
• USES:
1. Cold sterilization- Disinfection of surgical instruments ,
Endoscopes (to be kept for 12 hrs)
2. Hospital disinfectant of premises / OTs
35

36. Acids:-
• BORIC ACID:-
• Bacteriostatic & Weak antiseptics ,
• Non irritating
• USES:-
• Irritating eyes (4%),
• Mouth washes
• Boroglycerin paint (30%)- stomatitis ,Glossitis
2.CUTS AND ABRASION (10%),
3.PRICKLY HEAT POWDERS,EAR
DROPS,IRRIGATING BLADDER.
• ADRs:- vomiting ,Abdominal pain Diarrhoea, visual
& kidney damage 36

37. • ACETIC ACID:- Oldest antiseptic,
BACTERICIDAL – FOR BURN
DRESSING(>5%),
effective against Pseudomonas.
• Salicylic acid- Bacteriostatic, Keratolytic (>25%),
Fungicidal (3%- Whitfield Oint.)
• Benzoic acid- Fungistatic (6%- Whitfield Oint.)
37

38. METALLIC SALTS:-
Mercury compounds:-
• Bacterioststics & Poor antiseptics
• Low TI
• INACTIVATES SH-ENZYMES.
• 1.AMMONIUM MERCURY:
• 5-10% ointments, dermatophytosis
• Anal purities
38

39. • 2.PHENYL MERCURIC NITRATE:
USES: IN TINEA REMEDIES,ANORECTAL
PREPARATIONS, OTIC, OCULAR
PREPARATIONS & PRESERVATIVES.
MERBROMIN (Mercurochrome):
• BRIGHT RED, ORGANIC MERCURIAL.
• NON-IRRITATING & LESS TOXIC.
• USES: 1-2% FOR EYES AND SKIN
antiseptic.
39

40. SILVER COMOUNDS:
• ASTRINGENT & CAUSTIC.
• REACT WITH -SH,-COOH,-PO4,-NH2 PROTEINS.
• SILVER NITRATE (slow Ag release)
• RAPIDILY KILLS MICROBES.
• USES: Opthalmia Neonatarum (1% soln.) SOLN.,
APTHOUS ULCER
• Demerits: black discoloration of tissues
SILVER SULFADIAZINE:
• No black discoloration.
• USES: AS OINTMENT IN BURNS / effective in
Pseudomonas inf..
40

41. ZINC SALTS:
• ASTRINGENT & MILD ANTISEPTICS.
• 1.ZINC SULFATE: WATER SOLUBLE.
• USES: EYE & EAR DROPS, Mouth wash,
EYE WASH, FOR ACNE AND IMPETIGO,
Lotiocalamine (Zno + Calamine), Anti Perspirants.
41

42. DYES:
• Complex organic substances derived from coal tar
• Gentian violet (crystal violet):
• Rosaniline dye.
• Active against staphylococci,gram +ve bacteria, fungi.
• Uses: alcoholic soln (0.5%) for furunculosis, bed sores,
chronic ulcers,infective eczema, thrush, ringworm.
• Demerits- poor efficacy against Gm-ve & in the
presence of pus, blue stain on skin
Briliant green :-rosaniline dye.
42

43. • Acridine Dyes: Acriflavin and Proflavin:
• Orange-yellow acridine dyes
• Active against gram + ve bacteria &gonococci.
• Sensitive to light & lose efficacy
• Effective in alk. pH
• Non irritant.
• Uses: chronic ulcers,wounds, burn dressings, Triple dye
lotion-gentian violet 0.25%+briliant green 0.25%+
acriflavin 0.1% for burns. Dressing in umbilical stump in
neonates.
• Demerits- to be stored in amber coloured bottles
43

44. FURAN DERIVATIVES:
• Nitrofurozone:
• Cidal for gram +ve & gram –ve,aerobic
&anaerobic bacteria.
• Inhibits enzymes for carbohydrates metabolism.
• Use- Efficacious in burns,skin grafting.
44

45. Chronic Toxicity- Skeletal Fluorosis
45