Electrochemical Behavior of Verapamil at Graphite-Polyurethane Composite Electrodes: Determination of Release Profiles in Pharmaceutical Samples

A solid graphite-polyurethane composite electrode has been used to determine release profiles of verapamil, a calcium-channel blocker. The electro-oxidation process was characterized by cyclic voltammetry and electrochemical impedance spectroscopy and showed no adsorption of analyte or oxidation products, unlike at other carbon-based electrodes. Quantification gave linear ranges up to 40molL-1 with cyclic voltammetry and detection limits of 0.7molL-1 by differential pulse and square-wave voltammetry. Commercial product samples were successfully analyzed with results equal to those from spectrophotometry. Because no electrode surface renewal is needed, this electrode material has many advantages.

Applicatiion of Almost ideal demand system for a pharmaceutical

This thesis is an application of the Almost Ideal Demand System approach of Deaton and Muellbauer,1980, for a particular pharmaceutical, Citalopram, in which GORMAN´s (1971) multi-stage budgeting approach is applied basically since it is one of the most useful approach in estimating demand for differentiated products. Citalopram is an antidepressant drug that is used in the treatment of major depression. As for most other pharmaceuticals whose the patent has expired, there exist branded and generic versions of Citalopram. This paper is aimed to define its demand system with two stage models for the branded version and five generic versions, and to show whether generic versions are able to compete with the branded version. I calculated the own price elasticities, and it made me possible to compare and make a conclusion about the consumers’ choices over the brand and generic drugs. Even though the models need for being developed with some additional variables, estimation results of models and uncompensated price elasticities indicated that the branded version has still power in the market, and generics are able to compete with lower prices. One important point that has to be taken into consideration is that the Swedish pharmaceutical market faced a reform on October 1, 2002, that aims to make consumer better informed about the price and decrease the overall expenditures for pharmaceuticals. Since there were not significantly enough generic sales to take into calculation before the reform, my paper covers sales after the reform.

Development and validation of a stability-indicative agar diffusion assay to determine the potency of linezolid in tablets in the presence of photodegradation products

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Characterization of the excretory/secretory products of Dermatobia hominis larvae, the human bot fly

Proteolytic activity in excretory/secretory products (ESP) of first- (L1), second- (L2) and third-instar (L3) larvae of Dermatobia hominis was analyzed through gelatin-gel and colorimetric enzyme assays with the chromogenic substrates azocasein and BApNA. The functional characterization of proteases was based on inhibition assays including synthetic inhibitors. ESP were obtained from new-hatched larvae reared in the laboratory and from second- and third-instar larvae removed from naturally infested cattle. Gelatin-gel analysis evidenced few bands of proteolysis, predominantly of high apparent molecular masses, in ESP of L1, whereas in the gel of L2 and U ESP there was a wide range of proteolytic activity most of them not resolved in a single species. Azocasein assays revealed a progressive increase of protease activity from first- to third-instar larvae. Protease inhibitor assays revealed a predominance of metalloproteases in L1 ESP that could be related to a skin penetration process and to a diversion of host immune response. The predominance of serine proteases in L2 and L3 and the great tryptic activity presented by L3 ESP were attributed to an increasing trophic activity by the growing larvae, since the viability of adult flies strictly depends on larval abilities to assimilate nutrients from the host. Taking together, these results suggest that Dematobia larvae secrete/excrete different proteases that may be related to diverse functions during host penetration and infestation, which reinforces the relevance of the study of such proteolytic enzymes. (C) 2009 Elsevier B.V. All rights reserved.

Caenorhabditis elegans as a model to screen plant extracts and compounds as natural anthelmintics for veterinary use

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Zero valent iron mediated degradation of the pharmaceutical diazepam

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Study of the electrochemical reduction of amoebicide Teclozan and its amperometric determination in pharmaceutical formulations

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Sequential injection analysis system with spectrophotometric detection for determination of norfloxacin and ciprofloxacin in pharmaceutical formulations

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Flow-injection spectrophotometric determination of tetracycline and doxycycline in pharmaceutical formulations using chloramine-T as oxidizing agent

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Release of intermediate reactive hydrogen peroxide by macrophage cells activated by natural products

By determining the hydrogen peroxide (H2O2) released in cultures of peritoneal macrophage cells from Swiss mice, we evaluated the action of 27 vegetable compounds (pristimerin, tingenone, jatrophone, palustric acid, lupeol, cladrastin, ocoteine, boldine, tomatine, yohimbine, reserpine, escopoletin, esculine, plumericin, diosgenin, deoxyschizandrin, p-arbutin, mangiferin, and others) using a 2 mg/ml solution of each compound (100 mug/well). Macrophages are cells responsible for the development of the immunological response reaction, liberating more than one hundred compounds into the extracellular environment. Among these are the various cytokines and the intermediate compounds of nitrogen (NO) and oxygen (H2O2). This coordinated sequence of biochemical reactions is known as the oxidative burst. When we compared the results with those obtained with zymosan (an important stimulator of H2O2) we observed that the compounds showing the highest activity were substances 2 (tingenone), 16 (reserpine) and 20. Other substances such as compounds 1, 4, 5, 6, 8, 12, 13, 14, 15, 17, 19, 23, 24, 26, and 27 also showed a certain activity, but with less intensity than the aforementioned ones. Compounds 3, 7, 9, 10, 11, 18, 21, 22 and 25 presented no activity. These results suggest that natural products (mainly tingenone and reserpine and others) with different chemical structures are strong immunological modulators. However, further tests are needed to determine the 'oxidative burst' in future studies.

Pharmacokinetics of a new long acting endectocide formulation containing 2.25% ivermectin and 1.25% abamectin in cattle

The objective of this study was to determine the kinetic parameters of a new formulation that contained 2.25% ivermectin combined with 1.25% abamectin in bovine plasma. The results for 2.25% ivermectin: C-max (37.11 ng/mL +/- 7.42), T-max (16 days +/- 5.29), T-1/2 (44.62 days +/- 53.89), AUC (928.2 ng.day/mL +/- 153.83) and MRT (36.73 days +/- 33.64), and for 1.25% abamectin: C-max (28.70 ng/mL +/- 9.54), T-max (14 days +/- 4.04), T-1/2 (15.40 days +/- 11.43), AUC (618.05 ng.day/mL +/- 80.27) and MRT (20.79 days +/- 8.43) suggest that this combination of 2.25% ivermectin + 1.25% abamectin possesses properties that give this pharmaceutical formula a longer activity time than two of the commercial products tested (1% ivermectin and 1% abamectin), and showed similarity to 3.15% ivermectin.

A Validated Stability-Indicating LC Method for Orbifloxacin in the Presence of Degradation Products

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A simple spectrophotometry method for the determination of tetracycline and doxycycline in pharmaceutical formulations using chloramine-T

A simple, rapid, accurate and inexpensive spectrophotometric method for the determination of tetracycline and doxycycline has been developed. The method is based on the reaction between these drugs and chloramine-T in alkaline medium producing red color products with absorbance maximum at the λ=535 and 525 nm for the tetracycline and doxycycline, respectively. The best conditions for the reactions have been found using multivariate method. Beer's law is obeyed in a concentration ranges 1. 03 x 10 -5 to 3. 61 x 10 4mol L -1 and 1. 75 x 10 -5 to 3. 48 x 10 4mol L -1 for the tetracycline and doxycycline, respectively. The quantification limits were 5. 63 x 10 -6 mol L -1 and 7. 12 x 10 -7 mol L -1 for the tetracycline and doxycycline, respectively. The proposed method was successfully applied to the determination of these drugs in pharmaceutical formulations and the results obtained were in good agreement with those obtained by the comparative method at the 95% confidence level.

Biomass-to-bio-products application of feruloyl esterase from Aspergillus clavatus

The structural polysaccharides contained in plant cell walls have been pointed to as a promising renewable alternative to petroleum and natural gas. Ferulic acid is a ubiquitous component of plant polysaccharides, which is found in either monomeric or dimeric forms and is covalently linked to arabinosyl residues. Ferulic acid has several commercial applications in food and pharmaceutical industries. The study herein introduces a novel feruloyl esterase from Aspergillus clavatus (AcFAE). Along with a comprehensive functional and biophysical characterization, the low-resolution structure of this enzyme was also determined by small-angle X-ray scattering. In addition, we described the production of phenolic compounds with antioxidant capacity from wheat arabinoxylan and sugarcane bagasse using AcFAE. The ability to specifically cleave ester linkages in hemicellulose is useful in several biotechnological applications, including improved accessibility to lignocellulosic enzymes for biofuel production. © 2012 Springer-Verlag Berlin Heidelberg.

Natural Products from Cyanobacteria with Antimicrobial and Antitumor Activity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)