Chlorocresol

Colorless or almost colorless, dimorphous crystals or crystalline powder with a characteristic phenolic odor.

Nonproprietary Names

• BP: Chlorocresol
• PhEur: Chlorocresol
• USP-NF: Chlorocresol

Synonyms

Aptal; Baktol; chlorocresolum; 4-chloro-m-cresol; p-chloro-mcresol; 1-chloro-4-hydroxy-2-methylbenzene; 2-chloro-5-hydroxytoluene; 6-chloro-3-hydroxytoluene; 4-chloro-3-methylphenol; 3- methyl-4-chlorophenol; Nipacide PC; parachlorometacresol; PCMC.

Chemical Name and CAS Registry Number: 4-Chloro-3-methylphenol [59-50-7]

Empirical Formula and Molecular Weight: C7H7ClO 142.58

Functional Category: Antimicrobial preservative; disinfectant.

Applications in Pharmaceutical Formulation or Technology

Chlorocresol is used as an antimicrobial preservative in cosmetics and pharmaceutical formulations. It is generally used in concentrations up to 0.2% in a variety of preparations except those intended for oral administration or that contact mucous membrane.

Chlorocresol is effective against bacteria, spores, molds, and yeasts; it is most active in acidic media. Preservative efficacy may be reduced in the presence of some other excipients, particularly nonionic surfactants. In higher concentrations, chlorocresol is an effective disinfectant.