Mometasone furoate degradation and metabolism in human biological fluids and tissues

Pharmacokinetics of indacaterol, glycopyrronium and mometasone furoate following once-daily inhalation as a combination in healthy subjects

Indacaterol (IND), is co-formulated with glycopyrronium (GLY), and mometasone furoate (MF) as a once-daily (o.d.) inhaled fixed-dose combination (IND/GLY/MF) delivered via the Breezhaler® device for maintenance treatment of asthma. We evaluated the steady state plasma pharmacokinetics (PK) of IND, GLY and MF following inhalation of IND/GLY/MF or as monotherapies. This was a randomized, open-label, four-way crossover study. Subjects received IND/GLY/MF 150/50/160 μg (high-dose), IND 150 μg, GLY 50 μg or MF 190 μg (in vitro fine particle mass comparable to 160 μg MF in IND/GLY/MF) via the Breezhaler® device, o.d. for 14 days in each period, with a washout of at least 7 days. PK was characterized on Day 14, up to 24 h post-dose. In total, 36 healthy subjects were randomized. For IND, the geometric mean ratios (90% CI) for AUC0-24h,ss and Cmax,ss were 0.922 (0.878, 0.969) and 1.02 (0.967, 1.08), respectively for the IND/GLY/MF versus IND monotherapy comparison. For GLY, the geometric mean ratios (90% CI) for AUC0-24h,ss and Cmax,ss were 0.986 (0.944, 1.03) and 1.21 (1.09, 1.34), respectively for the IND/GLY/MF versus GLY comparison. For MF, the geometric mean ratios (90% CI) for AUC0-24h,ss and Cmax,ss were 1.16 (1.09, 1.24) and 1.17 (1.09, 1.25), respectively for IND/GLY/MF versus MF comparison. Similar systemic exposure was noted for IND/GLY/MF versus monotherapy for all three mono-components, indicating a lack of PK interaction. Multiple inhaled doses of IND, GLY and MF were safe and well tolerated, when administered alone or in combination. There was no clinically relevant pharmacokinetic interaction between IND, GLY and MF when administered as IND/GLY/MF.

Mometasone furoate nasal spray for the treatment of asthma

INTRODUCTION

Asthma is a common respiratory disease characterized by airway inflammation, bronchoconstriction and airway hyperresponsiveness and symptoms such as coughing, wheezing, shortness of breath and chest tightness. Allergic rhinitis is a common comorbidity in asthma and glucocorticoids are the key stone in the treatment of both diseases. Mometasone furoate is a potent synthetic steroid with a very high receptor affinity and a low bioavailability and shown to be superior compared to other inhaled corticosteroids. It is not clear whether the use of mometasone furoate nasal spray (MFNS) is associated with an improvement in asthma control.

AREAS COVERED

This current paper reviews the current knowledge on the effect of mometasone furoate nasal spray in the treatment of asthma and includes clinical trials in which both subjective and objective outcomes are assessed.

EXPERT OPINION

To date, only few clinical studies have investigated the effect of nasal steroids in the treatment of asthma. The studies investigating the effect of MFNS report contradicting results, although the most well-designed study to answer this question finds no improvement in asthma control. Thus, it seems unlikely that asthma guidelines will be influenced by the current knowledge on the effect of MFNS in the treatment of asthma.

Metabolism of beclomethasone dipropionate by cytochrome P450 3A enzymes

Inhaled glucocorticoids, such as beclomethasone dipropionate (BDP), are the mainstay treatment of asthma. However, ≈ 30% of patients exhibit little to no benefit from treatment. It has been postulated that glucocorticoid resistance, or insensitivity, is attributable to individual differences in glucocorticoid receptor-mediated processes. It is possible that variations in cytochrome P450 3A enzyme-mediated metabolism of BDP may contribute to this phenomenon. This hypothesis was explored by evaluating the contributions of CYP3A4, 3A5, 3A7, and esterase enzymes in the metabolism of BDP in vitro and relating metabolism to changes in CYP3A enzyme mRNA expression via the glucocorticoid receptor in lung and liver cells. CYP3A4 and CYP3A5 metabolized BDP via hydroxylation ([M4] and [M6]) and dehydrogenation ([M5]) at similar rates; CYP3A7 did not metabolize BDP. A new metabolite [M6], formed by the combined action of esterases and CYP3A4 hydroxylation, was also characterized. To validate the results observed using microsomes and recombinant enzymes, studies were also conducted using A549 lung and DPX2 liver cells. Both liver and lung cells produced esterase-dependent metabolites [M1-M3], with [M1] correlating with CYP3A5 mRNA induction in A549 cells. Liver cells produced both hydroxylated and dehydrogenated metabolites [M4, M5, and M6], but lung cells produced only the dehydrogenated metabolite [M5]. These studies show that CYP3A4 and CYP3A5 metabolize BDP to inactive metabolites and suggest that differences in the expression or function of these enzymes in the lung and/or liver could influence BDP disposition in humans.

Mometasone furoate in the management of asthma: a review

Inhaled corticosteroids (ICS) have proven to be the most effective and essential therapy for the treatment of bronchial asthma. The 2007 National Asthma Education and Prevention Program guidelines recommend ICS as preferred therapy for patients with mild to severe persistent asthma. Mometasone furoate (MF) is a relatively new ICS agent with high affinity for the glucocorticoid receptor. It is approved in the US for maintenance treatment of asthma for patients 4 years of age and older. It has been shown to be well tolerated with no significant adverse side effects observed in clinical trials and post-marketing surveillance. The efficacy of mometasone furoate has been established in large, well-designed studies. In patients with persistent asthma previously treated either with short-acting beta-agonists alone or twice-daily maintenance therapy with ICS, once-daily MF has been shown to be superior to placebo in improving lung function, symptom control, and quality of life; and has shown comparable efficacy compared with budesonide, beclomethasone, and fluticasone. Twice-daily dosing with MF has been demonstrated to successfully allow for reduction or elimination of oral corticosteroids in severe asthmatics.

Mometasone furoate dry powder inhaler for the treatment of asthma

INTRODUCTION

Asthma is a chronic inflammatory disease that causes significant morbidity and mortality. Inhaled corticosteroids are the preferred initial treatment for this disorder. Mometasone furoate dry powder is an inhaled corticosteroid that is approved for once-daily treatment of asthma in both adults and children as young as 4 years.

AREAS COVERED

The goal of this paper is to review the clinical efficacy and safety of mometasone furoate dry powder inhaler for the treatment of asthma. A literature search using PubMed was done using the terms 'mometasone furoate', 'inhaled corticosteroid' and 'asthma', focusing on articles that highlighted clinical trials and addressed efficacy of the medication.

EXPERT OPINION

Mometasone furoate dry powder inhaler has an excellent safety and efficacy profile. For patients with persistent asthma who require treatment with an inhaled corticosteroid, mometasone furoate is an excellent therapeutic choice.

Intranasal Mometasone Furoate for Treatment of Allergic Rhinitis

Allergic rhinitis (AR) is a chronic nasal disease that affects the upper respiratory tract. This disorder is characterized by inflammation of the mucous membranes and it manifests with several nasal symptoms accompanied sometimes by non-nasal symptoms. Best therapy aims to prevent and improve the AR-clinical picture. Steroids have an important role in the treatment of AR. The development of steroids administrated directly on nasal mucosa has much reduced the systemic adverse affects associated with oral steroids therapy. Mometasone furoate aqueous nasal spray is a synthetic steroid assessed for intranasal use in the therapy of adults and children affected by AR. Such topical nasal steroid is an effective molecule improving clinical picture of AR and it is also approved as prophylactic therapy. In this article, apart from a careful description of its successful clinical use the authors review pharmacokinetic/pharmacodynamic profile, mechanism of action, safety, and efficacy of such steroid molecule.

Dissolution in nasal fluid, retention and anti-inflammatory activity of fluticasone furoate in human nasal tissue ex vivo

BACKGROUND

Intranasal glucocorticoids represent the most effective pharmacologic treatment of allergic rhinitis. So far, no clinical data are available that compare fluticasone furoate (FF) with other intranasally applied glucocorticoids.

OBJECTIVE

Because the pharmacokinetic behaviour of drugs governs their presence at the therapeutic target site we analysed selected in vitro properties of FF in comparison with triamcinolone acetonide (TCA), budesonide (Bud), fluticasone propionate (FP) and mometasone furoate (MF). Additionally, we determined the anti-inflammatory activity of the glucocorticoid fraction residing in human nasal tissue samples after washing.

METHODS

We analysed the solubility of the compounds in artificial human nasal fluid and the retention in human nasal tissue as well as typical spray volumes of commercially available drug preparations. As an anti-inflammatory measure, we evaluated the inhibition of IL-8 release from epithelial cells.

RESULTS

FF is delivered in the smallest application volume per spray. Despite the low aqueous solubility of glucocorticoids, a fraction of the compounds is already dissolved in the aqueous supernatants of drug preparations (Bud>TCA>FP>MF>FF). The dissolution of FP, MF and FF was significantly enhanced in artificial nasal fluid and FF displayed the most pronounced enhancement of solubility in the presence of proteins. Consistent with this result, the highest retention in nasal tissue was observed for FF, followed by FP>MF>Bud>TCA. After washing of the nasal tissue samples, all compounds inhibited IL-8 release, with FF displaying the highest activity.

CONCLUSION

FF displayed beneficial properties for nasal application. Its low application volume per spray is a prerequisite for effective drug utilization by avoiding immediate loss by nose runoff or drip down the throat. Sustained dissolution and high tissue binding of FF should contribute towards an extended presence of compounds in nasal tissue as a basis for a prolonged pharmacologic activity.

Metabolism and disposition of fluticasone furoate, an enhanced-affinity glucocorticoid, in humans

The purpose of this study was to investigate the metabolism and disposition of fluticasone furoate, an enhanced-affinity glucocorticoid receptor agonist, in humans. In a two-part, open-label design study, five healthy male subjects received a p.o. dose of 2 mg of [(14)C]fluticasone furoate, followed 4 weeks later by an i.v. dose of 0.25 mg of [(14)C]fluticasone furoate (as a 30-min infusion). Oral absorption was rapid and estimated at approximately 30%, although the oral bioavailability was markedly lower at 1.6%, limited by extensive first-pass metabolism. Plasma clearance was 58.3 l/h, with a volume of distribution of 642 liters and a terminal elimination half-life of 15.3 h. The major circulating component identified in plasma extracts after i.v. and p.o. dosing was unchanged parent compound, with 17beta-carboxylic acid (GW694301X; M10) also being notable after p.o. administration. Mean recovery of radioactivity was approximately 92 and 102% at 216 and 168 h after i.v. and p.o. administration, respectively, with most (at least 90%) recovered in the feces. Fluticasone furoate was extensively metabolized, with only trace amounts of unchanged parent compound observed in feces following either route of administration. The predominant pathway was removal of the S-fluoromethyl carbothioate group to yield GW694301X (M10). Other pathways included oxidative defluorination to yield a hydroxyl at the C6 position. There was no evidence for metabolic loss of the furoate group from fluticasone furoate or any of its metabolites. Evidence presented suggests that enterocytes have a role in the metabolism of unabsorbed fluticasone furoate.

Human receptor kinetics and lung tissue retention of the enhanced-affinity glucocorticoid fluticasone furoate

Fluticasone furoate (FF)--USAN approved name, a new topically active glucocorticoid has been recently identified. The aim of this study was to characterise the binding affinity of this compound to the human lung glucocorticoid receptor in relation to other glucocorticoids. Additionally, we sought to determine the binding behaviour of fluticasone furoate to human lung tissue. The glucocorticoid receptor binding kinetics of fluticasone furoate revealed a remarkably fast association and a slow dissociation resulting in a relative receptor affinity (RRA) of 2989 +/- 135 with reference to dexamethasone (RRA: 100 +/- 5). Thus, the RRA of FF exceeds the RRAs of all currently clinically used corticosteroids such as mometasone furoate (MF; RRA 2244), fluticasone propionate (FP; RRA 1775), ciclesonide's active metabolite (RRA 1212 - rat receptor data) or budesonide (RRA 855). FP and FF displayed pronounced retention in human lung tissue in vitro. Lowest tissue binding was found for MF. There was no indication of instability or chemical modification of FF in human lung tissue. These advantageous binding attributes may contribute to a highly efficacious profile for FF as a topical treatment for inflammatory disorders of the respiratory tract.

Mometasone Furoate Nasal Spray

The development of corticosteroids that are delivered directly to the nasal mucosa has alleviated much of the concern about the systemic adverse effects associated with oral corticosteroid therapy. However, given the high potency of these drugs and their widespread use in the treatment of allergic rhinitis, it is important to ensure that intranasal corticosteroids have a favourable benefit-risk ratio. One agent that typifies the systemic safety found in the majority of intranasal corticosteroids is mometasone furoate nasal spray, a potent and effective treatment for seasonal and perennial allergic rhinitis and nasal polyposis. Mometasone furoate does not reach high systemic concentrations or cause clinically significant adverse effects. Results from pharmacokinetic studies in adults and children suggest that systemic exposure to mometasone furoate after intranasal administration is negligible. This is probably because of the inherently low aqueous solubility of mometasone furoate, which allows only a small fraction of the drug to cross the nasal mucosa and enter the bloodstream, and because a large amount of the administered drug is swallowed and undergoes extensive first-pass metabolism. There is no clinical evidence that mometasone furoate nasal spray suppresses the function of the hypothalamus-pituitary-adrenal axis when the drug is administered at clinically relevant doses (100-200 microg/day); consequently, mometasone furoate nasal spray has not been associated with growth inhibition in children. The safety and tolerability of mometasone furoate nasal spray have been rigorously assessed in clinical trials involving approximately 4,500 patients, with epistaxis, headache and pharyngitis being the most common adverse effects associated with treatment in adolescents and adults. The clinical effectiveness of mometasone furoate nasal spray, coupled with its agreeable safety and tolerability profile, confirms its favourable benefit-risk ratio.

Metabolism of mometasone furoate and biological activity of the metabolites

To better evaluate the pharmacokinetic and pharmacodynamic properties of the new inhaled glucocorticoid mometasone furoate (MF), the metabolism of MF was evaluated in rat and human tissues and in rat after i.v. administration. Metabolic studies with 3H-MF in human and rat plasma and S9 fractions of human and rat lung showed relatively high stability and a degradation pattern similar to that seen in buffer systems. MF was efficiently metabolized into at least five metabolites in S9 fractions of both rat and human liver. There were, however, quantitative differences in the metabolites between the two species. The apparent half-life of MF in the S9 fraction of human liver was found to be 3 times greater compared with that in rat. MET1, the most polar metabolite, was the major metabolite in rat liver fractions, whereas both MET1 and MET2 were formed to an equal extent in human liver. Metabolism and distribution studies in rats after intravenous and intratracheal administration of [1,2-(3)H]MF revealed that most of the radioactivity (approximately 90%) was present in the stomach, intestines, and intestinal contents, suggesting biliary excretion of MF and its metabolites. Radiochromatography showed that most radioactivity was associated with MET1, MET2, and MET 3. Fractionation of the high-performance liquid chromatography eluate (MET1-5) revealed that only MF [relative binding affinity (RBA) 2900] and MET2 (RBA 700) had appreciable glucocorticoid receptor binding affinity. These results suggest that MF undergoes distinct extrahepatic metabolism but generates active metabolites that might be in part responsible for the systemic side effects of MF.

Significant receptor affinities of metabolites and a degradation product of mometasone furoate

Mometasone furoate (MF) is a highly potent glucocorticoid used topically to treat inflammation in the lung, nose and on the skin. However, so far no information has been published on the human glucocorticoid receptor activity of the metabolites or degradation products of MF. We have now determined the relative receptor binding affinities of the known metabolite 6beta-OH MF and the degradation product 9,11-epoxy MF to understand their possible contribution to undesirable systemic side effects. In competition experiments with human lung glucocorticoid receptors we have determined the relative receptor affinities (RRA) of these substances with reference to dexamethasone (RRA = 100). We have discovered that 6beta-OH MF and 9,11-epoxy MF display RRAs of 206 +/- 15 and 220 +/- 22, respectively. This level of activity is similar to that of the clinically used inhaled corticosteroid flunisolide (RRA 180 +/- 11). Furthermore we observed that 9,11-epoxy MF is a chemically reactive metabolite. In recovery experiments with human plasma and lung tissue we found a time dependent decrease in extractability of the compound. Hence, we provide data that might contribute to the understanding of the pharmacokinetics as well as the clinical effects of MF.