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1.
Forensic Sci Int ; 309: 110191, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32092622

RESUMO

The dissemination of falsified medicines is a public health risk. Techniques such as attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy are commonly adopted for fraudulent drug detection. However, the spectrum generated by the ATR-FTIR typically results in hundreds of wavenumbers, reducing the performance of classification methods aimed at discriminating between authentic and falsified medicines. This article proposes a novel method for selecting a reduced size subset of wavenumbers that improves the classifier performance. The singular value decomposition SVD is used to generate a wavenumber importance index. An iterative process creates k-nearest neighbor (KNN) models by adding the wavenumbers in a decreasing order according to the importance index. Wavenumbers that increase classification accuracy are selected. When applied to Cialis® ATR-FTIR data, the proposed approach retained average 0.51% of the original wavenumbers with 100% accurate classifications; as for the Viagra® data set, the method yielded perfect classifications retaining average 0.17% of the original wavenumbers.


Assuntos
Medicamentos Falsificados/química , Algoritmos , Humanos , Análise de Componente Principal , Espectroscopia de Infravermelho com Transformada de Fourier
2.
J Pharm Biomed Anal ; 174: 198-205, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31174131

RESUMO

In this paper, we propose a novel framework to select the most relevant X-Ray Fluorescence (XRF) energy values (i.e., features) to enhance the clustering (grouping) of counterfeit and illicit medical tablets. The framework is based on the integration of multidimensional scaling (MDS) and Procrustes analysis (PA) multivariate techniques. MDS provides a projection of the original data into a lower dimension, while PA finds a projection matrix from the original data. Such outputs give rise to a feature importance index that guides an iterative feature selection process; after each feature is inserted in the subset, an optimization procedure based on a greedy search method is carried out to maximize the clustering quality assessed through the Silhouette Index (SI). The inorganic chemical fingerprinting of 41 commercial samples (Viagra®, Cialis®, Lazar®, Libiden®, Maxfil®, Plenovit®, Potent 75®, Rigix®, V-50®, Vimax® and Pramil®) and 56 seized counterfeit samples (Viagra and Cialis) was used to validate the proposed framework. From the original 2048 data points in the full spectra, we identified a subset comprised of 41 energy values that substantially improved clustering quality; the obtained groups were assessed by visual inspection of the PCA plots.


Assuntos
Medicamentos Falsificados/análise , Inibidores da Fosfodiesterase 5/análise , Espectrometria por Raios X/métodos , Análise por Conglomerados , Análise Multivariada , Análise de Componente Principal , Citrato de Sildenafila/análise , Comprimidos , Tadalafila/análise
3.
Int J Toxicol ; 31(2): 184-91, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22408069

RESUMO

p-Synephrine is an adrenergic amine found in Citrus aurantium L. fruits and has been used for weight loss in dietary supplements. There are commercial products containing this substance associated to caffeine, salicin, and ephedrine. The aim of this study was to evaluate the acute toxicity of this mixture in mice of both sexes. The significative results observed after acute oral administration to male and female mice of 300, 350, and 400 mg/kg total of p-synephrine, ephedrine, salicin, plus caffeine in a 10:4:6:80 w/w ratio included a reduction in locomotor activity and ptosis in all treated groups for both sexes. Seizures were also observed in male (400 mg/kg) and female groups (350 and 400 mg/kg). Gasping and tearing were observed in males. Salivation (400 mg/kg), agitation (350 and 400 mg/kg), and piloerection (all treated groups) were significantly observed only in females. Deaths occurred in males at 350 and 400 mg/kg treated groups and the necropsy showed cardiopulmonary hemorrhage. A reduction in locomotor activity was confirmed through the spontaneous locomotor activity test, in which the number of crossings considerably decreased (P < .01) in all treated groups. The rotarod test showed a decrease in motor coordination at 400 mg/kg. Body temperature decreased significantly (P < .01) in all treated groups compared to controls. The results suggested clear signs of toxicity of p-synephrine, ephedrine, salicin, and caffeine association; this toxicity augments the attentiveness on commercial products containing this mixture, given the expressive number of adverse events related to its utilization.


Assuntos
Fármacos Antiobesidade/toxicidade , Álcoois Benzílicos/toxicidade , Cafeína/toxicidade , Efedrina/toxicidade , Glucosídeos/toxicidade , Sinefrina/toxicidade , Adrenérgicos/toxicidade , Animais , Ataxia/induzido quimicamente , Temperatura Corporal , Estimulantes do Sistema Nervoso Central/toxicidade , Combinação de Medicamentos , Feminino , Masculino , Camundongos , Atividade Motora/efeitos dos fármacos
4.
J Pharm Biomed Anal ; 58: 7-11, 2012 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-22014651

RESUMO

The production of counterfeited drugs is a criminal problem that carries serious risks to public health in the worldwide. In Brazil, Viagra and Cialis are the most counterfeit medicines, being used to inhibit the phosphodiesterase type 5 (PDE-5), treating thus, problems related to erectile dysfunction. X-ray fluorescence (XRF) is a suitable technique to control the quality of new pharmaceutical formulations and distinguish between authentic and counterfeit tablets. XRF has advantageous features like multielemental capability, good detectivity, high precision, short analysis times, and is nondestructive, which makes it suitable to be extended to a great variety of samples. In this work, the inorganic fingerprinting chemical of forty-one commercial samples (Viagra, Cialis, Lazar, Libiden, Maxfil, Plenovit, Potent 75, Rigix, V-50, Vimax and Pramil) and fifty-six counterfeit samples (Viagra and Cialis) were obtained from XRF data. XRF presented an excellent analytical methodology for semi-quantitative determination of active ingredient (in case of sildenafil citrate that presents S in its structure) and excipients such as calcium phosphate, titanium oxide and iron oxide (P, Ca, Ti and Fe). The matrix data were allied to chemometric methods (Principal Component Analysis and Hierarchical Cluster Analysis) to classify the tablets investigated between authentic and counterfeit, grouping the samples into of seven groups: A, B, C, D and E (counterfeit group) and F and G (authentic group).


Assuntos
Carbolinas/análise , Medicamentos Falsificados/análise , Inibidores da Fosfodiesterase 5/análise , Piperazinas/análise , Sulfonas/análise , Brasil , Carbolinas/química , Química Farmacêutica/métodos , Medicamentos Falsificados/química , Análise Multivariada , Inibidores da Fosfodiesterase 5/química , Piperazinas/química , Análise de Componente Principal , Saúde Pública , Purinas/análise , Purinas/química , Citrato de Sildenafila , Espectrometria por Raios X/métodos , Sulfonas/química , Comprimidos/química , Tadalafila
5.
Anal Chim Acta ; 696(1-2): 67-76, 2011 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-21621034

RESUMO

A method for the simultaneous identification and quantification of amphetamine (AMP), methamphetamine (MET), fenproporex (FEN), diethylpropion (DIE) and methylphenidate (MPH) in oral fluid collected with Quantisal™ device has been developed and validated. Thereunto, in-matrix propylchloroformate derivatization followed by direct immersion solid-phase microextraction and gas chromatography-mass spectrometry were employed. Deuterium labeled AMP was used as internal standard for all the stimulants and analysis was performed using the selected ion monitoring mode. The detector response was linear for the studied drugs in the concentration range of 2-256 ng mL(-1) (neat oral fluid), except for FEN, whereas the linear range was 4-256 ng mL(-1). The detection limits were 0.5 ng mL(-1) (MET), 1 ng mL(-1) (MPH) and 2 ng mL(-1) (DIE, AMP, FEN), respectively. Accuracy of quality control samples remained within 98.2-111.9% of the target concentrations, while precision has not exceeded 15% of the relative standard deviation. Recoveries with Quantisal™ device ranged from 77.2% to 112.1%. Also, the goodness-of-fit concerning the ordinary least squares model in the statistical inference of data has been tested through residual plotting and ANOVA. The validated method can be easily automated and then used for screening and confirmation of amphetamine-type stimulants in drivers' oral fluid.


Assuntos
Anfetamina/análise , Estimulantes do Sistema Nervoso Central/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Saliva/química , Microextração em Fase Sólida/métodos , Anfetaminas/análise , Dietilpropiona/análise , Humanos , Limite de Detecção , Metanfetamina/análise , Metilfenidato/análise
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