Antisepsis: Is defined as destruction or inhibition of microorganisms on living tissues having the effect of limiting or preventing the harmful results of infection. Antiseptic: A substance that counters sepsis by destroying or inhibiting the growth of pathogenic microorganisms. Antiseptics are generally applied to living tissues in the form of wet dressings, creams, ointments or other substances that involve prolonged contact with the body.

Disinfection: is the process of removing microorganisms, including pathogens, from the surfaces of inanimate objects.



Disinfection: is the process of removing microorganisms, including pathogens, from the surfaces of inanimate objects. 
Disinfectant: An agent that prevents infection by destroying or removing pathogenic microorganisms. The term is confined to substances used for the treatment of inanimate objects.
In practice, both antiseptics and disinfectants are used to destroy or inhibit the growth of pathogenic microorganisms in the vegetative form.




Antiseptics


Ethanol
Has a bactericidal action against most vegetative organisms at a concentration of 60% and 95%, but is not effective against bacterial spores. Evaporating lotion used for hand and skin cleaning, surgical treatment for various skin lesions. Prevention of bedsores and diminishing sweating (reduce temperature). Used as solvent in different pharmaceutical preparations. A concentration of 70% either alone or with chlorhexidine or iodine for disinfection of skin before surgical procedures

Chlorhexidine
An antiseptic which is effective against a wide range of vegetative gram-positive and gram-negative bacteria, although it has no activity against acid fast bacteria, bacterial spores and some viruses. Chlorhexidine is used in disinfectant solutions, creams, gels and lozenges. It is also used in various concentrations for disinfection in the following conditions;
• Chlorhexidine 0.5% in 70% ethanol for the preoperative disinfection of the skin
• Chlorhexidine 0.05% solution in glycerin for urethral irrigation and catheter lubrication
•Chlorhexidine 0.02% solution for bladder irrigation
•Chlorhexidine 1% cream for use in obstetrics
•Chlorhexidine 0.01% as the diacetate for preservation of eye drops

Cetrimide
A quaternary ammonium disinfectant that has bacterial activity against both gram-positive and gram-negative organisms. 0.5% solution for preoperative skin disinfection. Cetrimide 0.05% to 1% is used for the cleansing of polythene tubing and catheters, but time of immersion should not exceed 30 minutes. Cetrimide in higher concentrations of 15 to 35 is used in shampoos to remove scales in seborrhea. Cetrimide 1.5% with chlorhexidine gluconate 0.15% is often used as a general purpose disinfectant

Povidone Iodine /polyvidone iodine
Acts by inhibiting enzymes essential to microbial metabolism. It kills on contact a broad spectrum of pathogenic bacteria, viruses, fungi, protozoa and yeasts. Skin antiseptics and germicidal skin cleansers. Disinfectant for wounds, abrasions and insect bites, Medicated spray for wounds, Antidandruff shampoos, Medicated adhesive plasters, Gargles and throat lozenges and vaginal gels and douches among others


Disinfectants


Sodium Hypochlorite
A solution 8% to about 18% of chlorine is prepared by absorption of chlorine in sodium hydroxide solution to give sodium hypochlorite. Sodium hypochlorite solutions release chlorine gas which kills most pathogenic organisms at neutral ph, Rapid disinfection of hard surfaces, Disinfection of food, Disinfection of dairy equipment and babies’ feeding bottles, Solutions containing up to 0.05% of available chlorine are suitable for use on skin and wounds.




Glutaral (Glutaraldehyde)
Glutaral is an effective disinfectant against vegetative forms of gram-positive and gram-negative bacteria. It is also effective against acid-fast bacteria, bacterial spores, some fungi and viruses. A 2% aqueous solution of Glutaral buffered to pH 7.5-8.5 (the ambient pH for activity) is used for the sterilization of endoscopic instruments, thermometers and rubber or plastic equipment that cannot be sterilized by heat

Cresol and Soap Solution
Cresol and soap solution BP (Lysol) is an old preparation which is still widely used in East Africa as a general disinfectant for hospital and domestic use. Cresol and soap solution is effective against a wide range of organisms, but its activity is reduced in the presence of organic matter. The bactericidal activity of cresol and soap solution varies with the soap used. Linseed and castor oil soaps give the highest values and oleic acid the lowest. 

It has further been verified that higher values are obtained with coconut oil. In addition to its use as a general disinfectant in hospitals, cresol and soap solution is widely used in commercial disinfectants. Because it is clear when diluted with water, its use is an advantage in the sterilization of surgical instruments, since cleanliness can be identified with speed and ease