The document discusses antiseptics and disinfectants, defining antiseptics as agents that eliminate microorganisms on living tissues and disinfectants as those targeting inanimate objects. It outlines the mechanisms of action, factors affecting germicide activity, and classifies various types including phenol derivatives, oxidizing agents, halogens, and alcohols. Additionally, it highlights specific examples and their uses in medical and hygiene applications.

1. ANTISEPTICS & DISINFECTANTS
ROLL NO - 70,71,72,73,74,75
CLASSIFICATION &
GENERAL MECHANISM OF
Prepared by :-
Pharmacology seminar || Date: 15/11/2024

2. DEFINITION
ANTISEPTIC: It is an agent used to
eliminate microorganism on living
tissues
DISINFECTANTS : It is an agent used to
eliminate microorganisms on
inanimate objects.
THE TERM GERMICIDE COVERS BOTH CATEGORY OF
DRUGS

3. MECHANISMS OF ACTION
Mechanism of action of germicides are varied ,but
can be grouped into
a) Oxidation of bacterial protoplasm
b) Denaturation of bacterial proteins including
enzymes
c) Detergent like action increasing permeability of
bacterial membrane.

4. MECHANISM OF
ACTION
FACTORS WHICH MODIFY THE
ACTIVITY OF GERMICIDES :-
• Temperature and pH
• period of contact with the microorganism
• nature of the microbe involved
• size of innoculum
• presence of blood ,pus or other organic matter

5. CLASSIFICATION
1.Phenol derivatives
2.Oxidizing agents
3.Halogens
4.Biguanide
5.Quarternary ammonium (Cationic )
6.Soaps
7.Alcohols
8.Aldehydes
9.Acids
10.Metalic salts
11.Dyes
12.Furan derivative

6. 1.PHENOLS
It is one of the earliest antiseptics.
It acts by disrupting bacterial
membranes and denaturing bacterial
proteins .
other phenol derivatives
are : Cresol
Chloroxylenol
Hexachlorophene

7. 2.OXIDIZING AGENT
POTASSIUM PERMANGANATE
BENZOYL PEROXIDE
It liberates nacent oxygen which oxidzes
necrotic matter and bacteria
It is specifically active against P acnes and
used on acne vulgaris
It liberates oxygen which oxidzes bacterial
protoplasm.
It is also used to disinfect water and for
stomach wash in alkaloidal poisoning.
HYDROGEN PEROXIDE

8. 3. HALOGENS
A powerful,non irritating cationic antiseptic that disrupts
bacterial cell membrane .
It is relatively more active against gram positive bacteria .
Chlorhexidine is the most widely employed antiseptic in
dentistry.
IODINE
It is a rapidly acting ,broad
spectrum microbicidal agent .
it acts by iodinating and
oxidizing microbial protoplasm
A highly reactive element
and a rapidly acting
potent germicide.
0.1-0.25 ppm kills most
pathogens in 30
sec .However the
germing action is soon
exhausted
• Act by releasing
iodine
• non irritant
• used in
burns ,boils ,bef
ore surgery
CHLORINE IODOPHORES
CHLORHEXIDINE
4. BIGUANIDE

9. 5.QUATERNARY AMMONIUM ANTISEPTICS
These are detergents;cidal to bacteria ,fungi and viruses.
It act by altering permeability of cell membranes and
denaturing of bacterial proteins.
Example : Cetrimide , Benzalkonium chloride, Dequalinium
chloride
6. SOAPS
Soaps are anionic detergents with weak antiseptic action.
They affect only gram positive bacteria.
Their usefulness primarily resides in their cleaning
action .
Washing with soap and warm water is one of the most
effective methods of preventing transmission of infection

10. 7.ALCOHOLS
They act by denaturing bacterial proteins and precipitating them
ETHYL ALCOHOL
70% Ethyl alcohol is used as an antiseptic on skin before
giving injections and surgical procedures.
It is highly irritant, it should not be used on open
wounds.
not useful for disinfecting instruments as it promotes
rusting
ISOPROPYL ALCOHOL
• more potent
• 68-72% isopropyl alcohol is used as an antiseptic.

11. 8.ALDEHYDES
It is less volatile, less pungent, less irritating and better
sterilizing agent than formalin
A 2% solution is used to disinfect surgical instruments.
FORMALDEHYDE It is a pungent gas _sometimes use for fumigation.
A 37% aqueous solution called Formalin is diluted to 4%
and used for hardening and preserving dead tissues.
It is a broad spectrum germicide.
GLUTERALDEHYDE

12. 9.ACIDS
It rapidly kills microbes,action persisting for long periods
because of slow release of Ag+ ions .
1% solution is used for opthalmia neo natorum.
BORIC ACID It is only bacteriostatic and a very weak antiseptic.
Boroglycerine paint (30%) is used for Stomatitis and
glossitis .
A 10% ointment ( BOROCIDE ) is available for cuts and
abrasion .
SILVER NITRATE
10.METALLIC SALTS
Others examples are Silver Sulfadiazine ,
Zinc sulfate etc .

13. 11. DYES
A rosaniline dye active against staphylococcus,other
gram positive bacteria and fungi but gram negative
bacteria and mycobacteria are insensitive.
They are used topically as antiseptic.
GENTIAN VIOLET ( CRYSTAL VIOLET)
It is cidal to both gram positive and gram negative , aerobic
and anaerobic even in high dilutions but activity is reduced in
the presence of serum .
It acts by inhibiting enzymes necessary for carbohydrate
metabolism in bacteria.
It is highly efficacious in burns and for skin grafting .
NITROFURAZONE
12.FURAN DERIVATIVES

14. THANK YOU