1. Lec No 2 Contd ANTISEPTICS AND DISINFECTANTS
Dr.K.Parameswari, Dept of Chemsitry

2. Drugs
are complex molecules containing carbon, hydrogen with some heteroatom like oxygen, nitrogen, sulfur. On the basis of their action of different microorganism and mode of action, drugs can be various types. Some common classes of drugs are as follows.
Antipyretics: These drugs used to reduce fever.
Analgesics: They are painkiller which used to reduce pain
Antimalarial drugs: these drugs use to treat malaria
Antibiotics: They inhibited the germ growth which caused disease
Antiseptics: They used to prevention of germ growth near burns, cuts and wounds

8. COMMONLY USED TERMS RELATED TO KILLING OF MICROORGANISMS

9. ORIGINS OF ANTISEPTICS
Joseph Lister ( )
Realised that deaths from operations mostly occurred from infection contracted during the operation as a result of unclean practices.
He started using Carbolic acid (phenol) during operations to maintain aseptic conditions with significant improvements.
Like Semmelweiss he initially encountered opposition, but use of his methods by the Germans during the Franco-Prussian war in 1870 provided his major breakthrough and over the next 10 years, the practise of aseptic surgery became accepted.

12. NATURAL ANTISEPTICS
Lemon: The presence of citrus juice in lemon make it a good antiseptic which effect on
immune function system, circulatory system and digestive systems. Because of its antibacterial nature, it can use to sterilize the air by using few of its drops in a spray bottle.
Honey: it is a natural antiseptic which used to prevent the infection of wounds due to presence of antibacterial agents which kill the bacteria present in and around the wound. It can also be used for treating ulcers and burns, diarrhea and any vomiting and stomach upsets.
Pineapple: This fruit is rich in vitamin- A, C, and B, with manganese, which involve
in metabolism of proteins and carbohydrates. Bromelain enzyme present in pineapple is used for digesting proteins and enhances medical antibiotics due to its antibacterial properties. Because of antiseptic and astringent nature of pineapple, it can used treatment of pneumonia and infection caused by worms. It is also effective in the treatment of kidney infections and kidney stones.
Tea Tree Oil: it used for skin disinfectant like acne, athlete's foot and wound healing.
Lavender: It is a natural antiseptic and astringent which helps with minor skin problems.
Eucalyptus: It has antiviral and antibacterial properties, thus used for the treatment of flu, throat infections, sinusitis and headaches. Compare to natural antiseptic, synthetic antiseptics are in much more uses due to their reactivity towards bacteria.

16. Common ANTISEPTICS

19. IODINE One of the oldest and most effective germicidal agents
IODINE One of the oldest and most effective germicidal agents. It inhibits protein synthesis and oxidizes –SH groups of amino acids. Also Halogenates tyrosine in protein. Tincture of Iodine (2% I2+2% Na2I in 70% alcohol) is a commonly used antiseptic for wounds.
Ethanol/SD Alcohol, 40 1–3%; fluid that acts as sanitizer. Isopropyl alcohol, 1–2%; partly responsible for Lysol's strong odor; acts as sanitizing agent and removes odor. p-Chloro-o-benzylphenol, 5–6%; antiseptic.

24. Disinfection
DISINFECTANTS are chemical agents that inhibit or kill microorganisms (surgical apparatus, periphery of the patient, and the objects used by the patient).
Disinfectants are used to kill bacteria. They are used to sterilize instruments, utensils, clothes, floors, sanitary fittings, sputum and excreta. They harm the living tissues and cannot be used on skin. Some examples are phenol, methyl phenol, hydrogen peroxide and sulfur dioxide

26. Disinfectant can be used as Antiseptics
Disinfectant and Antiseptics
When the concentration is less, it is an antiseptic and when the concentration is more, the substance acts as disinfectant.
For instance, 0.2% solution of phenol is an antiseptic and 1.0% solution of phenol is a disinfectant.
Povidon iodine (A complex of I with polivinyl pyrrolidone-surface active agent-). Can be used as antiseptics or disinfectants.
Kill vegetative bacteria, mycobacteria, fungi, lipid containing viruses. They kill spores as well on prolonged use

27. CHLORINE
Chlorine is a strong oxidizing agent. Hypochloric acid and sodium hypochlorite (household bleach 5.25%) are bactericidal and effective disinfectants
10dilutions it provides 5000 ppm of chlorine. This is the concentration recommended for disinfection of blood spills. Dilutions are made with tap water and when the opaque bottle is tightly closed it preserves its activity.

28. < 5 ppm kills vegetative bacteria
5000 ppm is needed to kill spores
,000 ppm is tuberculocidal
100 ppm kills vegetative fungal cells in 1 h
500 ppm kills fungal spores
ppm inactivate viruses
HOCl is the active form, pH↑ less active OCl- is formed→blood serum feces protein containing materials should be removed from surfaces

29. ACTIVITIES OF DISINFECTANTS

31. Application of Disinfectants
Food industry – sanitize food preparation areas, preservative functions
Drinking water – typically chlorine, other organic oxidizers
Medical – sterilization of equipment, facilities
Household – cleaners (kitchen, bathroom, multipurpose), soaps, detergents
Other industries – paints, inks, cosmetics (serves as preservative)
Garret