(i) Antiseptic: Chemical substances which prevent the growth of microorganism or kill then are called antiseptics. These are not harmful to human living tissue these are applied to cuts, wounds, alsars, diseased skin surface some common example of antiseptics are: Detol, Sevlon, Tinchar, Iodine etc.
(ii) Antacid: These are the chemical substances which nutrilize the excess acid and the race the pH to an appropriate level in the stomach the most commonly used anta acid are weak base such as sodium bicarbonate, magnesium hydroxide etc.
(iii) Sulpha drug: Like antibotics sulpha drugs are used to kill microorganism there are prepared inaboratory for ex: Sulphadizine.
(iv) Antifertility: Chemical substances which are used to control pragnency in women are called antifertility or birth control drugs. All these drug contain chemical relative to female sex harmones and steroids. Ex: Etynylesh adiol, Norethindrene.
(v) Antipyretic: Chemicals used to reduce the body temperature during fever are called antipyretic Ex: Asprin, Paracetamole.