Chloroxylenol's mechanism of action involves disrupting microbial cell membranes and inactivating essential enzymes. It causes disruption of cell membrane potentials, which blocks the production of adenosine triphosphate (ATP), the energy currency of the cell, leading to cell death. This makes it a potent and fast-acting antimicrobial agent.

In vitro, Chloroxylenol demonstrates broad-spectrum activity. It is bactericidal against most Gram-positive bacteria, but is less effective against Staphylococcus and Gram-negative bacteria, and is generally ineffective against Pseudomonas spp. It also exhibits antifungal and antiviral properties. Its potency is about 60 times that of phenol.

In vivo, Chloroxylenol is used topically as an antiseptic. It is effective in treating acne vulgaris and as an antifungal agent. It is commonly used in surgical scrubs and for wound cleansing, where it reduces the microbial load on the skin and prevents infection. It is well-tolerated at typical use concentrations (up to 5.0%).

The in vitro antimicrobial susceptibility assay for Chloroxylenol involves incubating the test organism (bacteria or fungi) with varying concentrations of the compound in a liquid broth. After incubation, the minimum inhibitory concentration (MIC) is determined by measuring the optical density (OD) of the culture or by performing a colony count on agar plates.

In vitro cell culture studies are not typically performed for disinfectants, as the primary mode of action is direct killing of microbes. However, skin irritation potential can be assessed using reconstructed human epidermis (RHE) models. In such assays, the compound is applied topically, and cell viability is measured via an MTT assay to determine the concentration that causes 50% cell death (ET50).

In vivo animal models are not commonly used for antimicrobial testing, but for regulatory purposes, skin sensitization tests may be performed. In a guinea pig maximization test, the compound is injected intradermally and applied topically to assess for allergic contact dermatitis. For acute toxicity, oral administration in rats may be used to determine the LD50.

Absorption, Distribution and Excretion
After applying 2 grams of chloroxylenol dissolved in ethanol/olive oil to the skin of human subjects, chloroxylenol was not detected in the blood. At a 5-gram dose, only trace amounts were detected; at an 8-gram dose, 1 mg/dL (1 mg/dL) was detected in the blood after 3 hours and 4 mg/dL (4 mg/dL) after 24 hours. At a 20-gram dose, 4 mg/dL (4 mg/dL) was detected after half an hour and 1 mg/dL (1 mg/dL) remained after 72 hours. Chloroxylenol is well absorbed when used externally as a disinfectant. Its primary route of excretion is likely urine, but small amounts may also be present in bile and trace amounts in exhaled breath. Currently, the only data regarding the volume of distribution (Vss) of chloroxylenol is the mean steady-state Vss of 22.45 liters measured after a single intravenous injection of 200 mg chloroxylenol in a healthy mongrel dog. The only data currently available regarding the clearance rate of chloroxylenol is a mean clearance of 13.76 L/h measured after a single intravenous injection of 200 mg chloroxylenol in healthy mongrel dogs. Furthermore, in another study, when 8 g of chloroxylenol was dissolved in an alcohol/glycerol solvent and applied to human subjects through the skin, 11% of the substance was excreted within 48 hours. Mongrel dogs received intravenous and oral single doses of 200 mg and 2000 mg of 4-chloro-3,5-dimethylphenol, respectively. Results showed low absorption rates. The kidneys are not the primary route of rapid clearance of unmetabolized 4-chloro-3,5-dimethylphenol. A 25% chloroxylenol solution test in Sprague-Dawley rats showed that after oral or skin contact, almost all of the chemical is excreted within 24 hours, primarily in urine, with a small amount excreted in feces. After skin contact, approximately half of the substance is not absorbed. High concentrations of the substance were found in kidney tissue, indicating that it is primarily excreted in urine. Lung concentrations indicate that some of the drug is expelled through exhaled air. A study in beagle dogs showed that almost all chloroxylenol was excreted in urine within 24 hours after oral administration. Small amounts of drug were present in feces, but almost no drug residue remained in any tissues. This study investigated the pharmacokinetics and metabolic characteristics of PCMX after intravenous and oral administration of single doses of 200 mg and 2000 mg, respectively, to healthy mongrel dogs. …The mean half-life and mean residence time were 1.84 hours and 1.69 hours, respectively. The steady-state apparent volume of distribution was estimated at 22.4 L, and the plasma clearance was 14.6 L/h. The bioavailability of PCMX was 21%. …Metabolic data for PCMX also showed a first-pass effect (pre-systemic elimination). Plasma concentrations were proportional to the administered dose after intravenous administration of 500 mg, 200 mg, and 100 mg doses of PCMX.

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Metabolism/Metabolites
Some animal studies have shown that chloroxylenol is rapidly absorbed after skin application, with peak plasma concentration (Cmax) occurring in 1-2 hours. The administered substance is excreted by the kidneys and is almost completely eliminated within 24 hours. The main metabolites found in urine are glucuronide and sulfate. Some chloroxylenol monographs describe its pharmacokinetic characteristics similar to another disinfectant—triclosan—which is also rapidly excreted in urine as a glucuronide metabolite, as observed in human models. Furthermore, in one subject, after a 5 mg chloroxylenol injection into the buttocks, 14% of the drug was excreted as glucuronide and 17% as sulfate after 3 days. Any chloroxylenol absorbed by the body is likely to be extensively metabolized in the liver and rapidly excreted, primarily in the urine as sulfate and glucuronide conjugates.
Mongrel dogs received intravenous and oral single doses of 200 mg and 2000 mg of 4-chloro-3,5-dimethylphenol, respectively. The main metabolites found in urine are glucuronide and sulfate.
Biological Half-Life
One study estimated that after a single intravenous injection of 200 mg of chloroxylenol in healthy mongrel dogs, the average terminal half-life and average residence time were 1.7 hours and 1.69 hours, respectively. Furthermore, some product instructions compare chloroxylenol to the similar liquid disinfectant triclosan, which has a urinary excretion half-life of approximately 10 hours in humans.
Chloroxylenol is characterized by its low solubility in water (1 g dissolves in 3 L of water at 20°C) but is more soluble in hot water and organic solvents. It is a stable compound. Upon topical application, it is absorbed through the human skin and gastrointestinal tract, but systemic absorption is generally limited at typical use concentrations. It is metabolized in the liver and excreted in urine.

Protein Binding
One study determined that chloromethol binds to serum albumin at a rate of approximately 85.2% +/- 2.32%, and to whole human serum at a rate of approximately 89.8% +/- 2.99%.
Chloroxylenol is considered safe and mild for topical use at concentrations up to 5.0%. However, it can be irritating to the skin and eyes at higher concentrations. Resistance can develop through enhanced efflux or membrane lipid modification. It is not classified as a carcinogen. Ingestion can cause gastrointestinal irritation and central nervous system depression.

[1]. Shigatoxin encoding Bacteriophage ϕ24B modulates bacterial metabolism to raise antimicrobial tolerance. Sci Rep. 2017 Jan 20;7:40424.

[2]. The action of three antiseptics/disinfectants against enveloped and non-enveloped viruses. J Hosp Infect. 1998 Apr;38(4):283-95.

[3]. Antimicrobial agent chloroxylenol targets β‑catenin‑mediated Wnt signaling and exerts anticancer activity in colorectal cancer. Int J Oncol. 2023 Nov;63(5):121.

4-Chloro-3,5-dimethylphenol belongs to the phenolic class of compounds. Its structure is similar to 3,5-xylenol, except that a chlorine is substituted at the 4-position. It is bactericidal against most Gram-positive bacteria, but less effective against Staphylococcus and Gram-negative bacteria, and is generally ineffective against Pseudomonas spp. It is ineffective against bacterial spores. 4-Chloro-3,5-dimethylphenol can be used as a preservative, disinfectant, and molluscicide. It belongs to the phenolic and monochlorobenzene classes of compounds. Its structure is similar to 3,5-xylenol. Chloroxylenol, also known as p-chloro-m-xylenol (PCMX), is a preservative and disinfectant used for skin disinfection and surgical instrument disinfection. It is found in antibacterial soaps, wound cleaners, and household disinfectants. Halogenated phenols are most effective against Gram-positive bacteria; their phenolic properties can disrupt bacterial cell walls. Chloroxylenol is listed in the World Health Organization's Essential Medicines List. See also: Phenol (containing active ingredient); Chloroxylenol; Triclosan (ingredient); Benzocaine; Chloroxylenol (ingredient)...See more...

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Drug Indications
The main indications for chloroxylenol are external use to treat cuts, bites, stings, and abrasions, and as a hand sanitizer.

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Mechanism of Action
As a phenolic disinfectant, the hydroxyl group (-OH) in the chloroxylenol molecule is believed to bind to certain proteins on the bacterial cell membrane, disrupting the cell membrane and causing leakage of bacterial cell contents. This allows chloroxylenol to enter bacterial cells and bind to more proteins and enzymes, thereby inhibiting cell function. When the concentration of chloroxylenol is particularly high, the proteins and nucleic acids targeting the bacterial cells coagulate and cease functioning, ultimately leading to rapid cell death.
Chloroxylenol was first registered as a fungicide in the United States in 1959 and has FDA clearance as a preservative in food packaging adhesives. It is widely used as an antiseptic and germicide. It is a common active ingredient in many over-the-counter antiseptic products globally, valued for its broad-spectrum antimicrobial activity and favorable safety profile at low concentrations.

C8H9CLO

156.6095

156.034

88-04-0

Chloroxylenol-d6;1407521-66-7

2723

White to off-white solid powder

1.2±0.1 g/cm3

246.0±0.0 °C at 760 mmHg

114-116 °C(lit.)

105.9±25.9 °C

0.0±0.5 mmHg at 25°C

1.558

3.35

1

1

0

10

104

0

OSDLLIBGSJNGJE-UHFFFAOYSA-N

InChI=1S/C8H9ClO/c1-5-3-7(10)4-6(2)8(5)9/h3-4,10H,1-2H3

4-chloro-3,5-dimethylphenol

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ≥ 100 mg/mL (~638.53 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (15.96 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (15.96 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (15.96 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)