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Mahaveer Prasad Kabra*, Sanjay Singh Bhandari, Shakti Singh, Paresh Mohan.
Kota College of Pharmacy, SP-1,
RIICO Industrial Area, Ranpur,
Jhalawar road, Kota, Rajasthan, India – 324009

Surfactant plays an important role in various drug delivery. To formulate the compounds sparingly soluble in water the surfactants are typically employed to increase solubility. Herbal are materials which have a tendency to preferentially get absorbed at the interface between two phases. The low solubility in biological fluids displayed by about 50% of the drugs still remains the main limitation in oral, parenteral and transdermal administration. Among the strategies to overcome these drawbacks surfactant is the most effective alternative. This article review about the herbal surfactants, their types, limitation, structure and mechanism, and evaluation of herbal surfactant.


A surfactant is a compound that can reduce the interfacial tension between two immiscible phases. When surfactants obtain from natural sources then they are called herbal surfactant. Herbal are materials which have a tendency to preferentially get absorbed at the interface between two phases.
This is due to the molecule containing two localised regions, one being hydrophilic in nature and the other hydrophobic. Hydrophilic part is polar in nature, while hydrophobic part is non polar in nature. Result of their surface absorption is that tension between the two phases is inevitabely lowered and phases acquired greater tendency to intermix mix each other. (1, 2)

Classification of herbal surfactant:
There are three categories of surfactants
1.    Non-ionic
2.    Anionic
3.    Cationic

1.    Non-ionic surfactant:
The properties of non-ionic surfactant are largely dependent on the proportions of these two groups in the molecule. Hydrophilic groups include the oxyethylene group (-O.CH2.CH2-) and the hydroxyl group (-OH). By varying the number of these groups in a hydrophobic molecule, such as a fatty acid, substances are obtained which range from strongly hydrophobic and water-insoluble compounds, such as glyceryl monostearate, to strongly hydrophobic and water soluble compounds, such as the macrogols. The range of non-ionic surfactant used in pharmaceutical practice is large and their classification can be varied and complex. The principal groups of non-ionic surfactants are outlined below.

Glycol and glycerol esters: These are a group of non-ionic surfactants consisting of fatty acid esters of glycols and glycerol.
Acetoglycerides: These are mixed glyceryl esters in which the glycerol is esterified partly with a fatty acid and partly with acetic acid.
Macrogol esters: These are polyoxyethylene esters of fatty acids, mainly stearates.
Macrogol ethers: These are condensation products prepared by reaction between fatty alcohols or alkylphenols and ethylene oxide.
Sorbitan derivatives: These are derivatives of the cyclic mono or di anhydrides of sorbitol.
Poloxamers: These are copolymers of polyoxyethylene and polyoxypropylene. (2, 3)

2.    Anionic surfactant:
Anionic are group of surfactants which ionise in aqueous media and whose surfactant activities related to the anionic part. The important hydrophilic group involved in the construction of anionic surfactant are carboxylic sulphate ester, sulfonic ester and phosphate ester groups and are broadly represented by the four groups are:
Soaps may be looked upon as esters of higher fatty acids or of rosin acids with metallic salts such as Na, K, Ca, Ba, Mg, etc. or with other alkaline material such as ammonia or organic alkalies.
Alkaline metal and ammonium soap: These are the sodium, potassium or ammonium salt of long chain fatty acids, such as oleic, stearic and ricinolic. They produce o/w emulsion.
Sulphated compounds: Sulphated compounds may be looked upon as derivative of sulphuric acid in which one of the H is replaced by R group.
Eg. Sodium lauryl sulphate, Sodium cetyl sulphate.
Sulphonated compound: Sulphonated compound may be considered as derivative of sulforous acids.
eg. Dioctyl sodium sulphosuccinate, triton X-200, Dodecyl benzene sulphonate. (4, 5, 6)

3.    Cationic surfactant:
Cationic surfactants are mostly quaternary ammonium compounds. Some of them are however amino salts, amino amides or immadazolines eg. Benzalkonium chloride, Cetyl ammonium bromide, zephiran. (3, 7)

Limitation of surfactant

Name of surfactant

Side effects

Cationic surfactant

These chemicals have a positive electrical charge. They contain a quaternary ammonium group and are often called quats.

They are synthetic, irritating, allergenic and toxic, and oral intake of them can be lethal.  

Stearic acid

May cause irritation; health effects not adequately investigated.

Sorbitan stearate

Generally recognised as being safe; may cause contact urticaria.

Sorbitan palmitate

May cause contact dermatitis.

sorbitan oleate

May cause contact urticaria and allergic reactions.

Sorbitan monolaurate

Caused adverse reproductive effects in animals and may be a carcinogen.

Sorbitan laurate

May cause contact urticaria.

Sodium oleth sulphate

May contain dangerous levels of ethylene oxide and 1, 4-dioxane both potent.

Sodium myreth sulphate

Mild to moderate eye irritation in animal studies.

Sodium methyl cocoyl taurate

May cause formation of nitrosamines.

Sodium lauryl sulphoacetate

Mild to moderate skin irritation; slight eye irritation; slightly toxic to rats in oral doses.

Cocoamidopropyl hydroxysultaine

May cause allergic skin rash, may contain nitrosamines.

Cetyl ricinoleate

May cause eye irritation.

Sodium lauryl sulphate(SLS)

May cause blindness and lead to cataracts. Eyes cannot heal properly. Retards the eye healing process.

Cetyl alcohol

Used as an opacifier, emollient, emulsifier, thickener, and carrying agent for other ingredients. Found in laxatives. May cause hives and contact dermatitis, skin disorders.

Cetalkonium chloride

Contact allergies, dry hair, ingestion can be fetal.

Cetearyl alcohol

May cause contact dermatitis and contact sensitisation in some people.

Cetearyl palmitate

May cause contact dermatitis.


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