Which antiseptic agent is often formulated in alcohol for skin preparation?

• A. Povidone-iodine
• B. Chlorhexidine gluconate
• C. Hydrogen peroxide
• D. Ethanol

Answer: (B)

Chlorhexidine gluconate in alcohol is favored for skin prep because the alcohol provides a rapid antibacterial action, while chlorhexidine adheres to the skin and offers sustained, or substantivity, antimicrobial effect. This combination delivers quick reduction in microbial load and longer-lasting protection during the procedure, which is why it’s commonly formulated in alcohol for preoperative skin preparation. Povidone-iodine is effective but typically used in aqueous or iodophor formulations and doesn’t offer the same level of persistent activity as CHG in alcohol. Hydrogen peroxide is not ideal for routine skin prep due to irritation and limited residual effect, and ethanol alone lacks lasting protection.