Octadecane does not have a specific, well-defined pharmacological target as it is primarily a chemical reagent and industrial compound rather than a therapeutic agent. As a hydrocarbon, it can interact with biological membranes, potentially affecting membrane fluidity and permeability. It may act as a substrate for certain metabolizing enzymes, such as cytochrome P450 monooxygenases, which can oxidize alkanes to their corresponding alcohols. However, these interactions are not the basis of a specific therapeutic mechanism.

Octadecane exhibits in vitro activity primarily as a chemical reagent. It has demonstrated antimicrobial activity against Proteus mirabilis and Bacillus subtilis. It is used as a standard in analytical chemistry for quantitative analysis and quality control. Additionally, it is utilized in research involving phase-change materials and as a model compound for studying the behavior of lipids and hydrocarbons in various in vitro systems.

Octadecane is not typically used as a therapeutic agent in vivo. Its primary applications are industrial and research-oriented. It can be used in in vivo experiments as a model compound for studying the metabolism and distribution of alkanes or as a component of formulations. As a phase change material, its properties are studied for potential applications in thermal regulation, but not for direct pharmacological effects.

Non-cellular assays for octadecane are primarily analytical and physicochemical. Its identity and purity are confirmed using techniques like gas chromatography (GC) and mass spectrometry (MS). Its thermal properties as a phase change material are assessed using differential scanning calorimetry (DSC) to measure melting point, heat of fusion, and specific heat capacity. Its lipophilicity and membrane interactions can be studied using model membrane systems like liposomes, where its effects on membrane fluidity are measured.

Octadecane is not typically used in standard pharmacological cellular assays. However, its effects on cell membranes can be studied using cell culture models. Cytotoxicity assays (e.g., MTT or LDH release) can be performed to assess its effects on cell viability, particularly in the context of its use as a solvent or excipient. Its effects on membrane integrity and permeability can also be assessed using fluorescent dye exclusion assays.

In vivo animal experiments with octadecane are primarily conducted for toxicological evaluation or for studying the pharmacokinetics of alkanes. Rodent models may be used to assess acute and subchronic toxicity via oral, dermal, or inhalation routes. Clinical signs, body weight, and organ weights are monitored. Histopathological examination of tissues is performed to assess target organ toxicity. It can also be used in dermal irritation and sensitization studies.

Absorption, Distribution and Excretion
Samples were collected from the liver, heart, kidney, muscle, and adipose tissue (perile and subcutaneous) of six cattle for hydrocarbon composition analysis. Qualitative and quantitative analyses were performed using gas chromatography and gas chromatography-mass spectrometry. Despite varying proportions, a series of homologous n-alkanes with carbon chain lengths ranging from n-C12 to n-C31 were found in all samples. In addition, isoprene hydrocarbons phytane and phyene (phytane-1 and phyene-2) were also identified. (These findings are closely related to human health from consuming hydrocarbon-contaminated meat.) /n-Alkanes/
Transmembrane transport of hydrocarbons is an important and complex process in the biodegradation of hydrocarbons by microorganisms. This study investigated the transport mechanism of (14)-n-octadecane by the alkane-degrading bacterium Pseudomonas genus DG17 using ATP inhibitors and different substrate concentrations. When the concentration of n-octadecane was above 4.54 μmol/L, the transport of (14)-n-octadecane mainly proceeded via a promoted passive mechanism along the intracellular/extracellular substrate concentration gradient. However, when cells were grown under low substrate concentration conditions, the accumulation of intracellular n-octadecane (an energy-dependent process) was significantly reduced under the action of ATP inhibitors, and the accumulation of n-octadecane continued to increase against the concentration gradient. Furthermore, the presence of unlabeled alkanes blocked the transport of 14-n-octadecane only in induced cells, and the transmembrane transport of n-octadecane was specific, with an apparent dissociation constant K_t of 11.27 μmol/L and V_max of 0.96 μmol/min/mg protein. The results indicate that the transmembrane transport of n-octadecane in Pseudomonas DG17 is related to substrate concentration and ATP level.
Octadecane is a lipophilic compound with very low water solubility. Following oral administration, it is absorbed and metabolized primarily by oxidation to the corresponding alcohol (octadecanol) and then to octadecanoic acid (stearic acid) via fatty acid oxidation pathways. The compound is typically stored as a powder at -20°C for up to 3 years or at 4°C for up to 2 years, and in solution at -80°C for 6 months or -20°C for 1 month.

Toxicity Summary
Identification and Uses: Octadecane is a solid n-alkane. It can be used as a solvent, organic synthesis reagent, and calibration standard. Human Exposure and Toxicity: No relevant data are currently available. Animal Studies: Structure-activity relationship studies of pure n-alkanes were conducted in a mouse ear edema model to explore their cumulative stimulatory mechanism. Alkanes were applied twice daily for 4 days. The activity of hexadecane, octadecane, and eicosane decreased sequentially. Ecotoxicity Studies: Acute toxicity tests were conducted on the marine copepod Acartia tonsa. Octadecane concentrations ranged from 9.7 to 3200 mg/L. A 48-hour test showed a 50% mortality rate (LL50 > 3200 mg). Interactions Transmembrane transport of hydrocarbons is an important and complex aspect of microbial biodegradation of hydrocarbons. This study investigated the transport mechanism of (14)C n-octadecane by the alkane-degrading bacterium Pseudomonas genus DG17 using ATP inhibitors and different substrate concentrations. When the n-octadecane concentration was above 4.54 μmol/L, the transport of (14)C n-octadecane was driven by a facilitated passive mechanism following the intracellular/extracellular substrate concentration gradient. However, when cells were grown under low substrate concentration conditions, intracellular accumulation of n-octadecane (an energy-dependent process) was significantly reduced in the presence of ATP inhibitors, and the accumulation of n-octadecane increased against the concentration gradient. Furthermore, the presence of unlabeled alkanes only blocked the transport of 14C-labeled n-octadecane in induced cells, and the transmembrane transport of n-octadecane was specific, with an apparent dissociation constant K_t of 11.27 μmol/L and a maximum transport rate V_max of 0.96 μmol/min/mg protein. The results showed that the transmembrane transport of n-octadecane by Pseudomonas DG17 was related to substrate concentration and ATP.
Octadecane is considered to have low acute toxicity but can be a skin and eye irritant. It is not classified as a carcinogen or mutagen. Standard laboratory safety precautions, including the use of personal protective equipment (gloves, goggles), should be followed when handling this compound. Inhalation of high concentrations of vapor or mist may cause respiratory irritation.

Octadecylane is a colorless liquid. (NTP, 1992)
Octadecylane is a straight-chain alkane containing 18 carbon atoms. It is a metabolic product of both bacteria and plants.
Octadecylane has been reported to be found in tea plants (Camellia sinensis), Madagascar vanilla (Vanilla madagascariensis), and other organisms for which relevant data exists.
Octadecane is a naturally occurring alkane hydrocarbon used as a standard in analytical chemistry and in research involving phase-change materials. It is also utilized in insect pheromone studies and as a model system for lipid behavior. Its antimicrobial activity against certain bacteria has been noted. Octadecane is not a pharmaceutical drug and has no approved therapeutic indications.

C18H38

254.4943

254.297

593-45-3

Octadecane-d38;16416-31-2

11635

Needles from alcohol, ether-methanol
Colorless liquid

0.8±0.1 g/cm3

316.3±5.0 °C at 760 mmHg

28 °C

165.6±0.0 °C

0.0±0.3 mmHg at 25°C

1.438

10.32

0

0

15

18

112

0

C([H])([H])(C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H]

RZJRJXONCZWCBN-UHFFFAOYSA-N

InChI=1S/C18H38/c1-3-5-7-9-11-13-15-17-18-16-14-12-10-8-6-4-2/h3-18H2,1-2H3

octadecane

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)

Ethanol : ~25 mg/mL (~98.24 mM)
DMSO : ~5 mg/mL (~19.65 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (9.82 mM) (saturation unknown) in 10% EtOH + 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 EtOH 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 (9.82 mM) (saturation unknown) in 10% EtOH + 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 EtOH 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 (9.82 mM) (saturation unknown) in 10% EtOH + 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 EtOH stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 4: ≥ 0.5 mg/mL (1.96 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 5.0 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 5: ≥ 0.5 mg/mL (1.96 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 5.0 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 6: ≥ 0.5 mg/mL (1.96 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 5.0 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.)