Esters bacteriostatic action

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). 

The bacteriostatic activity of a series of substituted trans-3-benzoylacrylic acids has been successfully correlated by Hansch linear free energy relations involving polar and partition substituent constants. The activity-lipophilicity relations for this series closely parallel those found previously for other antibacterial agents, with an ideal lipophilic character for gram-positive cells of 6.1 and, for linear dependence, a slope of 0.7. A polar reaction constant, p, of about —0.6 to —0.7 is given. A possible mode of action for these acids and their related substituted cis- and trans-3-benzoyl acrylic acids and esters is discussed as an enzyme-inhibitor interaction. 

The sulfonamides have a bacteriostatic rather than a bactericidal action. Many local anesthetics used in the eye are esters of para-aminobenzoic acid, and such drugs will interfere with the action of sulfonamides. Thus, to obtain the maximum effect from instillation of sulfonamide eye-drops, these drugs should not be used until the effect of the local anesthesia disappears. 

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