Through ester cleavage at the C21 position, the parent molecule ciclesonide is hydrolyzed to the active metabolite desisobutyryl ciclesonide (des-CIC), which subsequently reversibly produces fatty acid esters in lung cells. Normal human bronchial epithelial (NHBE) cells rapidly hydrolyze cleisonide (5 μM) (conversion rate around 30% at 4 hours), with nearly complete conversion at 24 hours [1].

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In human liver subcellular fractions, the conversion of ciclesonide (500 μM) to desisobutyrlyl-ciclesonide was 2.02 ± 0.38 nmol/mg protein/min in microsomes and 0.47 ± 0.07 nmol/mg protein/min in cytosol; at 5 μM, conversion was 1.02 ± 0.07 nmol/mg protein/min in microsomes and 0.25 ± 0.03 nmol/mg protein/min in cytosol.[1]

In human lung subcellular fractions, conversion of ciclesonide (500 μM) was 0.050 ± 0.010 nmol/mg protein/min in microsomes and 0.024 ± 0.005 nmol/mg protein/min in cytosol; at 5 μM, conversion was 0.086 ± 0.030 nmol/mg protein/min in microsomes and 0.008 ± 0.001 nmol/mg protein/min in cytosol.[1]

In normal human bronchial epithelial cells, ciclesonide (5 μM) was rapidly hydrolyzed: approximately 30% conversion to desisobutyrlyl-ciclesonide within 4 hours, and almost complete conversion (96%, reaching 3.60 ± 0.33 μM desisobutyrlyl-ciclesonide in medium) by 24 hours.[1]

Intracellular concentration of desisobutyrlyl-ciclesonide in normal human bronchial epithelial cells was higher than in culture medium at all time points, reaching a maximum of 1317 ± 158 μM at 4 hours, and decreasing to 1006 ± 127 μM by 24 hours.[1]

Inhibition studies in liver microsomes: paraoxon (100 μM) inhibited desisobutyrlyl-ciclesonide formation by 99% (500 μM ciclesonide) and 75% (5 μM ciclesonide); bis(p-nitrophenyl)phosphate inhibited by 75% and 58% respectively; iso-OMPA inhibited by 25% and 82% respectively; eserine inhibited by 63% and 96% respectively; EDTA inhibited by 40% and 48% respectively; p-hydroxymercuribenzoate showed 0% and 35% inhibition respectively.[1]

Inhibition studies in liver cytosol: paraoxon inhibited by 98% (500 μM) and 96% (5 μM); bis(p-nitrophenyl)phosphate by 58% and 95%; iso-OMPA by 22% and 88%; eserine by 64% and 95%; EDTA by 50% and 10%; p-hydroxymercuribenzoate by 0% and 20%.[1]

Inhibition studies in normal human bronchial epithelial cells (10 μM inhibitors, 5 μM ciclesonide): paraoxon inhibited desisobutyrlyl-ciclesonide formation by 84 ± 1%; bis(p-nitrophenyl)phosphate by 79 ± 3%; iso-OMPA by 77 ± 3%; eserine by 72 ± 3%; EDTA by 20 ± 3%; p-hydroxymercuribenzoate by 21 ± 7%.[1]

Kinetic parameters in human liver cytosol: biphasic Michaelis-Menten kinetics with Km1 = 5.4 μM, Vmax1 = 0.43 nmol/mg protein/min; Km2 = 910 μM, Vmax2 = 1.95 nmol/mg protein/min.[1]

Kinetic parameters in human liver microsomes: biphasic Michaelis-Menten kinetics with Km1 = 9.9 μM, Vmax1 = 2.10 nmol/mg protein/min; Km2 = 18.7 μM, Vmax2 = 1.09 nmol/mg protein/min.[1]

No spontaneous (nonenzymatic) conversion of ciclesonide to desisobutyrlyl-ciclesonide was observed at 5 μM ciclesonide; at 500 μM, spontaneous conversion was ≤10% of enzymatic activity.[1]

Ciclesonide hydrolysis assays in liver and lung subcellular fractions: incubations (0.5 mL) contained microsomal protein (liver 0.3 mg, lung 0.5 mg) or cytosolic protein (0.7 mg) in KCl/phosphate buffer (pH 7.4). The reaction was initiated by adding ciclesonide stock in DMSO to final concentrations of 5 μM or 500 μM. Incubations were conducted at 37°C for 5 min (liver) or 40 min (lung), then terminated by adding an equal volume of methanol and cooling on ice. Denatured proteins were removed by centrifugation, and supernatants were analyzed by HPLC for desisobutyrlyl-ciclesonide formation.[1]

Human plasma incubation: 50 μL plasma in 0.5 mL KCl/phosphate buffer (pH 7.4) with ciclesonide (5 μM or 500 μM) at 37°C for 30 min, terminated by adding equal volume of acetonitrile. After centrifugation, 200 μL supernatant was analyzed by HPLC.[1]

Inhibition studies: inhibitors (PMB, eserine, iso-OMPA, BNPP, POX, EDTA) at 100 μM (liver/lung) or 10 μM (NHBE cells) were pre-incubated with subcellular fractions or cells for 10 min before adding ciclesonide. Formation of desisobutyrlyl-ciclesonide was quantified by HPLC and compared to vehicle controls.[1]

Kinetic studies: incubations with seven ciclesonide concentrations ranging from 5 μM to 1000 μM. Michaelis-Menten parameters Vmax and Km were calculated using Eadie-Hofstee plots, and data points were fitted by least squares linear regression.[1]

HPLC analysis: separation using a reverse-phase column with gradient elution (acetonitrile from 80% to 100% over 25 min, then 100% for 10 min, then back to 80%). Detection at 242 nm. Retention times: desisobutyrlyl-ciclesonide 11.3 min, ciclesonide 25.9 min.[1]

Normal human bronchial epithelial cells were seeded into 12-well plates at 150 × 10^3 cells/mL and maintained in bronchial epithelial growth medium for 24 h before assay. Immediately before assay, medium was removed, cell surface washed with HEPES balanced saline solution, and 0.5 mL HBSS added. Ciclesonide in DMSO was added to final concentration of 5 μM to start reaction at 37°C. At 1, 2, 4, and 24 h post-dose, cells and HBSS were separated and placed on ice, and 0.5 mL methanol was added to stop reaction. After sonication and centrifugation, supernatant was analyzed by HPLC for desisobutyrlyl-ciclesonide formation.[1]

Inhibition studies in normal human bronchial epithelial cells: before assay, growth medium was removed, cell surface washed with HBSS, and 0.5 mL HBSS plus inhibitor stock (1 mM in methanol, final concentration 10 μM) added. Parallel controls received methanol only. Cells were pre-incubated with inhibitor or vehicle for 10 min before adding ciclesonide (5 μM). After 2 h, cells and HBSS were transferred to tubes on ice, methanol added, sonicated, centrifuged, and supernatant analyzed by HPLC.[1]

Intracellular concentration of desisobutyrlyl-ciclesonide was calculated based on a total cell volume of 0.63 μL per monolayer.[1]

Absorption, Distribution and Excretion
Due to low gastrointestinal absorption and high first-pass metabolism, the oral bioavailability of both ciroxonide and decicloxonide is extremely low (less than 1%). Serum ciroxonide concentrations are negligible after intranasal administration of ciroxonide at the recommended dose. 152 L/hr [after intravenous injection of 800 mcg ciroxonide]

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Metabolism/Metabolites Decicloxonide is primarily metabolized in the liver by cytochrome P450 (CYP) 3A4 isoenzymes to other metabolites, with a small amount metabolized by CYP 2D6.

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In human liver, hydrolysis of ciclesonide to desisobutyrlyl-ciclesonide showed high capacity: liver microsomes 25.4 nmol/g tissue/min and liver cytosol 62.9 nmol/g tissue/min at 500 μM ciclesonide.[1]

In human peripheral lung, hydrolysis activity was much lower: lung microsomes 0.089 nmol/g tissue/min and lung cytosol 0.915 nmol/g tissue/min at 500 μM ciclesonide.[1]

In human plasma, desisobutyrlyl-ciclesonide formation was very low: 9.7 ± 7.7 pmol/mL plasma/min (only observed at 500 μM ciclesonide).[1]

Ciclesonide is hydrolyzed by esterases to the active metabolite desisobutyrlyl-ciclesonide, which subsequently undergoes rapid oxidation by cytochrome P450 (CYP3A4) in the liver to inactive polar metabolites.[1]

Following ciclesonide inhalation, high metabolic clearance by the liver results in low systemic levels of active desisobutyrlyl-ciclesonide.[1]

In lung cells, desisobutyrlyl-ciclesonide forms highly lipophilic fatty acid conjugates (e.g., oleate) reversibly.[1]

No inactive polar metabolites were detected in lung slices.[1]

Effects During Pregnancy and Lactation
◉ Overview of Use During Lactation
Although measurements were not performed, the amount of inhaled corticosteroids absorbed into the maternal bloodstream and secreted into breast milk is likely too small to affect breastfed infants. Expert opinion is that inhaled, nasal, and oral corticosteroids are safe to use during lactation. ◉ Effects on Breastfed Infants
No effects on breastfed infants have been reported with any of the corticosteroids. ◉ Effects on Lactation and Breast Milk
As of the revision date, no relevant published information was found. Protein Binding
The average binding rates of cyclosporine and decyclosporine to human plasma proteins are ≥99%, and the free drug detected in systemic circulation is ≤1%.

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[1]. The role of esterases in the metabolism of ciclesonide to desisobutyryl-ciclesonide in human tissue. Biochem Pharmacol, 2007. 73(10): p. 1657-64.

Ciclesonide is an organic molecular entity. It is a glucocorticoid used to treat obstructive airway disease. Its brand name is Alvesco. Ciclesonide is a non-halogenated synthetic inhaled glucocorticoid (ICS) with anti-inflammatory and potential antiviral activity. After oral inhalation, Ciclesonide (CIC) is locally converted in the lungs by esterases to its active metabolite, des-ciclossonide (des-CIC), which binds to intracellular glucocorticoid receptors (GRs). The ligand-bound GRs regulate gene expression, thereby inhibiting various cell types, such as mast cells, eosinophils, basophils, lymphocytes, macrophages, and neutrophils, as well as various inflammation-related mediators, such as histamine, arachidic acid, leukotrienes, and cytokines. Furthermore, Ciclesonide may inhibit the replication of human coronaviruses by targeting viral nonstructural protein 15 (NSP15). Drug Indications For the treatment of nasal symptoms associated with seasonal and perennial allergic rhinitis in adults and adolescents aged 12 years and older. For the relief of clinical symptoms of severe equine asthma (formerly known as recurrent airway obstruction (RAO) and summer pasture-associated recurrent airway obstruction (SPA-RAO)). Mechanism of Action Glucocorticoids such as cecsonide inhibit leukocyte infiltration at sites of inflammation, interfere with mediators of the inflammatory response, and suppress humoral immune responses. The anti-inflammatory effects of glucocorticoids are thought to be related to lipocortin, a phospholipase A2 inhibitor that controls the biosynthesis of potent inflammatory mediators such as prostaglandins and leukotrienes. Cecsonide reduces inflammation by limiting capillary dilation and vascular permeability. These compounds limit the aggregation of polymorphonuclear leukocytes and macrophages and reduce the release of vasoactive kinins. Recent studies have shown that corticosteroids may inhibit the release of arachidonic acid from phospholipids, thereby reducing prostaglandin production. Ciclesonide is a glucocorticoid receptor agonist. Upon binding, the cortical 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-binding receptor then interacts with basal transcription factors, leading to an increase or decrease in the expression of specific target genes, including inhibition of IL-2 (interleukin 2) expression.

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Pharmacodynamics
Ciclossonide is a prodrug that, after intranasal administration, is enzymatically hydrolyzed to produce the pharmacologically active metabolite C21-decibutyrylCiclesonide (deciclossonide or RM1). Deciclossonide possesses anti-inflammatory activity and has a 120-fold higher affinity for glucocorticoid receptors than the parent compound. The exact mechanism by which ciclossonide affects allergic rhinitis symptoms is unclear. Corticosteroids have been shown to have a wide range of effects on various cell types, such as mast cells, eosinophils, neutrophils, macrophages, and lymphocytes, as well as on mediators involved in allergic inflammation, such as histamine, arachidic acid, leukotrienes, and cytokines.

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Ciclesonide is a non-halogenated topical inhaled glucocorticosteroid developed for the treatment of asthma. It achieves high concentrations in the lung with low oral bioavailability.[1]

The parent compound undergoes hydrolysis by ester cleavage at the C21 position to the active metabolite desisobutyrlyl-ciclesonide, followed by reversible formation of fatty acid esters within lung cells.[1]

In human liver, ciclesonide is metabolized to desisobutyrlyl-ciclesonide, with further metabolism to several inactive polar metabolites following oxidation by cytochrome P450 3A4.[1]

Inhibition profiles indicate that ciclesonide hydrolysis is mediated primarily by cytosolic and microsomal carboxylesterases (hCE-1 and hCE-2) with some contribution from cholinesterases, and not by A-esterases.[1]

The high levels of conversion in the liver (site of inactivation) and the low levels of carboxylesterase in human plasma contribute to negligible systemic conversion of ciclesonide to desisobutyrlyl-ciclesonide following administration.[1]

High levels of conversion by carboxylesterases in bronchial epithelial cells may contribute significantly to local activation of inhaled ciclesonide in the target organ (lung).[1]

In clinical studies (referenced but not detailed in this paper), ciclesonide significantly inhibits airway hyper-responsiveness and improves pulmonary function in patients with asthma.[1]

C32H44O7

540.6876

540.309

126544-47-6

Desisobutyryl-ciclesonide;161115-59-9;Ciclesonide (Standard);126544-47-6;Ciclesonide-d7;1225382-70-6

6918155

White to off-white solid powder

1.23 g/cm3

665ºC at 760 mmHg

202-209?C

210ºC

1.61E-20mmHg at 25°C

1.575

4.703

1

7

6

39

1100

9

O1[C@]([H])(C2([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C2([H])[H])O[C@]2([H])C([H])([H])[C@@]3([H])[C@]4([H])C([H])([H])C([H])([H])C5=C([H])C(C([H])=C([H])[C@]5(C([H])([H])[H])[C@@]4([H])[C@]([H])(C([H])([H])[C@]3(C([H])([H])[H])[C@]12C(C([H])([H])OC(C([H])(C([H])([H])[H])C([H])([H])[H])=O)=O)O[H])=O

LUKZNWIVRBCLON-GXOBDPJESA-N

InChI=1S/C32H44O7/c1-18(2)28(36)37-17-25(35)32-26(38-29(39-32)19-8-6-5-7-9-19)15-23-22-11-10-20-14-21(33)12-13-30(20,3)27(22)24(34)16-31(23,32)4/h12-14,18-19,22-24,26-27,29,34H,5-11,15-17H2,1-4H3/t22-,23-,24-,26+,27+,29+,30-,31-,32+/m0/s1

[2-[(1S,2S,4R,6R,8S,9S,11S,12S,13R)-6-cyclohexyl-11-hydroxy-9,13-dimethyl-16-oxo-5,7-dioxapentacyclo[10.8.0.02,9.04,8.013,18]icosa-14,17-dien-8-yl]-2-oxoethyl] 2-methylpropanoate

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 : ~50 mg/mL (~92.47 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (4.62 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 (4.62 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.)