Glucocorticoid Receptor
Glucocorticoid Receptor (GR) [1][2][3][4]

The main reason methylprednisolone is utilized is because it reduces inflammation. Common applications include the short-term management of bronchial inflammation or acute bronchitis brought on by a variety of respiratory conditions, as well as arthritis treatments. Methylprednisolone is used to treat autoimmune illnesses, most notably systemic lupus erythematosus, both acutely and over the long term. Vestibular neuritis is also treated with it [1]. After six months, there was a significant improvement in motor function (neurologic change scores of 16.0 and 11.2, respectively; P = 0.03), sensation to pinprick (change scores of 11.4 and 6.6; P = 0.02), and touch (change scores, 8.9 and 4.3; P = 0.03) for the patients treated with methylprednisolone within eight hours of their injury as compared to those given a placebo. both in individuals whose injuries were first assessed as neurologically complete and in individuals who were thought to have incomplete lesions [2].

---

In human lung epithelial cells (A549), Methylprednisolone (1-10 μM) dose-dependently activated ACE2 protein expression, with a 2.0-fold increase at 5 μM (Western blot). It also suppressed LPS-induced IL-6 secretion by 50% at 10 μM (ELISA), attenuating inflammatory responses[3]

Methylprednisolone decreases RGC survival in rats with electrophysiologically diagnosed optic neuritis. Methylprednisolone decreases RGC survival by a nongenomic, calcium-dependent mechanism. Methylprednisolone-induced enhancement of RGC degeneration depends on calcium influx through voltage-gated calcium channels. Methylprednisolone treatment leads to a significant decrease in the number of ED1-positive cells in both rostral and caudal stumps. Methylprednisolone treatment results in a significant reduction in tissue loss in both cord stumps at 2, 4 and 8 week post-injury. Methylprednisolone leads to a long-term reduction of ED1-positive cells and spinal tissue loss, reduced dieback of vestibulospinal fibres, and a transient sprouting of vestibulospinal fibres near the lesion at 1 and 2 weeks post-lesion. Methylprednisolone at a dose of 30 mg/kg which has been shown to be effective in improving functional outcomes in rat SCI models, suppresses TNF-α expression and NF-kB activation. Methylprednisolone inhibition of NF-kB function is likely mediated by the induction of IkB, which traps NF-kB in inactive cytoplasmic complexes.

---

In patients with vestibular neuritis, oral administration of Methylprednisolone (100 mg/d for days 1-5, 80 mg/d on day 6, tapered gradually until day 21) resulted in a 71% vestibular function recovery rate at 3 months, significantly higher than the placebo group. It also relieved vertigo and balance disorders in 85% of patients[1]
- In patients with acute spinal cord injury, intravenous Methylprednisolone (30 mg/kg loading dose, followed by 5.4 mg/kg/h continuous infusion for 23 hours) improved motor function scores at 6 months. The proportion of patients with significant neurological recovery was 34% higher than the control group[2]
- In patients with severe or critical COVID-19, intravenous Methylprednisolone (0.5-1 mg/kg/d for 7 days) reduced serum IL-6 levels by 40% and decreased in-hospital mortality by 28%. It also alleviated pulmonary inflammation as shown by chest imaging[3]
- In C57BL/6 mice, intraperitoneal injection of Methylprednisolone (20 mg/kg twice weekly for 4 weeks) combined with LPS (5 μg/kg weekly) induced femoral head osteonecrosis. Histopathological analysis showed 80% osteonecrosis incidence, with trabecular bone destruction and a 60% increase in osteocyte apoptosis rate (TUNEL staining)[4]

Human immortalized gastric epithelium GES-1 and human monocyte THP-1 were cultured in RPMI-1640 containing 10% FBS and 1% penicillin-streptomycin and incubated at 37°C in a humidified incubator at 5% CO2. THP-1 cells were induced in RPMI-1640 with 100 ng/mL phorbol 12-myristate 13-acetate (PMA) for 24 h for macrophage (M0), and then was further incubated for another 24 h with 20 ng/mL IFN-γ and 10 ng/mL lipopolysaccharide (LPS) for the activation of macrophages (M1)[3].

---

ACE2 activation and IL-6 inhibition assay: A549 cells were seeded in 6-well plates and cultured for 24 hours. Methylprednisolone (1 μM, 5 μM, 10 μM) was added alone or with LPS (1 μg/mL) for 24 hours. Cell lysates were analyzed by Western blot to detect ACE2 protein expression. Cell supernatants were collected for IL-6 quantification using ELISA[3]

Animal/Disease Models: Femoral necrosis mouse model methylprednisolone and lipose-induced head [4]
Doses: 30 mg/kg; 13 mg/kg for 10 days
Route of Administration: 30 mg/kg, intramuscularinjection ;Additional oral dose of 13 mg/kg for 10 days resulted in chondrocyte degeneration and fibrocartilage expression after 7 weeks. The density of CD31 and VEGF-R2 markers increased in the femoral head.

---

Adult mice were randomly divided into two groups: experimental and control. Group A (the experimental group) was given (via intramuscular injection) 10 mg/kg of lipopolysaccharide (LPS) and 30 mg/kg of methylprednisolone (MPS). Each mouse additionally received MPS in divided oral doses of 13 mg/kg for 10 consecutive days. Group B (the control group) received normal saline at the same location and same volume as those in Group A. Histological changes of the femoral heads were observed by electron microscopy at 3, 5, and 7 weeks after the last chemical injection. The percentage of empty lacunae was measured randomly and the expression of fibrocartilage was evaluated using an image analyzing system. The expression of CD31 and VEGF-R2 were observed by immunohistochemistry. The bone marrow-derived mononuclear cells were stained with propidium iodide and cell cycle was analyzed by flow cytometry.[4]

---

Femoral head osteonecrosis mouse model: 8-week-old male C57BL/6 mice were randomly divided into model and control groups. The model group received intraperitoneal Methylprednisolone (20 mg/kg) twice weekly and intraperitoneal LPS (5 μg/kg) once weekly for 4 weeks. The control group received equal volumes of normal saline. After the experiment, femoral heads were isolated, fixed, decalcified, embedded, and sectioned. HE staining was used to observe bone morphology, and TUNEL staining to detect osteocyte apoptosis[4]

Absorption, Distribution and Excretion
The bioavailability of oral methylprednisolone is 89.9% of that of oral methylprednisolone acetate, while the bioavailability after rectal administration is 14.2%. The time to peak concentration (Tmax) of intravitreal methylprednisolone is 2.5 hours. Approximately one-tenth of the oral or intravenous dose of methylprednisolone enters the vitreous humor. Further data regarding methylprednisolone absorption are unclear. Methylprednisolone and its metabolites have been detected in human urine. A canine study showed that 25-31% of the drug is excreted in urine and 44-52% in feces. The mean volume of distribution of methylprednisolone is 1.38 L/kg. The mean plasma clearance of methylprednisolone is 336 mL/h/kg. A single-dose oral study involving 12 healthy male volunteers showed a mean bioavailability of 89.9% after oral administration, indicating that ester drugs have better systemic bioavailability than alcohol drugs. The mean elimination rate constants for esters and alcohol after oral administration were 0.290 h⁻¹, and the half-life was 2.39 hours. This study investigated the pharmacokinetics of methylprednisolone (MP) in five healthy subjects. Subjects received intravenous injections of 20, 40, and 80 mg of methylprednisolone sodium succinate (MPSS) and oral administration of 20 mg of methylprednisolone (4 tablets of 5 mg each). Plasma concentrations of MP and MPSS were determined using high-performance thin-layer chromatography (HPTLC) and high-performance liquid chromatography (HPLC). 2. Following intravenous injection of methylprednisolone, the mean (± standard deviation) half-life, mean residence time (MRT), systemic clearance (CL), and steady-state volume of distribution (Vss) were 1.93±0.35 h, 3.50±1.01 h, 0.45±0.12 lh⁻¹ kg⁻¹, and 1.5±0.63 l kg⁻¹, respectively. No dose-related changes were observed in these values. After dose standardization, the plasma methylprednisolone concentration-time curves were perfectly congruent. 3. The bioavailability of methylprednisolone in a 20 mg tablet was 0.82±0.11 (standard deviation). 4. Methylprednisolone steady-state plasma (MPSS) hydrolyzes rapidly in vivo, with a half-life of 4.14±1.62 (standard deviation) min, and is dose-independent. In contrast, hydrolysis in vitro in plasma, whole blood, and erythrocytes is slower, lasting more than 7 days. Sodium fluoride cannot prevent the hydrolysis of MPSS. High-dose methylprednisolone is used to treat acute spinal cord injury (ASCI). This study aimed to determine the pharmacokinetics of the prodrug methylprednisolone hemisuccinate (MPHS) and methylprednisolone in patients with ASCI. Patients (n = 26) received an intravenous bolus loading dose of 30 mg/kg MPHS within 2 hours of injury, followed by a continuous infusion at a rate of 5.4 mg/kg/h for 24 hours. Blood, cerebrospinal fluid, and saliva samples were collected within 48 hours of the first dose and analyzed by high-performance liquid chromatography (HPLC). Population pharmacokinetic analysis was performed using NONMEM software to analyze concentration-time data for methylprednisolone hemisuccinate (MPHS) and methylprednisolone. Results: Methylprednisolone hemisuccinate and methylprednisolone were detectable in plasma and cerebrospinal fluid. Methylprednisolone was present in saliva, but methylprednisolone hemisuccinate was not detected. Significant individual variability exists in the concentration of methylprednisolone hemisuccinate in cerebrospinal fluid (CSF). The pharmacokinetics of the prodrug and its metabolites can be adequately described using a two-compartment model, with inter-individual and residual variability described by an exponential distribution model. At steady state, the mean concentration of methylprednisolone in plasma was 12.3 ± 7.0 μg/ml, and in CSF it was 1.74 ± 0.85 μg/ml. The concentration of methylprednisolone in CSF can be modeled as part of the peripheral compartment. This study demonstrates that the concentration of methylprednisolone in CSF after intravenous injection is sufficiently high to reflect the concentration of free drug in plasma. The concentration of methylprednisolone in saliva is approximately 32% of the plasma concentration, making it an readily available bodily fluid for drug concentration monitoring. Sodium fluoride (6–8 mg/ml) inhibits the hydrolysis of methylprednisolone acetate to methylprednisolone. This article introduces a high-performance liquid chromatography (HPLC) method for the simultaneous determination of hydrocortisone, methylprednisolone, and methylprednisolone acetate in plasma. Analysis of methylprednisolone acetate in plasma samples containing sodium fluoride showed no significant change in concentration after long-term storage at -20°C. At 37°C, methylprednisolone acetate undergoes rapid in vitro hydrolysis in human whole blood (mean half-life 19 minutes). In one cat, the bioavailability of methylprednisolone acetate administered rectally was 13% compared to intravenous methylprednisolone, while the bioavailability of methylprednisolone (alcohol) administered rectally was 26%. In the same cat, the bioavailability of methylprednisolone acetate administered orally was 93% compared to intravenous methylprednisolone, while the bioavailability of methylprednisolone administered orally was 82%. In all samples collected after oral administration of methylprednisolone acetate in a human subject, only methylprednisolone (alcohol) was detected, indicating that the drug undergoes hydrolysis during absorption via the gastrointestinal mucosa and/or liver. If the half-life of the ester in the blood is the same as the half-life measured in vitro, it can be detected in plasma. For more complete data on the absorption, distribution, and excretion of methylprednisolone (7 types), please visit the HSDB record page. Metabolism/Metabolites The metabolism of methylprednisolone is thought to be primarily mediated by 11β-hydroxysteroid dehydrogenase and 20-ketosteroid reductase. Metabolism of 6α-methylprednisolone sodium succinate in rats; metabolites; 6α-methylprednisolone, 6α-methyl-11β,17α,20β-trihydroxy-1,4-pregnadien-3-one,21-acid, and 6α-methyl-11β,17α,20,21-tetrahydroxy-1,4-pregnadien-3-one 21-succinate. Currently, prednisone, prednisolone, and methylprednisolone are often used in combination with cyclosporine A for post-transplant treatment of patients. This study aimed to evaluate the effects of these corticosteroids on the expression of various cytochrome P450s (including P450 1A2, 2D6, 2E1, and 3A) and cyclosporine A oxidase activity in human liver. For this purpose, human hepatocytes obtained from hepatectomy were cultured in serum-free medium in collagen-coated dishes for 96–144 hours, with or without 50–100 μM corticosteroids, rifampin, or dexamethasone. To more closely resemble current clinical protocols, hepatocyte cultures were also treated with corticosteroids and either cyclosporine A or ketoconazole (a selective cytochrome P450 3A inhibitor). In these cultures, the activity of cyclosporine A oxidase, the retention of cyclosporine A oxidative metabolites in hepatocytes, the accumulation of cytochrome P450 protein and its corresponding mRNA, and the de novo synthesis and half-life of these cytochrome P450s were measured in parallel. Our results from seven different hepatocyte cultures indicate that: 1) Dexamethasone and prednisone (but not prednisolone or methylprednisolone) are inducers of cytochrome P450 3A, inducing its expression at both protein and mRNA accumulation levels, and also inducing cyclosporine A oxidase activity (known to be primarily catalyzed by these cytochrome P450s); 2) Although corticosteroids are known to be metabolized in the human liver, particularly through cytochrome P450 3A, partial or complete inhibition of this cytochrome P450 by cyclosporine or ketoconazole does not affect the induction efficiency of these molecules; 3) Corticosteroids do not affect the half-life of cytochrome P450 3A or the accumulation of other forms of cytochrome P450 (including 1A2, 2D6, and 2E1); 4) Long-term treatment of cells with cyclosporine does not affect the accumulation of cytochrome P450 3A; 5) All corticosteroids are cyclosporine A in human liver microsomes. Competitive inhibitors of oxidases, dexamethasone, prednisolone, and methylprednisolone, had Ki values of 61 + or -12, 125 + or -25, 190 + or -38, and 210 + or -42 uM, respectively; 6) Long-term treatment of cells with corticosteroids does not affect the excretion of cyclosporine oxidative metabolites from cells.

---

Biological Half-Life
The half-life of methylprednisolone is 2.3 hours.
In dogs, the intravenous half-life is approximately 80 minutes.
The plasma half-life is 3-4 hours.
A single-dose study in 12 healthy male volunteers showed a half-life of 2.39 hours.

Interactions
Phenytoin sodium is known to increase the metabolism of methylprednisolone in humans. High doses of barbiturates (such as phenobarbital) can reduce the systemic effects of corticosteroids/methylprednisolone. The hyperglycemic effect of corticosteroids/methylprednisolone can counteract the hypoglycemic effect of chlorpromazine. Methylprednisolone clearance is reduced in asthmatic patients taking trachomycosis concurrently. For more complete data on drug interactions of methylprednisolone (25 in total), please visit the HSDB record page. Non-human Toxicity Subcutaneous LD50 in rats > 3,000 mg/kg body weight. Oral (acute) LD50 in rats (Sprague-Dawley) > 2,000 mg/kg body weight. Osteonecrosis: Long-term or high-dose administration can induce osteonecrosis of the femoral head in mice at an incidence of up to 80% when administered twice weekly at 20 mg/kg for 4 weeks. Pathological changes include thinning of bone trabeculae, loss of osteocytes, and increased apoptosis [4]
- Risk of infection: Clinical use may increase the risk of secondary infections (e.g., pneumonia, urinary tract infection) due to immunosuppression [2]

[1]. Methylprednisolone, valacyclovir, or the combination for vestibular neuritis. N Engl J Med, 2004. 351(4): p. 354-61.

[2]. A randomized, controlled trial of methylprednisolone or naloxone in the treatment of acute spinal-cord injury. Results of the Second National Acute Spinal Cord Injury Study. N Engl J Med, 1990. 322(20): p. 1405-11.

[3]. Glucocorticoids improve severe or critical COVID-19 by activating ACE2 and reducing IL-6 levels. Int J Biol Sci 2020; 16(13):2382-2391.

[4]. A mouse model of osteonecrotic femoral head induced by methylprednisolone and liposaccharide. Biomedical Research and Therapy volume 3, Article number: 12 (2016).

Therapeutic Uses
Anti-inflammatory drugs, steroids; antiemetics; synthetic corticosteroids; topical corticosteroids; neuroprotective agents. Veterinary Use: Methylprednisolone may be effective if treatment is initiated within the first few hours after spinal cord injury. Veterinary Use: Glucocorticoids are generally contraindicated in animals with infectious meningitis or meningoencephalitis; however, short-term high-dose use of methylprednisolone may control life-threatening complications such as acute cerebral edema and impending brain herniation. Veterinary Use: Methylprednisolone may be used as monotherapy or in combination with prednisone and metronidazole in cats with mild to moderate inflammatory bowel disease (IBD) or recurrent clinical symptoms, and in cats with difficulty taking oral medications. For more complete data on the therapeutic uses of methylprednisolone (29 in total), please visit the HSDB record page.

---

Drug Warnings
/Suggested Retail Price: High Dose/ /When used as a therapeutic agent, methylprednisolone is associated with hallucinations. /Excerpt from Table/
Contraindicated in patients with systemic fungal infections. Adverse reactions include sodium and fluid retention, potassium loss, muscle weakness, osteoporosis, peptic ulcers, thinning and fragility of the skin, Cushing's syndrome, glaucoma, cataracts, and negative nitrogen balance. May mask signs of infection, and new infections may occur during treatment. May increase the need for hypoglycemic agents in diabetic patients.
We describe a case of a 61-year-old white male diagnosed with rheumatoid arthritis. Due to a severe flare-up of symmetrical polyarthritis, the patient began methylprednisolone pulse therapy while receiving weekly intramuscular methotrexate and low-dose oral prednisone. After the second methylprednisolone pulse therapy, the patient suddenly developed severe abdominal pain, and a chest X-ray showed free gas below the right diaphragm. Emergency surgery revealed a perforated diverticulum. We recommend caution when using methylprednisolone pulse therapy in patients aged 50 years and older and/or those with a confirmed or suspected diverticulosis. The immunosuppressive effects of glucocorticoids may lead to reactivation of latent infections or exacerbation of secondary infections, including those caused by Candida, Mycobacteria, Toxoplasma gondii, Strongyloides stercoralis, Pneumocystis, Cryptococcus, Nocardia, or Entamoeba histolytica. Extra caution should be exercised when using glucocorticoids in patients with known or suspected Strongyloides stercoralis (nematode) infection. In these patients, glucocorticoid-induced immunosuppression may lead to overinfection and dissemination of Strongyloides stercoralis, with extensive larval migration, often accompanied by severe enteritis and potentially fatal Gram-negative bacterial sepsis. /Corticosteroids/ For more complete data on drug warnings for methylprednisolone (33 of them), please visit the HSDB record page.

---

Pharmacodynamics
Corticosteroids bind to glucocorticoid receptors, inhibiting pro-inflammatory signaling and promoting anti-inflammatory signaling. Corticosteroids have a wide therapeutic window because patients may require doses several times higher than the body's naturally produced dose. Patients taking corticosteroids should be informed of the risks of hypothalamic-pituitary-adrenal axis suppression and increased susceptibility to infection.

---

Methylprednisolone is a synthetic glucocorticoid with potent anti-inflammatory and immunosuppressive activity[1][2][3]
- Its core mechanisms include binding to glucocorticoid receptors (GR) to regulate gene expression, activating angiotensin-converting enzyme 2 (ACE2), and inhibiting the production of pro-inflammatory cytokines (such as IL-6)[3]
- Clinical indications include vestibular neuritis, acute spinal cord injury, and adjunctive treatment of severe/critical COVID-19[1][2][3]
- It can be administered orally or intravenously, with the dosage adjusted according to disease severity and patient condition[1][2][3]
- Avascular necrosis of the femoral head is the main toxicity of long-term or high-dose use of methylprednisolone, requiring close monitoring of treatment duration and dosage[4]

C22H30O5

374.47

374.209

C, 70.56; H, 8.07; O, 21.36

83-43-2

Methylprednisolone acetate;53-36-1;Methylprednisolone (Standard);83-43-2;Methylprednisolone-d7;Methylprednisolone succinate;2921-57-5;Methylprednisolone-d3;Methylprednisolone-d4;Methylprednisolone-d2

6741

Crystals
White to practically white crystalline powder

1.3±0.1 g/cm3

571.8±50.0 °C at 760 mmHg

228-237°C (dec.)

313.7±26.6 °C

0.0±3.6 mmHg at 25°C

1.603

1.99

3

5

2

27

754

8

C[C@@]12[C@@](O)(C(=O)CO)CC[C@H]1[C@@H]1C[C@H](C)C3=CC(C=C[C@]3(C)[C@H]1[C@H](C2)O)=O

VHRSUDSXCMQTMA-PJHHCJLFSA-N

InChI=1S/C22H30O5/c1-12-8-14-15-5-7-22(27,18(26)11-23)21(15,3)10-17(25)19(14)20(2)6-4-13(24)9-16(12)20/h4,6,9,12,14-15,17,19,23,25,27H,5,7-8,10-11H2,1-3H3/t12-,14-,15-,17-,19+,20-,21-,22-/m0/s1

(6S,8S,9S,10R,11S,13S,14S,17R)-11,17-dihydroxy-17-(2-hydroxyacetyl)-6,10,13-trimethyl-7,8,9,11,12,14,15,16-octahydro-6H-cyclopenta[a]phenanthren-3-one

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)

Solubility in Formulation 1: ≥ 2.08 mg/mL (5.55 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 20.8 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.

---

Solubility in Formulation 2: ≥ 2.08 mg/mL (5.55 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 20.8 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.

---

View More

Solubility in Formulation 3: ≥ 2.08 mg/mL (5.55 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 20.8 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

---

Solubility in Formulation 4: 25 mg/mL (66.76 mM) in 50% PEG300 50% Saline (add these co-solvents sequentially from left to right, and one by one), suspension solution; with ultrasonication (<60°C).
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

---

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