Chlorhexidin

Ghlorhexidine Gluconate. Chlorhexidine gluconate [18472-51 -0] (l,l -hexamethylene bis[5-(p-chlorophenyl) biguanide] di-D-gluconate) is used as an antimicrobial against both aerobic and anaerobic bacteria ia the oral cavity. It is used as a therapeutic supplement ia the treatment of gingivitis, periodontal disease, and dental caries. A mouth riase form is available as a 0.12 wt% aqueous solution (288). 

Active agents vary according to use. For controlling bad breath, 2iac salts, sodium lauryl sulfate, and flavors are used. To destroy oral microorganisms, chlorhexidine, cetylpyridinium chloride [123-03-5] and ben2alkonium chloride [68391-01-5] are valuable. Essential oils, such as thymol [89-83-8] eucalyptol [470-82-6] menthol, and methyl salicylate [119-36-8] reduce plaque-related gingivitis (see Oils, essential). Sodium fluoride aids ia caries coatrol. 

Chlorhexidine is the most poteat oral antimicrobial agent available. It has side effects and is sold only with a prescription. It is active deflvered from a riase, but a compatible toothpaste vehicle for chlorhexidine has yet to be developed. 

Ethanol and 2-propanol have also found use ia disinfecting clinical thermometers, and as preservatives to prevent microbial deterioration of cosmetics and mediciaals. They are sometimes combiaed with other disiafectants, namely formaldehyde (69), phenoHcs (70), chlorhexidine (71), hypochlorite (72), and phenols (70). 

The optimum pH for chlorhexidine antimicrobial activity is in the range 5.5—7.0 but varies with the buffer used and the organism, having a range of pH 5—8. With S. aureus and E. coli, activity increases with increased pH the reverse occurs with P. aeruginosa. 

After washing with chlorhexidine skin cleanser for 15 seconds, a 99.9% reduction of transient contaminants was achieved (216). Chlorhexidine is sometimes combined with alcohol to achieve the rapid reduction obtained with alcohol and the residual effect of chlorhexidine. It is substantive to the skin, and repeated use results in lower levels of bacteria on the skin. 

Chlorhexidine has found other medical appHcations, eg, in urology in preventing urinary tract infections (217), in obstetrics and gynecology (218), in controlling infection in bums and wounds (219), and in the prevention of oral disease (220). Hypersensitivity to chlorhexidine has been reported in Japan (221) but 0.05% concentration is considered to be safe. 

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