DEFAR - Artigos publicados em periódicos
URI permanente para esta coleçãohttp://www.hml.repositorio.ufop.br/handle/123456789/531
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Resultados da Pesquisa
Item Cloxacillin benzathine-loaded polymeric nanocapsules : physicochemical characterization, cell uptake, and intramammary antimicrobial effect.(2019) Araújo, Raquel Silva; Garcia, Giani Martins; Vilela, José Mário Carneiro; Andrade, Margareth Spangler; Oliveira, Laser Antônio Machado de; Kano, Eunice Kazue; Lange, Carla Christine; Brito, Maria Aparecida Vasconcelos Paiva; Brandão, Humberto de Mello; Mosqueira, Vanessa Carla FurtadoThe present work shows the development and evaluation of the veterinary antibiotic cloxacillin benzathine (CLOXB) loaded into poly-ε-caprolactone (PCL) nanocapsules (NC), as a potential new treatment strategy to manage bovine intramammary infections, such as mastitis. Staphylococcus aureus-induced mastitis is often a recurrent disease due to the persistence of bacteria within infected cells. CLOXB-PCL NC were prepared by interfacial deposition of preformed biodegradable polymer followed by solvent displacement method. The mean diameter of NC varied from 241 to 428 nm and from 326 to 375 nm, when determined by dynamic light scattering and by atomic force microscopy, respectively. The zeta potential of NC was negative and varied from −28 to −51 mV. In vitro release studies from the NC were performed in two media under sink conditions: PBS with 1% polyethylene glycol or milk. A reversed-phase HPLC method was developed to determine the NC entrapment efficiency and kinetics of CLOXB release from the NC. Free CLOXB dissolution occurred very fast in both media, while drug release from the NC was slower and incomplete (below 50%) after 9 h. CLOXB release kinetics from polymeric NC was fitted with the Korsmeyer-Peppas model indicating that CLOXB release is governed by diffusion following Fick's law. The fluorescence confocal microscopy images of macrophage-like J774A.1 cells reveal NC uptake and internalization in vitro. In addition, antimicrobial effect of the intramammary administration of CLOXB-PCL NC in cows with mastitis resulted in no clinical signs of toxicity and allowed complete pathogen elimination after treatment. The in vivo results obtained in this work suggest that CLOXB-PCL NC could be a promising formulation for the treatment of intramammary infections in cattle, considering their physicochemical properties, release profiles and effects on bovine mastitis control.Item LC UV methodology for simultaneous.(2008) Souza, Jacqueline de; Kano, Eunice Kazue; Koono, Eunice Emiko Mori; Schramm, Simone Grigoleto; Porta, Valentina; Storpirtis, SílviaThis study describes an accurate, sensitive, and specific chromatographic method for the simultaneous quantitative determination of lamivudine and zidovudine in human blood plasma, using stavudine as an internal standard. The chromatographic separation was performed using a C8 column (150 9 4.6 mm, 5 lm), and ultraviolet absorbency detection at 270 nm with gradient elution. Two mobile phases were used. Phase A contained 10 mM potassium phosphate and 3% acetonitrile, whereas Phase B contained methanol. A linear gradient was used with a variability of A-B phase proportion from 98–2% to 72–28%, respectively. The drug extraction was performed with two 4 mL aliquots of ethyl acetate.Item HPLC-DAD and UV-Spectrophotometry for the determination of lychnopholide in nanocapsule dosage dorm : validation and application to release kinetic study.(2012) Branquinho, Renata Tupinambá; Mosqueira, Vanessa Carla Furtado; Kano, Eunice Kazue; Souza, Jacqueline de; Dorim, Diego Dias Ramos; Guimarães, Dênia Antunes Saúde; Lana, Marta deSimple and sensitive methods using high-performance liquid chromatography– diode array detection (HPLC–DAD) and ultraviolet (UV)–spectrophotometry were developed and compared to quantify lychnopholide (LYC) in poly-1-caprolactone nanocapsules and to study its release kinetics. Both methods were validated concerning their specificity, linearity, limits of detection and quantification, precision, accuracy and stability. HPLC–DAD analyses were conducted using an RP C18 column, isocratic elution with a methanol–water (60:40 v/v) mobile phase at 0.8 mL/min flow rate and detection at 265 nm. The linear response (r2 > 0.999) was obtained within a concentration range of 2–25 mg/mL using HPLC–DAD and 5– 40 mg/mL using spectrophotometry. Intra-day and inter-day precision were obtained with low relative standard deviation values. The accuracy of the methods was within the range 98–101% for HPLC–DAD and from 96–100% for UV–spectrophotometry. Both methods were suitable to be applied for the determination of drug loading percentage (>96%) and encapsulation efficiency (>90%). Furthermore, the sensitivity of HPLC–DAD method allows studies of LYC release/dissolution in sink conditions. LYC presented 100% dissolution after 24 h, whereas only 60% of LYC was released from the nanocapsule dosage form, with no burst effect. The methods fulfilled all validation parameters evaluated for LYC quantification in the polymeric nanocapsules and have proven to be accurate, selective and sensitive in the previously mentioned applications.Item HPLC-FLD methods to quantify chloroaluminum phthalocyanine in nanoparticles, plasma and tissue : application in pharmacokinetic and biodistribution studies.(2011) Oliveira, Liliam Teixeira; Garcia, Giani Martins; Kano, Eunice Kazue; Tedesco, Antônio Cláudio; Mosqueira, Vanessa Carla FurtadoAnalytical and bioanalytical methods of high-performance liquid chromatography with fluorescence detection (HPLC-FLD) were developed and validated for the determination of chloroaluminum phthalocyanine in different formulations of polymeric nanocapsules, plasma and livers of mice. Plasma and homogenized liver samples were extracted with ethyl acetate, and zinc phthalocyanine was used as internal standard. The results indicated that the methods were linear and selective for all matrices studied. Analysis of accuracy and precision showed adequate values, with variations lower than 10% in biological samples and lower than 2% in analytical samples. The recoveries were as high as 96% and 99% in the plasma and livers, respectively. The quantification limit of the analytical method was 1.12 ng/ml, and the limits of quantification of the bioanalytical method were 15 ng/ml and 75 ng/g for plasma and liver samples, respectively. The bioanalytical method developed was sensitive in the ranges of 15–100 ng/ml in plasma and 75–500 ng/g in liver samples and was applied to studies of biodistribution and pharmacokinetics of AlClPc.