12-Hydroxystearic acid does not have a specific molecular target but functions as a structural lipid and industrial chemical. As a hydroxy fatty acid, it can be incorporated into various formulations to modify their physical properties. Its hydroxyl group allows for hydrogen bonding, which contributes to its ability to form gels and improve the rheological properties of formulations. The compound's amphiphilic nature, with a hydrophilic hydroxyl group and a hydrophobic hydrocarbon chain, makes it useful as a surfactant and emulsifier in cosmetics and industrial applications.

The efficiency of 12-Hydroxystearic acid (12HSA) and its derivatives as gelling agents and their use as lubricants have been the subject of substantial research [1].

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In vitro, 12-hydroxystearic acid is used in formulation studies for cosmetics, wax blends, greases, polishes, inks, and hot melt adhesives. It is also used as a lubricant for natural and synthetic rubbers. Its ability to form gels and modify rheological properties makes it valuable in formulation science. The compound's physical properties, including its melting point (75-80°C) and solubility in organic solvents, are characterized for quality control. Its in vitro activity is primarily related to its role as an industrial chemical rather than a pharmacologically active compound.

In vivo, 12-hydroxystearic acid is not used as a therapeutic agent. It is used in cosmetics and personal care products applied topically to the skin. When applied topically, it acts as a lubricant and emollient, improving the texture and feel of formulations. The compound is generally well-tolerated on the skin and does not cause significant irritation at typical use concentrations. As a fatty acid, it may be absorbed through the skin to a limited extent and incorporated into lipid metabolism pathways. The compound is for industrial and cosmetic use and is not approved for human therapeutic use.

The in vitro assays for 12-hydroxystearic acid typically involve characterization of its physical and chemical properties. The compound's melting point is determined by differential scanning calorimetry (DSC) or capillary tube method. Purity is assessed by GC or HPLC. Solubility is determined in various solvents. For formulation studies, the compound is incorporated into wax blends, greases, or cosmetic formulations, and the rheological properties are assessed using viscometry or rheometry. Emulsion stability is assessed by measuring droplet size distribution and visual observation over time. All experiments include appropriate controls (reference standards, known formulations) and are performed in triplicate.

For in vitro cellular assays, 12-hydroxystearic acid is not typically used, as it is primarily an industrial chemical rather than a pharmacologically active compound. If used in cell culture, keratinocytes or fibroblasts may be treated with the compound at concentrations ranging from 1 to 100 µM for 24-72 hours. Cell viability is assessed using MTT or CellTiter-Glo assays to evaluate potential cytotoxicity. Inflammatory markers (IL-1α, IL-6, TNF-α) may be measured by ELISA. For formulation studies, the compound is incorporated into emulsion formulations, and stability and performance are evaluated. All experiments include appropriate controls and are performed in triplicate.

For in vivo dermal safety studies, 12-hydroxystearic acid is typically tested in skin irritation and sensitization models. The compound is applied topically to the skin of rabbits or guinea pigs at concentrations typical of cosmetic formulations (typically 1-10%) for 24-48 hours. Skin irritation is assessed by visual scoring of erythema and edema. In repeat-dose studies, the compound is applied daily for 28 days, and skin condition is monitored. For absorption studies, radiolabeled 12-hydroxystearic acid may be applied to skin, and systemic absorption is measured by analyzing blood and urine samples. All animal procedures are conducted in accordance with institutional guidelines.

Absorption, Distribution and Excretion
This study assessed the distribution and metabolism of 12-hydroxystearic acid (12-hydroxystearic acid) in 90 young male albino rats (Wistar strain, Slonaker substrain; weighing 43–83 g). The rats were divided into six groups and fed three different diets for 16 weeks: 20% corn oil (control group); 1% hydrogenated castor oil and 19% corn oil; and 10% hydrogenated castor oil and 10% corn oil. Each diet contained 80% laboratory-standard feed. The fatty acid composition of the hydrogenated castor oil added to the diet was: 86.5% 12-hydroxystearic acid, 10.3% non-oxidized fatty acids, and 3.2% 12-ketostearic acid. Therefore, the actual dietary concentrations of 12-hydroxystearic acid ingested by the experimental animals were 0.87% (1% hydrogenated castor oil diet) and 8.7% (10% hydrogenated castor oil diet). Eight weeks after the start of feeding, half of the experimental groups were fed a corn oil diet for the remaining 16 weeks of the study. Lipids were extracted from adipose tissue samples and carcasses (n=3 rats per group) at weeks 8, 12, and 16. The number of surviving rats in each experimental diet at weeks 4, 8, 12, and 16 were 33, 30, 12, and 6, respectively. The number of surviving rats in the control group at weeks 4, 8, 12, and 16 were 15, 15, 12, and 6, respectively. 12-hydroxystearic acid and its metabolites (hydroxypalmitic acid, hydroxymyristic acid, and hydroxylauric acid) were deposited in abdominal fat and other body fat. The percentage composition of hydrogenated castor oil-derived hydroxy fatty acids in rat lipids was: 81% 12-hydroxystearic acid, 17% 10-hydroxypalmitic acid, 1.6% 8-hydroxymyristic acid, and 0.4% 6-hydroxylauric acid. After 4 weeks of feeding a diet containing 8.7% 12-hydroxystearic acid, the highest hydroxy fatty acid content (4.4%) was observed in the abdominal fat of rats. This concentration gradually decreased over the following weeks, falling below 2% at week 16 (roughly the same concentration detected in carcass lipids). Between weeks 8 and 16, the hydroxy fatty acid content (as a percentage of dry carcass body weight) increased in rats fed both diets (containing 0.87% and 8.7% 12-hydroxystearic acid, respectively). At week 8, switching half of the rats' diets to corn oil (control diet) resulted in a rapid decrease in tissue hydroxy fatty acid content. When 2.2 g/day of 12-hydroxystearic acid was added to the diet of a dog (weight not mentioned), 12-hydroxystearic acid accounted for 46% of total fecal fatty acids. When the amount added to the diet was increased to 8.8 g/day, 12-hydroxystearic acid accounted for 60.2% of total fecal fatty acids.
No steatorrhea occurred in normal dogs after being fed 12-hydroxystearic acid, and the absorption rate was similar to that of unsubstituted stearic acid.

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Metabolism/Metabolites
10-hydroxypalmitic acid and 8-hydroxymyristic acid were identified as metabolites of 12-hydroxystearic acid.

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The pharmacokinetic properties of 12-hydroxystearic acid have not been extensively characterized, as it is primarily used as an industrial chemical and cosmetic ingredient rather than a therapeutic agent. The compound has a molecular weight of 300.48 and is a lipophilic hydroxy fatty acid. When applied topically, it is expected to have limited skin penetration and systemic absorption due to its lipophilic nature. If absorbed, it would enter fatty acid metabolism pathways, undergo β-oxidation, and be incorporated into cellular lipids. The compound is eliminated primarily via CO2 exhalation and renal excretion as metabolites. Detailed PK data are not available.

Interactions
Low molecular weight gelling agents can form soft solids in various organic liquids and vegetable oils. These soft solids are commonly referred to as organic gels. This study investigated organic gels prepared using 12-hydroxystearic acid (12-HSA) as a gelling agent and soybean oil as a matrix, and studied their properties as controlled-release formulations of lipophilic compounds. The release rate of the model lipophilic compound ibuprofen from the organic gel decreased with increasing 12-HSA concentration in the formulation; however, differences in 12-HSA concentration in the formulation did not affect the diffusion coefficient of ibuprofen in the organic gel. This study used simulated gastric and intestinal fluids to investigate the erosion constant of the organic gel in the intestine. The results showed that the organic gel was very stable in simulated gastric fluid regardless of the 12-HSA concentration in the formulation. On the other hand, in simulated intestinal fluid, the erosion constant of the organic gel increased with decreasing 12-HSA concentration. Therefore, it is speculated that the difference in ibuprofen release rate among organic gels at different 12-HSA concentrations is mainly caused by differences in erosion rate. To characterize the in vivo effects of the organic gel, ibuprofen was orally administered to rats in either an aqueous suspension or the organic gel form. The results showed that after oral administration of the aqueous suspension, plasma ibuprofen concentration increased rapidly, while the organic gel inhibited its rapid absorption. In conclusion, the organic gel shows promising application potential as an oral controlled-release formulation of lipophilic compounds.

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The toxicology of 12-hydroxystearic acid has been partially characterized. In topical application studies, the compound is generally well-tolerated and does not cause significant skin irritation at typical use concentrations. In acute oral toxicity studies, the compound shows low toxicity, with LD50 values typically >2,000 mg/kg in rodents. The compound is not genotoxic in standard in vitro assays. In repeat-dose studies, no significant organ toxicity or systemic effects are observed. The compound is not considered a skin sensitizer. Environmental toxicity data indicate low toxicity to aquatic organisms. 12-Hydroxystearic acid is approved for use in cosmetic products and is generally recognized as safe for its intended uses.

[1]. Aggregation of 12-Hydroxystearic Acid and Its Lithium Salt in Hexane: Molecular Dynamics Simulations. J Phys Chem B. 2016;120(29):7164-7173.

12-Hydroxyoctadecanoic acid is a hydroxy fatty acid, a compound of stearic acid with a hydroxyl substituent at the 12-position. It is both a plant metabolite and a bacterial xenobiotic metabolite. It is a hydroxyoctadecanoic acid and a secondary alcohol. It is the conjugate acid of 12-hydroxyoctadecanoate.
12-Hydroxyoctadecanoic acid has been reported in Bacillus cereus and Elaeagnus angustifolia, with relevant data available.
See also: Pentaerythritol tripolyhydroxystearate (monomer); Polyglycerol-2-dipolyhydroxystearate (monomer). Polyhydroxystearic acid (2300 MW) (monomer)...see more...

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Mechanism of Action
In a study on primary and secondary lipid peroxidation products as regulators of DNA synthesis, we treated mouse Lewis cancer cells with physiological concentrations (50 and 100 μM) of hydroxystearic acid. The test substance was dissolved in 90% ethanol and then added to the culture medium. DNA profiling obtained by flow cytometry analysis of the cell cycle revealed that cell accumulation in the G2-M phase was time- and dose-dependent compared to untreated exponential growth phase cells. To determine whether this effect was mediated by the interaction of hydroxystearic acid with the cyclin-dependent kinase-cyclin complex, we measured histone H1 kinase activity in crude C108 cell extracts. We found that hydroxystearic acid inhibited histone H1 kinase activity by up to 95% in mitotic cells (synchronous control C108 cells). 12-Hydroxystearic acid (30 μM) also induced mitochondrial ATPase activity. Lutamycin (which blocks ATP phosphorylation) inhibited ATPase activity; this inhibition is expected for ATP-powered mitochondrial responses. 30 pM 12-hydroxystearic acid induced a small but significant change in mitochondrial volume (swelling) without ATP assistance. Respiratory inhibitors antimycin or dinitrophenol inhibited this swelling, while rutamycin did not; therefore, this swelling is dependent on oxidative phosphorylation. Adding ATP to the reaction mixture enhanced 12-hydroxystearic acid-induced mitochondrial swelling. Researchers concluded that 12-hydroxystearic acid interferes with the oxidative phosphorylation mechanism in rat liver mitochondria.

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Therapeutic Uses
/Experimental Therapy/ Low molecular weight gelling agents can form soft solids in a variety of organic liquids and vegetable oils. These soft solids are commonly referred to as organic gels. …This study investigated organic gels prepared using 12-hydroxystearic acid (12-HSA) as a gelling agent and soybean oil as a solvent, and studied their properties as controlled-release formulations of lipophilic compounds. …Organic gels can clearly be used as oral controlled-release formulations of lipophilic compounds.

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12-Hydroxystearic acid is a saturated hydroxy fatty acid used in cosmetics, wax blends, greases, polishes, inks, and adhesives. It has a molecular formula of C18H36O3 and a molecular weight of 300.48. The compound is not approved as a therapeutic agent but is widely used in cosmetic and industrial applications. Its hydroxy fatty acid structure makes it valuable for modifying the physical properties of formulations.

C18H36O3

300.47664

300.266

106-14-9

12-Hydroxystearic acid-d5;2468637-39-8

7789

White to off-white solid powder

0.9±0.1 g/cm3

436.3±18.0 °C at 760 mmHg

80-81ºC

231.8±17.7 °C

0.0±2.4 mmHg at 25°C

1.468

6.03

2

3

16

21

229

0

ULQISTXYYBZJSJ-UHFFFAOYSA-N

InChI=1S/C18H36O3/c1-2-3-4-11-14-17(19)15-12-9-7-5-6-8-10-13-16-18(20)21/h17,19H,2-16H2,1H3,(H,20,21)

12-hydroxyoctadecanoic acid

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 (~332.80 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (8.32 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.)