Determination of thiabendazole in honeysuckle flower by LC-MS/MS / 国际中医中药杂志

Objective To establish a rapid and sensitive liquid chromatograph-mass spectrometry (LC-MS/MS) method for the determination of thiabendazole in honeysuckle flowers. Methods The acetic ether was selected as extraction solvent. The mass spectrometer analysis was conducted in the positive ionization electrospray mode using SIM. The transitions m/z 202→175 was used to quantify thiabendazole. Results The satisfactory linearity was obtained in the range of 0.1×10-5-2×10-5mg for thiabendazole (r=0.999 5), and the limit of detection (LOD) of 10.0 ng/ml and the mean recovery of 93.70% were obtained by this LC-MS/MS method. Conclusions The method of LC-MS/MS is sensitive, simple and accurate, and it proved to be suitable for the determination of thiabendazole in Honeysuckle flowers.

Development of a spectrofluorimetric method for determination of thiabendazole in tablets.

In this study a spectrofluorimetric method has been developed for determination of thiabendazole drug active compound in tablets. For this purpose; thiabendazole drug active compound was measured fluorescence intensities at excitation (ex) and emission (em) wavelength in various solvents. Suitable solvent was determined for each compound from calibration graphs and tablets' excipients. Spectrofluorimetric method for the determination of thiabendazole in tablet was described under the optimum conditions. The wavelengths of excitation and emission were 370,0 nm and 428.8 nm respectively. The fluorescence intensity was linearly related to the drug concentration and the method was found to be highly accurate and precise, having a relative standard deviation of less than 0.8 %. This proposed method was applied to the determination of thiabendazole in tablet. The validity of the method was tested by the recovery studies of standard addition to pharmaceuticals and the result was found to be satisfactory. The results compared with official USP 24 HPLC method were in good agreement and statistical comparison by means of Student’s t-test and the variance ratio F-test showed no significant difference between the two methods. The proposed method is simple and sufficiently precise for quality control purposes in routine analysis.

Tratamento fungicida e peliculização de sementes de soja submetidas ao armazenamento / Fungicide treatment and film coating of soybean seeds submitted to storage

O tratamento de sementes de soja com fungicidas vem sendo utilizado como importante ferramenta no controle de patógenos. Nesse trabalho, objetivou-se estudar o desempenho de sementes de soja tratadas com fungicidas e peliculizadas, antes e após o armazenamento. Foram utilizados cinco lotes de sementes, cultivar Monsoy 6101, submetidos aos tratamentos: thiabendazole+thiram sem polímero, carbendazin+thiram sem polímero, sem fungicida (testemunha) sem polímero, além desses tratamentos realizados via peliculização (com polímero). A qualidade fisiológica e sanitária das sementes foi avaliada inicialmente e após seis meses de armazenamento em condições ambientais, pelas seguintes determinações: teor de água, teste de germinação, emergência em bandeja, teste de frio e de sanidade. Conclui-se que a peliculização, em associação com fungicidas, não afeta a qualidade fisiológica das sementes de soja e o tratamento de lotes de sementes de soja com os fungicidas thiabendazole+thiram e carbendazin+thiram melhora seu desempenho e qualidade sanitária.

The treatment of soybean seeds by fungicides has been used as an important tool in pathogen control. The objective of this work was to verify the performance of soybean seeds treated with fungicide and film coating, prior and after storage. Five seed lots, cultivar Monsoy 6101, were treated with thiabendazole+thiram without polymer, carbendazin+thiram without polymer, without fungicide (control), without polymer, and treatments by film coating (with polymer). The physiological and sanitary quality of the seeds was evaluated initially and after six months storage, under environmental conditions, according to the following characteristics: water content, test of germination and emergence on tray, blotter test and cold test. The film coating associated with fungicides does not affect the physiological quality of soybean seeds and the soybean seed treatment with the fungicides thiabendazole+thiram and carbendazin+thiram improves performance and sanitary quality.

CLSI broth microdilution method for testing susceptibility of Malasseziapachydermatis to thiabendazole / CLSI método de Microdiluição em Caldo para teste de suscetibilidade da Malassezia pachydermatis frente ao tiabendazol

Thiabendazole, classified as antiparasitic and also used as an antifungal drug, can be found as otological solution indicated for treatment of parasitic and fungal external otitis in small animals. Malassezia pachydermatis is a yeast recognized as a normal inhabitant on the skin and mucous membranes of dogs andcats. However, it is considered an opportunistic agent that causes external otitis and dermatitis in these animals. The aim of this study was to evaluate the in vitro effect of thiabendazole against 51 isolates of M. pachydermatis using the CLSI Broth Microdilution method that has been adapted for this yeast species (NCCLS, 2002). Based on this test, the Minimum Inhibitory Concentrations (MIC) of thiabendazol was calculated. Subsequently, the susceptibility of each isolate against this antifungal was determined. It wasobserved that the MIC of thiabendazole against M. pachydermatis ranged from 0.03 to > 4 μg/mL. A total of 13.7% of the isolates were found to be resistant, 47.1% were intermediate and 39.2% were sensitive to the drug. The rate of resistance of the yeasts against thiabendazole was similar to the results previously obtained with other antifungals, while the adapted broth microdilution technique used in this study proved to be efficient.

Tiabendazol, um fármaco classificado como antiparasitário e também usado como antifúngico, pode ser encontrado como solução otologica indicada no tratamento da otite externa parasitária e fungica em pequenos animais. Malassezia pachydermatis é uma levedura considerada habitante normalda pele e das mucosas de cães e gatos. Entretanto, considerase um agente do oportunista causador de otite externa edermatite nestes animais. A finalidade deste estudo foi avaliar o efeito in vitro do tiabendazol frente a 51 amostras de M. pachydermatis através do método CLSI de Microdiluição em Caldo adaptado para esta espécie de levedura (NCCLS, 2002). Baseado neste teste calculou-se as Concentrações InibitóriasMínimas (CIM) do tiabendazol e, subseqüentemente, foi detectada a suscetibilidade de cada amostra frente a este antifungico. Observou-se que a CIM do tiabendazol frente a M. pachydermatis variou de 0,03 a > 4 μg/mL. Estas amostras foram classificadas em resistente (13,7%), sensibilidade intermediária (47,1%) e sensível (39,2%). A resistência dalevedura frente ao tiabendazol mostrou similaridade com resultados anteriormente observados com outros antifúngicos e a adaptação da técnica de Microdiluição em Caldo utilizada mostrou-se eficiente.

Genotoxicidad de tres plaguicidas utilizados en la actividad bananera de Costa Rica / Genotoxicity of three pesticides used in Costa Rican banana plantations

The in vitro genotoxicity of imazalil and thiabendazole fungicides and the insecticide chlorpyrifos, compounds used in Costa Rican banana plantations, was evaluated with the single-cell gel electrophoresis technique (comet assay). The comet assay is a simple, rapid and low cost technique for quantification of DNA damage. This assay detects DNA single-strand breaks and alkali-labile sites in individual cells. The effects were analyzed by using human lymphocytes exposed to doses of 0, 25, 50, 75 and 100 microg/ml of each pesticide for 30 min at 37 degrees C. The cells were embedded in agarose, lysed, subjected to alkaline electrophoresis (pH >13) for 20 min at 25V, neutralized and dehydrated to be stained with a fluorescent dye and later comets visualization with the epifluorescence microscope. Chlorpyrifos and imazalil induced significant DNA damage in a dose-dependent manner. Chlorpyrifos was the major inductor of DNA breaks. These results indicate that both are genotoxic compounds in vitro. Thiabendazole fungicide did not induced DNA damage using the comet assay for all concentrations tested.

In vitro study on thiabendazole action on viability of Ascaris lumbricoides (Lineu, 1758) eggs

The in vitro activity of thiabendazole on Ascaris lumbricoides eggs, which were recovered from uteri of worm excreted after chemotherapeutic treatment, was studied. Four concentrations of the drug were used: 1 - 2.5 - 5 - and 10 ppm during 24, 48 and 72 hours of exposure. Subsequently, the eggs were centrifuged, washed three times and H(2)SO(4)0.1N was added. The eggs were maintained in an incubator for 20 days at 28 degrees C. Finally, the percentage of embryonated eggs was determined under a lightmicroscope at a 100X magnification. After 48 and 72 hours of thiabendazole exposure, at a concentration of 10ppm, the drug showed complete inhibition of egg embryonation.

Foi estudada, in vitro, a ação do tiabendazol, contra ovos de Ascaris lumbricoides , retirados de úteros de vermes eliminados após tratamento. Foram utilizadas quatro concentrações da droga: 1 ¾ 2,5 - 5 e 10 ppm em três diferentes períodos de tempo: 24, 48 e 72 horas. Decorridos estes tempos a suspensão com os ovos foi centrifugada, lavada por três vezes com água destilada, adicionada de solução de H2SO4, 0,1N e mantida em estufa a 28°C por 20 dias. Em seguida, os ovos foram levados ao microscópio óptico, no aumento de 100X, para observação do percentual de embrionamento. Na concentração de 10ppm, nos tempos de 48 e 72 horas de exposição à droga, verificou-se completa inibição do embrionamento dos ovos.