ANTI-INFECTIVES

• Alcohol


  Ethanol (ethyl alcohol, wine spirit) - clear, colorless, volatile liquid with a burning taste and a characteristic pleasant odor. It is flammable, miscible with water in all proportions.
• As the primary alcohol chain length increases

  Van der Waals interactions increase, ability to penetrate microbial membranes increases, but water solubility increases so apparent antimicrobial potency diminishes with molecular weight.
• Alcohols and Related Compounds


  • The antibacterial potencies of the primary alcohols (against test cultures of Staphylococcus aureus) increase with molecular weight until the 8-carbon atom (octanol).
• Dehydrated Ethanol

  Dehydrated ethanol, or absolute ethanol, contains not less than 99% w/w of C2H5OH. It is prepared commercially by azeotropic distillation of an ethanol–benzene mixture, with provisions made for efficient removal of water.
• isopropyl alcohol

  The alcohol is rapidly bactericidal in the concentration range of 50% to 95%. A 40% concentration is considered equal in antiseptic efficacy to a 60% ethanol in water solution.
• Isopropyl Alcohol


  Isopropyl alcohol is also used in pharmaceuticals and toiletries as a solvent and preservative. Azeotropic isopropyl alcohol, United States Pharmacopeia (USP), is used on gauze pads for sterilization of the skin prior to hypodermic injections.
• Formaldehyde


  Oxidation and Polymerization of Formaldehyde
• Glutaraldehyde


  Glutaraldehyde (Cidex, a 5-carbon dialdehyde) is used as a dilute solution for sterilization of equipment and instruments that cannot be autoclaved. Commercial glutaraldehyde is stabilized in alkaline solution. At higher pH (8.5),glutaraldehyde rapidly polymerizes.
• Phenol


  Phenol, USP, remains the standard to which the activity of most germicidal substances is compared.
• Phenol Derivatives


  • Substitution with alkyl, aryl, and halogen (especially in the para position) groups increases bactericidal activity. Straight-chain alkyl groups enhance bactericidal activity more than branched groups.
• Phenol Uses


  • 4% solution of phenol in glycerin has been used to cauterize small wounds. Still used occasionally as an antipruritic in phenolated calamine lotion (0.1%–1% concentrations).
• Hexachlorophene


  A biphenol such as hexachlorophene will, in general, possess greater potency than a monophenol. The increased degree of chlorination of hexachlorophene increases its antiseptic potency further.
• Cresol


  Cresol is actually a mixture of three isomeric methylphenols obtained from coal tar or petroleum by alkaline extraction into aqueous medium, acidification, and fractional distillation.
• Benzoyl Peroxide


  The compound is formulated with 30% water to make it safer to handle. It consists of two benzoyl groups bridged by a peroxide link.
• Povidone Iodine


  The preparation provides a nontoxic, nonvolatile, and nonstaining form of iodine that is not irritating to the skin or to wounds. Used as an aqueous solution for presurgical disinfection of the incision site.
• Chlorine-Containing Compounds


  These compounds release hypochlorous acid when dissolved in water, especially in the presence of acid.
• Chlorhexidine Gluconate


  The most effective of a series of antibacterial biguanides, originally developed in Great Britain. Has broad-spectrum antibacterial activity but is not active against acid-fast bacteria, spores, or viruses.
• Methylene Blue


  Has weak antiseptic properties that make it useful for the treatment of cystitis and urethritis. The highly conjugated action of methylene blue is considered to be bacteriostatic. The compound colors the urine and stool blue green.
• Mercurials


  Elemental mercury incorporated into ointment bases was used topically for the treatment of localized infections and syphilis. Several inorganic salts of mercury, such as mercuric chloride (HgCl2) and mercurous chloride (calomel, Hg2Cl2) were at one time widely used as antiseptics.
• Organomercurials


  Organomercurials can be grouped into two general classes: (a) compounds with at least one carbon-mercury bond that does not ionize readily; and (b) compounds with mercury bonded to heteroatoms (e.g., oxygen, nitrogen, sulfur) that ionize partially or completely.
• Nitromersol


  Nitromersol (metaphen) - 3-(Hydroxymercuri)-4-nitro-o-cresol inner salt (Metaphen) occurs as yellow powder that is practically water and sparingly soluble in alcohol and most organic solvents. Nonirritating to mucous membrane, nonstaining.
• Thimerosal


  Thimerosal [(o-Carboxyphenyl)-thio]ethyl mercury sodium salt (Merthiolate) - cream colored, water soluble powder. Nonstaining, nonirritating to tissues, bacteriostatic antiseptic, applied topically in ointments or aqueous solutions.
• Methyl Paraben


  Used as a safeguard against mold growth.
• Propyl Paraben


  Used as a preservative, primarily to retard yeast growth.
• Chlorobutanol


  A bacteriostatic agent in pharmaceuticals for injection, ophthalmic use, and intranasal administration.
• Benzyl Alcohol


  Occurs naturally as the unesterified form in oil of jasmine and in esters of acetic, cinnamic, and benzoic acids in gum benzoin, storax resin, Peru balsam, tolu balsam, and some volatile oils. Used as a preservative in vials of injectable drugs in concentrations of 1% to 4% in water or saline solution. Also used in ointments and lotions as an antiseptic in the treatment of various pruritic skin conditions.
• Zinc Propionate


  This salt form is unstable to moisture, forming zinc hydroxide and propionic acid. Used as a fungicide, particularly on adhesive tape.
• Undecylenic Acid


  10-Undecenoic acid (Desenex, Crusex) - obtained from the destructive distillation of castor oil. A fatty acid that resembles like sebum which augments antifungal properties. It has reactive double bonds. Ø10% for topical prep. Traditionally used for athletes foot.
• Triacetin


  Glyceryl triacetate (Enzactin, Fungacetin) - The activity of triacetin is a result of the acetic acid released by hydrolysis of the compound by esterases present in the skin.
• Salicylic Acid


  Possesses both antiseptic and keratolytic properties. Used externally in ointments and solutions for its antifungal and keratolytic properties.
• Resorcinol


  1. Hydroxyphenol - possesses antiseptic and keratolytic activity.
• Benzoic Acid


  Possesses appreciable antifungal effects, but it cannot penetrate the outer layer of the skin in infected areas. When used as an antifungal agent must be admixed with a keratolytic agent. Whitfield's ointment, USP contains benzoic acid, 6%, and salicylic acid, 6%, in a petrolatum base.
• Joseph Lister (1867) – introduce the principles for surgery and post traumatic injury

  Used phenol (carbolic acid) as a wash for the hands, as a spray on an incision site, and on bandages applied to wounds.
• Paul Ehrlich (1905) – introduced Salvarsan
• Paul Ehrlich

  • “magic bullets” , compound 606 , selective toxicity, Cinchona – for malaria, ipecac – amebic dysentery
• antisepsis - application of an agent to living tissue for the purpose of preventing infection
• decontamination - destruction or marked reduction in the number or activity of microorganisms
• disinfection - chemical or physical treatment that destroys most vegetative microbes or viruses, but not spores, in or on inanimate surfaces
• sanitization - reduction of microbial load on an inanimate surface to a level considered acceptable for public health purposes
• sterilization - process intended to kill or remove all types of microorganisms, including spores, and usually including viruses with an acceptably low probability of survival