Pharmaceutical Importance of Anti-Microbials


Safa Mohammed Sadiq1*, Amtul Kareem2, Nuha Rasheed3, Abdul Saleem Mohammad4

1Department of Pharma.D, Nizam Institute of Pharmacy, Deshmukhi (V), Pochampally (M), Behind Mount Opera, Yadadri (Dist)-508284, Telangana, India.

2Department of Pharma.D, Nizam Institute of Pharmacy, Deshmukhi (V), Pochampally (M), Behind Mount Opera, Yadadri (Dist)-508284, Telangana, India.

3Department of Pharmaceutics, Nizam Institute of Pharmacy, Deshmukhi (V), Pochampally (M), Behind Mount Opera, Yadadri (Dist)-508284, Telangana, India.

4Department of Pharmaceutical Analysis and Quality Assurance, Nizam Institute of Pharmacy, Deshmukhi (V), Pochampally (M), Behind Mount Opera, Yadadri (Dist)-508284, Telangana, India.

*Corresponding Author E-mail:



The treatment of microbial infection is increasingly complicated by the ability of microbe to develop resistance to antimicrobial agents. Antimicrobial agents are often categorized according to their principle mechanism of action. Mechanism includes interference with cell wall synthesis, inhibition of protein synthesis, interference with nucleic acid synthesis and disruption of bacterial membrane structure.


KEY WORDS: Antimicrobials, Antiseptics, Disinfectants, Germicides, Bacteriostatics, Sanitizers, Oxidation, Halogenation, Protein precipitation, Zinc peroxide, Sodium hypochlorite, Mild silver protein.




Destroying or inhibiting the growth of micro-organisms and especially pathogenic organism is a chemical compound called antimicrobials. The word antimicrobial was derived from the Greek words ‘Anti’-Against, ‘mikros’-little and bios-life. It refers to all agents that act against microbial organism.


It is a drug that kills micro-organism in the body or a drug which inhibits the growth of organism or increase immunity and resistance to the infectious body. These are mainly classified into antiseptics, disinfectants, germicides, bacteriostatics, and sanitizers. [1-3]


Based upon the mechanism of action inorganic antimicrobial agents can be divided into 3 general categories.

·        Oxidation

·        Halogenation

·        Protein precipitation



Convert sulfhydryl into a disulphide bridge, thus altering the conformation of the protein and thereby alter its function.

Example: H2O2, KMnO4, Iodine Solution of Iodine Povidone-Iodine



Hypohalides can react with amide hydrogen to form N-chloro derivatives. Example: Sodium hypochlorite


Protein precipitation:

The complex of protein precipitants results in a radical change in the properties of the proteins and they “tie-up” important functional groups at the active site of enzymes resulting in antimicrobial activity


Example: AgNO3, Mild silver Protein, Mercury, Yellow Mercuric oxide, Ammoniated mercury.



Applied to living tissues like wound, cut, ulcers. These are the chemicals used in destroying disease causing micro-organism (also called microbial, microbiological, pathogens) externally on wound or (under medical supervision) taken internally to treat infection. An ideal antiseptic should destroy bacteria, spores, fungi, viruses, or any other infective agent without causing any harm to the tissues of the host. They can be applied to all tissues of the body and may b use in the form of mouth washes, soaps, deodorants, throat and nasal spray. All antiseptics or protein denaturants and act on enzymes in the bacteria.

Examples: Dettol, tincture of iodine.



These are the substances that prevent infection by the destruction of pathogenic micro-organisms. These are generally applied to inanimate objects.


These are widely used for houses and hospital sanitation. They are bactericidal and rapidly produce irreversible lethal effects. Some chemical disinfectants are too irritant to the skin or tissues.



These are substances which kill micro-organism. More specific terminology like ‘bactericide’ (against bacteria) ‘fungicide’ (against fungi), ‘viricide’ (against virus) etc; exact action.



These are substances which primarily function by inhibiting the growth of bacteria. Thus, bacteriostatic drugs or agents donot kill but inhibit the growth of bacteria.



Disinfecatant that are used to maintain general public health standards, are termed as sanitizeres. Sanitizers is mainly concerned with cleaning or washing away the organic matter (eg saliva). [4-7]




Oxidation (mixture of ZnO2, ZnCO3 and Zn (OH)2 about 50% of ZnO2).Halogenation (NaOH, Cl). Protein precipitation (Stillargol, vitargenol).

Oxidative Antimicrobial Agents       

Zinc Peroxide (Medicinal zinc Peroxide)



By reaction with hydrogen peroxide to a solution of Zn+2

ZnCO3 + H2O2                ZnO2 + H2O + CO2



It is a fine, white odorless powder which is practically insoluble in water and organic solvents.


·        With water it slowly hydrolyses to produce zinc oxide and hydrogen peroxide.

ZnO2 +H2O           ZnO + H2O2

This reaction is responsible for its antibacterial action and zinc oxide will exert an astringent action.

·        With dil. acids it releases hydrogen peroxide.

ZnO2 + 2HCl           ZnCl2 + H2O2



It may be used as an antibacterial and mild astringent in the treatment of infection in various types of wounds. It may be found to be useful in oral infection, e.g. Vincent’s stomatitis. A 25% suspension may be used to treat mouth infection caused by anaerobic organism.



With warm moist air, heavy metal ions, oxidizing and reducing agents, and alkaline solution.


§  Halogenative Antimicrobial Agents

§  Sodium Hypochlorite (NaOCl)



It is prepared industrially by the Hooker’s process. It is manufactured from the reaction of chlorine and sodium hydroxide (caustic soda) solution or directly by electrolysis of salt solution.


2NaOH + Cl2                  NaOCl + NaCl + H2O



Sodium Hypochlorite also known as chlorine bleach is a transparent yellowish solution in water at room temperature. It is a powerful oxidant and is used in variety of applications, including in the home as a disinfectant.



Its main uses are as bleaching agents. Sodium Hypochlorite topical is used to treat or prevent infection caused by cuts or abrasions, skin, ulcers, diabetic foot ulcers or surgery. It can be used to remove mold stains, dental stains caused by fluorosis. It is also used to reduce to odors.



With acids-hydrochloric acid, acidic compounds-ferrous or ferric chloride, metals such as copper, cobalt, nickel. Mixing of metals may lead release of oxygen gas could cause over pressure/rupture of a closed system.


·        Protein Precipitant Antimicrobial Agents

·        Mild silver protein (Silver Nucleinate)




It is prepared by interaction of silveroxide with a protein in the presence of alkali. It contains 19.0% and not more than 23% of silver.



It occurs as dark brownish, shining scales, odorless, frequently, hygroscopic, and affected by light. It is purely soluble in water to give a colloidal solution. The product contains very little free silver ions, therefore it causes no astringent or irritating effects; and not readily precipitated by chloride ions or tissue proteins. 



It has bacteriostatic action. It was widely used in the treatment of conjunctivitis, cystitis, nose and throat infections, and in prophylaxis of gonorrhea.



Topical, in 5 to 25 % solution


Dosage forms:

Solutions 5,10and 20%.EDTA-stabilized solution, Argyrol 55-10 and 20%solution.



Should be stored in well-closed container, protected from light in amber-glass containers.


Zinc Peroxide: The germicidal properties of zinc peroxide prepstations have been known to the medical art for a long period of time. It has been suggested to use such zinc peroxide preparations in the treatment of several dermatologic diseases. Employment of zinc peroxide preparations has been more or less restricted to deodorants and similar cosmetic preparation. More recently the therapeutic effects have been investigated from the from the bacteriological view point. It was found that zinc peroxide has a specific action on anaerobic and microaerophilic and on certain aerobic infection. It is used in the treatment of ulcers, as a disinfectant in surgical infection. It is used to treat diaper rash, minor burns, severely chapped skin or others minor skin irritation. Zinc has been observed to be more effective in the elimination of gram-positive bacteria and gram-negative bacteria. It is used as an antiseptic ointment. It has been used as an oxidant in explosives and pyrotechnique mixture.


Sodium Hypochlorite: Biomechanical preparation with NaOCl has been proven effective in eliminating micro-organism present in the root canal system. It is being used as the irrigation of choice in root canal treatment.

·        Removes the organic part of smear layer.

·        It acts as lubricant.

·        Excellent organic tissue solvent.

·        Corrodes and has an unpleasant order to it.

·        It is very effective antimicrobial agents.


Even though the microbial action of NaOCl has not yet been fully understood. Hypochlorite acid is formed in the presence of water containing active chlorine. A powerful oxidizer that produces a powerful antimicrobial effect. Higher concentrations of NaOCl present give faster and greater bactericidal effect.


Mild Silver Protein: Silver has benefited mankind health for thousands of years. In ancient Rome and Greece people used silver containers to keep liquids fresh. Silver works on a wide range of bacteria without any side effects or damage to the cells of the body and can stimulate major growth of injured tissues. Silver deficiency is also a reason for the improper functioning of the immune system. Mild silver protein is a powerful, natural antibiotic.

·        It may be directly applied on cuts, wounds, burns, moles, sores etc.

·        It keeps germ and bacteria free in 1st and 2nd degree burns.

·        It helps to eliminate fermentation in stomach.

·        It is used to treat pathogenic eye infection.


Tests proved that due to high absorption of silver in the small intestine, the friendly bacteria in the large intestine are not affected. It is harmless to human enzymes and has no reactions with other medications. [7-10]



Antimicrobials are the chemicals and their preparations which help in reducing or preventing infections due to microbes. Based on mechanism of action it is divided into antiseptics, disinfectants, germicides, bacteriostatics and sanitizers. Antiseptics are substances that are able to kill or prevent the growth of micro-organism. These are applied on living tissues. Disinfectants are the substances that prevent infection by destruction of pathogens. Germicide are disinfectant which are classified as bactericide, fungicide, viricide denotes exact action. Bacteriostatic are substances which primarily function by inhibiting the growth of bacteria. Sanitizers are disinfectants that are used to maintain general public health standard. Antimicrobial agent should posses certain characteristics like antiseptic or germicide activity, rapid onset and sustained activity, good therapeutic index, broad spectrum activity etc. Inorganically antimicrobial agents can be divided into oxidation, Halogenation, protein precipitation. Zinc peroxide; Sodium hypochlorite and Mild silver protein are taken as examples respectively for the above categories. Zinc peroxide is a white odorless powder. It is used as an antibacterial and mild astringent in the treatment of infection in various types of wounds. Sodium hypochlorite is a transparent yellowish solution. It is prepared industrially by the Hooker process. Its main uses are as bleaching agents. It is used to treat skin wound or ulcer. Mild silver protein occurs as dark brownish, shiny scales, odorless and affected by light. It is used in the treatment of conjunctivitis, cystitis and throat infections.


This article explains in detail the uses of antimicrobials, preparations of some inorganically classified antimicrobial agents based on oxidation, halogenations and protein precipitation.



1.       A.H. Beckett and J.B. Stenlake, Practical pharmaceutical chemistry, Part-I. The Athtone press, University of London, London.

2.       P. Gundu Rao, Inorganic pharmaceutical chemistry; Vallabh  Prakashan, Delhi.

3.       Advanced Inorganic Chemistry by Satya Prakash, G. D. Tuli

4.       Jolly-Modern Inorganic Chemistry

5.       Pharmaceutical Inorganic Chemistry textbook by Alagarsamy.

6.       L.M. Atherden, Bentley and Driver’s Textbook of Pharmaceutical Chemistry Oxford University Press, London.

7.       Indian Pharmacopoeia 1996, 2006.

8.       J.H Block, E. Roche, T.O Soine and C.O. Wilson, Inorganic Medical and Pharmaceutical Chemistry Lea & Febiger Philadelphia PA.

9.       Pharmaceutical inorganic chemistry by S. Chand, R. D. Madan, Anita Madan

10.     Pharmaceutical Inorganic Chemistry by Soma Shekar Rao





Received on 08.12.2016       Accepted on 08.01.2017     

© Asian Pharma Press All Right Reserved

Asian J. Pharm. Tech.  2017; 7(1): 7-10.

DOI: 10.5958/2231-5713.2017.00002.2