Surfactants of Pharmaceutical Interest

The most commonly used soaps are the alkali metal soaps, RCOOX, where X is sodium, potassium or ammonium, and R is generally between Cio and 20- 

These are esters of sulphuric acid - the most commonly used compound is sodium lauryl sulphate, which is a mixture of sodium alkyl sulphates. The main component is sodium dodecyl sulphate, Ci2H25-0-S0 Na+. It is used pharmaceutically as a preoperative skin cleanser having bacteriostatic action against Gram positive bacteria. It is also used in medicated shampoos and tooth paste (as foam producer). 

R-(0CH2-CH2) -0-S03 M+ (n 6). This has better water solubility than the alkyl sulphates, better resistance to electrolyte and less irritation to the eye and the skin. 

These include, for example, sulphated castor oil (triglyceride of the fatty acid 12-hydroxyoleic acid). This is used as an emulsifying agent for oil-in-water creams and ointments (non-irritant). 

This is a mixture consisting of tetradecyl ( 68%), dodecyl ( 22%) and hexadecyl ( 7%) trimethylammonium bromide. Solutions containing 0.1-1% cetrimide are used to dean skin, wounds and burns, in shampoos to remove scales of sebor-rhoea, and also in Cetavlon cream. 

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General properties of some surfactants of pharmaceutical interest... 

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