Disinfectants & antiseptics
Disinfectants – compounds used for killing of germs
outside of the body (desinfection of floors, walls, tables,
instruments...)
Antiseptics – compounds used for killing of germs on skin
and mucous menbranes of the body - „externally“
„Intestinal disinfectants“ – non-exact designation for nonabsorbable
antibacterial chemotherapeutics acting in
gastrointestinal tract (will be reffered among antidiarrhoics)
© Oldřich Farsa 2012
Classification of disinfectants and antiseptics
1. Heavy metals and their compounds
2. Compounds with oxidation mechanism
2.1 Peroxo compouns
2.2 Halogens and labile compounds containing
them
2.3 KMnO4
3. Alcohols and phenols
4. Aldehydes
5. Quarternary ammonium salts
6. Biquanide derivatives
7. Dyes
1. Heavy metals and their compounds
• today namely Ag, Bi
Ag: colloidal silver: colloidal particles of metallic silver forming a clear solution
in water; contain 70 - 80 % of silver, the rest is a stabilizing protein
Argentum colloidale ad usum externum PhEur
AgNO3 – sometimes in eye drops; „lapis infernalis“ (= “hell stone“): the stick for
treatment of superficial lessions and ulcerations
Bi
O
O
O
OH
OH
OH
bismuth subgallate; Bismuthi subgallas PhEur –
antiseptic powder for wounds healing etc.
2. Compounds with oxidation mechanism
2.1 Peroxo compounds
H2O2 – antiseptic in 3% concentration
•oxidative damage of both lipids and proteins of cell membranes of microorganisms
CH3COOOH – peroxoacetic acid – disinfection of medical instruments etc.
•supplied as approx. 30% solution in CH3COOH, dilution with water in time of need
O
O
O
O
dibenzoylperoxide
•topical treatment of Acne vulgaris
2.2 Halogens and compounds releasing them
2.2.1 Halogens
F2, Cl2 – disinfection of drinking water and water in pools
(F2 also for ehnhancement of teeth growing and against osteoporosis)
Br2 not used due to its toxicity/reactivity
I2 Solutio iodi spirituosa, glycerolica
Aqueous solution: iodine is not stable
I2
OH2 IH HIO
I2
KI KI3
NO
*
*
n
I2
+ +
That is why Lugol solution is prepared
+
Iodine-polyvidone
potassium triiodide
a complex of iodine with poly(1-vinylpyrrolidin-2-one)
Jox®, Betadine®
2.2.2 Labile compounds containing halogens
R
S
N
O O
Cl
Na
+
Sodium hypochlorite NaClO
•approx. 5 % aqueous solution for disinfection of pool water, sanitary
ceramics, bleaching of clothes etc.
•agains bacteria, fungi and viruses
Savo ® , Domestos ®
R = -H benzenesulfochloramide sodium salt Chloramin B ®
R = -CH3 p-toluenesulfochloramide sodium salt Chloramin T®
●discovered during 1st
World War as a substitution for gaseous Cl2
●
disinfection of floors, water etc.
SO O
N
-
ClNa
+
+ OH2
SO O
NH2
+ NaClO
Labile compounds containing halogens (continued)
S OO
N
O OH
Cl Cl
N,N-dichloro-4-sulfamoylbenzoic acid
halazone
syn. pantocide
•pressed together with Na2
CO3
or Na2
B4
O7
into effervescent/soluble
tablets
•disinfection of water (= to make drinking water from any surface
water)
3. Alcohols & phenols
Lower alcanols – ethanol, propane-2-ol
•ethanol has antimicrobial activity in concentrations > 15 %
•mechanism of action: denaturation of superficial proteins
•abroad („old“ EU countries) propan-2-ol used more than ethanol due to the alcohol
tax
Lower alkanediols – propane-1,2-diol (propyleneglycol)
Arylalcanols – benzylalcohol, phenethylalcohol (= 2-phenylethanol) – vaccines
preservatives
Phenols
phenol – today not used as antiseptic, high toxicity, necroses
•inactivation of live components of vaccines
•remains a standard for evaluation of antimicrobial activity
cresols – methylpenols: –o-, m-, p-cresol – mixture = tricresol (Lyzol) – disinfection
of hospital floors; Kresolum saponatum ® - solution in potassium soap
OH
CH3
4. Aldehydes
formaldehyde – methanal HCO
Formaldehydi solutio 35 % PhEur
• preservation of anatomical specimens (aquaeous solution – „formalin“)
•antiseptic of mouth and larynx – gargles – Gargarisma formaldehydi Kutvirt
•mechanism of action: interaction with bacterial proteins – forming of Schiff bases
with free amino groups ⇒ protein denaturation
malondialdehyde – propanedial HOC-CH2
-COH
5. Qurternary ammonium salts
•surface-active compounds – cationic tensides - „inversion soaps“
•mechanism of action: damage surface proteins of bacteria
•efficient only against bacteria
N
+
R
1
R
2
R
3
R
4
X O
O
N
+
CH3
CH3
CH3
Br
N
+
CH3
CH3
R X
carbethopendecinium bromide
Carbethopendecinii bromidum ČL 2009
R = -C12H25 X = Br
benzododecinium bromide
Benzododecinium bromatum ČSL 4
Ajatin
R = C8H17 - C18H37 X = Cl
benzalkonium chloride
Benzalkonii chloridi solutio PhEur
6. Biguanide derivatives
Cl NH
NH
NH
NH
NH
NH
NH
NH
NH
NH Cl
1,1'-Hexamethylenebis[5-(4-chlorophenyl)biguanide]
chlorhexidine
•antiseptic impregnation of adhesive plasters with a “pillow”, mouth waters
•mechanism of action: interaction with cell mebrane – blocks live-important
processes there
7. Dyes
Triphenylmethane dyes
OH S
O
-
O
O
CH3
N
CH3
N
+
CH3
CH3
Brilliant green
Viride nitens
•Solutio Novikov: antiseptic “lacquer”
(paint) consisting of collodium (4% of
nitrocellulose in ether), brilliant green
and ethanol for treatment and
covering of scratches
NCH3
CH3
N
CH3
CH3
N
+
CH3
CH3Cl
-(I)
Methylrosaniline chloride
gentian violet
•antibacterial, antifungal, anthelmitic
•local treatment of throat or mouth
inflammations by smearing with its solution
on a cotton wool roll on a wooden stick
•skin lesions
7. Dyes (continued)
Acridine dyes
CH3O
NNH2
NH2
2,5-Diamino-7-ethoxyacridine
ethacridine
Ethacridini lactas monohydricus PhEur
•mechanism of action: intercalation (= inserting) into DNA of a germ
•wounds, skin disorders