Page 47 - MNU-PM502- Pharmaeutical Microbiology Theoritical Book

Pharm D- Clinical Pharmacy Program Third Level Pharmaceutical Microbiology& Antimicrobials (PM 502)

5- Peroxygens
- Hydrogen Peroxide (H2O2)

• Peroxides produce highly reactive free radicals that damage proteins and DNA

• antiseptics (3% solutions)
• High-level disinfectants (25% solutions)

• At high concentrations and increased temperature, hydrogen peroxide is sporicidal
Sterilants (30% peroxide vapor)

- Peracetic Acid

• characterized by a very rapid action against all microorganisms.

• Liquid peracetic acid (PAA) and vaporized peracetic acid (VPA) are highly biocidal

sterilants that maintain efficacy in the presence of organic soil while removing
surface contaminants.

• used for processing heat-sensitive semicritical and critical devices cannot be
sterilized by other methods

6- Quaternary ammonium compounds "quats."

(Soaps, detergents)

• Quats are weak disinfectants or antiseptics. They are unable to kill endospore-

forming bacteria (low level disinfection)

• Act as surfactants to disrupt the cellular membranes of some bacteria and fungi.

• Examples: Laundry detergent (benzalkonium chloride), dish soap, household
cleaners and some mouthwashes (cetylpyridinium chloride).

7- Heavy metals

• Copper, zinc, mercury and silver can be used as low-level disinfectants or

antiseptics.

• Heavy metals are not sporicidal

• Heavy metals oxidize and inactivate proteins and can be toxic to humans

• Examples: - Mercuric chloride is used as disinfectant

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