Antimicrobials chlorhexidine

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). 

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. 

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. 

As is apparent from the above information, there is no ideal disinfectant, antiseptic or preservative. All chemical agents have their limitations either in terms of their antimicrobial activity, resistance to organic matter, stability, incompatibility, irritancy, toxicity or corrosivity. To overcome the limitations of an individual agent, formulations consisting of combinations of agents are available. For example, ethanol has been combined with chlorhexidine and iodine to produce more active preparations. The combination of chlorhexidine and cetrimide is also considered to improve activity. QACs and phenols have been combined with glutaraldehyde so that the same effect can be achieved with lower, less irritant concentrations of glutaraldehyde. Some... 

Examples of preservatives are phenylmercuric nitrate or acetate (0.002% w/v), chlorhexidine acetate (0.01 % w/v), thiomersal (0.01 % w/v) and benzalkorrium chloride (0.01 % w/v). Chlorocresol is too toxic to the comeal epithehum, but 8-hydroxyquinoline and thiomersal may be used in specific instances. The principal considerahon in relation to antimicrobial properties is the activity of the bactericide against Pseudomonas aeruginosa, a major source of serious nosocomial eye infections. Although benzal-konium chloride is probably the most active of the recommended preservatives, it cannot always be used because of its incompatibility with many compounds commonly used to treat eye diseases, nor should it be used to preserve eye-drops containing anaesthetics. Since benzalkonium chloride reacts with natural mbber, silicone or butyl rabber teats should be substituted. Since silicone mbber is permeable to water vapour, products should not be stored for more than 3 months after manufacture. As with all mbber components, the mbber teat should be pre-equilibrated with the preservative prior to... 

Controlled and sustained drug delivery has recently begun to make an impression in the area of treatment of dental diseases. Many researchers have demonstrated that controlled delivery of antimicrobial agents, such as chlorhexidine [128-130], ofloxacin [131-133], and metronidazole [134], can effectively treat and prevent periodontitis. The incidence of dental caries and formation of plaque can also be reduced by controlled delivery of fluoride [135,136]. Delivery systems used are film-forming solutions [129,130], polymeric inserts [132], implants, and patches. Since dental disease is usually chronic, sustained release of therapeutic agents in the oral cavity would obviously be desirable. 

The most widely used and effective disinfectant solutions are based on iodine (iodophor) with concentrations ranging between 0.05% and 0.1%, but sometimes higher concentrations are recommended. Other agents such as chlorhexidine or chlorine dioxide, peroxide, sodium chloride and lactic acid may also be effective (Wilson et al., 1997) but are not common. Recent trials show positive effects of aloe vera-based dipping agents (Leon et al., 2004). One problem of iodine containing products is their low pH value (<4.0), which is necessary for their antimicrobial activity (Hansen and Hamann, 2003). 

Optional II Same basic composition and mass as above, but adjusted for the following postaddition of antimicrobial agents (e.g., chlorhexidine, etc.). Antimicrobial agents 0.5-10.0 of total solids Emulsification and polymerization procedure ... 

Controlled solubility and ionic diffusion of the antimicrobial agent, such as, chlorhexidine, to the microorganisms (see Figs. 2.23 and 2.24), and... 

In a microorganism prone environment, it is preferable to protect a dressing with a preservative such as chlorhexidine to prevent the contamination of the dressing. It is necessary to consider the solubility of an agent in the liquid phase of the dressing during the selection of an antimicrobial agent. The formulated polyvinyl acetate and polybutyral materials were dissolved in ethanol that is also a solvent for chlorhexidine diacetate. The information (Block, 2001) in Table 2.12 provides solubilities of chlorhexidine compounds in different solvents. 

Ethyl alcohol or isopropyl alcohol in an aqueous solution (between 70 and 92%) is an inexpensive and easily accessible disinfectant, which is rapidly acting and bactericidal as well as germicidal to most viruses, fungi, and other pathogens.13 However, its residual activity is limited and it should be used in conjunction with a longer-acting disinfectant (i.e., chlorhexidine) for optimal antimicrobial... 

A newer development in controlled local delivery, one that utilizes the antiseptic chlorhexidine as the antimicrobial agent, has been introduced in a number of countries and was recently cleared by the FDA for use in the United States. This delivery system, PerioChip (manufactured by Perio Products Ltd., Jerusalem, Israel distributed by Dexell Pharmaceuticals, Edison, NJ), was developed in Israel and has been tested in the United States as well as in Europe. 

Briner, W.W. Kayrouz, G.A. Chanak, M.X. Comparative antimicrobial effectiveness of a substantive (0.12% Chlorhexidine) and a non-substantive (Phenolic) mouthrinse in vivo and in vitro. Compend. Contin. Educ. Dent. 1994, 15, 1158-1168. 

Gongwer LE, Hubben K, Lenkiewicz RS, Hart ER, Cockrell BY. The effects of daily bathing of neonatal rhesus monkeys with an antimicrobial skin cleanser containing chlorhexidine gluconate. Toxicol Appl Pharmacol 1980 52(2) 255-61. 

Chlorhexidine salts are widely used in pharmaceutical formulations in Europe and Japan for their antimicrobial properties. Although mainly used as disinfectants, chlorhexidine salts are also used as antimicrobial preservatives. 

Chlorhexidine and its salts are widely used, primarily as topical disinfectants. As excipients, chlorhexidine salts are mainly used as antimicrobial preservatives in ophthalmic formulations. 

Schafer E, Bossmann K. Antimicrobial efficacy of chloroxylenol and chlorhexidine in the treatment of infected root canals. Am ] Dent 2001 14(4) 233-237. 

Pllloni AP, Buttini G, Glannerelll D, et al. Antimicrobial action of Nltens mouthwash (cetylpyridinium naproxenate) on multiple Isolates of pharyngeal microbes a controlled study against chlorhexidine, benzydamine, hexetidine, amoxicillin clavulanate, clarithromycin and cefaclor. Chemotherapy 2002 48(4) 168-173... 

Three classes of antimycotic antibiotic are available polyenes, azoles and nucleoside analogs. In addition, non-specific antimicrobial agents such as povidone iodine, chlorhexidine and silver sulfadiazine can be adapted for ophthalmic use. 

Topical 2% povidone iodine solution and 0.2% chlorhexidine gluconate solution have broad antimicrobial profiles and may be used as cheap spectrum and effective antifungal agents in equine ketomycosis, particularly where Fusarium spp. are involved. A1% dermatological cream formulation of silver sulfadiazine has both antifungal and antibacterial properties and is reasonably well tolerated topically in the horse eye. Its use is advocated where cost restraints exist or for prophylaxis in comeal injuries involving embedded plant material (Hamor Whelan 1999). 

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