Population Pharmacokinetic Analysis of Fluticasone Furoate/Umeclidinium Bromide/Vilanterol in Patients with Chronic Obstructive Pulmonary Disease.

BACKGROUND: Population pharmacokinetic methods were used to characterize the pharmacokinetics of fluticasone furoate (FF), umeclidinium (UMEC), and vilanterol (VI) in patients with chronic obstructive pulmonary disease (COPD) when administered as a fixed-dose combination via a single closed inhaler. METHODS: Plasma concentration data from three studies were analyzed using non-linear mixed-effects modeling in NONMEM®. RESULTS: The pooled dataset consisted of 2948, 2589, and 3331 FF, UMEC, and VI observations from 714, 622, and 817 patients with COPD, respectively. There were 41%, 13%, and 21% of observations below the quantification limit for FF, UMEC, and VI, respectively. The pharmacokinetics of FF, UMEC, and VI were all adequately described by a two-compartment model with first-order absorption. The following covariates were statistically significant, but none were considered to be clinically relevant. For FF, Japanese heritage and FF/VI treatment on apparent inhaled clearance (CL/F) with FF CL/F 35% lower in patients of Japanese heritage across all treatments and FF CL/F 42% higher in patients with COPD following FF/VI administration. This is in line with the product label. For UMEC, weight, age, and smoking status on CL/F and weight on apparent volume of distribution (V2/F) with every 10% increase in age from 60 years of age leading to approximately a 6% decrease in UMEC CL/F and every 10% increase in weight from 70 kg leading to approximately a 6% increase in UMEC CL/F and approximately an 8% increase in UMEC V2/F. For a subject with COPD who smoked, UMEC CL/F was 28% higher. For VI, weight on CL/F and smoking status on V2/F with an approximately 4% increase in VI CL/F for every 10% increase in weight from 70 kg, and for a subject with COPD who smoked, VI V2/F was 46% higher. The majority of these covariates have been previously identified in historical analyses. None of these effects were clinically relevant in terms of systemic exposures and do not warrant dose adjustment. CONCLUSIONS: All FF, UMEC, and VI plasma concentrations were well interspersed with historical data and were all adequately described by a two-compartment model with first-order absorption. There were no clinically relevant differences in FF, UMEC, or VI systemic exposures when administered as FF/UMEC/VI, FF/VI + UMEC, or the dual combinations FF/VI and/or UMEC/VI.

HPLC-UV and spectrofluorimetric methods for simultaneous estimation of fluticasone furoate and vilanterol in rabbit plasma: A pharmacokinetic study.

Fluticasone furoate (FF) and vilanterol trifenatate (VT) is a widely prescribed combination in the management of asthma and chronic obstructive pulmonary disease. In the present study, two quantitative methods based on HPLC-UV and spectrofluorimetric analysis had been developed and validated for simultaneous estimation of FF and VT in rabbit plasma using baclomethasone as internal standard (ISTD). Analytes and ISTD were separated from plasma using simple step of protein precipitation with acetonitrile. Chromatographic separation was achieved on Spherisorb S5 ODS2 (250 mm × 4.6 mm, 5.0 µm) column using mobile phase that constitute acetonitrile-0.01% glacial acetic acid in water (70:30, v/v) and then detected on a UV detector at 235 nm wavelength. Spectrofluorimetric detection was performed using absorption/emission wavelength (λabs/em) of 286/352 nm and 362/407 nm for FF and VT, respectively. For both analytes, linearity ranged from 4-200 ng/mL to 10-200 ng/mL using HPLC-UV and spectrofluorimetric method, respectively. Methods were validated as per FDA recommendations. Statistical analysis revealed that these detection methods are statistically insignificant difference and can be used interchangeably without any bias. Further, these methods were applied in pharmacokinetic study for simultaneous estimation of FF and VT in rabbit plasma.

Blood eosinophils and treatment response with triple and dual combination therapy in chronic obstructive pulmonary disease: analysis of the IMPACT trial.

BACKGROUND: Previous studies have highlighted a relationship between reduction in rate of exacerbations with therapies containing inhaled corticosteroids (ICS) and baseline blood eosinophil count in patients with chronic obstructive pulmonary disease (COPD). The IMPACT trial showed that once-daily single-inhaler triple therapy significantly reduced exacerbations versus dual therapies. Blood eosinophil counts and smoking status could be important modifiers of treatment response to ICS. We aimed to model these relationships and their interactions, including outcomes other than exacerbations. METHODS: IMPACT was a phase 3, randomised, double-blind, parallel-group, 52-week global study comparing once-daily single-inhaler triple therapy (fluticasone furoate-umeclidinium-vilanterol) with dual inhaled therapy (fluticasone furoate-vilanterol or umeclidinium-vilanterol). Eligible patients had moderate-to-very-severe COPD and at least one moderate or severe exacerbation in the previous year. We used fractional polynomials to model continuous blood eosinophil counts. We used negative binomial regression for numbers of moderate and severe exacerbations, severe exacerbations, and pneumonia. We modelled differences at week 52 in trough FEV1, St George's Respiratory Questionnaire (SGRQ) total score, and Transition Dyspnoea Index using repeated measurements mixed effect models. IMPACT was registered with ClinicalTrials.gov, number NCT02164513. FINDINGS: The magnitude of benefit of regimens containing ICS (fluticasone furoate-umeclidinium-vilanterol n=4151 and fluticasone furoate-vilanterol n=4134) in reducing rates of moderate and severe exacerbations increased in proportion with blood eosinophil count, compared with a non-ICS dual long-acting bronchodilator (umeclidinium-vilanterol n=2070). The moderate and severe exacerbation rate ratio for triple therapy versus umeclidinium-vilanterol was 0·88 (95% CI 0·74 to 1·04) at blood eosinophil count less than 90 cells per µL and 0·56 (0·47 to 0·66) at counts of 310 cells per µL or more; the corresponding rate ratio for fluticasone furoate-vilanterol versus umeclidinium-vilanterol was 1·09 (0·91 to 1·29) and 0·56 (0·47 to 0·66), respectively. Similar results were observed for FEV1, Transition Dyspnoea Index, and SGRQ total score; however, the relationship with FEV1 was less marked. At blood eosinophil counts less than 90 cells per µL and at counts of 310 cells per µL or more, the triple therapy versus umeclidinium-vilanterol treatment difference was 40 mL (95% CI 10 to 70) and 60 mL (20 to 100) for trough FEV1, -0·01 (-0·68 to 0·66) and 0·30 (-0·37 to 0·97) for Transition Dyspnoea Index score, and -0·01 (-1·81 to 1·78) and -2·78 (-4·64 to -0·92) for SGRQ total score, respectively. Smoking status modified the relationship between observed efficacy and blood eosinophil count for moderate or severe exacerbations, Transition Dyspnoea Index, and FEV1, with former smokers being more corticosteroid responsive at any eosinophil count than current smokers. INTERPRETATION: This analysis of the IMPACT trial shows that assessment of blood eosinophil count and smoking status has the potential to optimise ICS use in clinical practice in patients with COPD and a history of exacerbations. FUNDING: GlaxoSmithKline.

Identification of phase-II metabolites from human serum samples after oral intake of a willow bark extract.

BACKGROUND: Willow bark (Salicis cortex) is a herbal medicinal drug used to treat fever and pain, such as headaches and lower back pain. Until now, it has not been fully understood which compounds are responsible for the efficacy of the drug. PURPOSE: Although salicylic acid is known as a metabolite of salicylic alcohol derivatives of willow bark in vivo, it has been shown in previous studies that its concentration is too low to account for the overall efficacy of Salicis cortex. The aim this study was to broaden the knowledge regarding phenolic phase-II metabolites after oral intake of a willow bark extract. STUDY DESIGN/METHODS: Serum samples of a human pharmacokinetic study (Salicis cortex extract intake corresponding to 240 mg of total salicin, 10 volunteers, 12 h fasting time, controlled diet low in phenolics, and 12 blood withdrawals over a period of 24 h) were analyzed by LC-ESI-MS. A library of 142 possible metabolites associated with salicylic alcohol derivatives, flavonoids, and proanthocyanidins was used to characterize possible metabolization products. Their structures were confirmed by LC-ESI-MS experiments with reference compounds after a cleavage reaction using glucuronidase and sulfatase as well as by LC-MS/MS experiments. RESULTS: In the serum samples, phase-II metabolites of naringenin (2x glucuronides, 2x sulfates, 2x mixed glucuronide-sulfates), eriodictyol (3x glucuronides, 1x sulfate), taxifolin (1x sulfate), catechin (1x sulfate, 1x mixed glucuronide sulfate), ferulic acid (1x sulfate), hydroxyphenyl-propionic acid (1x sulfate), dihydroxyphenyl-valerolactone (1x sulfate), saligenin (1x glucuronide, 1x sulfate), salicylic acid (1x sulfate, 1x unconjugated, 1x salicyluric acid), and catechol (1x glucuronide, 1x sulfate) were characterized. Because taxifolin, dihydroxyphenyl-valerolactone, ferulic acid, and hydroxyphenyl-propionic acid could not be detected in the willow bark preparation, they could be metabolization products of genuine flavanones and flavan-3-ols as well as coumaric acid or C-ring cleavage products of flavonoids, which were present in the extract. No phase-II metabolites of procyanidins and no genuine flavonoid glycosides were detected in all serum samples. CONCLUSION: This is the first study to identify human metabolites of flavonoids, proanthocyanidins and salicylic alcohol derivatives of Salicis cortex beside salicylic acid or catechol. For the most characterized metabolites, anti-inflammatory activity has been described in the literature, and the present results are an important step in understanding the anti-inflammatory efficacy of willow bark in vivo.

Stable isotope labeling derivatization and magnetic dispersive solid phase extraction coupled with UHPLC-MS/MS for the measurement of brain neurotransmitters in post-stroke depression rats administrated with gastrodin.

Synchronous measurement of brain neurotransmitters and blood drug metabolism by dual sites in vivo microdialysis can provide very important information for several neurological disorders such as post-stroke depression (PSD). In this work, d0/d3-6-N-methyl-rhodamine 6G-N-hydroxysuccinimidyl formate (d0/d3-MRSF) were firstly designed, synthesized and used as stable isotope labeling derivatization reagents for the determination of multiple neurotransmitters by ultra-high performance liquid chromatography-tandem mass spectrometry. The light d0-MRSF was used to label neurotransmitters in real samples and the heavy d3-MRSF was used to label standards, which served as internal standards for quantification to minimize matrix effect. The d0/d3-MRSF-neurotransmitter derivatives were easily adsorbed onto the surface of Fe3O4@graphene oxide. Magnetic dispersive solid phase extraction followed with stable isotope labeling derivatization was developed for efficient sample pretreatment. The permanent positively charged moiety of d0/d3-MRSF significantly enhanced the ionization efficiency of neurotransmitters. The comparison results indicated that the synthesized MRSF derivatization method can bring better detection sensitivity than the commercial dansyl chloride method about tens to hundreds of times on the same instrumentation. Specific and regular product ions of m/z 413.3 and 416.3, m/z 429.4 and 432.4 were observed for d0-and d3-MRSF labeled neurotransmitters, respectively. The limits of detection were in the range of 2.0-40.0 pM. The accuracies ranged from 92.3% to 108.2% with the intra- and inter-day precisions in the range of 2.2-12.8%. Synchronous and dynamic determination of concentrations changes of brain neurotransmitters and blood gastrodin of PSD rats was achieved. The results indicated that gastrodin had analogous regulating effect of brain neurotransmitter, which like the clinical medicine fluoxetine of PSD. Taken together, the developed method was demonstrated to be promising for sensitive, accurate and simultaneous determination of multiple neurotransmitters in trace biofluids.

An Optimized and Sensitive Pharmacokinetic Quantitative Method of Investigating Gastrodin, Parishin, and Parishin B, C and E in Beagle Dog Plasma using LC-MS/MS after Intragastric Administration of Tall Gastrodia Capsules.

Gastrodia elata Blume, called Tianma in China, has been widely used to treat headaches, convulsions and epilepsy for thousands of years. In the present study, a series of optimizations were employed to develop a rapid, sensitive, and reliable high-performance liquid chromatography-triple quadrupole mass spectrometry method, which was then used for the simultaneous determination of gastrodin, parishin, parishin B, parishin C and parishin E in beagle dog plasma after intragastric administration of tall Gastrodia capsules (Tianma brand). The chromatographic separation was achieved on a C18 column with gradient elution by using a mixture of 0.4% formic acid aqueous solution and acetonitrile as the mobile phase at a flow rate of 0.15 mL/min. A tandem mass spectrometric detection was conducted using multiple-reaction monitoring (MRM) via electrospray ionization (ESI) source in negative ionization mode. Samples were pre-treated by a single-step protein precipitation with methanol, and bergenin was used as internal standard (IS). Under the optimized conditions, the lower limit of quantification (LLOQ) was 0.10 ng/mL for gastrodin, 0.40 ng/mL for parishin B, 0.02 ng/mL for parishin E and 0.20 ng/mL for parishin and parishin C, all of which previously were the highest levels of sensitivity. The methods were optimized for selectivity, calibration curves, accuracy and precision. Extraction recoveries, matrix effects and stability were within acceptable ranges. Pharmacokinetic parameters of the tested substances were also quantitatively determined. Finally, a possible metabolic pathway was induced based on correlations obtained from quantitative and qualitative data analysis in vivo.

Simultaneous determination of ferulic acid and gastrodin of Tianshu Capsule in rat plasma by ultra-fast liquid chromatography with tandem mass spectrometry and its application to a comparative pharmacokinetic study in normal and migraine rats.

Tianshu Capsule, consisting of Ligusticum chuanxiong Hort and Gastrodia elata Blume, is a widely used Traditional Chinese Medicine preparation for the treatment of migraine. Ferulic acid and gastrodin are main active constituents in Ligusticum chuanxiong Hort and Gastrodia elata Blume, and have been used as marker components for quality control of Tianshu Capsule. In this study, a selective, sensitive, and reliable ultra-fast liquid chromatography with tandem mass spectrometry method was developed for simultaneous determination of ferulic acid and gastrodin in rat plasma using geniposide as internal standard. The plasma samples were extracted by protein precipitation with methanol after acidification and separated on a Shim-Pack XR-ODS C18 column (75 × 3.0 mm, 2.2 µm) using gradient elution with a mobile phase consisting of water (containing 0.1% formic acid) and acetonitrile at a flow rate of 0.6 mL/min. Detection was performed on 3200 QTRAP mass spectrometry equipped with turbo ion spray source in negative ionization mode. Validation parameters were within acceptable ranges. The validated method was applied to compare the pharmacokinetic profiles of ferulic acid and gastrodin in normal and migraine rats. Our results showed that there were remarkable differences in the pharmacokinetic properties of the analytes between the normal and migraine groups.

Pharmacokinetic comparative study of gastrodin after oral administration of Gastrodia elata Bl. extract and its compatibility with the different indigents of Ligusticum chuanxiong Hort. to rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Da Chuan Xiong Decoction Compound preparation (DCXDCP) is a classic TCM formula of an aqueous extract made from Chuanxiong Rhizoma (Ligusticum chuanxiong Hort., umbelliferae) and Tianma Rhizoma (Gastrodia elata Bl., Orchidaceae). Gastrodin (GAS), a bioactive component of tianma, its pharmacokinetic (PK) behavior significantly changed after oral administration of DCXDCP compared with the extract of tianma. However, little is known about how the ingredients of chuanxiong influenced on the PK of GAS. AIM OF THE STUDY: To study the possible PK behavior differences of GAS after individually oral administration of tianma extract and tianma extract mixed with different active ingredients of chuanxiong to rats, as well as explore whether there were some herb-herb interactions. MATERIALS AND METHODS: Different DCXDCP suspensions were prepared by mixing tianma extract with different active ingredients of chuanxiong. The rats were randomly assigned to six groups and were orally treated with different DCXDCP. At different predetermined time points after administration, the concentrations of GAS in the rat plasma were determined using HPLC, and the main PK parameters were investigated. RESULTS: The results showed that tetramethylpyrazine had no significant effects on the PK parameters of GAS (p>0.05), whereas ferulic acid (FA), total phenolic acids and total alkaloids significantly increased AUC0-∞ (p<0.05). In general the observed changes in the PK parameters of GAS in DCXDCP could be closely related to the total phenolic acids and total alkaloids. CONCLUSION: It could be shown that total phenolic acids and total alkaloids present in Ligusticum chuanxiong in addition to other components not tested yet play an important role in affecting the PK of gastrodin in DCXDCP.

Concentration-QT analysis of the randomized, placebo- and moxifloxacin-controlled thorough QT study of umeclidinium monotherapy and umeclidinium/vilanterol combination in healthy subjects.

The long-acting muscarinic antagonist umeclidinium (UMEC) is approved as a once-daily monotherapy and in combination with the long-acting ß2 agonist vilanterol (VI) for chronic obstructive pulmonary disease. The objective of this analysis was to assess the relationship between observed plasma UMEC and/or VI concentrations and QT interval corrected using Fridericia's correction (QTcF). 103 subjects were enrolled and 86 (83 %) completed the study. Subjects were randomized to 4 of 5 repeat-dose treatments (days 1-10: n = 77 subjects received placebo, n = 76 UMEC 500 µg, n = 78 UMEC/VI 125/25 µg, or n = 76 UMEC/VI 500/100 µg; day 10: n = 74 oral tablet moxifloxacin 400 mg [positive control]). The concentration-QTcF interval relationship was examined using nonlinear mixed-effects methods. For UMEC, predicted QTcF interval prolongation (at observed geometric mean of maximum plasma concentrations) was -2.38 ms (90 % prediction interval [PI] -3.82, -0.85) with UMEC 500 µg and -0.50 ms (90 % PI -0.80, -0.18) and -2.01 ms (90 % PI -3.22, -0.72) with UMEC/VI 125/25 µg and 500/100 µg, respectively. For VI, estimates were 5.89 ms (90 % PI 4.89, 6.91) and 7.23 ms (90 % PI 5.88, 8.55) with UMEC/VI 125/25 µg and 500/100 µg, respectively. Combined additive mean effects were estimated for UMEC/VI 125/25 µg (5.39 ms [90 % PI 4.40, 6.47]) and 500/100 µg (5.22 ms [90 % PI 3.72, 6.80]). The model-predicted decrease with UMEC and increase with UMEC/VI combination in QTcF interval suggest that the QT effect is likely attributable to VI. These model-predicted results support those of previously-published traditional statistical analyses.

Population Pharmacokinetics of Inhaled Fluticasone Furoate and Vilanterol in Subjects with Chronic Obstructive Pulmonary Disease.

BACKGROUND AND OBJECTIVES: Previous pharmacokinetic studies of the inhaled corticosteroid, fluticasone furoate (FF), and the long-acting, beta2-receptor agonist, vilanterol (VI) have been performed in relatively small populations using non-compartmental pharmacokinetic methods and censored data (due to low drug exposure relative to assay sensitivity). This paper presents a population pharmacokinetic analysis, utilizing pooled concentration-time data from clinical studies in healthy subjects and from global trials in patients with chronic obstructive pulmonary disease (COPD). The objective of this analysis was to characterize the population pharmacokinetics of FF and VI following once-daily inhalation dosing of FF/VI or the individual components (FF and VI) and to identify significant covariates that impact systemic exposure to FF and VI in this population. METHODS: Population pharmacokinetic methods that maximize the likelihood of all data were developed to describe systemic exposure to FF and VI following once-daily FF/VI, FF, or VI, and to identify significant covariates that impact the pharmacokinetics. COPD patients (N = 1225 for the FF analysis and N = 1091 for the VI analysis; 94 and 93 % of total data, respectively) and healthy subjects contributed to the analysis. RESULTS: FF data were described by a two-compartment model with first-order absorption and elimination. The population grouping "race" was a significant covariate on inhaled clearance (CL/F). The area under the curve over 24 h (AUC0-24) for FF was higher for East Asian, Japanese, and South East Asian (average 23-30 %) and Asian Central, White Arabic, American Indian/Native Alaskan, and 'other' (10-26 %) subjects compared with White/Caucasians. VI pharmacokinetics were described by a three-compartment model with zero-order absorption and first-order elimination. Significant demographic covariates identified to affect pharmacokinetics of VI were age [on CL/F and central volume (V 1/F)], bodyweight (on CL/F), sex and smoking (on V 1/F). CONCLUSIONS: While significant effects of the covariates were observed in this study, the magnitude of these effects on systemic exposure is not large enough to warrant FF/VI dosage adjustment in patients with COPD.

Comparative pharmacokinetics of gastrodin in rats after intragastric administration of free gastrodin, parishin and Gastrodia elata extract.

ETHNOPHARMACOLOGICAL RELEVANCE: Gastrodia elata Blume, a traditional Chinese herb, was widely used against convulsant, vertigo, paralysis, epilepsy, tetanus, asthma and immune dysfunctions. Gastrodin is one of the major bioactive components of G. elata and it is known for its anticonvulsive, anti-inflammatory, antiepileptic and neuroprotective effects. MATERIALS AND METHODS: An ultra high performance liquid chromatography-fluorescence detection (UHPLC-FLD) method was developed to determine gastrodin in rat plasma. Gastrodin and Thiamphenicol (internal standard, IS) were extracted from rat plasma by immediately protein precipitation. The pharmacokinetics of gastrodin in rats by following differently administered types was studies: intragastric administration of gastrodin (100mg/kg), parishin (116 mg/kg, with the same mole of gastrodin moiety) and G. elata extract (2.3g/kg, with the same mole of gastrodin moiety). Non-compartmental pharmacokinetic profiles were constructed using the software of WinNonlin (Phoenix, version 6.3), and the pharmacokinetic parameters were compared using unpaired Student's t-test. RESULTS: The results showed that the pharmacokinetic parameters, including Cmax, Tmax, AUC0-∞, t1/2, MRT, Vd, CL, were quite different among the three types of gastrodin administration. The administration of parishin and G. elata extract, which either could convert to gastrodin in vivo or contained free gastrodin and abundant gastrodin conjugates, gave rise to higher elimination half-life (t1/2) and mean residence time (MRT) values for gastrodin compared to free gastrodin administered. CONCLUSION: The comparison of the pharmacokinetics of gastrodin among three different administered types of gastrodin in rats suggested that administration of parishin or G. elata extract in clinic may result in a longer duration time of action than that of the administration of free gastrodin. The results may provide some guidance for the clinical applications of parishin and G. elata.

Pharmacokinetic study of Gastrodia elata in rats.

The pharmacokinetics of parishin, gastrodin, Gastrodia elata extract and Rhizoma Gastrodiae capsule was investigated by intragastric and/or intravenous administration to rats. Parishin was metabolized into nine metabolites after intravenous administration, and the area under the curve (AUC0-∞) of parishin and its metabolites (except parishin G and parishin E) increased nonlinearly from 72.5 to 220 mg/kg. When combining regression equation with the AUC0-∞ and dose of gastrodin injection, the percent conversion of parishin to gastrodin was obtained as 50 %. Based on multi-active metabolites of parishin in vivo, integrated pharmacokinetic mode was established. It is notable that each metabolite from parishin shares the similar metabolic process at three dosages of parishin and the bioavailability of parishin was approximately 14 %. The integrated pharmacokinetic mode was successfully applied to evaluate the holistic pharmacokinetics of gastrodin injection, G. elata extract and Rhizoma Gastrodiae capsule. The results showed that the holistic pharmacokinetics of gastrodin injection and G. elata extract was closed to that of gastrodin, but for parishin and Rhizoma Gastrodiae capsule, integrated pharmacokinetic parameters were more suitable to evaluate its holistic pharmacokinetics. Graphical abstract Pharmacokinetic study of Gastrodia elata in rats.

[Pharmacokinetic study on combined application of gastrodin and puerarin in rats].

To establish a HPLC method for simultaneously determining plasma concentrations of gastrodin (Gas) and its metabolites hydroxybenzyl alcohol (HBA), puerarin (Pur) and internal standard (IS) p-hydroxyphenylethanol (Tyr) in rats and studying the pharmacokinetic process and interactions of gastrodin and puerarin after single and combined intravenous injection and oral administration. With Tyr as the internal standard, plasma samples were processed with methanol for protein precipitation, supernatant was dried with N2, and residues were re-dissolved with acetonitrile-0.05% phosphoric acid (20: 80). Chromatography was carried out on an Agilent ZORBAX SB-Aq C18 column (4.6 mm x 250 mm, 5 µm), with acetonitrile-0.05% phosphoric acid as the gradient mobile phase for the gradient elution. The UV detector wavelength was set at 221 nm for Gas HBA and IS and 250 nm for Pur. After the single or combined administration of Gas and Pur, their plasma concentrations in rats were detected. WinNonlin 5.2 pharmacokinetic software and SPSS 17. 0 software were used to respectively calculate pharmacokinetic parameters of each group, make a statistical analysis and compare the pharmacokinetic processes of Gas and Pur after the single or combined administration. According to the results, the absolute recoveries between low, media and high concentrations of Gas, HBA and Pur and IS as well as Tyr were more than 77.20%, with a good linearity (r > 0.999 6, n = 5) for Gas, HBA and Pur within concentration ranges of 0.10-101, 0.03-7.58 and 0.05-5.98 mg xL ('1) respectively. The lower limits of quantification for Gas, HBA and Pur were 0.10, 0.03, 0.05 mg x L(-1), respectively. Their in-ra-day and inter-day precisions were less than 12% with the accuracy between 85. 1% -1 10. %. All of the three substances and IS were stable during the whole analysis process. The findings showed significant differences in the main in vivo pharmacokinetic parame-ers in rats (AUC, C.(max) T,½ T.(max) MRT) after the single and combined administration of Gas and Pur. Either after the oral adminis-ration or after the intravenous injection, parameters showed a lower clearance rate ( L) longer mean residence time ( RT) and higher relative bioavailability, especially after the oral administration. Specifically, the relative bioavailability of the combined oral ad-inistration of Pur was 10. 7 times of that of the single administration, while that of Gas was 1. times of that of the single administra-ion. The combined administration of Gas and Pur can promote the absorption, decrease the elimination rate and prolong the mean resi-ence time. The method is simple and accurate and can be applied in the simultaneous determination of plasma concentrations of Gas, HBA and Pur in rats and the pharmacokinetic studies.

Analysis of the metabolic profile of parishin by ultra-performance liquid chromatography/quadrupole-time of flight mass spectrometry.

Parishin is a dominant active ingredient originating from Gastrodia elata Blume, and has good neuroprotective effects against brain disorders. In the present study, the metabolic profile of parishin by in vitro and in vivo experiments was investigated using ultra-high performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry (UHPLC/Q-TOF MS) combined with an automated MS(E) technique. By comparison with reference compounds, accurate mass measurement, the characteristic fragmentation patterns of the parent drug parishin and gastrodin and relevant bio-transformation knowledge, 14 metabolites (seven hydrolyzates and seven derivatives of gastrodin) were detected and identified in rat plasma and urine after intragastric administration of parishin, including processes of hydrolyzation, oxidation, sulfation and glucuronidation. According to the proposed metabolic pathways of parishin, in vitro hydrolytic experiments and metabolic study of gastrodin in rat plasma, it can be inferred that parishin mainly functions as a prodrug and undergoes hydrolysis before being absorbed into the blood. The hydrolyzate, mainly gastrodin, was involved in further metabolism, which was responsible for pharmacological activities of parishin. In conclusion, this work provides valuable information on parishin metabolism using a rapid and reliable UHPLC/Q-TOF MS method, which could be widely used for the metabolic investigation of natural product.

Blood eosinophil counts, exacerbations, and response to the addition of inhaled fluticasone furoate to vilanterol in patients with chronic obstructive pulmonary disease: a secondary analysis of data from two parallel randomised controlled trials.

BACKGROUND: The short-term benefits of inhaled corticosteroids for patients with chronic obstructive pulmonary disease (COPD) are greater in patients with evidence of eosinophilic airway inflammation. We investigated whether blood eosinophil count is a useful biomarker of the long-term effect of the inhaled corticosteroid fluticasone furoate on exacerbation frequency. METHODS: We did a post-hoc analysis of data from two replicate, randomised, double-blind trials of 12 months' duration (Sept 25, 2009 to Oct 21, 2011 and Oct 17, 2011) in which once a day vilanterol 25 µg was compared with 25 µg vilanterol plus 50 µg, 100 µg, or 200 µg fluticasone furoate in patients with moderate-to-severe COPD and a history of one or more exacerbation in the previous year. We compared exacerbation rates according to two baseline eosinophil cell count strata (<2% and ≥2%), and according to four baseline percentage groupings. We also assessed lung function and incidence of pneumonia per strata in treatment groups. FINDINGS: We included 3177 patients in the analyses, with 2083 patients (66%) having an eosinophil count of 2% or higher at study entry. Across all doses of inhaled corticosteroids, fluticasone furoate and vilanterol reduced exacerbations by 29% compared with vilanterol alone (mean 0·91 vs 1·28 exacerbations per patient per year; p<0·0001) in patients with eosinophil counts of 2% or higher, and by 10% (0·79 vs 0·89; p=0·2827) in patients with eosinophil counts lower than 2%. Reductions in exacerbations with fluticasone furoate and vilanterol, compared with vilanterol alone, were 24% in patients with baseline eosinophil counts of ≥2-<4%, 32% for those with counts of 4-<6%, and 42% for those with eosinophil counts of ≥6%. In patients treated with vilanterol alone, exacerbation rates increased progressively with increasing eosinophil count percentage category. Improvement in trough forced expiratory volume in 1 s (FEV1) and the increased risk of pneumonia with fluticasone furoate and vilanterol compared with vilanterol alone were not associated with eosinophil count. INTERPRETATION: Blood eosinophil count is a promising biomarker of response to inhaled corticosteroids in patients with COPD. Blood eosinophil count could potentially be used to stratify patients for different exacerbation rate reduction strategies. FUNDING: GlaxoSmithKline (study ID 201595).

The pharmacodynamics, pharmacokinetics, safety and tolerability of inhaled fluticasone furoate and vilanterol administered alone or simultaneously as fluticasone furoate/vilanterol.

PURPOSE: To investigate the potential for systemic pharmacokinetic (PK) and pharmacodynamic (PD) interactions between inhaled fluticasone furoate (FF) and vilanterol (VI) when delivered simultaneously via the ELLIPTA™ dry powder inhaler (DPI). METHODS: Randomized, double-blind, placebo-controlled, crossover study. Healthy subjects (n = 16) received single doses of FF (800 mcg), VI (100 mcg), FF/VI (800/100 mcg), and placebo. Endpoints measured were systemic PD (FF: serum cortisol; VI: heart rate), FF and VI plasma PK (0-48 hours), pharyngometry, inhalation and breath hold profiles and safety assessments. RESULTS: Treatment differences [90% confidence interval (CI)] in weighted mean serum cortisol (0-24 hours) were 12.3% [4.4, 20.9] (FF/VI vs. FF) and for maximum heart rate (0-4 hours) were -1.2 bpm [-4.6, 2.1] (FF/VI vs. VI). When delivered simultaneously, FF and VI systemic exposures were slightly lower (<20%) versus delivery of either agent alone (although this was not a formal bioequivalence study). In vitro simulation of selected inhalation profiles and modeling supported the PK and PD findings. FF/VI, FF and VI were well tolerated with an AE incidence comparable to placebo. CONCLUSIONS: These results suggest there was a slight PK interaction and no PD interactions of concern between inhaled FF and VI when delivered simultaneously via the ELLIPTA DPI in healthy subjects.

Relative bioavailability of gastrodin and parishin from extract and powder of Gastrodiae rhizoma in rat.

A rapid, sensitive and reliable UHPLC-ESI-MS/MS method was developed for simultaneous determination of gastrodin and parishin in rat plasma. The LLOQ of the two analytes were 1.00×10(-1) and 8.30×10(-5)µg/mL, respectively. The intra-day and inter-day precision were all less than 10% of the relative standard deviation (RSD), whilst the accuracy were all within ±15% of the relative error (RE). The proposed method was successfully applied for pharmacokinetics study on the two analytes in rats after oral administration of Gastrodiae rhizoma (GR) extract and powder at low, medium and high dosages. Blood samples were collected from the suborbital vein at predetermined time points and were precipitated using methanol. Chromatographic separations were carried out on a Kinetex XB-C18 column (2.1mm×150mm, 1.7µm) with a gradient mobile phase of acetonitrile-water with 0.1% formic acid as a modifier. The pharmacokinetic parameters of the two analytes in rats were obtained and the relative bioavailability of gastrodin and parishin in two formulations were calculated. The results indicated that higher bioavailability was obtained when low dosage of GR powder was used, whereas, higher bioavailability values were obtained when medium and high dosages of GR extract were used.

Analysis and pharmacokinetics studies of gastrodin and p-hydroxybenzyl alcohol in dogs using ultra fast liquid chromatography-tandem mass spectrometry method.

A simple, sensitive and reliable ultra fast liquid chromatography-electrospray ionization-tandem mass spectrometry (UFLC-ESI-MS/MS) method was developed for simultaneously quantifying gastrodin (p-hydroxy-methyl-phenol-ß-d-glucoside) and its metabolite p-hydroxybenzyl alcohol (HBA) in dog plasma. Separation was performed on an ultra fast liquid chromatography (UFLC) system. Detection was carried out on a tandem mass spectrometry (MS/MS) in multiple reaction monitoring (MRM) mode via an electrospray ionization (ESI) interface. MRM mode of precursor-product ion transitions was used for gastrodin, HBA and the internal standard (IS, bergeninum) at m/z 285.0→123.0, 123.0→105.0 and 326.9→192.2, respectively. The lower limits of quantification (LLOQ) of this method for both gastrodin and HBA were 1ng/mL, with their linear concentration ranging from 0.001 to 10µg/mL. The methods were validated for selectivity, calibration curves, accuracy and precision, extraction recoveries, matrix effects, carry-over, cross talk, dilution integrity, stability and incurred sample reanalysis (ISR). Using this validated method, pharmacokinetic behaviors of gastrodin and HBA after intragastric administration (ig) of gastrodin to dogs were studied for the first time.

Identification and analysis of gastrodin and its five metabolites using ultra fast liquid chromatography electrospray ionization tandem mass spectrometry to investigate influence of multiple-dose and food.

A reliable and highly sensitive ultra performance liquid chromatography electrospray ionization tandem mass spectrometry (UFLC-ESI-MS/MS) analytical method was developed for identification and quantification of gastrodin (GAS) and its metabolites in rat plasma. Five metabolites were identified: p-formylphenyl-ß-d-glucopyranoside (M1), p-hydroxybenzonic acid (M2), p-hydroxybenzyl alcohol (M3), p-formaldehydephenyl-ß-d-glucopyranoside (M4), p-hydroxybenzaldehyde (M5). The molecular structures of metabolites were proposed based on the characters of their precursor ions, product ions and chromatographic retention time. Four of them were reported firstly in rat plasma. This method involved the addition of bergeninum as the internal standard (IS), UFLC separation, and quantification by MS/MS system using negative electrospray ionization in the multiple reaction monitoring (MRM) mode. The lower limit of quantification of gastrodin and five metabolites were all 1ng/mL. The method was linear in the concentration range of 0.001-10µg/mL. The intra- and inter-day precisions (R.S.D %) were within 15.0% for all analytes. No interference was noted due to endogenous substances. All analytes were stable in rat plasma stored at room temperature and 4°C for at least 4h, -20°C combined with three freeze-thaw cycles for at least 1 month. By this method, the influence of multiple-dose and food on the pharmacokinetics behaviors of GAS and its metabolites were studied for the first time. We hope pharmacokinetic data of present study may inspire rational clinical usage of GAS.

Effect of verapamil on systemic exposure and safety of umeclidinium and vilanterol: a randomized and open-label study.

BACKGROUND: The combination of umeclidinium (UMEC), a long-acting muscarinic receptor antagonist, and vilanterol (VI), a selective long-acting ß2 agonist, is in development for the treatment of chronic obstructive pulmonary disease (COPD). This study evaluated the pharmacokinetics, safety and tolerability, and pharmacodynamics of once-daily, inhaled UMEC and UMEC/VI when co-administered with oral verapamil, a moderate P-glycoprotein transporter and moderate cytochrome P450 3A4 (CYP3A4) inhibitor frequently used by patients with COPD and cardiovascular comorbidities. METHODS: Subjects were randomized to one of two 13-day treatment regimens: UMEC 500 µg or UMEC 500 µg/VI 25 µg. All subjects received a single tablet containing 240 mg verapamil on each of days 9-13. RESULTS: Repeat doses of UMEC and UMEC/VI in combination with and without verapamil were safe and well tolerated. There was no increase in systemic exposure of UMEC when administered in combination with VI compared to UMEC alone. UMEC maximum concentration was similar with or without verapamil; a moderate increase in UMEC area under the curve (approximately 1.4-fold) was observed with verapamil. Verapamil did not increase systemic exposure to VI following administration of the UMEC/VI combination. CONCLUSION: Administration of UMEC and UMEC/VI combination was well tolerated and did not show clinically relevant increases in systemic exposure for either drug. The UMEC/VI combination is unlikely to have a clinically meaningful drug-drug interaction with moderate P-glycoprotein transporter and CYP3A4 inhibitor drugs.