Glucocorticoid receptor [1,2]
Hydrocortisone acetate exerts its effects by binding to the cytosolic glucocorticoid receptor (GR), a member of the nuclear receptor superfamily . Upon binding, the receptor-ligand complex translocates to the cell nucleus, where it binds to glucocorticoid response elements (GREs) in the promoter regions of target genes, leading to increased expression of specific anti-inflammatory proteins. The primary anti-inflammatory mechanism involves the induction of lipocortin-1 (annexin-1), a protein that inhibits cytosolic phospholipase A2 (cPLA2). This inhibition prevents the release of arachidonic acid from cell membrane phospholipids, thereby blocking the biosynthesis of prostaglandins and leukotrienes—both potent inflammatory mediators . Additionally, the expression of cyclooxygenase (both COX-1 and COX-2) is suppressed, further reducing eicosanoid production. At the cellular level, hydrocortisone acetate inhibits edema, fibrin deposition, capillary dilatation, leukocyte migration, neoangiogenesis, fibroblast proliferation, collagen deposition, and scar formation .

In vitro studies have demonstrated that hydrocortisone acetate exhibits concentration-dependent inhibitory effects on various cell types. Using bovine bone marrow progenitor cell cultures, hydrocortisone acetate (10–100 ng/mL) significantly inhibited the proliferation of both erythroid and myeloid progenitor cells (P < 0.05) . This effect is relevant to understanding glucocorticoid-induced alterations in circulating leukocyte counts. In lymphocyte activation studies, hydrocortisone acetate suppressed T-cell blast transformation in mixed lymphocyte culture and inhibited the production of hemagglutinating antibodies in response to sheep erythrocytes . The compound also demonstrates the ability to reduce thymocyte populations, particularly affecting Lyt-2+ (CD8+) cells, with the thymus showing considerable depletion of these cells as early as 48 hours post-exposure . Comparative studies have shown that while hydrocortisone acetate is effective in suppressing immune responses, other glucocorticoid derivatives such as beclomethasone dipropionate or tixocortol pivalate may exhibit different potency and toxicity profiles .

- Effect on embryo development: Hydrocortisone acetate affects the development of mouse embryos. It can cause macroscopic - visible dilatation of the venous marginal blood sinus of the foot plates in mouse embryos. It may also lead to other developmental abnormalities, interfering with normal limb development [1]
- Effect on immunoglobulin metabolism: In normal and low - pathogen mice, Hydrocortisone acetate reduces the serum concentration of all sub - classes of IgG (γ2a, γ2b, and γ1), as well as IgA and IgM. Turnover studies using 131I - labeled γ2a subclass of IgG show that high - dose corticosteroids cause a significantly shortened survival (increased catabolic rate) of IgG, contributing to hypogammaglobulinemia. The increase in fractional catabolism is due to an increase in endogenous catabolism, not excess loss in the urine or stool [2]

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In vivo studies have confirmed the potent anti-inflammatory and immunosuppressive activities of hydrocortisone acetate across multiple animal models. In murine models, a single intraperitoneal dose of 100 mg/kg hydrocortisone acetate resulted in significant thymic involution, with depletion of Lyt-2+ thymocytes observed as early as 48 hours post-administration. The thymus began regenerating thereafter, with CTL-P (cytolytic T lymphocyte precursor) frequencies returning to normal levels by day 28 . In subcutaneous cage implant studies, hydrocortisone acetate released from poly(dl-lactide) films over 21 days markedly reduced leukocyte accumulation at the inflammation site and significantly decreased fibrous capsule formation, providing direct evidence of its potent local anti-inflammatory and anti-fibrotic effects . In mouse immunization studies, hydrocortisone acetate administered at sufficient doses produced immunosuppressive effects, though it was also associated with toxicity at the highest dose levels tested . In neonatal rat studies, hydrocortisone acetate treatment diminished subsequent catecholamine-induced increases in pineal serotonin N-acetyltransferase (NAT) activity, with a minimal effective dose of 200 μg per rat .

The primary non-cellular method for characterizing hydrocortisone acetate's receptor interaction is the glucocorticoid receptor competitive binding assay. In this cell-free procedure, cytosolic glucocorticoid receptors are typically isolated from target tissues such as rat liver or thymus through homogenization and ultracentrifugation. The receptor preparation is then incubated with a radiolabeled high-affinity glucocorticoid ligand, most commonly [³H]dexamethasone or [³H]hydrocortisone, in the presence of varying concentrations of unlabeled hydrocortisone acetate . Incubation is carried out at 4°C for 12–24 hours to achieve equilibrium while minimizing ligand degradation. Separation of bound radioligand from free ligand can be achieved using several validated methods: hydroxylapatite adsorption, dextran-coated charcoal (DCC) absorption, or rapid vacuum filtration through glass fiber filters (e.g., GF/B filters) . The bound radioactivity retained is quantified by liquid scintillation counting. The ability of hydrocortisone acetate to displace the radiolabeled ligand is directly proportional to the reduction in radioactive signal, allowing calculation of the half-maximal inhibitory concentration (IC50) and inhibition constant (Ki) using standard curve-fitting software and the Cheng-Prusoff equation.

A validated in vitro cell-based assay for evaluating hydrocortisone acetate's biological activity utilizes primary bone marrow progenitor cell cultures in methylcellulose-based semi-solid media . In this protocol, bone marrow cells are harvested from the femurs of donor animals (typically cows or rodents) and suspended in methylcellulose culture medium supplemented with appropriate growth factors: for myeloid progenitor assessment, concanavalin A-stimulated leukocyte conditioned medium (LCM) is used as a source of colony-stimulating factors; for erythroid progenitor assessment, erythropoietin (2 U/mL) combined with hemin (0.1 mM) is added. Hydrocortisone acetate is added to the cultures at varying concentrations (typically 10–100 ng/mL). The cell mixtures are plated in 35-mm culture dishes and incubated at 37°C in a humidified atmosphere of 5% CO₂ and 95% air. Myeloid colonies (CFU-GM) are scored on day 7, while erythroid colonies (BFU-E, burst-forming units-erythroid) are scored on day 5 using an inverted microscope. Cytotoxicity is assessed by reduced colony counts compared to vehicle-treated controls, and results are expressed as percent inhibition relative to control cultures. For lymphocyte activation studies, mixed lymphocyte cultures or mitogen-stimulated peripheral blood mononuclear cells can be used to assess suppression of T-cell blast transformation .

- Embryo development experiment: Pregnant mice were injected with Hydrocortisone acetate at a certain dose during pregnancy. The specific injection dose and frequency are not mentioned in the literature. After a certain period, the embryos were isolated, and the morphological changes of the embryos were observed, especially the development of the foot plates, to assess the impact of Hydrocortisone acetate on embryo development [1]
- Immunoglobulin metabolism experiment: Normal and low - pathogen mice were given Hydrocortisone acetate, and the administration route, dose, and frequency are not mentioned in the literature. Blood samples were taken at different time points, and the serum concentrations of IgG sub - classes, IgA, and IgM were measured. 131I - labeled γ2a subclass of IgG was used for turnover studies, and the catabolic rate of IgG was calculated by detecting the radioactivity in the blood [2]
- Additional Info - Hydrocortisone acetate is a corticosteroid drug. Its mechanism of action may be related to binding to the glucocorticoid receptor, regulating gene expression, and then affecting various physiological processes. It has a cell - stabilizing effect, which can stabilize lipoprotein membranes and prevent lysosomes from releasing hydrolytic enzymes. However, in some cases, it may also delay the repair of cellular injury, possibly due to the stimulation of the synthesis of enzymes deaminating amino acids [1]

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A classic in vivo model for studying hydrocortisone acetate's immunosuppressive effects utilizes the murine thymocyte depletion assay . In this protocol, female C57BL/6 mice aged 6–12 weeks receive a single intraperitoneal injection of hydrocortisone acetate at a dose of 100 mg/kg body weight, suspended in sterile saline or a suitable vehicle (e.g., 0.5% carboxymethylcellulose). Control animals receive vehicle alone. At various time points post-injection (2, 4, 6, 8, 14, and 28 days), mice are euthanized, and their thymuses are surgically removed. Thymocytes are harvested by gently pressing the thymus through a stainless steel mesh into cold phosphate-buffered saline. Total thymocyte counts are determined using a hemocytometer. For phenotypic analysis, cells are stained with monoclonal antibodies against Thy-1.2 (pan-T cell marker), Lyt-2 (CD8), or L3T4 (CD4) and analyzed by flow cytometry (fluorescence-activated cell sorting). Functional assessment of cytolytic T lymphocyte precursors (CTL-P) is performed by limiting dilution analysis in mixed leukocyte microcultures. An alternative in vivo model is the subcutaneous cage implant system, where steroid-eluting polymer films are implanted subcutaneously in rats, and inflammatory responses (leukocyte accumulation, fibrous capsule formation) are assessed over 7–21 days .

Absorption, Distribution and Excretion
Topical corticosteroids are absorbed through normal, intact skin. Skin inflammation and/or other conditions can increase percutaneous absorption. Corticosteroids are primarily metabolized in the liver and then excreted via the kidneys. Some topical corticosteroids and their metabolites are also excreted via bile. Metabolism/Metabolites Primarily metabolized in the liver via CYP3A4. Biological Half-Life 6-8 hours

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The pharmacokinetic properties of hydrocortisone acetate are highly dependent on the route of administration. For topical application, the extent of percutaneous absorption is determined by multiple factors including the vehicle formulation, the integrity of the epidermal barrier, the presence of skin inflammation, and the use of occlusive dressings . Inflammation and skin disease significantly increase percutaneous absorption, and occlusive dressings substantially enhance drug penetration. For rectal administration (e.g., as a foam for distal colitis), extensive pharmacokinetic studies have been conducted: the absolute rectal bioavailability is approximately 3.1% in healthy volunteers and 4.5% in patients with inflammatory bowel disease, indicating that only a very small fraction of the administered dose reaches systemic circulation . Maximum hydrocortisone concentrations (Cmax) were 610 ± 334 nmol/L in healthy subjects and 277 ± 215 nmol/L in patients (P = 0.03), with time to peak concentration (Tmax) of approximately 2.5–2.8 hours . Once absorbed, corticosteroids are highly bound to plasma proteins (approximately 90–95%), metabolized primarily in the liver via the cytochrome P450 system (CYP3A4), and then excreted by the kidneys . Some metabolites are also excreted into the bile. The biological half-life of hydrocortisone itself is approximately 1.0–1.5 hours.

Protein Binding
95% 5744 Rat Subcutaneous Injection LD50 250 mg/kg Arzneimittel-Forschung. Drug Research., 27(2102), 1977 [PMID:580008] 5744 Mouse Intraperitoneal Injection LD50 2300 mg/kg Compilation of LD50 Values of New Drugs. 5744 Mouse Subcutaneous Injection LD50 45050 ug/kg National Cancer Institute Screening Program Data Summary, Developmental Therapeutics Program., JAN1986

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The toxicological profile of hydrocortisone acetate is well-characterized through extensive clinical use and preclinical studies. Local (cutaneous) adverse reactions, though infrequent, may include burning, itching, irritation, dryness, folliculitis, hypertrichosis, acneiform eruptions, hypopigmentation, perioral dermatitis, allergic contact dermatitis, skin maceration, secondary infection, skin atrophy, striae, and miliaria . Prolonged or extensive use can lead to systemic toxicity via hypothalamic-pituitary-adrenal (HPA) axis suppression, which may manifest as Cushing's syndrome, hyperglycemia, glucosuria, adrenal insufficiency, and growth retardation in children . Conditions augmenting systemic absorption include application of more potent steroids, use over large surface areas, prolonged use, and the addition of occlusive dressings. Children may absorb proportionally larger amounts due to a higher body surface area-to-body weight ratio, making them more susceptible to systemic toxicity . Recovery of HPA axis function is generally prompt and complete upon drug discontinuation, though infrequently, signs of steroid withdrawal may occur requiring supplemental systemic corticosteroids. In animal studies, high intraperitoneal doses (e.g., >100 mg/kg) have been associated with immunosuppressive effects as well as general toxicity . For rectal administration, systemic bioavailability is very low (3–5%), so the risk of systemic side effects is considered very low .

[1]. The effect of hydrocortisone acetate on the development of mouse embryos. J Embryol Exp Morphol. 1968 Nov;20(3):355-66.
[2]. The effect of hydrocortisone on immunoglobulin metabolism. J Clin Invest. 1970 Sep;49(9):1679-84.

21-Cardiolide acetate is a tertiary α-hydroxy ketone and also a cortisol ester. Hydrocortisone acetate is the synthetic acetate form of hydrocortisone, a corticosteroid with anti-inflammatory and immunosuppressive effects. Hydrocortisone acetate first binds to cytoplasmic glucocorticoid receptors; then, the receptor-ligand complex translocates to the nucleus, where it initiates the transcription of genes encoding anti-inflammatory mediators such as cytokines and lipocortin. Lipocorticoids inhibit phospholipase A2, thereby preventing the release of arachidonic acid from membrane phospholipids and inhibiting the synthesis of prostaglandins and leukotrienes. See also: Hydrocortisone acetate; Promocaine hydrochloride (ingredient); Hydrocortisone acetate; Neomycin sulfate (ingredient); Chloramphenicol; Hydrocortisone acetate (ingredient)... See more...

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Drug Indications
For the relief of inflammatory and pruritus symptoms in corticosteroid-responsive dermatitis.
It is also used to treat endocrine (hormonal) disorders (adrenal insufficiency, Addison's disease). In addition, it is used to treat a variety of immune and allergic diseases, such as arthritis, lupus, severe psoriasis, severe asthma, ulcerative colitis, and Crohn's disease.

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Mechanism of Action
Hydrocortisone binds to cytoplasmic glucocorticoid receptors. After binding to the receptor, the newly formed receptor-ligand complex translocates to the cell nucleus and binds to multiple glucocorticoid response elements (GREs) in the promoter regions of target genes. The DNA-bound receptor then interacts with basic transcription factors, leading to increased expression of specific target genes. The anti-inflammatory effect of glucocorticoids is thought to be related to lipocortin, a phospholipase A2 inhibitory protein that controls the biosynthesis of prostaglandins and leukotrienes by inhibiting arachidonic acid. Specifically, glucocorticoids induce the synthesis of lipocortin-1 (annexin-1), which then binds to the cell membrane, preventing phospholipase A2 from contacting its substrate arachidonic acid. This results in reduced arachidonic acid production. The expression of cyclooxygenases (COX-1 and COX-2) is also inhibited, thereby enhancing this effect. In other words, the two main products of inflammation—prostaglandins and leukotrienes—are suppressed by glucocorticoids. Glucocorticoids can also stimulate lipocortin-1 to escape into the extracellular space. Lipocortictin-1 binds to leukocyte membrane receptors, inhibiting various inflammatory responses, including epithelial cell adhesion, migration, chemotaxis, phagocytosis, respiratory burst, and the release of various inflammatory mediators (lysosomal enzymes, cytokines, tissue plasminogen activator, chemokines, etc.) from neutrophils, macrophages, and mast cells. In addition, glucocorticoids suppress the immune system through mechanisms including decreased lymphatic system function, reduced immunoglobulin and complement concentrations, lymphopenia, and interference with antigen-antibody binding.

C23H32O6

404.4966

404.219

C, 68.29; H, 7.97; O, 23.73

50-03-3

Hydrocortisone 17-butyrate;13609-67-1;Hydrocortisone 17-valerate;57524-89-7;Hydrocortisone hemisuccinate;2203-97-6;Hydrocortisone;50-23-7;Hydrocortisone phosphate;3863-59-0

5744

White to light yellow solid powder

1.3±0.1 g/cm3

576.6±50.0 °C at 760 mmHg

223 °C (dec.)(lit.)

196.2±23.6 °C

0.0±3.6 mmHg at 25°C

1.573

2.51

2

6

4

29

786

7

CC(=O)OCC(=O)[C@]1(CC[C@@H]2[C@@]1(C[C@@H]([C@H]3[C@H]2CCC4=CC(=O)CC[C@]34C)O)C)O

ALEXXDVDDISNDU-JZYPGELDSA-N

InChI=1S/C23H32O6/c1-13(24)29-12-19(27)23(28)9-7-17-16-5-4-14-10-15(25)6-8-21(14,2)20(16)18(26)11-22(17,23)3/h10,16-18,20,26,28H,4-9,11-12H2,1-3H3/t16-,17-,18-,20+,21-,22-,23-/m0/s1

[2-[(8S,9S,10R,11S,13S,14S,17R)-11,17-dihydroxy-10,13-dimethyl-3-oxo-2,6,7,8,9,11,12,14,15,16-decahydro-1H-cyclopenta[a]phenanthren-17-yl]-2-oxoethyl] acetate

hydrocortisone acetate; 50-03-3; Cortisol 21-acetate; Hydrocortisone 21-acetate; Cortell; Cortifoam; Cortef acetate; Cortisol acetate;

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: This product requires protection from light (avoid light exposure) during transportation and storage.

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

DMSO : ≥ 38 mg/mL (~93.94 mM)
H2O : ~1 mg/mL (~2.47 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (6.18 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.)