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Spectrophotometric determination of fenoterol hydrobromide in pharmaceutical preparations

ZAMUNER, Maria Lucilia Motinha; CARRION, Regina Celli Espires; MAGALHAES, Joao Fernandes
Fonte: UNIV SAO PAULO, CONJUNTO QUIMICAS Publicador: UNIV SAO PAULO, CONJUNTO QUIMICAS
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
35.98%
A simple spectrophotometric method has been developed,for the determination of fenoterol hydrobromide (FH) in tablets, drops and syrup, as the only active principle and associated with ibuprofen. The method is based on the oxidative coupling reaction of the FH with 3-methyl-2-benzothiazolinone hydrazone (MBTH) and ceric sulphate as oxidant reagent. The mixture of the drug, MBTH and ceric sulfate, in acid medium, produces a red brown color compound, with absorption maximum at 475 nm. The calibration curve was linear over a concentration range from 3.0 to 12.0 mu g/mL, with correlation coefficient of 0.9998. The different experimental parameters affecting the development and stability of the color compound were carefully studied and optimized. The method was applied successfully to assay FH in dosage forms and simulated samples. The coefficient of variation was from 0.25 % to 0.82 % and average recoveries of the standard from 98 % to 102 %. The excipients (tablets and drops) did not interfere in the analysis and the results showed that method can be used for determination of the FH isolated or associated with ibuprofen with precision, accuracy and specificity. In case of syrup, the interference in the analysis suggests a possible reaction between vehicle components with MBTH.

Formação de agentes comunitários de saúde para o desenvolvimento de práticas de atenção básica relativas ao consumo prejudicial de drogas; Education of community health workers for the development of primary health care practices addressing harmful drug consumption

Cordeiro, Luciana
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 02/09/2013 PT
Relevância na Pesquisa
35.94%
Esta investigação toma como objeto o desenvolvimento de recursos teórico-práticos dos trabalhadores da saúde na atenção básica (AB), particularmente os agentes comunitários de saúde (ACS), para lidar com problemas relativos ao consumo de drogas dos moradores da área de abrangência de Unidades de Saúde da Família (USF). As práticas da AB voltadas para a problemática das drogas constituem preocupação de toda equipe de saúde. Os ACS são particularmente afetados porque se deparam cotidianamente com situações muito próximas diante das quais se sentem despreparados, o que ocasiona frustação e desgaste. A partir da orientação paradigmática da redução de danos e dos pressupostos da educação emancipatória, o objetivo geral desta investigação foi construir um arcabouço teórico-metodológico e operacional para conduzir a formação de trabalhadores sobre drogas da AB. Trata-se de uma pesquisa-ação emancipatória, que contou com 18 ACS de quatro USF do distrito de Sapopemba, município de São Paulo. Foram realizadas 9 oficinas de educação sobre drogas e mais 6, para elaboração de material de apoio. Os dados foram analisados a partir de duas categorias de análise: 1) a unidade objeto-sujeito, conforme tomada pelas práticas em saúde da AB relacionadas ao consumo prejudicial de drogas e 2) o processo de trabalho...

Desenvolvimento de métodos analíticos para a identificação de drogas facilitadoras de crime em amostras de urina; Developing analytical methods for identification of drug-facilitated crime in urine samples

Bairros, André Valle de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 12/12/2014 PT
Relevância na Pesquisa
35.97%
As drogas facilitadoras de crime (DFC) são uma série de substâncias químicas que permitem o ato sexual e/ou roubo com pouca ou nenhuma resistência da vítima. Benzodiazepínicos, gama-hidroxibutirato (GHB), cetamina e etanol são clássicas DFC, porém outras substâncias também têm sido utilizadas. Devido às diferentes classes de DFC e a necessidade de métodos sensíveis, a determinação dessas substâncias é um desafio aos toxicologistas forenses. A proposta do estudo foi desenvolver métodos analíticos para determinação principais analitos alvos de DFC para benzodiazepínicos, cetamina e GHB em amostras de urina. Esta matriz biológica é considerada uma amostra não-invasiva e apresenta um período de detecção maior que o sangue. A preparação das amostras foi avaliada através de microextração em fase líquida (LPME) e extração líquido-líquido (LLE). A LPME é uma técnica de extração de drogas que utiliza menor quantidade de solventes orgânicos, maior praticidade e possibilidade de obtenção de altos valores de recuperação. Os analitos foram determinados por cromatografia gasosa acoplada à espectrometria de massas (GC-MS). A LPME validada para benzodiazepínicos e seus produtos de biotransformação exigiu uma combinação de solventes e dupla derivatização para atingir a sensibilidade exigida...

Desenvolvimento e validação da metodologia SPE-LC-MS/MS para a determinação de fármacos e droga de abuso nas águas da represa Guarapiranga - São Paulo/SP, Brasil; Development and validation of methodology SPE-LC-MS/MS for pharmaceuticals and illicit drug determination in the waters of Guarapiranga dam - Sao Paulo/SP, Brazil

Shihomatsu, Helena Miho
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 18/03/2015 PT
Relevância na Pesquisa
45.93%
Este estudo apresenta o desenvolvimento da metodologia de extração em fase sólida e separação em cromatográfica líquida acoplada a espectrometria de massas em sequencia, SPE-LC-MS/MS, para a determinação de 21 (vinte e um) fármacos pertencentes a diferentes classes terapeuticas, 1 (uma) droga de abuso e seu principal metabólito, em amostras de água superficial. A separação cromatográfica foi otimizada estudando o desempenho de fases estacionárias e fases móvies. A quantificação dos compostos selecionados foi realizada com a ionização por eletronebulização (electrospray ionization- ESI) e o espectrômetro de massas operando no modo de Monitoramento de Múltiplas Reações (Multiplas Reaction Monitoring- MRM). A validação da metodologia proposta foi realizada utilizando os parâmetros de seletividade, efeito de matriz, faixa de trabalho, linearidade, limites de detecção (LD) e quantificação (LQ), precisão, exatidão, recuperação e robustez. A validação da metodologia permitiu a sua aplicação na avaliação da distribuição dos 23 compostos selecionados, nas águas da represa Guarapiranga, um dos principais sistemas produtor de água potável da Região Metropolitana de São Paulo (RMSP). A presença desses poluentes nos ambientes aquáticos é proveniente da liberação direta do esgoto urbano das habitações do seu entorno...

Electrochemical, Spectrophotometric and Liquid-Chromatographic Approaches for Analysis of Tropical Disease Drugs

Santos, Andre L.; Takeuchi, Regina M.; Stradiotto, Nelson R.
Fonte: Bentham Science Publ Ltd Publicador: Bentham Science Publ Ltd
Tipo: Revisão Formato: 69-88
ENG
Relevância na Pesquisa
36.03%
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Processo FAPESP: 03/05567-7; Processo FAPESP: 03/09334-7; Drug analysis is important in several phases of drug development, such as formulation, stability studies and quality control. The importance of reliable analytical methods for drug determination in a fast, inexpensive, sensitive and selective way is thus evident. Although there are countless works describing new analytical methods for determination of drugs that act against tropical diseases, a review organizing these works in a systematic and complete way is lacking. In this context, the objective of this review is to present the main advances in the development of analytical methods for determination of tropical disease drugs using electroanalytical, spectrophotometric and liquid chromatographic techniques.

Electrochemical study of hydroxychloroquine and its determination in plaquenil by differential pulse voltammetry

Arguelho, MLPM; Andrade, J. F.; Stradiotto, N. R.
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 269-275
ENG
Relevância na Pesquisa
35.98%
Hydroxychloroquine (HCQ) is a halogenated aminoquinoline that presents wide biological activity, often being used as an antimalarial drug. The electrochemical reduction of HCQ was investigated by cyclic voltammetry and chronoamperometry using glassy carbon electrodes. By cyclic voltammetry, in acid medium, only the cathodic peak was observed. The electrochemical behavior of this peak is dependent on pH and the electrodic process occurs through an ErCi mechanism. The electron number (le) consumed in the reduction of HCQ was obtained by chronoamperometry. A method for the electrochemical determination of HCQ in pharmaceutical tablets was developed using differential pulse voltammetry. The detection limit reached was 11.2 mug ml(-1) of HCQ with a relative standard deviation of 0.46%. A spectrophotometric study of HCQ has been also carried out utilizing a band at 343 nm. The obtained detection limit and the relative standard deviation were 0.1 mug ml(-1) and 0.36%, respectively. The electrochemical methods are sufficiently accurate and precise to be applied for HCQ determination, in laboratorial routine, which can be used to determine the drug at low level. (C) 2003 Elsevier B.V. B.V. All rights reserved.

Determination of cinnamic acid in human urine by differential-pulse polarography

Ferreira, V. S.; Melios, C. B.; Zanoni, Maria Valnice Boldrin; Stradiotto, N. R.
Fonte: Royal Soc Chemistry Publicador: Royal Soc Chemistry
Tipo: Artigo de Revista Científica Formato: 263-267
ENG
Relevância na Pesquisa
35.98%
The differential pulse polarographic behaviour of cinnamic acid was studied in acetate and phosphate buffer solutions (pH 3.5-7.5). The reduction mechanism is discussed. The drug can be determined at pH 5.0 over the concentration range 5 X 10(-5)-1 X 10(-3) mol l(-1). The effect of tetraalkylammonium salts on the electroanalytical determination of cinnamic acid was investigated, the direct determination of the drug (0.7-5.5 mu g ml(-1)) in urine samples diluted with acetate buffer (pH 5.0) can be effected in the presence of 1 x 10(-3) mol l(-1) cetyldimethylethylammonium bromide solution. The detection limit was found to be 0.1 mu g ml(-1). The relative standard deviation from six determinations at the 5.5 mu g ml(-1) level was 1%.

Determination of salicylate in blood serum using an amperometric biosensor based on salicylate hydroxylase immobilized in a polypyrrole- glutaraldehyde matrix

Rover Júnior, Laércio; De Oliveira Neto, Graciliano; Roberto Fernandes, João; Tatsuo Kubota, Lauro
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 547-557
ENG
Relevância na Pesquisa
45.9%
The use of an amperometric biosensor for the salicylate determination in blood serum is described. The biosensor is based on salicylate hydroxylase (EC 1.14.13.1) electropolymerized onto a glassy carbon-working electrode with polypyrrole and glutaraldehyde, to improve the biosensor lifetime. The hexacyanoferrate (II) was also incorporated to work as a redox mediator to minimize possible interferences. The salicylate is enzymatically converted to catechol, which is monitored amperometrically by its electrooxidation at +0.170 V versus SCE (saturated calomel electrode). Salicylate determination was carried out maintaining the ratio between β-NADH and salicylate at 4:1 (30°C). The amperometric response of the biosensor was linearly proportional to the salicylate concentration between 2.3 x 10-6 and 1.4 x 10-5 mol l- 1, in 0.1 mol l-1 phosphate buffer (pH 7.8), containing 0.1 mol l-1 KCl and 5.0 x 10-4 mol l-1 Na2H2EDTA, as supporting electrolyte. The recovery studies, in the presence of several interfering compounds, showed recoveries between 96.4 and 104.8%. The useful lifetime of the biosensor in the concentration range evaluated was at least 40 days, in continuous use. Blood serum samples analyzed by this biosensor showed a good correlation compared to the spectrophotometric method (Trinder) used as reference...

Determination of flutamide in tablets by high-performance liquid chromatography

Salgado, Hérida Regina Nunes; De Menezes, Manoel; Storti, Madge Patrícia Betto
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 246-249
ENG
Relevância na Pesquisa
45.83%
Flutamide is a potent antiandrogen used for the treatment of prostatic cancer. A simple, sensitive and accurate high-performance liquid Chromatographic (HPLC) method is presented for quantitative determination of flutamide in tablets, using a reversed-phase technique and UV detection at 240 nm. The isocratic elution was used to quantify the analyte. The samples were chromatographed on Luna-C18 column and the mobile phase was 0.05 M phosphate buffer pH 4.0 - acetonitrile (50:50, v/v). The method was linear between 2.9 - 11.6 mg L -1. Over the tested concentration range the intra-day relative standard deviation for replicate analysis in tablets ranged from 0.44 to 0.78%. It was also found that the excipients in the commercial tablets did not interfere with the method.

Comparative study of disk diffusion and microdilution methods for evaluation of antifungal activity of natural compounds against medical yeasts Candida spp and Cryptococcus sp

Scorzoni, L.; Benaducci, T.; Almeida, A. M F; Silva, D. H S; Bolzani, Vanderlan da Silva; Mendes Giannini, Maria José Soares
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 25-34
ENG
Relevância na Pesquisa
35.97%
Antifungal activity of natural products has been tested by adapting methods designed for synthetic drugs. In this study, two methods for the determination of antifungal activity of natural products, agar diffusion and broth microdilution, the CLSI reference methods for synthetic drugs, are compared and discussed. The microdilution method was more sensitive. The minimal inhibitory concentrations (MIC) of crude extracts, fractions and pure substances from different species of the plant families Piperaceae, Rubiaceae, Clusiaceae, Fabaceae and Lauraceae, from the Biota project, were determined. Antifungal activities against Candida albicans, C.krusei, C.parapsilosis and Cryptococcus neoformans were produced by several samples.

Development and validation of a microbiological agar assay for determination of orbifloxacin in pharmaceutical preparations

Cazedey, Edith C. L.; Salgado, Hérida R. N.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 572-581
ENG
Relevância na Pesquisa
45.83%
Orbifloxacin is a fluoroquinolone with broad-spectrum antimicrobial activity, and belongs to the third generation of quinolones. Regarding the quality control of medicines, a validated microbiological assay for determination of orbifloxacin in pharmaceutical formulations has not as yet been reported. For this purpose, this paper reports the development and validation of a simple, sensitive, accurate and reproducible agar diffusion method to quantify orbifloxacin in tablet formulations. The assay is based on the inhibitory effect of orbifloxacin upon the strain of Staphylococcus aureus ATCC 25923 used as test microorganism. The results were treated statistically by analysis of variance and were found to be linear (r = 0.9992) in the selected range of 16.0-64.0 μg/mL, precise with relative standard deviation (RSD) of repeatability intraday = 2.88%, intermediate precision RSD = 3.33%, and accurate (100.31%). The results demonstrated the validity of the proposed bioassay, which allows reliable orbifloxacin quantitation in pharmaceutical samples and therefore can be used as a useful alternative methodology for the routine quality control of this medicine. © 2011 by the authors; licensee MDPI, Basel, Switzerland.

Validation of microbiological assay for determination of cefuroxime in injectable preparations

Vieira, Daniela C.M.; Ricarte, Patrícia C.; Salgado, Hérida R.N.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 746-750
ENG
Relevância na Pesquisa
46.04%
The validation of a microbiological assay, applying agar diffusion method for determination of the active of cefuroxime in power for injection, is described. Using a strain of Micrococcus luteus ATCC 9341 as the test organism, cefuroxime was measured in concentrations ranging from 30.0 to 120.0 μg/mL. The method validation showed that it is linear (r = 0.9999), precise (relative standard deviation = 0.37%) and accurate (it measured the added quantities). Microbiological assay is satisfactory for quantitation of cefuroxime in powder for injection and the validity of the proposed bioassay, which is a simple and a useful alternative methodology for cefuroxime determination in routine quality control.

Development and validation of a successful microbiological agar assay for determination of ceftriaxone sodium in powder for injectable solution

Aléssio, Patrícia V.; Salgado, Hérida R. N.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 334-342
ENG
Relevância na Pesquisa
45.94%
Ceftriaxone sodium is a cephalosporin with broad-spectrum antimicrobial activity and belongs to the third generation of cephalosporins. Regarding the quality control of medicines, a validated microbiological assay for the determination of ceftriaxone sodium in powder for injectable solution has not been reported yet. This paper reports the development and validation of a simple, accurate and reproducible agar diffusion method to quantify ceftriaxone sodium in powder for injectable solution. The assay is based on the inhibitory effect of ceftriaxone sodium on the strain of Bacillus subtilis ATCC 9371 IAL 1027 used as test microorganism. The results were treated statistically by analysis of variance and were found to be linear (r = 0.999) in the selected range of 15.0-60.0 μg/mL, precise with a relative standard deviation (RSD) of repeatability intraday = 1.40%, accurate (100.46%) and robust with a RSD lower than 1.28%. The results demonstrated the validity of the proposed bioassay, which allows reliable ceftriaxone sodium quantitation in pharmaceutical samples and therefore can be used as a useful alternative methodology for the routine quality control of this medicine. © 2012 by the authors; licensee MDPI, Basel, Switzerland.

Development and validation of a microbiological assay for determination of chlorhexidine digluconate in aqueous solution

Fiorentino, Flávia Angélica Másquio; Corrêa, Marcos Antonio; Salgado, Hérida Regina Nunes
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 351-358
ENG
Relevância na Pesquisa
45.87%
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Chlorhexidine (CHX) is a broad-spectrum antiseptic that is used in many topical pharmaceutical formulations. Because there is no official microbiological assay reported in the literature that is used to quantify CHX, this paper reports the development and validation of a simple, sensitive, accurate and reproducible agar diffusion method for the dosage of chlorhexidine digluconate (CHX-D) in an aqueous solution. The assay is based on the inhibitory effect of CHX-D upon the strain of Staphylococcus aureus ATCC 25923, which is used as the test microorganism. The design 3x3 parallel-line model was used. The results were treated statistically by analysis of variance (ANOVA), and they were excellent in terms of linearity (r = 0.9999), presenting a significant regression between the zone diameter of growth inhibition and the logarithm of the concentration within the range of 0.5 to 4.5%. The results obtained were precise, having relative standard deviations (RSD) for intra-day and inter-day precision of 2.03% and 2.94%, respectively. The accuracy was 99.03%. The method proved to be very useful and appropriate for the microbiological dosage of CHX-D in pharmaceutical formulations; it might also be used for routine drug analysis during quality control in pharmaceutical industries.

Electro-oxidation of carbamazepine metabolites: Characterization and influence in the voltammetric determination of the parent drug

Ginja Teixeira, Jorge; Veiga, Alfredina; Palace Carvalho, Alfredo J.; Martins Teixeira, Dora
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
35.98%
Abstract The electro-oxidation behavior of five important metabolites of carbamazepine (CBZ) and their potential influence on the voltammetric determination of the parent drug in biological fluids was investigated for the first time. This investigation was performed using cyclic voltammetry, in combination with controlled potential electrolysis and HPLC-DAD-MS analysis of oxidation products of these compounds. Using a sensitive glassy carbon electrode modified with multi-walled carbon nanotubes it was found that each metabolite produces a voltammetric response, that differs from the parent molecule and which can be used in its identification and to gain some insight about the electro-oxidation mechanisms of this class of molecules. Taking into account the HPLC-DAD-MS data, these electro-oxidation mechanisms were advanced and discussed. A voltammetric procedure for the determination of CBZ in human fluids was also been tested. Selecting the most appropriate experimental conditions was verified that the interference of each metabolite and their oxidation products on the voltammetric signal of CBZ may be neglected. The analytical performance of the proposed voltammetric procedure, as well as the correlation of its results with the results obtained from LC–MS...

Quality of cocaine seized in 1997 in the street-drug market of São Paulo city, Brazil

Carvalho,Débora Gonçalves de; Mídio,Antonio Flávio
Fonte: Divisão de Biblioteca e Documentação do Conjunto das Químicas da Universidade de São Paulo Publicador: Divisão de Biblioteca e Documentação do Conjunto das Químicas da Universidade de São Paulo
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2003 EN
Relevância na Pesquisa
35.97%
Street drugs when in great demand in an illicit market become not only more expensive but are also subject to extensive adulteration and dilution. These fraudulent practices may also contribute to the amplification of toxic effects observed in the abuse of certain drugs including cocaine hydrochloride. The number of seizures reflects the increase of illicit use of cocaine powder in the city of S.Paulo, where the identity of the suspected drug is its hydrochloride form. Routine analytical procedures in enforcement laboratories in Brazil now comprise techniques involving thin layer chromatography for presumptive identification of the drug and eventually gas chromatography for its confirmation or quantification whenever required. The determination of cocaine content, adulterants and diluents in street samples is not only of clinical value but also important for enforcement activities, recognition of its geographical distribution and allocation. So, the aim of this study was to continue examining the quality of cocaine hydrochloride in the illicit market of the city of S.Paulo. Cocaine and adulterant contents were determined as well as the identification of several diluents in 389 out of 1958 samples of "white powder" seized in the city of São Paulo. Thin-layer and gas-liquid chromatography (FID) and GC-MS were used for the determination of cocaine and adulterant contents. Spot-tests and thin-layer chromatography were the techniques applied for the identification of diluents. The results were as follows: neither cocaine nor adulterants were detected in 17 samples (4.4%); of all positive samples (95.6 %) for cocaine...

A review of analytical methods for the determination of four new phosphodiesterase type 5 inhibitors in biological samples and pharmaceutical preparations

Codevilla,Cristiane Franco; Castilhos,Tamara dos Santos; Bergold,Ana Maria
Fonte: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas Publicador: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2013 EN
Relevância na Pesquisa
36.01%
The introduction of oral phosphodiesterase type 5 inhibitor therapy in 1998 revolutionized the treatment of erectile dysfunction. Erectile dysfunction is the most common sexual problem in men. It often has a profound effect on intimate relationships and quality of life. The analysis of pharmaceuticals is an important part of the drug development process as well as for routine analysis and quality control of commercial formulations. Whereas the determination of sildenafil citrate, vardenafil and tadalafil are well documented by a variety of methods, there are few publications about the determination of udenafil, lodenafil carbonate, mirodenafil and avanafil. The paper presents a brief review of the action mechanism, adverse effects, pharmacokinetics and the most recent analytical methods that can determine drug concentration in biological matrices and pharmaceutical formulations of these four drugs.

Determination of mirtazapine in spiked human plasma and tablets by first derivative spectrofluorimetric method

Youssef, Rasha M.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.98%
A sensitive first derivative spectrofluorimetric method (1D-spectrofluorimetry) was developed for the determination of mirtazapine. Calibration graph for mirtazapine determination was established using the first derivative amplitudes of the mirtazapine emission spectrum (λex = 314 nm) in 0.1 M sulphuric acid measured at 375–435 nm from peak to peak, as the analytical signals. Moreover, the ratio of 1D-spectrophotometric peak amplitudes at these wavelengths was calculated and used for the detection of the presence of interferences. Linearity range was found to be between 1 and 40 ng ml−1 with correlation coefficient (r) = 0.9999. The limit of quantitation (LOQ) was 1.0 ng ml−1 and the limit of detection (LOD) was 0.2 ng ml−1. The proposed method was validated according to ICH; and it has been applied for the drug determination in human plasma without prior extraction and in tablets. The proposed method’s accuracy, reproducibility, selectivity and simplicity suggest its application in quality control analysis of the drug.

Simple and practicable methods for the determination of astemizole in pharmaceuticals using bromate-bromide and two dyes

Nagegowda,Paregowda; Basavaiah,Kanakapura
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2005 EN
Relevância na Pesquisa
36.01%
One titrimetric and two spectrophotometric methods, which are simple and sensitive, are described for the determination of astemizole (AST) in bulk drug and formulations. The methods use bromate-bromide mixture and two dyes, methyl orange and indigo carmine. In titrimetry (Method A), astemizole is treated with a known excess of bromate-bromide mixture in acid medium and after the bromination reaction is ensured to be complete, the residual bromine is back-titrated iodometrically. In spectrophotometric methods, the excess of bromine is estimated by treating it with a fixed amount of either methyl orange (Method B) or indigo carmine (Method C) and measuring the change in absorbance either at 520 or 610 nm. In all the methods, the amount of bromate reacted corresponds to the drug content. Titrimetric method is applicable over 4-16 mg range and the calculations are based on a 1:0.666 (AST: bromate) reacting ratio. In spectrophotometry, the calibration graph is found to be linear over 0.5-4.0 µg mL-1 (Method B) and 1.25 12.5 µg mL-1 (Method C) with molar absorptivity values of 6.6 x 10(4) L mol-1 cm-1 and 2.1 x 10(4) L mol-1 cm-1, respectively. The limits of detection and quantification are reported for methods B and C. The statistical evaluation of the methods was examined by determining intra-day and inter-day precision. The methods were applied to the determination of AST in tablets and syrups and the results were found to agree well with the label claim. The accuracy and reliability of the methods were further ascertained by parallel determination by a reference method and by calculating the Student's t-value and F-value at the 95% confidence level...

Qualidade da cocaína traficada em 1997 na cidade de São Paulo, Brasil; Quality of cocaine seized in 1997 in the street-drug market of São Paulo city, Brazil

Carvalho, Débora Gonçalves de; Mídio, Antonio Flávio
Fonte: Universidade de São Paulo. Faculdade de Ciências Farmacêuticas Publicador: Universidade de São Paulo. Faculdade de Ciências Farmacêuticas
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Artigo Avaliado pelos Pares Formato: application/pdf
Publicado em 01/03/2003 ENG
Relevância na Pesquisa
35.97%
Teores de cocaína e adulterantes bem como vários diluentes foram determinados em 389 amostras de pó branco apreendidas na cidade de São Paulo, no ano de 1997. Cocaína e seus adulterantes foram analisados por cromatografia em camada delgada, cromatografia em fase gasosa (detetor de ionização de chama) e cromatografia em fase gasosa acoplado a espectrometria de massa (CG/MS). Diluentes foram analisados através de "spot tests" e da cromatografia em camada delgada. Foram obtidos os seguintes resultados: em 4,4% das amostras não foram detectados cocaína e adulterantes; de todas as amostras positivas para cocaína, 14% não continham mais que 200 mg/g de pó; em 70% a pureza da cocaína variou de 201 a 550 mg/g e em 16% não foi maior que 700 mg/g. Os anestésicos locais lidocaína e procaína foram detectados em 19 amostras em concentrações que variaram de 10 a 602 mg/g de pó. Cafeína foi encontrada em duas amostras. Os principais diluentes detectados foram: carbonatos e bicarbonatos, silicatos, açúcares, amido, borato e sulfatos. Contaminantes (produtos secundários) originários do refino da pasta de coca ou de processos de decomposição não foram analisados.; Street drugs when in great demand in an illicit market become not only more expensive but are also subject to extensive adulteration and dilution. These fraudulent practices may also contribute to the amplification of toxic effects observed in the abuse of certain drugs including cocaine hydrochloride. The number of seizures reflects the increase of illicit use of cocaine powder in the city of S.Paulo...