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1.
Cureus ; 16(5): e60309, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38756716

RESUMO

Introduction Benign prostatic hyperplasia (BPH) is a prevalent condition among aging men that affects their life quality due to urinary symptoms. Current pharmacologic treatments, often lead to sexual dysfunction, so dietary supplements (DS) containing plant-based compounds such as ß-sitosterol (SIT) are preferred. DS are highly accessible and widely used, but poorly regulated, so often patients are victims of fraud. The use of DS to treat BPH symptoms is questionable, and this may be due not to the efficacity of the active compound but to the quality of commonly available DS. Aim This study aimed to assess the concentration of SIT in DS available on the market and evaluate whether the concentration of the active compound at the recommended dosage is sufficient to elicit beneficial effects in BPH. Method An HPLC-UV method based on direct saponification and acid hydrolysis was developed for the quantification of free and conjugated SIT in DS. The concentration of SIT in various DS was determined and compared with the one declared on the label. Results The chromatographic analysis confirmed the presence of SIT in all the DS but also showed a considerable variability of SIT content among DS, with only one product meeting the necessary concentration to bring potential benefits in BPH. Conclusion The study highlights inconsistencies in SIT content among DS and the importance of DS containing a standardized extract of SIT. Quality control measures are imperative to ensure that consumers receive effective and safe SIT-based DS to manage BPH symptoms. Further research is needed to establish standardized dosages and to evaluate their long-term efficacy and safety.

2.
J Chromatogr Sci ; 62(2): 191-200, 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-36715315

RESUMO

Liquid chromatography coupled to mass spectrometry already started to surpass the major drawbacks in terms of sensitivity, specificity and cross-reactivity that some analytical methods used in the clinical laboratory exhibit. This hyphenated technique is already preferred for specific applications while finding its own place in the clinical laboratory setting. However, large-scale usage, high-throughput analysis and lack of automation emerge as shortcomings that liquid chromatography coupled to mass spectrometry still has to overrun in order to be used on a larger scale in the clinical laboratory. The aim of this review article is to point out the present-day position of the liquid chromatography coupled to mass spectrometry technique while trying to understand how this analytical method relates to the basic working framework of the clinical laboratory. This paper offers insights about the main regulation and traceability criteria that this coupling method has to align and comply to, automation and standardization issues and finally the critical steps in sample preparation workflows all related to the high-throughput analysis framework. Further steps are to be made toward automation, speed and easy-to-use concept; however, the current technological and quality premises are favorable for chromatographic coupled to mass spectral methods.


Assuntos
Laboratórios Clínicos , Cromatografia Líquida/métodos , Espectrometria de Massas/métodos , Automação , Padrões de Referência
3.
Front Mol Biosci ; 10: 1243103, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37828919

RESUMO

Introduction: Ropivacaine is a popular local anesthetic used for regional anesthesia or for pain management. Although designed as an enantiomerically pure drug, an aspect that reduces the adverse effects, its toxicological effects are still a risk. As such, biomonitoring to assure appropriate dosage and bioavailability are essential to avoid complications during or post-surgery. Methods: The study focused on developing a sensitive, selective, and accurate liquid chromatography-mass spectrometry (LCMS/MS) method which facilitates the biomonitoring of ropivacaine and its main metabolite in plasma after regional anesthesia using ropivacaine. Results and Discussion: The method was validated with regards to all relevant parameters, such as sensitivity, selectivity, accuracy, precision, and the effect of sample matrix. The method was successfully used in a pilot study, which included one patient undergoing plane block anesthesia for cardiac device implantation. The results showed the method is appropriate for its intended purpose and could even be used in other, similar applications.

4.
Chirality ; 35(10): 779-792, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37221930

RESUMO

Carvedilol, a highly protein-bound beta-blocker, is used in therapy as a racemic mixture of its two enantiomers that exhibit different pharmacological activity. The aim of this study was to evaluate the stereoselective nature of its binding to the two major plasma proteins: albumin and alpha-1-acid glycoprotein. The determination of the plasma protein-binding degree for carvedilol and its enantiomers was achieved using ultrafiltration for the separation of the free fraction, followed by LC-MS/MS quantification, using two different developed and validated methods in terms of stationary phase: achiral C18 type and chiral ovomucoid type. Furthermore, molecular docking methods were applied in order to investigate and to better understand the mechanism of protein-binding for S-(-)- and R-(+)-carvedilol. A difference in the binding behavior of the two enantiomers to the plasma proteins was observed when taken individually, with R-(+)-carvedilol having a higher affinity for albumin and S-(-)-carvedilol for alpha-1-acid glycoprotein. However, in the case of the racemic mixture, the binding of the S enantiomer to alpha-1-acid glycoprotein seemed to be influenced by the presence of its antipode, although no such influence was observed in the case of albumin. The results raise the question of a binding competition between the two enantiomers for alpha-1-acid glycoprotein.


Assuntos
Antagonistas Adrenérgicos beta , Carvedilol , Orosomucoide , Albumina Sérica Humana , Humanos , Albuminas , Carbazóis/química , Carvedilol/química , Cromatografia Líquida/métodos , Simulação de Acoplamento Molecular , Orosomucoide/química , Albumina Sérica Humana/química , Estereoisomerismo , Espectrometria de Massas em Tandem/métodos , Ligação Proteica , Ligação Competitiva , Antagonistas Adrenérgicos beta/química
5.
Pharmaceutics ; 15(4)2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37111791

RESUMO

The development of safe and effective pediatric formulations is essential, especially in therapeutic areas such as pediatric cardiology, where the treatment requires multiple dosing or outpatient care. Although liquid oral dosage forms are considered the formulation of choice given the dose flexibility and acceptability, the compounding practices are not endorsed by the health authorities, and achieving stability can be problematic. The purpose of this study is to provide a comprehensive overview of the stability of liquid oral dosage forms used in pediatric cardiology. An extensive review of the literature has been performed, with a particular focus on cardiovascular pharmacotherapy, by consulting the current studies indexed in PubMed, ScienceDirect, PLoS One, and Google Scholar databases. Regulations and guidelines have been considered against the studies found in the literature. Overall, the stability study is well-designed, and the critical quality attributes (CQAs) have been selected for testing. Several approaches have been identified as innovative in order to optimize stability, but opportunities to improve have been also identified, such as in-use studies and achieving dose standardization. Consequently, the information gathering and the results of the studies can be translated into clinical practice in order to achieve the desired stability of liquid oral dosage forms.

6.
Plants (Basel) ; 12(8)2023 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-37111945

RESUMO

The prevalence of benign prostatic hyperplasia (BPH) markedly increases with age. Phytotherapeutic approaches have been developed over time owing to the adverse side effects of conventional medications such as 5-reductase inhibitors and α1-adrenergic receptor antagonists. Therefore, dietary supplements (DS) containing active compounds that benefit BPH are widely available. Phytosterols (PSs) are well recognized for their role in maintaining blood cholesterol levels; however, their potential in BPH treatment remains unexplored. This review aims to provide a general overview of the available data regarding the clinical evidence and a good understanding of the detailed pharmacological roles of PSs-induced activities at a molecular level in BPH. Furthermore, we will explore the authenticity of PSs content in DS used by patients with BPH compared to the current legislation and appropriate analytical methods for tracking DS containing PSs. The results showed that PSs might be a useful pharmacological treatment option for men with mild to moderate BPH, but the lack of standardized extracts linked with the regulation of DS containing PSs and experimental evidence to elucidate the mechanisms of action limit the use of PSs in BPH. Moreover, the results suggest multiple research directions in this field.

7.
Nutrients ; 15(3)2023 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-36771293

RESUMO

Stroke prevention, a significant public-health concern, begins with recognizing and addressing risk factors. Interventions targeted at modifiable risk factors can effectively prevent ischemic stroke, while Omega-3 fatty acids have been shown to improve stroke outcomes. Our study aimed to investigate the relationship between ischemic-stroke risk factors and fatty acids using a prospective observational study with 274 patients. We collected clinical data on risk factors and measured fatty-acid levels using high-performance liquid chromatography coupled with mass spectrometry. We found that several risk factors, including age, sex, smoking, atrial fibrillation, dyslipidemia, and previous stroke history, had a direct relationship with fatty acids. Of these, smoking had the most significant impact, negatively impacting levels of docosahexaenoic and eicosapentaenoic acid. Conversely, dyslipidemia and atrial fibrillation positively correlated with fatty acids, particularly in female patients and those with recurrent strokes. Age was found to directly correlate with other risk factors and variations in fatty-acid ratios. The stroke rate was higher in males than females before the age of 70, but this trend reversed. Our findings suggest that better management of risk factors, particularly modifiable lifestyle factors, could improve fatty-acid profiles and the balance of Omega-3 and Omega-6 in patients with ischemic stroke.


Assuntos
Fibrilação Atrial , Ácidos Graxos Ômega-3 , AVC Isquêmico , Acidente Vascular Cerebral , Masculino , Humanos , Feminino , Ácidos Graxos , AVC Isquêmico/etiologia , AVC Isquêmico/complicações , Fibrilação Atrial/complicações , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/etiologia , Ácido Eicosapentaenoico , Ácidos Docosa-Hexaenoicos
8.
Artigo em Inglês | MEDLINE | ID: mdl-36834010

RESUMO

Glyphosate, and the ever growing reliance on its use in agriculture, has been a point of contention for many years. There have been debates regarding the risk and safety of using glyphosate-based herbicides as well as the effects of occupational, accidental, or systematic. Although there have been a number of studies conducted, the biomonitoring of glyphosate poses a series of challenges. Researchers attempting to determine the occupational exposure face questions regarding the most appropriate analytical techniques and sampling procedures. The present review aims to summarize and synthetize the analytical methodologies available and suitable for the purpose of glyphosate biomonitoring studies as well as discuss the advantages and disadvantages of each analytical technique, from the most modern to more well-established and older ones. The most relevant publications that have described analytical methods and published within the last 12 years were studied. Methods were compared, and the advantages and disadvantages of each methods were discussed. A total of 35 manuscripts describing analytical methods for glyphosate determination were summarized and discussed, with the most relevant one being compared. For methods that were not intended for biological samples, we discussed if they could be used for biomonitoring and approaches to adapt these methods for this purpose.


Assuntos
Herbicidas , Exposição Ocupacional , Monitoramento Biológico , Exposição Ocupacional/análise , Glicina , Agricultura , Glifosato
9.
Int J Mol Sci ; 23(18)2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-36142720

RESUMO

Stroke is the primary cause of death and disability worldwide, with ischemic stroke up to 80% of the total cases. Lipid profile was established as a major risk factor for stroke, but recent studies show a paradoxical relationship between serum values and the outcome of stroke patients. Our study aims to analyze the impact of the classic extended lipid profile, including fatty acids as potential neuroprotective biomarkers for the outcome of ischemic stroke patients. We included 298 patients and collected clinical, paraclinical, and outcome parameters. We used a method consisting of high-performance liquid chromatography coupled with mass spectrometry to quantify serum fatty acids. We observed a negative correlation between National Institutes of Health Stroke Scale (NIHSS) at admission and total cholesterol (p = 0.040; r = -0.120), respectively triglycerides (p = 0.041; r = -0.122). The eicosapentaenoic to arachidonic acid ratio has a negative correlation, while the docosahexaenoic to eicosapentaenoic acid ratio positively correlates with all the prognostic parameters, showing a potential neuroprotective role for eicosapentaenoic acid in preventing severe ischemic stroke. The impact of the lipid profile paradox and the dependency relationship with the fatty acids represent a significant predictive factor for the functional and disability prognostic of ischemic stroke patients.


Assuntos
Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Ácido Araquidônico , Biomarcadores , Colesterol , Ácido Eicosapentaenoico , Ácidos Graxos , Humanos , Triglicerídeos
10.
Pharmaceutics ; 14(7)2022 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-35890362

RESUMO

Orodispersible tablets (ODTs) are pharmaceutical formulations used to obtain fast therapeutic effects, usually recommended for geriatric and pediatric patients due to their improved compliance, bioavailability, ease of administration, and good palatability. This study aimed to develop ODTs with cannabidiol (CBD) phytocannabinoid extracted from Cannabis sativa used in the treatment of Lennox-Gastaut and Dravet syndromes. The tablets were obtained using an eccentric tableting machine and 9 mm punches. To develop CBD ODTs, the following parameters were varied: the Poloxamer 407 concentration (0 and 10%), the type of co-processed excipient (Prosolv® ODT G2-PODTG2 and Prosolv® EasyTab sp-PETsp), and the type of superdisintegrant (Croscarmellose-CCS, and Soy Polysaccharides-Emcosoy®-EMCS), resulting in eleven formulations (O1-O11). The following dependent parameters were evaluated: friability, disintegration time, crushing strength, and the CBD dissolution at 1, 3, 5, 10, 15, and 30 min. The dependent parameters were verified according to European Pharmacopoeia (Ph. Eur.) requirements. All the tablets obtained were in accordance with quality requirements in terms of friability (less than 1%), and disintegration time (less than 180 s). The crushing strength was between 19 N and 80 N. Regarding the dissolution test, only four formulations exhibited an amount of CBD released higher than 80% at 30 min. Taking into consideration the results obtained and using the Modde 13.1 software, an optimal formulation was developed (O12), which respected the quality criteria chosen (friability 0.23%, crushing strength of 37 N, a disintegration time of 27 s, and the target amount of CBD released in 30 min of 99.3 ± 6%).

11.
Artigo em Inglês | MEDLINE | ID: mdl-34639747

RESUMO

Off-label use of drugs is widely known as unapproved use of approved drugs, and it can be perceived as a relatively simple concept. Even though it has been in existence for many years, prescribing and dispensing of drugs in an off-label regimen is still a current issue, triggered especially by unmet clinical needs. Several therapeutic areas require off-label approaches; therefore, this practice is challenging for prescribing physicians. Meanwhile, the regulatory agencies are making efforts in order to ensure a safe practice. The present paper defines the off-label concept, and it describes its regulation, together with several complex aspects associated with clinical practices regarding rare diseases, oncology, pediatrics, psychiatry therapeutic areas, and the safety issues that arise. A systematic research of the literature was performed, using terms, such as "off-label", "prevalence", "rare diseases", "oncology", "psychiatry", "pediatrics", and "drug repurposing". There are several reasons for which off-label practice remains indispensable in the present; therefore, efforts are made worldwide, by the regulatory agencies and governmental bodies, to raise awareness and to ensure safe practice, while also encouraging further research.


Assuntos
Médicos , Psiquiatria , Criança , Humanos , Oncologia , Uso Off-Label , Prevalência
12.
Saudi Pharm J ; 29(9): 1029-1042, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34588849

RESUMO

Obtaining orodispersible tablets (ODT) containing substances from the second Biopharmaceutical Class has raised concerns as the dissolution test is challenging. This study aimed to select suitable excipients for developing orodispersible tablets containing cannabidiol (CBD) by direct compression method. No similar studies were found in the literature. Excipients from different classes were characterized using the SeDeM-ODT tool: fillers - lactose (LCT) and microcrystalline cellulose (CelMC), sweeteners - sorbitol (SRB) and mannitol (MNT), disintegrants - sodium starch glycolate (SSG), sodium croscarmellose (CCS), soy polysaccharides (Emcosoy® - EMCS) and two co-processed excipients (Prosolv®-ODT G2 - PODTG2 and Prosolv® EasyTab sp - PETsp). Drug compatibility with excipients in binary mixtures (1:1) was verified by Differential Scanning Calorimetry (DSC) and Fourier Transform-Infrared (FTIR) spectroscopy. Using the SeDeM-ODT expert system, the fillers and the co-processed excipients showed good properties regarding compressibility and disintegration behavior. Also, the DSC and FTIR results showed that small or no interactions between the CBD and the excipients took place.

13.
J Chromatogr Sci ; 57(3): 243-248, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30615090

RESUMO

The mandatory strategy of using internal standard in HPLC is still controversial. Despite that the introduction of internal standard methodology in the early stage of development of HPLC technology was used to improve method accuracy and precision, there are still practical situations in which a simple external standard quantification is adequate. The aim of the study is to compare the determination of meloxicam (MXC) in human plasma by HPLC with or without using an internal standard according to some key points related to the reason of introducing the internal standardization such as the reducing of sample preparation errors or variability for low injection volumes. The HPLC analysis was performed on reversed phase with UV detection after protein precipitation. Piroxicam (PXC) was used as an internal standard. The two methods are compared in terms of accuracy and precision over the same concentration range. The stability of the analyte has been proved. According to the results, the quantitative determination of MXC in human plasma after simple protein precipitation by using PXC as an internal standard does not bring any significant improvement of accuracy and precision of the experimental measurements.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida de Alta Pressão/normas , Estabilidade de Medicamentos , Humanos , Meloxicam/sangue , Meloxicam/química , Piroxicam/análise , Piroxicam/normas , Padrões de Referência , Reprodutibilidade dos Testes
14.
Molecules ; 23(10)2018 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-30248903

RESUMO

Non-steroidal anti-inflammatory drugs (NSAIDs) are an important pharmacological class of drugs used for the treatment of inflammatory diseases. They are also characterized by severe side effects, such as gastrointestinal damage, increased cardiovascular risk and renal function abnormalities. In order to synthesize new anti-inflammatory and analgesic compounds with a safer profile of side effects, a series of 2,6-diaryl-imidazo[2,1-b][1,3,4]thiadiazole derivatives 5a⁻l were synthesized and evaluated in vivo for their anti-inflammatory and analgesic activities in carrageenan-induced rat paw edema. Among all compounds, 5c showed better anti-inflammatory activity compared to diclofenac, the standard drug, and compounds 5g, 5i, 5j presented a comparable antinociceptive activity to diclofenac. None of the compounds showed ulcerogenic activity. Molecular docking studies were carried out to investigate the theoretical bond interactions between the compounds and target, the cyclooxygenases (COX-1/COX-2). The compound 5c exhibited a higher inhibition of COX-2 compared to diclofenac.


Assuntos
Analgésicos/síntese química , Anti-Inflamatórios não Esteroides/síntese química , Edema/tratamento farmacológico , Imidazóis/síntese química , Tiadiazóis/síntese química , Analgésicos/administração & dosagem , Analgésicos/química , Analgésicos/farmacologia , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/farmacologia , Carragenina/efeitos adversos , Ciclo-Oxigenase 1/química , Ciclo-Oxigenase 1/metabolismo , Ciclo-Oxigenase 2/química , Ciclo-Oxigenase 2/metabolismo , Diclofenaco/administração & dosagem , Diclofenaco/uso terapêutico , Edema/induzido quimicamente , Feminino , Imidazóis/administração & dosagem , Imidazóis/química , Imidazóis/farmacologia , Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Conformação Molecular , Simulação de Acoplamento Molecular , Estrutura Molecular , Ratos , Relação Estrutura-Atividade , Tiadiazóis/administração & dosagem , Tiadiazóis/química , Tiadiazóis/farmacologia
15.
Adv Pharm Bull ; 8(2): 181-189, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30023319

RESUMO

To describe the chemical structure and characterize physico-chemical properties of organometallic complexes it is necessary to use a complex set of analysis methods. Thus, this review has been compiled as a relevant guide which includes the most commonly used methods of analysis in the study of silver complexes with antibacterial quinolones, compounds with promising biological potential. This selection of analysis methods puts on balance the obtained data and the accessibility of the experimental approach. The steps to follow in order to obtain reliable structural information about organometallic complexes of silver, particularly the silver complexes of antibacterial quinolones, are established and presented in the review.

16.
J Med Food ; 21(11): 1106-1112, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29847743

RESUMO

Antihyperglycemic effects of four extracts obtained from leaves and fruits of Vaccinium myrtillus and Vaccinium corymbosum were assessed in diabetic rats. In addition, the effects of extracts on diabetic-related complications such as the development of diabetic cataract and oxidative stress were evaluated. Type 1 diabetes was induced with a single dose of streptozotocin in Wistar rats. The rats were randomly divided into seven equal groups: NC-normal control, DC-diabetic control, PC-positive control treated with metformin, VML-received V. myrtillus leaf extract, VMLF-received VML and fruit extract, VCL-received V. corymbosum leaf extract, and VCLF-received VCL and fruit extract. Body weight and glucose levels were monitored every second week. After 8 weeks of treatment, serum glucose, insulin, and malondialdehyde were measured. Lenses were removed after sacrifice and eight lenses from each group were randomly selected for evaluation of cataract development. A decrease in body weight was observed in all diabetic groups in the first weeks. In the VML group, no significant decrease was observed. Glucose levels during the experiment were high in DC, PC, and VCL groups, with no improvement during the 8 weeks. In VML, VMLF, and VCLF groups, a decrease in blood glucose levels was observed. Similar results regarding serum insulin and glucose levels at the end of the experiment were observed within groups. V. myrtillus extracts prevented the development of cataract compared with the DC group (P < .05).


Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Extratos Vegetais/administração & dosagem , Vaccinium myrtillus/química , Vaccinium/química , Animais , Glicemia/metabolismo , Diabetes Mellitus Tipo 1/induzido quimicamente , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/metabolismo , Feminino , Humanos , Hipoglicemiantes/química , Insulina/metabolismo , Malondialdeído/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/química , Ratos , Ratos Wistar , Estreptozocina/efeitos adversos
17.
J Chromatogr Sci ; 54(9): 1578-1583, 2016 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-27402671

RESUMO

The purpose of this study was to separate single and multiple pairs of six ß-blockers enantiomers by high performance liquid chromatography on ovomucoid (OM) column in optimal conditions. The separation was performed isocratically or in gradient elution at 25°C, flow rate of 1 mL/min and 220 nm. The mobile phase consisted of phosphate buffer/acetonitrile or methanol. The effect of the organic modifier, the influence of pH and the percentage of the aqueous phase on resolution were investigated. The elution order of propranolol (PRP) enantiomers was established as well as the detection and quantification limits. The results show that OM was suitable for enantiomeric separation of the nonselective ß-blockers carvedilol, PRP, pindolol and oxprenolol, and not for the two ß-1 selective blockers, atenolol and metoprolol. A hypothesis regarding a possible correlation between structure-pharmacological activity-chromatographic behavior is proposed.

18.
Talanta ; 79(2): 436-41, 2009 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-19559901

RESUMO

A new simple, sensitive and selective liquid chromatography coupled with mass spectrometry (LC/MS) method for quantification of captopril after precolumn derivatization with p-bromo-phenacyl-bromide in human plasma was validated. Plasma samples were analysed on a monolithic column (Cromolith Performance-RP 18e, 100 mm x 4.6 mm I.D., 3 microm) under isocratic conditions using a mobile phase of a 40:60 (v/v) mixture of acetonitrile and 0.1% (v/v) formic acid in water. The flow rate was 1 mL/min at the column temperature of 30 degrees C. In these chromatographic conditions, the retention time was 4.4 min for captopril derivative. The detection of the analyte was in MRM mode using an ion trap mass spectrometer with electrospray positive ionisation. The monitored ions were 216, 253, 255, 268, 270 m/z derived from 415 m/z for derivatized captopril. The sample preparation was very simple and consisted in plasma protein precipitation from 0.2 mL plasma using 0.3 mL methanol after the derivatization reaction was completed. Calibration curves were generated over the range of 10-3000 ng/mL with values for coefficient of correlation greater than 0.993 and by using a weighted (1/y(2)) quadratic regression. The values for precision (CV %) and accuracy (relative error %) at quantification limit were less than 9.9% and 3.9%, for within- and between-run, respectively. The mean recovery of the analyte was 99%. Derivatized samples demonstrated good short-term, long-term, post-preparative and freeze-thaw stability. This is the first reported LC-MS/MS method for analysis of captopril in human plasma that uses protein precipitation as sample processing procedure. The method is very simple and allows obtaining a very good recovery of the analyte. The validated LC-MS/MS method has been applied to a pharmacokinetic study of 50mg captopril tablets on healthy volunteers.


Assuntos
Captopril/sangue , Espectrometria de Massas em Tandem/métodos , Calibragem , Captopril/administração & dosagem , Captopril/farmacocinética , Cromatografia Líquida/métodos , Avaliação de Medicamentos , Monitoramento de Medicamentos/métodos , Humanos , Espectrometria de Massas por Ionização por Electrospray
19.
Talanta ; 75(4): 1104-9, 2008 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-18585190

RESUMO

A new simple, sensitive and selective liquid chromatography coupled with mass spectrometry (LC/MS) method for quantification of tramadol and its active metabolite O-desmethyltramadol in human plasma was validated. The tramadol and its metabolite were separated on a reversed phase column (Zorbax SB-C18, 100 mm x 3.0 mm I.D., 3.5 microm) under isocratic conditions using a mobile phase of a 10:90 (v/v) mixture of acetonitrile and 0.2% (v/v) trifluoroacetic acid in water. The flow rate was 1 ml/min at the column temperature 45 degrees C. In these chromatographic conditions, the retention times were 2.3 min for O-desmethyltramadol and 3.5 min for tramadol, respectively. The detection of both analytes was in SIM mode using an ion trap mass spectrometer with electrospray positive ionisation. The monitored ions were m/z 264 for tramadol and m/z 250 for its metabolite. The sample preparation was very simple and rapid and consisted in plasma protein precipitation from 0.2 ml plasma using 0.2 ml solution of perchloric acid 7%. Calibration curves were generated over the range of 2-300 ng/ml for both analytes with values for coefficient of correlation greater than 0.998 and by using a weighted (1/y) quadratic regression. The values of precision and accuracy for tramadol at quantification limit were less than 10.9% and 5.1, respectively, both for within- and between-run. For O-desmethyltramadol, precision and accuracy at quantification limit were 10.1% and -9.9% for within-run determinations and 6.7% and 10.4% for between-run determinations, respectively. The mean recovery for both analytes was 96%. Both tramadol and its metabolite demonstrated good short-term, long-term, post-preparative and freeze-thaw stability. This is the first reported method for analysis of tramadol and O-desmethyltramadol in human plasma that uses protein precipitation as sample processing procedure. The method is very simple and allows obtaining a very good recovery of both analytes. The validated LC/MS method has been applied to a pharmacokinetic study of 50 mg tramadol tablets on healthy volunteers.


Assuntos
Tramadol/análogos & derivados , Tramadol/sangue , Administração Oral , Cromatografia Líquida de Alta Pressão , Humanos , Reprodutibilidade dos Testes , Espectrometria de Massas por Ionização por Electrospray , Fatores de Tempo , Tramadol/metabolismo
20.
Rev Med Chir Soc Med Nat Iasi ; 112(3): 837-42, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-20201278

RESUMO

UNLABELLED: A new simple, sensitive and selective liquid chromatography coupled with mass spectrometry (LC/MS) method for quantification of dydrogesterone in human plasma was validated. MATERIAL AND METHOD: The analytes was eluted in 1.3 minutes on a reversed phase column (Zorbax SB-C18, 100 mm x 3.0 mm I.D., 3.5 microm) under isocratic conditions using a mobile phase of a 20 : 80 (v/v) mixture of ammonium acetate 1 mM and acetonitrile. The flow rate was 1 mL/min at the column temperature of 35 degrees C. The detection of the analyte was in MS/ MS mode using an atmospheric pressure chemical ionization source (APCI+, m/z 313 > m/z 295). The sample preparation was very simple and rapid and consisted in plasma protein precipitation from 0.2 mL plasma using 0.6 mL methanol. RESULTS: Calibration curves were generated over the range of 5-150 ng/mL with values for coefficient of determination greater than 0.997 and by using a weighted (1/y) linear regression. The values of precision and accuracy were less than 12.5% and 7.5%, respectively, both for within- and between-run analysis. The mean recovery of the analyte was 99.8%. This is the first reported method for analysis dydrogesterone in human plasma that uses protein precipitation as sample processing procedure. The validated LC/MS method could be applied for determination of dydrogesterone in human plasma for therapeutic drug monitoring in gynecological disorders.


Assuntos
Monitoramento de Medicamentos/métodos , Didrogesterona/sangue , Doenças dos Genitais Femininos/sangue , Doenças dos Genitais Femininos/tratamento farmacológico , Progestinas/sangue , Cromatografia Líquida , Didrogesterona/farmacocinética , Didrogesterona/uso terapêutico , Feminino , Humanos , Espectrometria de Massas , Progestinas/farmacocinética , Progestinas/uso terapêutico , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
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