Visualizing the spatial localization of ciclesonide and its metabolites in rat lungs after inhalation of 1-µm aerosol of ciclesonide by desorption electrospray ionization-time of flight mass spectrometry imaging.

Inhaled ciclesonide (CIC), a corticosteroid used to treat asthma that is also being investigated for the treatment of corona virus disease 2019, hydrolyzes to desisobutyryl-ciclesonide (des-CIC) followed by reversible esterification when exposed to fatty acids in lungs. While previous studies have described the distribution and metabolism of the compounds after inhalation, spatial localization in the lungs remains unclear. We visualized two-dimensional spatial localization of CIC and its metabolites in rat lungs after administration of a single dose of a CIC aerosol (with the mass median aerodynamic diameter of 0.918-1.168 µm) using desorption electrospray ionization-time of flight mass spectrometry imaging (DESI-MSI). In the analysis, CIC, des-CIC, and des-CIC-oleate were imaged in frozen lung sections at high spatial and mass resolutions in negative-ion mode. MSI revealed the coexistence of CIC, des-CIC, and des-CIC-oleate on the airway epithelium, and the distribution of des-CIC and des-CIC-oleate in peripheral lung regions. In addition, a part of CIC independently localized on the airway epithelium. These results suggest that distribution of CIC and its metabolites in lungs is related to both the intended delivery of aerosols to pulmonary alveoli and peripheral regions, and the potential deposition of CIC particles on the airway epithelium.

Metabolite V, an epoxide species is a minor circulating metabolite in humans following a single oral dose of deflazacort.

Deflazacort (Emflaza) was approved in the United States in 2017 for the treatment of the Duchenne muscular dystrophy in patients aged 2 years and older. Several deflazacort metabolites were isolated and identified from rats, dogs, monkeys, and humans. Among them, 1ß,2ß-epoxy-3ß-hydroxy-21-desacetyl deflazacort, referred to as Metabolite V, was reported to be one of the major circulating metabolites in humans. However, its quantitative distribution in plasma was not fully characterized. The objective of this study was to determine deflazacort plasma pharmacokinetics, metabolite profiles and their quantitative exposures in humans following a single oral dose. Six healthy male subjects were each administered a single oral dose of 60 mg [14 C]-deflazacort. Plasma and urine were collected and deflazacort metabolites in plasma were quantified by high performance liquid chromatography radio-profiling followed by liquid chromatography-mass spectrometry characterization. Metabolite V was isolated from urine and its structure was further confirmed by nuclear magnetic resonance analysis. These analyses demonstrated that deflazacort was not detectable in plasma; of the eight circulating deflazacort metabolites identified or characterized, the pharmacologically active metabolite 21-desacetyl deflazacort and inactive metabolite 6ß-hydroxy-21-desacetyl deflazacort accounted for 25.0% and 32.9% of the 0-24 hours plasma total radioactivity, respectively, while Metabolite V, an epoxide species, was a minor circulating metabolite, representing only about 4.7% of the total plasma radioactivity.

Storage stability of five steroids and in dried blood spots for newborn screening and retrospective diagnosis of congenital adrenal hyperplasia.

Congenital adrenal hyperplasia (CAH) is a severe inherited disorder of cortisol biosynthesis that is potentially lethal or can seriously affect quality of life. For the first time, we aimed to assess the stability of 21-deoxycortisol (21Deox), 11-deoxycortisol (11Deox), 4-androstenedione (4AD), 17-hydroxyprogesterone (17OHP) and cortisol (Cort), diagnostic for CAH, in dried blood spots (DBSs) during a 1 year storage at different temperatures. Spiked DBS samples were stored at room temperature, 4 °C, -20 °C or -70 °C, respectively and analyzed in triplicates using liquid chromatography-tandem mass spectrometry at Weeks 0, 1, 2, 3 and 4, Month 6 and Year 1. Analyte levels within ±15% vs the baseline were considered stable. Our observations show that 21Deox, 4AD and 17OHP were not significantly changed for 1 year even at room temperature at either analyte levels. In contrast, Cort required storage at 4 °C, -20 °C or -70 °C for long-term stability, being significantly decreased at room temperature from Month 6 (p<0.01) in both the 30(60) nM and the 90(180) nM samples. 11Deox was significantly decreased at room temperature at Year 1 (p<0.01) and only in the 30(60) nM samples. Thus, all biomarkers were stable for up to 1 year at 4 °C, -20 °C or -70 °C and at least for 4 weeks at room temperature. These findings have implications for analyses of stored DBS samples in 2nd-tier assays in newborn screening and for retrospective CAH studies.

Development and validation of a LC-MS/MS method for simultaneous determination of six glucocorticoids and its application to a pharmacokinetic study in nude mice.

In this study, a simple, rapid and sensitive LC-MS/MS analytical method for simultaneous determination of six glucocorticoids including 21-hydroxy deflazacort (21-OH DFZ), prednisolone (PNL), betamethasone (BET), beclomethasone (BEC), triamcinolone acetonide (TCA), budesonide (BUD) in nude mice plasma was developed and validated. Using testosterone as internal standard, the plasma samples were prepared by precipitation with acetonitrile and separated using an ACQUITY UPLC BEH C18 column (100 mm × 2.1 mm, 1.7 µm) with a mobile phase composed of acetonitrile and 0.1 % (v/v) formic acid aqueous solution by gradient elution at a flow rate of 0.3 mL/min. Quantitation was performed on a triple quadruple tandem mass spectrometer by multiple reaction monitoring in positive electrospray ionization mode. Calibration curves were developed over the range of 1-400 ng/mL for TCA, 5-2000 ng/mL for 21-OH DFZ, BET, BEC as well as BUD, and 10-2000 ng/mL for PNL. The accuracy, precision, matrix effect, recovery and stability were validated to be within acceptable criteria. The method was successfully applied to a preclinical pharmacokinetic (PK) study of the six GCs on female nude mice after a single oral dose of 1 mg/kg. The PK profiles of all the six GCs were described by two-compartment model with first-order absorption rate.

Simultaneous Determination of Co-administrated Deflazacort, Aprepitant and Granisetron in Dosage Forms and Spiked Human Plasma by RP-HPLC/PAD.

A selective reversed phase high performance liquid chromatography/photodiode array detector (RP-HPLC/PAD) method has been developed for simultaneous determination of the three co-administrated deflazacort, aprepitant and granisetron drugs used with chemotherapy. The three cited drugs have been chromatographed on C18 column using a mobile phase consisting of acetonitrile-0.2% v/v triethylamine (80:20 v/v, pH of 6.6 ± 0.05) with isocratic elution and monitored by photodiode array at 220 nm. International conference on harmonization (ICH) guidelines were followed to validate the developed method. Successful application of the developed method was assessed by the simultaneous determination of the studied drugs in pure forms, dosage forms and plasma samples in the ranges of 0.2-20, 0.4-40 and 0.2-20 µg/mL for deflazacort, aprepitant and granisetron, respectively.

Pharmacokinetics of deflazacort in rabbits after intravenous and oral administration and its interaction with erythromycin.

The pharmacokinetic of deflazacort after intravenous and oral administration and the effect of erythromycin on the disposition of deflazacort in rabbits were investigated. A parallel study was carried out in twelve rabbits. The plasma concentration-time profiles of deflazacort were determined after intravenous and oral administration of single dosages of 5 mg/kg in the presence and absence (baseline) of multiple dose erythromycin regimens. Plasma concentrations of 21-desacetyldeflazacort were determined by HPLC. Plasma concentration-time curves were analysed by compartmental pharmacokinetic and noncompartmental methods. The t½λz values following intravenous and oral administration were 3.67 and 4.96 hr, respectively. The apparent volume of distribution at steady-state (Vss ) was 4.08 ± 0.31 L/kg, this value indicates that deflazacort is widely distributed into the extravascular tissues. Moreover, bioavailability after oral administration of deflazacort (F = 87.48%) was high. Pharmacokinetic analysis after both routes of administration revealed a significant reduction in total body clearance, a significant increase in mean residence time, half-life and plasma concentrations of the steroid in the presence of multiple dose erythromycin. The results indicated the influence of the erythromycin on deflazacort disposition, which is consistent with a pharmacokinetic-type interaction in the elimination of the drug from the body. Moreover, this interaction should be considered to avoid adverse effects when using both drugs concomitantly.

Assessment of in vitro metabolic stability, plasma protein binding, and pharmacokinetics of E- and Z-guggulsterone in rat.

Guggulsterone is a racemic mixture of two stereoisomers (E- and Z-), obtained from the gum resin of Commiphora mukul and it is marketed as an antihyperlipidemic drug. The aim of our study was to assess the in vitro and in vivo absorption, distribution, metabolism, and excretion (ADME) properties namely solubility, in vitro metabolism, plasma protein binding and oral pharmacokinetic studies of E- and Z-guggulsterone. In vitro metabolism experiments were performed by using rat liver and intestinal microsomes. In vitro intrinsic clearance (CLint ) was found to be 33.34 ± 0.51 and 39.23 ± 8.12 µL/min/mg protein in rat liver microsomes for E- and Z-isomers, respectively. Plasma protein binding was determined by equilibrium dialysis method and in vivo pharmacokinetic studies were performed in male Sprague Dawley (SD) rats. Both isomers were highly bound to rat plasma proteins (>95% bound). Plasma concentration of E- and Z-isomers decreased rapidly following oral administration and were eliminated from systemic circulation with a terminal half-life of 0.63 ± 0.25 and 0.74 ± 0.35 h, respectively. The clearance (CL) for E-isomer was 2.79 ± 0.73 compared to 3.01 ± 0.61 L/h/kg for Z-isomer, indicating no significant difference (student t test; p <0.05) in their elimination.The pharmacokinetics of both isomers was characterized by extensive hepatic metabolism as seen with rat liver microsomes with high clearance and low systemic availability in rats. In brief, first-pass metabolism seems to be responsible factor for low bioavailability of guggulsterone. Copyright © 2015 John Wiley & Sons, Ltd.

Analysis of 21-hydroxy deflazacort in human plasma by UPLC-MS/MS: application to a bioequivalence study in healthy volunteers.

A sensitive and rapid ultra performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method has been developed for the determination of 21-hydroxy deflazacort in human plasma using betamethasone as the internal standard (IS). After solid-phase extraction from 100 µL human plasma, the analyte and IS were analyzed on Waters Acquity UPLC BEH C18 (50 mm × 2.1 mm, 1.7 µm) column using acetonitrile-4.0mM ammonium formate, pH 3.5 (90:10, v/v) as the mobile phase. The protonated analyte was quantified by selected reaction monitoring in the positive ionization mode by triple quadrupole mass spectrometer. The calibration plots were linear over the concentration range 0.50-500 ng/mL. Intra-batch and inter-batch precision (% CV) and accuracy (%) for five quality control samples ranged within 1.40-4.82% and 98.0-102.0% respectively. The overall mean extraction recovery of 21-hydroxy deflazacort from plasma ranged from 95.3 to 97.3%. Matrix effect was assessed by post-column analyte infusion and the extraction recovery was >95.0% across four quality control levels for the analyte and IS. Stability was evaluated under different conditions like bench top, autosampler, processed sample (at room temperature and in cooling chamber), freeze-thaw and long term stability. The method was applied to support a bioequivalence study of 30 mg deflazacort tablet formulation in 28 healthy subjects. Assay reproducibility was demonstrated by reanalysis of 115 incurred samples.

Breastfeeding status and maternal cardiovascular variables across the postpartum.

BACKGROUND: There have been recent reports that lactational history is associated with long-term women's health benefits. Most of these studies are epidemiological. If particular cardiometabolic changes that occur during lactation ultimately influence women's health later is unknown. METHODS: Seventy-one healthy women participated in a prospective postpartum study that provided an opportunity to study anthropometric, endocrine, immune, and behavioral variables across time. Variables studied were heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), C-reactive protein, body mass index (BMI), perceived stress, and hormones. A cohort of women without a change in breastfeeding (N=22) or formula feeding (N=23) group membership for 5 months was used for analysis of effects of feeding status. The data were analyzed using factorial repeated measures analysis of variance and analysis of covariance. RESULTS: SBP and HR declined across the postpartum and were significantly lower in breastfeeding compared to formula feeding mothers (p<0.05). These differences remained statistically significant when BMI was added to the model. Other covariates of income, stress, marital status, and ethnicity were not significantly associated with these variables over time. DBP was also lower, but the significance was reduced by the addition of BMI as a covariate. Stress also was lower in breastfeeders, but this effect was reduced by the addition of income as a covariate. CONCLUSIONS: These data suggest that there are important physiological differences in women during months of breastfeeding. These may have roles in influencing or programming later risks for a number of midlife diseases.

Simultaneous determination of ciclesonide and its active metabolite desisobutyryl-ciclesonide in human plasma by LC-APCI-MS/MS: application to pharmacokinetic study in healthy Chinese volunteers.

A sensitive and highly selective liquid chromatography tandem mass spectrometric (LC/MS/MS) method was developed and validated for the determination of ciclesonide (CIC) and its active metabolite, desisobutyryl-ciclesonide (des-CIC), in human plasma. Plasma samples were extracted using methyl tert-butyl ether with mifepristone as an internal standard (IS). Separation was carried out on a C(18) column using a mixture of 0.1% formic acid solution and methanol as the mobile phase with linear gradient elution. The detection was operated with positive atmospheric pressure chemical ionization (APCI) by selective multiple reaction monitoring (SRM). The chief benefit of the present method was the high sensitivity, with the lower limit of quantification (LLOQ) as low as 10pg/mL and the linearity ranging from 10 to 10,000pg/mL for both CIC and des-CIC. The method was fully validated and successfully applied to determine CIC and des-CIC simultaneously in human plasma and proved to be suitable for phase I clinical pharmacokinetic study of inhaled ciclesonide in healthy Chinese volunteers.

Quantification of 2-hydrazinopyridine derivatized steroid hormones in fathead minnow (Pimephales promelas) blood plasma using LC-ESI+/MS/MS.

Fathead minnows (Pimephales promelas) comprise a species-of-choice for the hazard assessments of various environmental contaminants, including compounds capable of disrupting endocrine function. Towards this end, the use of liquid chromatography coupled with mass spectrometry (LC-MS) and/or tandem mass spectrometry (MS/MS) is gaining common use for the quantification of steroid hormones as biomarkers of endocrine stress in small-fish toxicological studies. In this work, 2-hydrazinopyridine (2-HP) was used to derivatize and quantify the physiologically relevant steroid hormones of: 17α-hydroxypregnenolone, progesterone, 11-ketotestosterone, 11-deoxycortisol and 17α,20ß-dihydroxypregnenone, in the blood plasma of male and female fathead minnows. Liquid chromatographic separation was achieved using a Waters™ Sunfire C(18) column (2.1 mm×50 mm with a 3.5 µm particle size) and Milli-Q water:methanol (both with 0.1% formic acid) mobile phase over a gradient of 15 min. All mass analyses were conducted using electrospray ionization in the positive mode with tandem mass spectrometry (ESI+/MS/MS). This is the first such application of 2-HP derivatization for the quantifications of the structurally and functionally diverse C19 androgen of 11-ketotestosterone; C21 progestogens of 17α-hydroxypregnenolone, progesterone and17α,20ß-dihydroxypregnenone; and C21 corticosteroid of 11-deoxycortisol, in fathead minnow blood plasma. The limits of detection (LOD) were set to the lowest calibration standard that gave a signal-to-background response of ≥3, and were: 0.16 ng/ml for progesterone, 0.63 ng/ml for 17α-hydroxypregnenolone, 11-deoxycortisol and 17α,20ß-dihydroxypregnenone, and 1.25 ng/ml for 11-ketotestosterone. This study demonstrates the application of 2-HP derivatization for the analysis of a variety of steroid hormones representative of endocrine function in a species of fish commonly used in toxicological studies.

Simultaneous estimation of E- and Z-isomers of guggulsterone in rabbit plasma using liquid chromatography tandem mass spectrometry and its application to pharmacokinetic study.

A sensitive and selective liquid chromatography/tandem mass spectrometric method was developed for simultaneous determination of E- and Z-guggulsterone isomers (antihyperlipidemic drug) in rabbit plasma. Both the isomers were resolved on a Symmetry-Shield C(18) (5 µm, 4.6 × 150 mm) column, using gradient elution comprising a mobile phase of methanol, 0.5% v/v formic acid and acetonitrile. With dexamethasone as internal standard, plasma samples were extracted by an automated solid-phase extraction method using C(18) cartridges. Detection was performed by electrospray ionization in multiple reaction monitoring (MRM) in positive mode. The calibration curve was linear over the concentration range of 1.56-200 ng/mL (r(2) ≥ 0.998) for both analytes. The intra-day and inter-day accuracy and precision were within -0.96 to 4.12 (%bias) and 2.73 to 8.00 (%RSD) respectively. The analytes were stable after three freeze-thaw cycles. The method was successfully applied to study steriospecific pharmacokinetics of E- and Z-guggulsterone in NZ rabbit.

Deposition and metabolism of inhaled ciclesonide in the human lung.

Ciclesonide is an inhaled corticosteroid, administered as a prodrug via a metered-dose inhaler. Following deposition in the lung, ciclesonide is hydrolysed by esterases to form the pharmacologically active metabolite desisobutyryl-ciclesonide (des-CIC). Formation of des-CIC, as well as reversible esterification of des-CIC with fatty acids, has been demonstrated in vitro. The aim of this study was to investigate the in vivo metabolism of ciclesonide in the human lung. This single-dose, open-label, nonrandomised study was performed in 20 patients undergoing planned lung surgery for treatment of malignant pulmonary lesions. Patients inhaled a single dose of 1,280 µg ciclesonide at various time-points between 2 and 24 h prior to lung tissue resection. The concentration of ciclesonide, des-CIC and fatty acid conjugates of des-CIC in tissue samples was determined. Serum samples for pharmacokinetic analysis were taken at several time-points after inhalation. The pharmacokinetics in serum indicated that the inhalation by the patients was adequate. Metabolites (des-CIC, des-CIC oleate and des-CIC palmitate) were detected in the resected central and peripheral lung tissues. A substantial portion of ciclesonide was already activated to des-CIC at the first time-point of tissue analysis. Activation of ciclesonide and formation of des-CIC fatty acid conjugates was confirmed in vivo in the human lung.

Pharmacokinetics of ciclesonide and desisobutyryl ciclesonide after administration via aqueous nasal spray or hydrofluoroalkane nasal aerosol compared with orally inhaled ciclesonide: an open-label, single-dose, three-period crossover study in healthy volunteers.

BACKGROUND: Ciclesonide, an intranasal corticosteroid, is administered as a prodrug and is converted to the active metabolite, desisobutyryl ciclesonide, in the upper and lower airways. Previous studies have assessed systemic exposure with the ciclesonide hydrofluoroalkane metered dose inhaler (CIC HFA-MDI) and the ciclesonide aqueous nasal spray (CIC-AQ) formulations. However, systemic exposure with ciclesonide HFA nasal aerosol (CIC-HFA) developed for the treatment of allergic rhinitis has not been investigated. OBJECTIVE: This study compared the systemic exposure of ciclesonide and desisobutyryl ciclesonide after administration of ciclesonide formulated as an aqueous nasal spray, an HFA nasal aerosol, or as an orally inhaled HFA-MDI. METHODS: Healthy adults (aged 18-60 years) were randomly assigned in an open-label, singledose, 3-period crossover design to CIC-AQ 300 microg, CIC-HFA 300 microg, or CIC HFA-MDI 320 microg. Serum samples were collected before study drug administration and at 5, 15, and 30 minutes and 1, 1.5, 2, 3, 4, 6, 8, 10, 12, 14, 18, 22, and 24 hours after dosing. The primary pharmacokinetic parameters were AUC(0-infinity) and C(max) of desisobutyryl ciclesonide. Adverse events were elicited by direct questioning of participants throughout the study. RESULTS: Thirty volunteers were randomly assigned. Most of the volunteers were male (63% [19/30]) and white (83% [25/30]); the mean age was 36 years and mean weight was 68 kg. Concentrations of desisobutyryl ciclesonide were quantifiable (lower limit of quantitation [LLOQ] = 10 ng/L) in the serum samples of only 5 volunteers (of 30) receiving CIC-AQ, and the highest C(max) value of desisobutyryl ciclesonide was 26.7 ng/L (mean C(max), 15.2 ng/L). The AUC(0-infinity) of desisobutyryl ciclesonide for CIC-AQ was below the LLOQ of the bioanalytic assay. Mean C(max) and AUC(0-infinity) of desisobutyryl ciclesonide were 59.1 ng/L and 397.5 ng . h/L, respectively, for CIC-HFA; and 586.2 ng/L and 2685.0 ng . h/L, respectively, for CIC HFA-MDI. Concentrations of the parent compound, ciclesonide, were below the LLOQ in serum samples after administration of CIC-AQ; they were detectable up to 2 hours after administration of CIC-HFA and up to 4 hours after administration of CIC HFA-MDI. Treatment-emergent adverse events occurred with a low frequency in all 3 treatment groups (30% [9/30] overall) and were mild in intensity as determined by the study investigator. CONCLUSIONS: In this study, compared with that of CIC HFA-MDI, the systemic exposure of desisobutyryl ciclesonide was 10-fold lower after administration of CIC-HFA and at least 40-fold lower after administration of CIC-AQ. All treatments were well tolerated.

Determination of hormones inducing oocyte maturation in Chalcalburnus tarichi (Pallas, 1811).

Chalcalburnus tarichi is an endemic cyprinid species living in the Lake Van basin, in eastern Anatolia, Turkey. The present study was undertaken to determine which hormones induce oocyte maturation in C. tarichi. The levels of 17alpha,20beta,21-trihydroxyprogesterone (20beta-S), progesterone (P), 17alpha-hydroxyprogesterone (17alpha-HOP), 11-deoxycortisol (11-DOC), and 17alpha-hydroxy-20beta-dihydroprogesterone (17,20beta-P) were measured in fish caught from Lake Van and the Karasu River, and injected with human chorionic hormone (hCG) (1,000 and 1,500 IU/kg). Oocytes of fish caught from the lake were also incubated in vitro with different doses (50, 200, and 1,000 ng/ml) of 20beta-S, 17alpha-HOP, 11-DOC, and 17,20beta-P. 11-DOC was found to be the most effective hormone among those measured for inducing oocyte maturation in vivo and in vitro. 17,20beta-P could not be determined in the plasma of any fish in vivo (P < 0.05). 1,000 IU/kg dose of hCG given by injection caused a statistically significant increase in all plasma hormone levels (P < 0.05). It was found that there was a significant decrease in the P level only at 1,500 IU/kg dose of hCG injected (P < 0.05), while the level of other hormones increased at this dose (P < 0.05). It was also determined that all the hormones were effective in germinal vesicle breakdown (GVBD) in in vitro oocyte culture (P < 0.05). However, 11-DOC was found to be the most effective hormone in GVBD at a dose of 200 ng/ml (70% GVBD). In conclusion, 11-DOC synthesized during final oocyte maturation in C. tarichi was found to be a potent inducer of GVBD, which shows that 11-DOC may be described as an oocyte maturation steroid in this species.

Sensitive simultaneous determination of ciclesonide, ciclesonide-M1-metabolite and fluticasone propionate in human serum by HPLC-MS/MS with APPI.

A new and very sensitive analytical method has been developed and validated to jointly determine the anti-inflammatory drug ciclesonide (CIC), its active principle metabolite M1 (CIC-M1) and fluticasone propionate (FP) in human serum, in the low concentration range from 10 to 1000 pg/mL. This was accomplished by high-performance liquid chromatography and tandem mass spectrometry using atmospheric pressure photo ionisation (HPLC-MS/MS with APPI) using 0.5 mL of serum. Serum was mixed with the internal standards (IS) D11-CIC and D11-CIC-M1 and extracted with diisopropylether. A gradient with acetonitrile (containing 10 mM of acetic acid and 10% of acetone) was used. HPLC-MS/MS of the acetic acid adducts of the analytes was performed in negative mode. The novel aspect of this method is that instead of the dopant being introduced directly into the source by means of an external HPLC pump, it was added to the mobile phase. This provided significantly better sensitivity than the usual method of in-source addition of the dopant, and with no loss in HPLC performance. Sensitivity for the analytes was about four times greater than with either APCI or ESI. Validation was performed in three batches. The inter-batch precision (CV) of the quality control samples in human serum ranged from 4.08% to 6.78% for CIC, from 2.57% to 7.74% for CIC-M1, and from 2.38% to 9.61% for FP. The inter-batch accuracy (with reference to the mean value) of the quality control samples in human serum ranged from 99.3% to 110.0% for CIC, from 101.8% to 104.7% for CIC-M1, and from 100.4% to 101.8% for FP. Calibration data and LLOQ data are also presented in this paper. The analytes were stable in human serum over three freeze/thaw cycles, or for 4h at room temperature, or for at least 18 months when stored at below -20 degrees C. This method was used for quantifying the analytes after inhalation of low-mug amounts of the drugs by patients.

Evaluation of cortisol precursors for the diagnosis of pituitary-dependent hypercortisolism in dogs.

The serum concentrations of cortisol, 17alpha-hydroxypregnenolone, 17alpha-hydroxyprogesterone, 21-deoxycortisol and 11-deoxycortisol were measured in 19 healthy dogs, 15 dogs with pituitary-dependent hypercortisolism (pdh) and eight dogs with other diseases before and one hour after an injection of synthetic adrenocorticotrophic hormone (acth). At both times the dogs with pdh had significantly higher concentrations of cortisol, 17alpha-hydroxypregnenolone, 17alpha-hydroxyprogesterone and 21-deoxycortisol than the healthy dogs. Basal 11-deoxycortisol concentrations were also significantly higher in dogs with pdh compared with healthy dogs. When compared with the dogs with other diseases, the dogs with pdh had significantly higher basal and post-acth cortisol and basal 21-deoxycortisol, and significantly lower post-acth 11-deoxycortisol concentrations. The dogs with other diseases had significantly higher post-acth cortisol, 17alpha-hydroxyprogesterone and 11-deoxycortisol concentrations than the healthy dogs. In general, the post-acth concentrations of 17alpha-hydroxypregnenolone, 17alpha-hydroxyprogesterone, 11-deoxycortisol and 21-deoxycortisol were more variable than the post-acth concentrations of cortisol, resulting in large overlaps of the concentrations of these hormones between the three groups. A two-graph receiver operating characteristic (ROC) analysis was used to maximise the sensitivity and specificity of each hormone for diagnosing hypercortisolism; it showed that the post-acth concentration of cortisol had the highest sensitivity and specificity. The overlaps between the healthy dogs, the dogs with pdh and the dogs with other diseases suggested that the individual precursor hormones would not be useful as a screening test for hypercortisolism.

Ciclesonide disposition and metabolism: pharmacokinetics, metabolism, and excretion in the mouse, rat, rabbit, and dog.

The pharmacokinetics, metabolism, and excretion of ciclesonide, a novel and effective inhaled glucocorticoid for the treatment of asthma, were investigated after intravenous and oral administration of 14C-ciclesonide in the mouse, rat, rabbit, and dog. The pharmacokinetics of ciclesonide in all animal species were characterized by a low oral bioavailability (approximately 6% or less), a high clearance, and a large volume of distribution. The apparent terminal half-life of ciclesonide was short; the apparent terminal half-life of the active desisobutyryl-ciclesonide metabolite (des-CIC or M1) was longer and ranged from 2.4 to 6.9 hours in the 4 species. Metabolites derived from ciclesonide in serum (or plasma) and excreta samples from the 4 animal species were profiled and identified by LC/RAM/MS (liquid chromatography/radioactivity monitor/mass spectrometry). Ciclesonide was extensively metabolized to yield des-CIC, which was further metabolized to primarily yield hippuric acid and hydroxylated metabolites, namely, isomers of cyclohexane-monohydroxylated des-CIC and B-ring-monohydroxylated des-CIC. Greater than 90% of intravenous and oral 14C-ciclesonide doses were recovered in all species; the main elimination route was fecal/biliary. A comparison of in vitro and in vivo metabolite profiles between mice, rats, rabbits, and dogs with those from humans indicated that metabolic pathways for ciclesonide were qualitatively similar in humans and in the 4 animal species.

Safety, tolerability, and exposure of ciclesonide nasal spray in healthy and asymptomatic subjects with seasonal allergic rhinitis.

Ciclesonide is an intranasal corticosteroid in development for the treatment of allergic rhinitis. To assess the safety, tolerability, and pharmacokinetics of ciclesonide, adult healthy volunteers and asymptomatic subjects with seasonal allergic rhinitis were randomized to receive intranasal ciclesonide or placebo for 14 days. Serum concentrations of ciclesonide and its active metabolite, desisobutyryl-ciclesonide, were measured using high-performance liquid chromatography assay with tandem mass spectrometric detection, with lower limits of quantification of 25 and 10 pg/mL, respectively. Adrenal function was monitored by diurnal serum free and 24-hour urine cortisol concentrations. Despite the use of a sensitive assay and a high ciclesonide dose (800 microg/d), serum levels of ciclesonide and desisobutyryl-ciclesonide were below the lower limits of quantification for the majority of samples assayed. Ciclesonide was well tolerated and did not appear to affect serum or urine free cortisol levels. The low systemic exposure and favorable safety profile support the continued clinical development of ciclesonide nasal spray.

Pharmacokinetic disposition of inhaled ciclesonide and its metabolite desisobutyryl-ciclesonide in healthy subjects and patients with asthma are similar.

OBJECTIVE: To evaluate whether the inflammatory process and bronchial constriction associated with asthma influence the pulmonary distribution and airway penetration of inhaled ciclesonide by investigating the pharmacokinetics of ciclesonide and its active metabolite, desisobutyryl-ciclesonide (des-CIC) in patients with asthma and matched healthy subjects. METHODS: 12 patients with asthma (8 males, 4 females) and 12 healthy subjects matched for age, sex, height, and weight received a single inhaled dose of 1,280 microg (ex-actuator, equivalent to 1,600 microg ex-valve) ciclesonide by metered-dose inhaler in a parallel-group study. Timed blood samples were collected for measurement of serum concentrations of des-CIC and ciclesonide by liquid chromatography with tandem mass spectrometry. RESULTS: There were no differences in the pharmacokinetics of des-CIC between healthy subjects and patients with asthma. Ratio analysis of the primary variable, the area under the concentration-time curve from time 0 to infinity (AUC(0 - inf)) showed equivalence for des-CIC in healthy subjects and patients with asthma, with a ratio of 1.003 (90% confidence interval between 0.815 and 1.234). The mean terminal half-life (t1/2) for des-CIC was also similar in patients with asthma (3.15 hours) and healthy subjects (3.33 hours). Furthermore, the pharmacokinetic parameter estimates for ciclesonide were comparable between the study groups. CONCLUSION: After administration of a single dose of ciclesonide, the pharmacokinetic parameter estimates for des-CIC were equivalent between patients with mild-to-moderate asthma and healthy subjects, suggesting that there is comparable lung deposition and activation of ciclesonide in the 2 populations.