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Antiseptic & Disinfectant

Antiseptics:
Antiseptics are the agents that are used on living tissues & act as
antimicrobial but don’t kill them necessarily.

Disinfectants:
–
Disinfectants are agents which are applied on inanimate objects & kill the
microbes outright.

When the
word end with

–cide means to kill the
microbes e.g. bactericide means to kill bacteria

–stat means to prevent the growth (multiplications) of microbes

E.g. bacteriostatic means to prevent the growth of bacteria.

Classification of Antiseptic & Disinfectant:-

• Phenols & related compound: Phenol,
Chlorocresol. Chloroxylenol, Hexachlorophene

• Alcohols & related compound: Ethanol, Isopropyl alcohol

• Aldehyde: Formaldehyde

• Carboxylic acid and their derivatives: Benzoic acid, Methyl P- hydroxy benzoate.

• Halophors:

a) Chlorophors: e.g. Chloramines.

b) Iodophors: e.g. Povidone –iodine, Iodoform

• Heavy metal compound:

a) Organic mercurial’s:
Thiomarsal

b) Silver compound: Silver
sulphadiazine, silver protein

• Quaternary ammonium compound /cationic compound: Benzalkonium chloride, cetrimide.

• Dyes: Proflavin, brilliant
green.

• Miscellaneous agents

a) Topical – Nitorfurazone
,Icthamol

b) Urinary antiseptic –Nitrofurantoin

Proflavin
/Proflavin Hemisulphate / Neutral Hemisulphate

Structure of Proflavin:

3, 6
acridine diamine/3, 6 Diamino acridine,

• It is an acridine derivative.

• The acridine cation is largely
responsible for antibacterial activity.

• The presence of two amino group, at
position 3 and 6 brings about the resonance stabilization of the cation which
increase the base strength.

This lead to the higher conc. Of cation
at pH (7.3) thus providing increased bacteriostatic activity.

Physical Properties of Proflavin:

• It occurs as orange to red crystalline hygroscopic powder.

• It is odourless.

• It is sparingly soluble in water.

• Very soluble in hot water.

• It is practically insoluble in a chloroform and ether.

Chemical properties of Proflavin:

• When it is treated with potassium fericynide in slightly acidic
medium it is precipitate as its fericynide salt.

K3Fe (CN)
6 +3HCL ————- H3Fe (CN) 6+3KCL

Stability &Storage of Proflavin:

• It is hygroscopic and affected by light;
hence it is stored in tightly closed light resistant container.

Uses of Proflavin:

• It is slow
acting antiseptic.

• It is
effective against many gram positive and gram negative bacteria.

• It is used
in the treatment of infected wound.

• For the
dressing of wound and burns.

• For the
treatment of local infection of external ear, mouth, throat and skin.

Pharmaceutical
formulations: Proflavine cream

Brand names: Triple
Dye, Kerr Triple dye

Benzalkonium chloride

Structure of Benzalkonium chloride:

• It is the
mixture of alkyl benzyl dimethyl ammonium chloride .in this alkyl group has 8
to 18 carbon atoms.

I.e. R=
C8H5 to C18H37

• Quaternary
ammonium compound is the derivatives of an ammonium salt having general formula
N+R4X-

• Where R=
alkyl or other organic radical,
X=
acid radicals like CL, Br, OH

Properties of Benzalkonium chloride:

• It is
white to pale yellow gel.

• It has
aromatic odour.

• Very
bitter in taste.

• It is
miscible with water.

• The
aqueous solution is alkaline to litmus and foams strongly on shaking.

Stability
and Storage of Benzalkonium chloride:

• It is decomposed by alkali hydroxide
and affected by light .hence it is stored in tightly closed light resistant
containers.

Uses of Benzalkonium chloride:

• It is an antiseptic and detergent

• For cleansing intact skin.

• For irrigation of bladder, urethra and
vagina.

• To get relief from painful infection
of mouth and throat.

• It is also used as preservative in eye
drops.

Pharmaceutical
formulations: Benzalkonium chloride, Benzalkonium chloride
lozenges.

Brand names: Azep
Nasal, Tanac, Herpetrol (benzalkonium chloride/menthol topical)

Cetrimide

Structure of Cetrimide:

• It is cetyl trimethyl ammonium bromide.

• In smaller proportion; it contains
dodecyl and hexadecyl trimethyl ammonium bromide.

Properties of Cetrimide:

• It is white or creamy white free
flowing powder.

• It has faint and characteristic odour

• It is freely soluble in water.

• Soluble in alcohol.

• Practically insoluble in ether.

Storage of Cetrimide:

• Stored in well closed containers.

Uses of Cetrimide:

It is an antiseptic and detergent and
hence it is used as

• To treat the burns and wounds.

• To remove scabs

Phenol

Structure of Phenol:

Properties of Phenol:

• It is colourless liquid which may turn
pinkish blue on keeping.

• It has characteristic, somewhat
aromatic odour.

• It is caustic.

• It gives clear solution when 15, parts
of water is added to 1 part to it.

• It is miscible with glycerin.

Storage
& Stability of Phenol:

• Stored in a well closed light
resistant container.

• The crystal may get deposited if
stored at a temperature below 4 degree C.

• In such cases it should be completely
melted before use.

Uses of Phenol:

It
is bactericidal and germicidal. It is used

• For a dressing of small wound.

• To get relief from itching (due to
anesthetic property.)

• As an analgesic in dentistry

• As an antiseptic and analgesic in
mouth ulcers and tonsillitis.

• In the treatment of boils in ears.

Chloroxylenol

Properties of Chloroxylenol:

• It occurs as a white crystalline
powder.

• It has characteristic odour.

• It is practically insoluble in water.

• Soluble in alkali hydroxide solution,
fixed oil, alcohol.

• It is volatile in steam.

Stability
and storage of Chloroxylenol:

• It is affected by light; hence it is
stored in tightly closed light resistant container.

Uses of Chloroxylenol:

• It is relatively non-irritant
antiseptic, for cuts, wound and abrasions.

• It is also used as a disinfectant.

Pharmaceutical
formulations: Chloxylenol
solutions

Brand
names: Fairgenol

CHLOROCRESOL / PARA- CHLORCRESOL

Structure of Chlorocresol:

Chemical
names: 4-Chloro-3-methylphenol

Chemistry of Chlorocresol:

• It is substituted phenol in which
methyl group and chloro group are attached at C3 and C4 respectively.

• Introduction of –CH3 group at 3
positions and chloro group at 4 position increase antibacterial activity.

• The disadvantage is that water
solubility is reduced.

Physical properties of Chlorocresol:

• It occurs as colourless or faintly
coloured crystals.

• It having characteristic odour.

• It is slightly soluble in water,
soluble in hot water

• It is readily soluble in alcohol and
ether.

• It is steam volatile.

Stability and storage of Chlorocresol:

• It is oxidized by air or oxygen and
hence it is stored in tightly closed containers.

Uses of Chlorocresol:

• Used as powerful bactericide and
fungicide.

• Used as preservative in creams in
pharmaceutical preparations.

Pharmaceutical preparations:

Chlorocresol solution

FORMALDEHYDE SOLUTION/FORMALIN /FORMOL

Properties of Formaldehyde Solution:

• It is colourless liquid.

• It’s having characteristics irritating
odour.

• It’s having burning taste.

• It is miscible with water and
alcohol.

Chemical properties of Formaldehyde Solution:

• When formaldehyde solution is treated
with 2% sulphuric acid and the vapor are condensed quickly, a trimer, trioxane
or trioxymethylene is formed.

• When formaldehyde solution is evaporated,
a white friable mass of polyformaldehyde is obtained.

• Stability
and storage of Formaldehyde Solution:

• It is oxidized readily in air and oxygen.

• It undergoes polymerization on storage
and the process is accelerated in cool place.

• Hence it is stored in tightly closed
containers in moderately warm place.

• Contact with rubber, plastic,
polythene is avoided.

Uses of Formaldehyde Solution:

it is
powerful antibacterial agent hence it is used as

• In treatment of chronic skin disease.

• As an antiseptic (in mouthwashes and gargles).

• To disinfect rooms, instruments,
clothing, hands or site of operation.

• It is also used as preservative for
pathological specimens.

• Hexamine (formaldehyde + ammonia) use
as urinary antiseptics.

Pharmaceutical formulations: Formaldehyde
Lotions, Formaldehyde Gels

Brand names: Kanpip

HEXACHLOROPHENE/HEXACHLOROPHANE

Structure of Hexachlorophene:

Chemistry of Hexachlorophene:

• It is biphenolic Compound.

• Two phenol rings are bridged through a
methylene group (-CH2-) through C2 of each.

• It contains 6 chlorine atoms attached
to 3, 3’, 5, 5’, 6 and 6 carbon atoms.

• Due to higher chlorine contents and
less water solubility it is used as antiseptic in low concentration and
activity is prolonged.

Properties of Hexachlorophene:

• It occurs as white or pale buff
crystalline powder.

• It is odourless.

• It is practically insoluble in water
and soluble in dilute solution of alkali hydroxide.

Chemical Properties of Hexachlorophene:

• When it is treated with sodium
hydroxide at pH 9 it is converted to monosodio derivatives.

It gives purple colour with ferric chloride.

Storage of Hexachlorophene:

• It is
affected by light hence it is stored in tightly closed, light resistant
containers.

Uses of Hexachlorophene:

It has antibacterial property hence it is used
as,

• To reduce the bacterial flora on skin
(in the form of soaps)

• To reduce the bacterial infections

• To disinfect the hands of surgeon

Pharmaceutical formulations: Concentrated hexachlorophene solution,
dusting powder, drench (mixture), cleansing emulsion, and liquid soap.

Brand names: Sterzac, Zalpon

Nitrofurantion

Physical properties of Nitrofurantion:

• It occurs as yellow crystal or
crystalline powder.

• It is odourless.

• It has bitter taste.

• It is very slightly soluble in water.

Storage of Nitrofurantion:

• It is affected by light hence it is
stored in tightly closed

• Light resistant containers temperature
not exceeding 25 degree Celsius.

Uses of Nitrofurantion:

• It is broad spectrum antibacterial
agents.

• It is used in treatment of urinary
tract infection.

Pharmaceutical formulations: Nitrofurantoin suspension, capsules, tablets

Brand names: Furadantin, Urantoin, NFT