scholarly journals LC-MS/MS Quantification of Nevirapine and Its Metabolites in Hair for Assessing Long-Term Adherence

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5692
Author(s):  
Haoran Yang ◽  
Liuxi Chu ◽  
Yan Wu ◽  
Wei Wang ◽  
Jin Yang ◽  
...  
Keyword(s):  
Population Analysis ◽  
Multiple Reaction Monitoring ◽  
Simultaneous Detection ◽  
Oral Drug ◽  
Limit Of Quantification ◽  
Selective Method ◽  
Coefficients Of Variation ◽  
Adherence Assessment ◽  
High Consistency

The adherence assessment based on the combination of nevirapine (NVP) and its two metabolites (2-hydroxynevirapine and 3-hydroxynevirapine) would more comprehensively and accurately reflect long-term adherence than that of a single prototype. This study aimed to develop a specific, sensitive and selective method for simultaneous detection of the three compounds in hair and explore whether there was consistency among the three compounds in assessing long-term adherence. Furthermore, 75 HIV-positive patients who were taking the NVP drug were randomly recruited and divided into two groups (high-and low-adherence group). All participants self-reported their days of oral drug administration per month and provided their hair strands closest to the scalp at the region of posterior vertex. The concentrations of three compounds in the hair were determined using a developed LC-MS/MS method in multiple reaction monitoring. This method showed good performances in limit of quantification and accuracy with the recoveries from 85 to 115% and in precision with the intra-day and inter-day coefficients of variation within 15% for the three compounds. The population analysis revealed that patients with high-adherence showed significantly higher concentrations than those with low-adherence for all three compounds. There were significantly moderate correlations of nevirapine with 2-hydroxynevirapine and 3-hydroxynevirapin and high correlation between 2-hydroxynevirapine and 3-hydroxynevirapin. The two NVP’s metabolites showed high consistency with NVP in evaluating long-term adherence.

LRF and TRF test during long-term danazol treatment: increase of the LH and FSH responses but decrease of the prolactin and TSH responses

1983 ◽  
Vol 104 (1) ◽  
pp. 1-5 ◽  
Author(s):  
J. Leppäluoto ◽  
L. Rönnberg ◽  
P. Ylöstalo
Keyword(s):  
Clinical Symptoms ◽  
Follicular Phase ◽  
Blood Samples ◽  
Hormone Levels ◽  
Coefficients Of Variation ◽  
The Mean ◽  
Thyroid Hormone Levels ◽  
Low Serum

Abstract. Seven patients suffering from severe endometriosis were treated with danazol 200 mg × 3 daily for 6 months. Clinical symptoms were alleviated and menses disappeared in response to the treatment. After cessation of the treatment the menstrual bleedings returned in 1–3 months. Blood samples for determination of gonadotrophins, prolactin (Prl), oestradiol (E2), progesterone, thyroid hormones and thyrotrophin in radioimmunoassays were taken and a combined TRF and LRF test carried out in the follicular phase before treatment, at the 6th month of treatment and after reappearance of the first menses. There were no statistically significant changes in the basal levels of serum FSH, LH or TSH during the danazol treatment. Neither was there any change in episodic secretions of FSH, LH or Prl, as determined by the mean coefficients of variation of the hormone levels in seven consecutive samples taken at 20 min intervals. On the other hand, serum E2, Prl and thyroid hormone levels were significantly decreased in the 6th month of treatment. In the TRF-LRF test the responses of serum FSH and LH were significantly higher and those of serum Prl and TSH significantly lower during danazol treatment than before. Prl responses remained lowered after the treatment. It appears that low serum oestrogen levels, induced by the danazol treatment, sensitize the pituitary gonadotrophs to exogenous LRF, but make the sensitivity of thyrotrophs and lactotrophs lower to exogenous TRF. These results thus indicate that danazol does not make the pituitary gonadotrophs insensitive to LRF, but danazol may rather inhibit the secretion of hypothalamic LRF.

scholarly journals Determination of sarecycline by UPLC-MS/MS and its application to pharmacokinetic study in rats

2020 ◽  
Author(s):  
Yonghui Shen ◽  
Deru Meng ◽  
Feifei Chen ◽  
Hui Jiang ◽  
Liming Hu ◽  
...  
Keyword(s):  
Pharmacokinetic Study ◽  
Multiple Reaction Monitoring ◽  
Internal Standard ◽  
Gradient Elution ◽  
Rat Plasma ◽  
Chronic Inflammatory Disease ◽  
Linear Calibration ◽  
Limit Of Quantification ◽  
Acquity Uplc ◽  
Intravenous And Oral Administration

AbstractSarecycline is a narrow-spectrum antibiotic for the treatment of acne, which is a chronic inflammatory disease of the hair follicle sebaceous glands. In the study, UPLC-MS/MS was used to establish a rapid and accurate analytical method. The sarecycline was determined with poziotinib as internal standard (IS) in rat plasma. An ACQUITY UPLC HSS T3 column (2.1 × 100 mm, 1.8 μm) could performe chromatographic separation with the mobile phase (methanol: water of 0.1% formic acid) with gradient elution. The ions of target fragment were m/z 488.19→410.14 for sarecycline and m/z 492.06→354.55 for poziotinib, which could quantify the electrospray ionization of positive multiple reaction monitoring (MRM) mode. The linear calibration curve of the concentration range was 1–1,000 ng/mL for sarecycline with a lower limit of quantification (LLOQ) of 1 ng/mL. The mean recovery was between 82.46 and 95.85% for sarecycline and poziotinib in rat plasma. RSD for precision of inter-day and intra-day were between 3.24 and 13.36%, and the accuracy ranged from 105.26 to 109.75%. The developed and validated method was perfectly used in the pharmacokinetic study and bioavailability of sarecycline after intravenous and oral administration in rats.

scholarly journals Dasatinib Nanoemulsion and Nanocrystal for Enhanced Oral Drug Delivery

Pharmaceutics ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 197
Author(s):  
Chuanqi Wang ◽  
Manting Wang ◽  
Peng Chen ◽  
Jiexin Wang ◽  
Yuan Le
Keyword(s):  
Mass Production ◽  
Oral Drug Delivery ◽  
Active Pharmaceutical Ingredient ◽  
Cell Permeability ◽  
Oral Drug ◽  
High Gravity ◽  
Gravity Level ◽  
Dilution Experiments

In this work, dasatinib (DAS) nanoemulsion and nanocrystal are produced by high-gravity technology that approaches to practical mass production. The drug nanoformulations were systematically characterized and evaluated. At a low high-gravity level (β) = 47, nanoemulsion droplets were 16.15 ± 0.42 nm with a PDI of 0.122 ± 0.021. The nanoemulsion’s size and active pharmaceutical ingredient (API) content remained stable at long-term (4 months) freeze–thaw and dilution experiments. At a high β = 188, the as-prepared nanocrystal was lamellar with a short diameter of about 200 nm and a long diameter of about 750 nm. In vitro performances demonstrated the nanoemulsion displayed higher cytotoxicity on MDA-MB-231 tumor cells, Caco-2 cell permeability and drug release than that of the nanocrystal, indicating that nanoemulsion should be an ideal alternative for dasatinib oral administration.

scholarly journals Compatibility of different measurement techniques. Long-term global solar radiation observations at Izaña Observatory

2016 ◽  
Author(s):  
Rosa Delia García ◽  
Emilio Cuevas ◽  
Omaira Elena García ◽  
Ramon Ramón ◽  
Pedro Miguel Romero-Campos ◽  
...  
Keyword(s):  
Time Series ◽  
Solar Radiation ◽  
Sunshine Duration ◽  
Measurement Techniques ◽  
Temporal Stability ◽  
Global Solar Radiation ◽  
Surface Radiation ◽  
Multifilter Rotating Shadowband Radiometer ◽  
High Consistency

Abstract. A 1-year intercomparison of classical and modern radiation and sunshine duration instruments has been performed at Izaña Atmospheric Observatory (IZO) located in Tenerife (Canary Islands, Spain) starting on July 17, 2014. We compare global solar radiation (GSR) records measured with a CM-21 pyranometer Kipp & Zonen, taken in the framework of the Baseline Surface Radiation Network, with those measured with a Multifilter Rotating Shadowband Radiometer (MFRSR), and a bimetallic pyranometer (PYR), and GSR estimated from sunshine duration performed by a Campbell-Stokes sunshine recorder (CS) and a Kipp & Zonen sunshine duration sensor (CSD). Given the GSR BSRN records are subject of strict quality controls (based on principles of physical limits and comparison with the LibRadtran model), they have been used as reference in the intercomparison study. We obtain an overall root mean square error (RMSE) of ~0.9 MJm2 (4 %) for GSR PYR and GSR MFRSR, 1.9 MJm2 (7 %) and 1.2 MJm2 (5 %) for GSR CS and GSR CSD, respectively. Factors such as temperature, fraction of the clear sky, relative humidity and the solar zenith angle have shown to moderately affect the GSR observations. As application of the methodology developed in this work, we have re-evaluated the GSR time series between 1977 and 1991 obtained with two PYRs at IZO. By comparing with coincident GSR estimates from SD observations, we probe the high consistency of those measurements and their temporal stability. These results demonstrate that 1) the continuous-basis intercomparison of different GSR techniques offers important diagnostics for identifying inconsistencies between GSR data records, and 2) the GSR measurements performed with classical and more simple instruments are consistent with more modern techniques and, thus, valid to recover GSR time series and complete worldwide distributed GSR data. The intercomparison and quality assessment of these different techniques have allowed to obtain a complete and consistent long-term global solar radiation series (1977–2015) at Izaña.

scholarly journals Quantification of Venturia inaequalis Growth in Malus × domestica with Quantitative Real-Time Polymerase Chain Reaction

Plant Disease ◽  
2012 ◽  
Vol 96 (12) ◽  
pp. 1791-1797 ◽  
Author(s):  
Michele Gusberti ◽  
Andrea Patocchi ◽  
Cesare Gessler ◽  
Giovanni A. L. Broggini
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
Malus Domestica ◽  
Venturia Inaequalis ◽  
Simultaneous Detection ◽  
Scab Resistance ◽  
Infected Leaf ◽  
Chain Reaction ◽  
Limit Of Quantification ◽  
Polymerase Chain

A quantitative real-time polymerase chain reaction (qPCR) was developed and validated for quantification of Venturia inaequalis in infected leaf tissue of Malus × domestica. The method is based on dual-labeled hybridization probes, allowing simultaneous detection of host and pathogen DNA within one single reaction. Limit of quantification for the pathogen was 0.5 pg per reaction and, for the host, reached 5 pg per reaction. The fungal growth measured in four apple cultivars 2 weeks after inoculation significantly correlated with their different level of scab resistance and allowed the observation of ontogenic resistance. After sporulation on the youngest leaf, fungal biomass in susceptible ‘Gala’ was 118 times higher than in resistant ‘Florina’ and ‘Discovery’ while intermediate values were found with the intermediate susceptible ‘Milwa’. Correlation was also observed between severity classes obtained by visual scoring of symptoms and qPCR results. Moreover, qPCR demonstrated validity of the developed method as a disease severity forecast tool 10 days after the pathogen's inoculation and prior to the appearance of the symptoms. Applications of the methodology can include the quantification of scab resistance during breeding programs, evaluation of fungicide and biocontrol efficacy, and quantification of the fitness of different pathogenic strains.

Quantification of the Plasma Concentrations of Perampanel Using High-Performance Liquid Chromatography and Effects of the CYP3A4*1G Polymorphism in Japanese Patients

2020 ◽  
Vol 58 (10) ◽  
pp. 915-921
Author(s):  
Sho Ohkubo ◽  
Yumiko Akamine ◽  
Tadashi Ohkubo ◽  
Yuka Kikuchi ◽  
Masatomo Miura
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Clinical Practice ◽  
Plasma Volume ◽  
High Performance ◽  
Plasma Concentrations ◽  
Japanese Patients ◽  
Hplc Method ◽  
Limit Of Quantification ◽  
Coefficients Of Variation

Abstract Here, we developed a novel high-performance liquid chromatography (HPLC) method for quantification of perampanel in clinical practice and investigated the relationships between the plasma concentrations of perampanel obtained by this HPLC method and the CYP3A4*1G polymorphism. The developed HPLC method was validated based on US Food and Drug Administration. The developed HPLC method could be performed with a plasma volume of only 200 μL and had a limit of quantification (LOQ) of 2.5 ng/mL. The coefficients of variation (CVs) for intra- and inter-day assays were less than 10.4 and 7.2%, respectively, and the accuracy was <2.4% for both assays. A total of 12 patients who received 2 mg perampanel had C0 values ranging from 70.5 to 451 ng/mL, and the CV showed a large variation of 51.4%. No correlations were observed between the dose-adjusted C0 and the CYP3A4*1G polymorphism. This method was superior to previously reported methods in terms of plasma volume and LOQ and was clinically applicable. Perampanel showed high variations in individual plasma concentrations; however, individual differences could not be predicted from analysis of the CYP3A4*1G polymorphism before perampanel administration. Therefore, after beginning perampanel treatment, the dose should be determined based on the observed plasma concentration.

scholarly journals Development and Validation of a Sensitive UHPLC-MS/MS Method for the Measurement of Gardneramine in Rat Plasma and Tissues and its Application to Pharmacokinetics and Tissue Distribution Study

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3953 ◽  
Author(s):  
Zhao ◽  
Tan ◽  
Chen ◽  
Sun ◽  
Wang ◽  
...  
Keyword(s):  
Multiple Reaction Monitoring ◽  
Indole Alkaloid ◽  
Internal Standard ◽  
Gradient Elution ◽  
Rat Plasma ◽  
Limit Of Quantification ◽  
Tissue Samples ◽  
Distribution Study

As a novel monoterpenoid indole alkaloid, gardneramine has been confirmed to possess excellent nervous depressive effects. However, there have been no reports about the measurement of gardneramine in vitro and in vivo. The motivation of this study was to establish and validate a specific, sensitive, and robust analytical method based on UHPLC-MS/MS for quantification of gardneramine in rat plasma and various tissues after intravenous administration. The analyte was extracted from plasma and tissue samples by protein precipitation with methanol using theophylline as an internal standard (I.S.). The analytes were separated on an Agilent ZORBAX Eclipse Plus C18 column using a gradient elution of acetonitrile and 0.1% formic acid in water at a flow rate of 0.3 mL/min. Gardneramine and I.S. were detected and quantified using positive electrospray ionization in multiple reaction monitoring (MRM) mode with transitions of m/z 413.1→217.9 for gardneramine and m/z 181.2→124.1 for I.S.. Perfect linearity range was 1–2000 ng/mL with a correlation coefficient (r2) of ≥0.990. The lower limit of quantification (LLOQ) of 1.0 ng/mL was adequate for application to different preclinical studies. The method was successfully applied for determination of gardneramine in bio-samples.

scholarly journals 2249

2017 ◽  
Vol 1 (S1) ◽  
pp. 59-59
Author(s):  
Darrell Dinwiddie ◽  
Walter Dehority ◽  
Kurt C. Schwalm ◽  
Raymond J. Langley ◽  
Stephen A. Young ◽  
...  
Keyword(s):  
Immune Response ◽  
Innate Immune Response ◽  
Pediatric Patients ◽  
Simultaneous Detection ◽  
Innate Immune ◽  
Host Gene ◽  
Mixed Cell ◽  
Significant Differential Expression ◽  
Rsv Infection

OBJECTIVES/SPECIFIC AIMS: Respiratory viruses cause enormous medical burden, yet many of the specific virus and host genetic factors that impact pathogenesis are still largely unknown or poorly understood. To better understand the drivers of both acute clinical pathogenesis and long-term impacts, such as the development of asthma, we investigated the host response to respiratory syncytial virus (RSV) infections in pediatric patients. METHODS/STUDY POPULATION: We collected nasopharyngeal swabs from 32 pediatric patients with acute RSV infection. The swabs represented a mixed cell population including epithelial and immune cells at the active site of infection. Unbiased RNA sequencing with ribosomal RNA depletion allowed the simultaneous detection of host gene expression and RSV infection. We sequenced samples 2×75 bp on an Illumina NextSeq 500. Sequences were mapped to the human genome using the TopHat 2 aligner and FPKM estimation of reference genes and transcripts and assembly of novel transcripts were conducted with Cufflinks 2. RESULTS/ANTICIPATED RESULTS: During acute RSV infection we identified 7343 genes that were significantly expressed. Pathway analysis using KEGG revealed significant upregulation of pathways involved in innate immune response infection, ribosome function, oxidative phosphorylation, spliceosome and autoimmune disorders. We found high levels of innate immune response genes including CXCL8, IFITM1, IFITM2, IFITM3, IL1RN, and ISG15. In comparing RSV subtype A to RSV B we found significant differential expression of multiple noncoding RNAs. DISCUSSION/SIGNIFICANCE OF IMPACT: Examination of the host gene response during acute RSV infections, yielded important insight into the mechanisms that cause clinical pathogenesis and may provide understanding of the mechanisms that lead to known long-term impacts, such as the development of asthma. Together, this data may be used to guide clinical treatment and management decisions for children with severe RSV infections.

scholarly journals Transdermal patches: Design and current approaches to painless drug delivery

2019 ◽  
Vol 69 (2) ◽  
pp. 197-215 ◽  
Author(s):  
Othman A. Al Hanbali ◽  
Haji Muhammad Shoaib Khan ◽  
Muhammad Sarfraz ◽  
Mosab Arafat ◽  
Shakeel Ijaz ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Oral Drug Delivery ◽  
Hepatic Metabolism ◽  
Enzymatic Digestion ◽  
Assessment Tools ◽  
Oral Drug ◽  
Formulation Development ◽  
Transdermal Patches ◽  
Cardiac Disorders

Abstract Use of transdermal patches can evade many issues associated with oral drug delivery, such as first-pass hepatic metabolism, enzymatic digestion attack, drug hydrolysis and degradation in acidic media, drug fluctuations, and gastrointestinal irritation. This article reviews various transdermal patches available in the market, types, structural components, polymer role, and the required assessment tools. Although transdermal patches have medical applications for smoking cessation, pain relief, osteoporosis, contraception, motion sickness, angina pectoris, and cardiac disorders, advances in formulation development are ongoing to make transdermal patches capable of delivering more challenging drugs. Transdermal patches can be tailored and developed according to the physicochemical properties of active and inactive components, and applicability for long-term use. Therefore, a number of chemical approaches and physical techniques for transdermal patch development are under investigation.

scholarly journals A simple spectrophotometric method for the determination of methyldopa using p-chloranil in the presence of hydrogen peroxide

2008 ◽  
Vol 33 (3) ◽  
pp. 7-12 ◽  
Author(s):  
M. A. Gotardo ◽  
L. S. Lima ◽  
R. Sequinel ◽  
J. L. Rufino ◽  
L. Pezza ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Spectrophotometric Method ◽  
Limit Of Detection ◽  
Pharmaceutical Formulations ◽  
Limit Of Quantification ◽  
Coefficients Of Variation ◽  
The Common ◽  
Interday Precision ◽  
Sensitive Spectrophotometric Method

A simple, rapid and sensitive spectrophotometric method has been developed for the determination of methyldopa in pharmaceutical formulations. The method is based on the reaction between tetrachloro-p-benzoquinone (p-chloranil) and methyldopa, accelerated by hydrogen peroxide (H2O2), producing a violet-red compound (λmax = 535 nm) at ambient temperature (25.0 ± 0.2 ºC). Experimental design methodologies were used to optimize the measurement conditions. Beer's law is obeyed in a concentration range from 2.10 x 10-4 to 2.48 x 10-3 mol L-1 (r = 0.9997). The limit of detection was 7.55 x 10-6 mol L-1 and the limit of quantification was 2.52 x 10-5 mol L-1. The intraday precision and interday precision were studied for 10 replicate analyses of 1.59 x 10-3 mol L-1 methyldopa solution and the respective coefficients of variation were 0.7 and 1.1 %. The proposed method was successfully applied to the determination of methyldopa in commercial brands of pharmaceuticals. No interferences were observed from the common excipients in the formulations. The results obtained by the proposed method were favorably compared with those given by the Brazilian Pharmacopoeia procedure at 95 % confidence level.

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