bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and evaluation of lornoxicam bilayered tablets for biphasic release
Authors: Sunil Songa Ambedkar , Srikanth Meka Venkata , Rao Nali Sreenivasa , Balaji Sakamuri , Murthy Kolapalli Venkata Ramana
Published: February 2013

The objective of the present investigation was to develop bilayered tablets of lornoxicam to achieve biphasic release pattern. A bilayered tablet, consisting of an immediate and controlled release layer, was prepared by direct compression technique. The controlled release effect was achieved by using various hydrophilic natural, semi synthetic and synthetic controlled release polymers such as xanthan gum, hydroxypropyl methylcellulose (HPMC) and polyethylene oxide (PEO) to modulate the release of the drug. The in vitro drug release profiles showed the biphasic release behavior in which the immediate release (IR) layer containing the lornoxicam was released within 15 minutes, whereas the controlled release (CR) layer controlled the drug release for up to 24 h. All the bilayered tablets formulated have followed the zero order release with non-Fickian diffusion controlled release mechanism after the initial burst release. FTIR studies revealed that there was no interaction between the drug and polymers used in the study. Statistical analysis (ANOVA) showed no significant difference in the cumulative amount of drug release after 15 min, but significant difference (p < 0.05) in the amount of drug released after 24 h from optimized formulations was observed. Based on the release kinetic parameters obtained, it can be concluded that xanthan gum polymer was suitable for providing a biphasic release of lornoxicam.
Development and evaluation of sustained release losartan potassium matrix tablet using kollidon SR as release retardant
Authors: Sarwar Shahid , Hossain Mohammad Salim
Published: February 2013

The present study was undertaken to develop sustained release (SR) matrix tablets of losartan potassium, an angiotensin-II antagonist for the treatment of hypertension. The tablets were prepared by direct compression method, along with Kollidon SR as release retardant polymer. The amount of losartan potassium remains fixed (100 mg) for all the three formulations whereas the amounts of Kollidon SR were 250 mg, 225 mg, and 200 mg for F-1, F-2, and F-3 respectively. The evaluation involves three stages: the micromeritic properties evaluation of granules, physical property studies of tablets, and in-vitro release kinetics studies. The USP apparatus type II was selected to perform the dissolution test, and the dissolution medium was 900 mL phosphate buffer pH 6.8. The test was carried out at 75 rpm, and the temperature was maintained at 37 ºC ± 0.5 ºC. The release kinetics was analyzed using several kinetics models. Higher polymeric content in the matrix decreased the release rate of drug. At lower polymeric level, the rate and extent of drug release were enhanced. All the formulations followed Higuchi release kinetics where the Regression co-efficient (R²) values are 0.958, 0.944, and 0.920 for F-1, F-2, and F-3 respectively, and they exhibited diffusion dominated drug release. Statistically significant (P<0.05) differences were found among the drug release profile from different level of polymeric matrices. The release mechanism changed from non-fickian (n=0.489 for F-1) to fickian (n=0.439 and 0.429 for F-2, and F-3 respectively) as a function of decreasing the polymer concentration. The Mean Dissolution Time (MDT) values were increased with the increase in polymer concentration.
Efficacy and safety of cumaru syrup as complementary therapy in mild persistent asthma: a double-blind, randomized, placebo-controlled study
Authors: Carvalho Elisete Mendes , Cunha Gilmara Holanda da , Fechine Francisco Vagnaldo , Uchôa Célia Regina Amaral , Moraes Filho Manoel Odorico de , Bezerra Fernando Antônio Frota , Moraes Maria Elisabete Amaral de
Published: February 2013

Amburana cearensis is a medicinal plant known as "cumaru". It is used in Northeast Brazil in the treatment of respiratory diseases. This was a randomized, double-blind, placebo-controlled study, with the aim of evaluating the efficacy and safety of cumaru syrup as complementary therapy in mild persistent asthma. The study consisted of 3 phases, pre-treatment, treatment and post-treatment. The primary efficacy outcome was comparison of the changes reported by patients of the cumaru and placebo groups after treatment, using the "Asthma Quality of Life Questionnaire" (AQLQ). The secondary outcome was the effect of cumaru syrup on lung function based on spirometry. The results showed that in the cumaru group, the proportion of patients who had global improvement in asthma symptoms was significantly greater (61.90%, P=0.0009) than in the placebo group (9.52%). Only the spirometric parameters Forced Vital Capacity (FVC) and Forced Expiratory Volume in 1 second (FEV1) showed significant intergroup differences in post-treatment (P<0.05). The hematological and serum chemistry tests performed in the pre-treatment and post-treatment showed no statistically significant differences (P>0.05). Adverse events were reported by 3 patients (14.29%) in the cumaru group and 3 patients (14.29%) in the placebo group. All adverse events were considered non-serious and mild.
Square-wave voltammetric determination of rutin in pharmaceutical formulations using a carbon composite electrode modified with copper (II) phosphate immobilized in polyester resin
Authors: Freitas Kellen Heloizy Garcia , Fatibello-Filho Orlando , Mattos Ivanildo Luiz de
Published: February 2013

A carbon composite electrode modified with copper (II) phosphate immobilized in a polyester resin (Cu3(PO4)2-Poly) for the determination of rutin in pharmaceutical samples by square-wave voltammetry is described herein. The modified electrode allows the determination of rutin at a potential (0.20 V vs. Ag/AgCl (3.0 mol L-1 KCl)) lower than that observed at an unmodified electrode. The peak current was found to be linear to the rutin concentration in the range from 9.9 × 10-8 to 2.5 × 10-6 mol L-1, with a detection limit of 1.2×10-8 mol L-1. The response of the electrode was stable, with no variation in baseline levels within several hours of continuous operation. The surface morphology of the modified electrode was characterized by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) system. The results obtained are precise and accurate. In addition, these results are in agreement with those obtained by the chromatographic method at a 95% confidence level.
Nutritional composition of rice bran submitted to different stabilization procedures
Authors: Faria Simone Aparecida dos Santos Conceição , Bassinello Priscila Zaczuk , Penteado Marilene de Vuono Camargo
Published: February 2013

In order to inactivate enzymatic deterioration, whole rice bran samples were subjected to two stabilization methods. Changes in nutritional value in terms of, concerning chemical composition, minerals and fatty acid content, were evaluated to supplement existing data and promote the utilization of rice bran in the human diet. The following homemade heat treatments were applied: roasting on a conventional stove or heating in a microwave oven. Based on the results, the different heating methods affected sample composition, since the levels of some nutrients of treated samples showed significant changes (p<0.05) compared to corresponding raw samples. The rice bran treated on a conventional stove produced products with lower moisture (5.14±0.10 g/100 g) and nutrients such as sodium 11.8%; palmitic acid 9.9% and stearic acid 8.1%. The microwave oven procedure resulted in better nutrient preservation, with slightly higher moisture content (6.28±0.10 g/100 g), and appears to be a practical and rapid tool for home heat stabilization of rice bran.
Ginkgo biloba extract (EGb 761) attenuates oxidative stress induction in erythrocytes of sickle cell disease patients
Authors: Furman Aline Emmer Ferreira , Henneberg Railson , Hermann Priscila Bacarin , Leonart Maria Suely Soares , Nascimento Aguinaldo José do
Published: February 2013

Sickle cell disease promotes hemolytic anemia and occlusion of small blood vessels due to the presence of high concentrations of hemoglobin S, resulting in increased production of reactive oxygen species and decreased antioxidant defense capacity. The aim of this study was to evaluate the protective action of a standardized extract of Ginkgo biloba (EGb 761), selected due to its high content of flavonoids and terpenoids, in erythrocytes of patients with sickle cell anemia (HbSS, SS erythrocytes) subjected to oxidative stress using tert-butylhydroperoxide or 2,2-azobis-(amidinepropane)-dihydrochloride, in vitro. Hemolysis indexes, reduced glutathione, methemoglobin concentrations, lipid peroxidation, and intracellular reactive oxygen species were determined. SS erythrocytes displayed increased rates of oxidation of hemoglobin and membrane lipid peroxidation compared to normal erythrocytes (HbAA, AA erythrocytes), and the concentration of EGb 761 necessary to achieve the same antioxidant effect in SS erythrocytes was at least two times higher than in normal ones, inhibiting the formation of intracellular reactive oxygen species (IC50 of 13.6 µg/mL), partially preventing lipid peroxidation (IC50 of 242.5 µg/mL) and preventing hemolysis (IC50 of 10.5 µg/mL). Thus, EGb 761 has a beneficial effect on the oxidative status of SS erythrocytes. Moreover, EGb 761 failed to prevent oxidation of hemoglobin and reduced glutathione at the concentrations examined.
Improved dissolution and micromeritic properties of naproxen from spherical agglomerates: preparation, in vitro and in vivo characterization
Authors: Saritha Damineni , Bose Penjuri Subhash Chandra , Reddy Poreddy Srikanth , Madhuri Grandhi , Nagaraju Ravouru
Published: February 2013

Naproxen, an anti-inflammatory drug, exhibits poor aqueous solubility, which limits the pharmacological effects. The present work was carried out to study the effect of agglomeration on micromeritic properties and dissolution. Naproxen agglomerates were prepared by using a three solvents system composed of acetone (good solvent), water (non-solvent) and dichloromethane (bridging liquid). Differential Scanning Calorimetry (DSC) results showed no change in the drug after crystallization process. X-Ray Powder Diffraction (XRPD) studies showed the sharp peaks are present in the diffractograms of spherical agglomerates with minor reduction in height of the peaks. The residual solvents are largely below the tolerated limits in the agglomerates. Scanning Electronic Microscopy (SEM) studies showed that agglomerates were spherical in structure and formed by cluster of small crystals. The agglomerates exhibited improved solubility, dissolution rate and micromeritic properties compared to pure drug. Anti-inflammatory studies were conducted in Wistar strain male albino rats and naproxen agglomerates showed more significant activity than the pure drug.
Comparison of selective agars recommended by method ISO 11290-1 and chromogenic agars for the isolation of Listeria sp. in refrigerated sausages
Authors: Benetti Thalyta Marina , Monteiro Cristina Leise Bastos , Beux Márcia Regina , Abrahão Wanda Moscalewski
Published: February 2013

The aim of this study was to determine the prevalence of Listeria sp. in refrigerated sausages, and to compare the performance of the selective plating media employed in the ISO 11290-1 method (PALCAM and Oxford agars) with chromogenic agars (Chromogenic Listeria agars CM 1080 (OCLA) and CM 1084). The prevalence of Listeria sp. detected was 52.9%, comprising 13.7% L. monocytogenes strains. The efficacy of the four agars for the isolation of L. monocytogenes proved to be satisfactory. Despite differences in composition of the chromogenic media assessed, these disparities did not affect concordance among results. However, PALCAM agar was shown to suppress other microorganisms more effectively, being more applicable for detecting Listeria strains present in lower quantities. Based on these results, the use of PALCAM agar, in combination with a chromogenic media, is recommended for enhanced isolation of atypical Listeria sp. strains in meat products.
Preparation, characterization and evaluation of moisturizing and UV protecting effects of topical solid lipid nanoparticles
Authors: Golmohammadzadeh Shiva , Mokhtari Mohsen , Jaafari Mahmoud Reza
Published: February 2013

Solid lipid nanoparticles (SLN) were recently proposed as carriers for various pharmaceutical and cosmetic actives. These lipid nanoparticles can act as moisturizers and physical sunscreens on their own. Therefore, the full potential of these carriers has yet to be determined. The present study was aimed to determine and compare moisturizing and UV-protecting effects of different solid lipid nanoparticles (SLN) prepared by different solid lipids including Glyceryl monostearate (GMS), Precirol® (P) and cetyl palmitate (CP) as carrier systems of moisturizers and sunscreens. The influence of the size and matrix crystallinity of the solid lipids on the occlusive factor, skin hydration and UV-protection were evaluated by in vitro and in vivo methods. The SLN were prepared by high-shear homogenization and ultrasound methods. Size, zeta potential and morphological characteristics of the samples were assessed by transmission electron microscopy (TEM) and thermotropic properties with differential scanning calorimetry (DSC) technique. Results of the assessments showed that SLN-CP significantly increases skin hydration and UV-protection, compared to SLN-GMS and SLN-P. It was demonstrated that the size of SLN, crystallinity index of solid lipid in SLN and probably other mechanisms besides the occlusive factor can influence skin hydration and UV-protection indices. Furthermore, findings of the assessments demonstrated significant difference between in vitro and in vivo assessments regarding occlusive factor and moisturizing effects. Findings of the present study indicate that the SLN-CP could be a promising carrier for sunscreens and moisturizers.
Biological and physicochemical stability of ceftazidime and aminophylline on glucose parenteral solution
Authors: Santos Carolina Alves dos , Oliveira-Nascimento Laura , Knirsch Marcos Camargo , Stephano Marco Antônio , Pessoa Júnior Adalberto , Penna Thereza Christina Vessoni
Published: February 2013

Ceftazidime is a broad spectrum antibiotic administered mainly by the parenteral route, and it is especially effective against Pseudomonas aeruginosa. The period of time in which serum levels exceed the Minimum Inhibitory Concentration (MIC) is an important pharmacodynamic parameter for its efficacy. One of the forms to extend this period is to administer the antibiotic by continuous infusion, after prior dilution in a Parenteral Solution (PS). The present work assessed the stability of ceftazidime in 5% glucose PS for 24 hours, combined or not with aminophylline, through High Performance Liquid Chromatography (HPLC). The physicochemical evaluation was accompanied by in vitro antimicrobial activity compared MIC test in the 24-hour period. Escherichia coli and Pseudomonas aeruginosa were the microorganisms chosen for the MIC comparison. The HPLC analysis confirmed ceftazidime and aminophylline individual stability on PS, while the MIC values were slightly higher than the mean described in the literature. When both drugs were associated in the same PS, the ceftazidime concentration by HPLC decreased 25% after 24 hours. Not only did the MIC values show high loss of antibiotic activity within the same period, but also altered MIC values immediately after the preparation, which was not detected by HPLC. Our results indicate that this drug combination is not compatible, even if used right away, and that PS might not be the best vehicle for ceftazidime, emphasizing the importance of the MIC evaluation for drug interactions.
Biodegradable microparticulate drug delivery system of diltiazem HCl
Authors: Gupta Manish Kumar , Prakash Deepak , Mishra Brahmeshwar
Published: February 2013

The efficacy of a drug in a specific application requires the maintenance of appropriate drug blood level concentration during a prolonged period of time. Controlled release delivery is available for many routes of administration and offers many advantages (as microparticles and nanoparticles) over immediate release delivery. These advantages include reduced dosing frequency, better therapeutic control, fewer side effects, and, consequently, these dosage forms are well accepted by patients. Advances in polymer material science, particle engineering design, manufacture, and nanotechnology have led the way to the introduction of several marketed controlled release products and several more are in pre-clinical and clinical development. The objective of this work is to prepare and evaluate diltiazem HCl loaded albumin microparticles using a factorial design. Albumin (natural polymer) microparticles were prepared by emulsion heat-stabilization method. Selected formulations were characterized for their entrapment efficiency, particle size, surface morphology, and release behavior. Analysis of variance for entrapment efficiency indicates that entrapment efficiency is best fitted to a response surface linear model. Surface morphology was studied by scanning electron microscopy. Scanning electron microscopy of the microparticles revealed a spherical, nonporous and uniform appearance, with a smooth surface. The geometric mean diameter of the microparticles was found to be 2-9 µm, which more than 75% were below 3.5 µm and drug incorporation efficiency of 59.74 to 72.48% (w/w). In vitro release profile for formulations containing diltiazem HCl loaded BSA microparticles with heat stabilization technique shows slow controlled the release of the drug up to 24 hours. The release pattern was biphasic, characterized by an initial burst effect followed by a slow release. All selected microparticles exhibited a prolonged release for almost 24 hours. On comparing regression-coefficient (r²) values for Hixson Crowel, Higuchi and Peppas kinetic models, different batches of microparticles showed Fickian, non-Fickian, and diffusion kinetics. The release mechanism was regulated by D:P ratio. From the statistical analysis it was observed that as the drug:polymer (D:P) ratio increased, there was a significant increase in the encapsulation efficiency. Based on the particle size, entrapment efficiency and physical appearance, DTM-3 formulations were selected for in vivo release study and stability study. The in vivo result of drug loaded microparticles showed preferential drug targeting to liver followed by lungs, kidneys and spleen. Stability studies showed that maximum drug content and closest in vitro release to initial data were found in the formulation stored at 4 ºC. In present study, diltiazem HCl loaded BSA microparticles were prepared and targeted to various organs to satisfactory level and were found to be stable at 4 ºC.
Quality of life of HIV+ patients undergoing pharmacotherapeutic follow-up
Authors: Loureiro Catarine Vitor , Reis Henry Pablo Lopes Campos e , Magalhães Karla do Nascimento , Carmo Cristiane Policarpo , Leite Francisca Ana Maria , Passos Ana Cláudia de Brito , Firmino Paulo Yuri Milen , Kheir Nadir , Woods David John , Ponciano Ângela Maria de Souza , Fonteles Marta Maria de França
Published: February 2013

The influence of pharmacotherapeutic follow-up (PTF) on quality of life was evaluated in 45 HIV+ patients, who were undergoing initial antiretroviral therapy at a specialized care center in northeast Brazil. PTF lasted nine months and quality of life was analyzed at the 1st and 9th meetings using a questionnaire validated for Brazil. The study identified 643 problems related to antiretrovirals and there were 590 pharmaceutical interventions during the PTF. The comparative analysis between the results of the 1st and the 9th meeting was statistically significant for all domains of the questionnaire. For asymptomatic patients, only one domain was statistically significant. For symptomatic patients, six domains were significant. Patients with one year of HIV/AIDS diagnosis had statistically significant differences in five domains. The results suggest that the PTF contributed to improving quality of life, particularly for symptomatic patients and those diagnosed for at least one year - important target groups for Pharmaceutical Treatment.
Spectrofluorimetric determination of amlodipine in human plasma without derivatization
Authors: Kadioglu Yucel , Ozturk Murat
Published: February 2013

A rapid and sensitive spectrofluorimetric method was developed for the determination of amlodipine (AD), a calcium channel blocker, in the plasma. The type of solvent, the wavelength range, and the range of AD concentration were selected to optimize the experimental conditions. The calibration curves were linear (r² >0.997) in the concentration range of 0.1-12.5 ppm of AD. The limit of quantitation and limit of detection values for the method for plasma samples were 0.1 ppm and 0.07 ppm, respectively. The precision calculated as the relative standard deviation was less than 3.5%, and the accuracy (relative error) was better than 5.5% (n=6). The method developed in this study can be directly and easily applied for the determination of AD in the plasma without derivatization in plasma.
Management of effluents and waste from pharmaceutical industry in Minas Gerais, Brazil
Authors: Deschamps Eleonora , Vasconcelos Olivia , Lange Lisete , Donnici Claudio Luis , Silva Merces Coelho da , Sales Juliana Aparecida
Published: February 2013

Today the management of solid waste and wastewater is a major concern for humanity. In the last decade, traces of pharmaceuticals have been reported in the water cycle and have raised concerns among regulators, water suppliers and the public regarding the potential risks to human health. This study evaluated solid waste management in the state of Minas Gerais and concluded that the main fate of hazardous waste has been incineration, while the non-hazardous waste has been recycled or sent to landfills. However, complaints to the Environmental Agency - FEAM have indicated that a significant number of companies just send their hazardous wastes to landfills or even to garbage dumps, thus highlighting the urgent need for adequate waste management in Minas Gerais. Most of the pharmaceutical companies in Minas Gerais use conventional wastewater treatment. Mass spectrometry with electrospray ionization (ESI-MS) showed that the treatment routes adopted by the two 2 selected pharmaceutical industries were not effective enough since residues and degradation products of antibiotics were detected. The physicochemical analysis of the effluents showed variability in their characteristics, which may influence their treatability. The degradation assay with Fenton's reagent stood out as a promising route in achieving a higher removal capacity compared to the conventional treatment. This study contributes to enhancing our knowledge of the management of wastewater as well as of solid waste from the pharmaceutical industry in Minas Gerais and points out the need for further research.
Adhesion and biofilm formation by Staphylococcus aureus from food processing plants as affected by growth medium, surface type and incubation temperature
Authors: Jerônimo Heloísa Maria Ângelo , Queiroga Rita de Cássia Ramos do Egypto , Costa Ana Caroliny Vieira da , Barbosa Isabella de Medeiros , Conceição Maria Lúcia da , Souza Evandro Leite de
Published: February 2013

This study assessed the effect of different growth media [BHI broth, BHI broth plus glucose (10 g/100 mL) and BHI broth plus NaCl (5 g/100 mL)] and incubation temperatures (28 or 37 ºC) on the adherence, detachment and biofilm formation on polypropylene and stainless steel surfaces (2 x 2 cm coupons) for a prolonged period (24-72 h) by some strains of Staphylococcus aureus (S3, S28 and S54) from food processing plants. The efficacy of the sanitizers sodium hypochlorite (250 mg/mL) and peracetic acid (30 mg/mL) in reducing the number of viable bacterial cells in a preformed biofilm was also evaluated. S. aureus strains adhered in highest numbers in BHI broth, regardless of the type of surface or incubation temperature. Cell detachment from surfaces revealed high persistence over the incubation period. The number of cells needed for biofilm formation was noted in all experimental systems after 3 days. Peracetic acid and sodium hypochlorite were not efficient in completely removing the cells of S. aureus adhered onto polypropylene and stainless steel surfaces. From these results, the assayed strains revealed high capacities to adhere and form biofilms on polypropylene and stainless steel surfaces under the different growth conditions, and the cells in biofilm matrixes were resistant to total removal when exposed to the sanitizers sodium hypochlorite and peracetic acid.
Analysis of whey protein hydrolysates: peptide profile and ACE inhibitory activity
Authors: Silvestre Marialice Pinto Coelho , Silva Mauro Ramalho , Silva Viviane Dias Medeiros , Souza Mariana Wanessa Santana de , Lopes Junior Carlos de Oliveira , Afonso Wendel de Oliveira
Published: February 2013

The aim of this study was to prepare enzymatic hydrolysates from whey protein concentrate with a nutritionally adequate peptide profile and the ability to inhibit angiotensin-converting enzyme (ACE) activity. The effects of the type of enzyme used (pancreatin or papain), the enzyme:substrate ratio (E:S ratio=0.5:100, 1:100, 2:100 and 3:100) and the use of ultrafiltration (UF) were investigated. The fractionation of peptides was performed by size-exclusion-HPLC, and the quantification of the components of the chromatographic fractions was carried out by a rapid Corrected Fraction Area method. The ACE inhibitory activity (ACE-IA) was determined by Reverse Phase-HPLC. All parameters tested affected both the peptide profile and the ACE-IA. The best peptide profile was achieved for the hydrolysates obtained with papain, whereas pancreatin was more advantageous in terms of ACE-IA. The beneficial effect of using a lower E:S ratio on the peptide profile and ACE-IA was observed for both enzymes depending on the conditions used to prepare the hydrolysates. The beneficial effect of not using UF on the peptide profile was observed in some cases for pancreatin and papain. However, the absence of UF yielded greater ACE-IA only when using papain.
In vitro/in vivo performance of different complexes of itraconazole used in the treatment of vaginal candidiasis
Authors: Mirza Mohammad Aamir , Rahman Mohammad Akhlaquer , Talegaonkar Sushama , Iqbal Zeenat
Published: February 2013

A large majority of new chemical entities and many existing drug molecules exhibit poor aqueous solubility, which may limit their potential use in developing drug formulations, with optimum bioavailability. One of the approaches to improve the solubility of a poorly water soluble drug and eventually its bioavailability is complexation with agents like humic acid (HA), fulvic acid (FA), β-cyclodextrin (β-CD), 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) and caffeine (Caff). The current work emphasized at employing these agents to prepare different complexes and their in vitro/in vivo assessment. All the complexes evaluated for their complexation efficiency and authenticated by molecular modeling; conformational analysis, differential scanning calorimetry (DSC), X-ray diffraction (XRD), nuclear magnetic resonance (NMR) and mass spectroscopy. Furthermore, the complexes were assessed in an in vivo, rat vaginal model for their efficacy in treatment of vaginal candidiasis. Amongst the five tested complexes, fulvic acid-itraconazole complex yielded better solubility as well as in vivo efficacy and therefore may further be explored for developing a commercial formulation for treating vaginal candidiasis.
Microspheres prepared with biodegradable PHBV and PLA polymers as prolonged-release system for ibuprofen: in vitro drug release and in vivo evaluation
Authors: Bazzo Giovana Carolina , Macedo Aline Teixeira de , Crenca Janine Paula , Silva Virgínia Emiliana , Pereira Eduardo Manoel , Zétola Melissa , Pezzini Bianca Ramos
Published: February 2013

In this study, poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and poly(l-lactide) (PLA) microspheres containing ibuprofen were prepared with the aim of prolonging the drug release. The oil-in-water (O/W) emulsion solvent evaporation technique was used, varying the polymer ratio. All formulations provided spherical particles with drug crystals on the surface and a porous and rough polymeric matrix when PHBV was used and smooth external surface when prepared with PLA. The in vitro dissolution profiles show that the formulation containing PHBV/PLA at the proportion of 30/70 presented the best results in terms of prolonging the ibuprofen release. The analysis of the concentration of ibuprofen in the blood of rats showed that maximum levels were achieved at between one and two hours after administration of the immediate-release form (pure drug), while the prolonged microspheres led to a small amount of the drug being released within the first two hours and reached the maximum level after six hours of administration. It was concluded that it is possible to prolong the release of ibuprofen through its incorporation into PHBV/PLA microspheres.
Efficacy, safety and tolerability of using abatacept for the treatment of rheumatoid arthritis
Authors: Venson Rafael , Wiens Astrid , Correr Cassyano Januário , Pontarolo Roberto
Published: February 2013

The objective is to provide an update on the clinical efficacy, safety and tolerability of the use of abatacept for treating rheumatoid arthritis. A systematic review (up to June 2011) followed by meta-analyses was performed. Randomized controlled clinical trials comparing abatacept at a dose of 10 mg/kg with a placebo, both with concomitant methotrexate, were used. Only high- or moderate-quality studies were included. The efficacy was evaluated based on changes in the ACR, DAS and HAQ; safety was assessed based on serious adverse events, serious infections, malignancies and deaths; tolerability was evaluated based on the withdrawals due to adverse events, serious adverse events and lack of efficacy. All these parameters were evaluated within one year of treatment. Nine studies met the inclusion criteria, comprising 4,219 patients. For all of the efficacy parameters, the abatacept group had better results than the placebo group, except in the case of HAQ improvement >0.3, which presented no statistically significant difference. None of the safety parameters presented a significant difference between the groups. The tolerability parameters were also similar between groups, with the exception of withdrawals due to lack of efficacy. For this criterion, the abatacept group presented favorably compared to the control group. Abatacept showed a higher efficacy compared to placebo without significant differences between the abatacept and control group in terms of safety.
Maprotiline treatment differentially influences cardiac β-adrenoreceptors expression under normal and stress conditions
Authors: Spasojevic Natasa , Jovanovic Predrag , Dronjak Sladjana
Published: February 2013

Alterations in cardiac function were observed in antidepressants treated patients and published in several clinical reports. These detected changes could be either a consequence of the treatment or of depression itself, which has already been proved to be a risk factor in heart diseases. In order to determine a possible influence of chronic treatment with norepinephrinergic reuptake inhibitor, maprotiline, on the heart, we investigated gene expression of cardiac β-adrenoceptors both in controls and in animals with signs of depression. The rats were divided into two groups, unstressed controls and those exposed to chronic unpredictable mild stress (CUMS). The groups were further divided into two subgroups, one receiving daily intraperitoneal injections of vehicle (sterile water) and another one maprotiline (10 mg/kg) for four weeks. Tissue samples were collected after the last application. Gene expression of cardiac β1- and β2-adrenoceptor was determined using Real-time RT-PCR analysis. Our results show that in control animals expression of both adrenoreceptors was decreased in the right atria after 4 weeks of maprotiline application. Contrary, the same treatment led to a significant increase in expression of cardiac β1-adrenoceptor in the stressed rats, with no change in the characteristics of β2-adrenoceptor. Our findings might reflect the that molecular mechanisms are underlying factors involved in the development of cardiovascular diseases linked with antidepressant treatment.
Developing methods to compare tablet formulations of atorvastatin
Authors: Oliveira Marcelo Antonio de , Lacerda Caroline Dutra , Bonella André Fazôlo
Published: February 2013

Atorvastatin (ATV) is an antilipemic drug of great interest to the pharmaceutical industry. ATV does not appear in the monographs of Brazilian pharmacopoeia, and analytical methodologies for its determination have been validated. The chromatographic conditions used included: RP-18 column-octadecylsilane (250 x 4.6 mm, 5 mm), detection at 238 nm, mobile phase containing 0.1% phosphoric acid and acetonitrile (35:65% v/v), flow at 1.5 mL min-1, oven temperature at 30ºC, and injection volume of 10 mL. ATV is classified as a class II product, according to the biopharmaceutical classification system. As such, a dissolution test was proposed to evaluate pharmaceutical formulations on the market today, under the following conditions: water as a dissolution medium, 1000 mL as a volume, paddle apparatus at a rotation speed of 50 rpm, 80% (Q) in 15 minutes with UV spectrophotometer readings at 238 nm. In the pattern condition proposed as the ideal dissolution test, which appropriately differentiates amongst formulations, the generic product was not considered pharmaceutically equivalent; however, in other less differential dissolution methods, which also fall within appropriate legal parameters, this product could come to be regarded as generic.
In vitro skin penetration of clobetasol from lipid nanoparticles: drug extraction and quantitation in different skin layers
Authors: Silva Luís Antônio Dantas , Taveira Stephânia Fleury , Lima Eliana Martins , Marreto Ricardo Neves
Published: February 2013

Clobetasol propionate (CP) is a potent topical corticosteroid that causes several cutaneous and systemic side effects. In the present work, CP was encapsulated in nanostructured lipid carriers (NLCs) to increase drug retention in the outer skin layers and improve the safety of topical therapy. NLCs were prepared using a microemulsion technique with a mixture of lecithin, taurodeoxycholate, stearic acid, and oleic acid. In vitro penetration studies were performed in a modified Franz-type diffusion cell, and porcine ears were used as a model of human skin. A simple and sensitive liquid chromatographic method was developed and validated for clobetasol determination in different skin layers. NLCs presented uniform size distribution, high zeta potentialand entrapment efficiency values (> 98%). The analytical procedure was validated according to FDA guidelines. Clobetasol recoveries from skin samples were higher than 85%, with no interference of skin components and NLC ingredients. In experiments, after 6 h, a higher drug accumulation in the stratum corneum arising from NLCs compared to aqueous CP solution was observed. Thus, the NLCs demonstrated high potential for targeting CP to the skin and ensuring drug accumulation in the stratum corneum.
Transdermal iontophoretic delivery of timolol maleate
Authors: Patni Mayur , Puranik Prashant , Sonawane Aravind , Panzade Prabhakar
Published: February 2013

Transdermal iontophoresis would be a promising method for the systemic delivery of water soluble and ionic drugs of relatively high molecular size, including peptides. The objective of the present study was to investigate the effect of biological variable such as guinea pig and human cadaver skin and other variables like drug concentration, current density on the transdermal iontophoretic transport of timolol maleate. The permeation profile of drug using solution and gel formulation was studied and compared. For better bioavailability, better patient compliance, and enhanced delivery, an iontophoretic drug delivery system of a timolol maleate matrix gel was formulated using Carbopol 974P. The study was conducted using silver-silver chloride electrodes across the guinea pig and human cadaver skin. Viscosity measurements and flux calculations indicated the suitability of the Carbopol 974P gel for transdermal iontophoretic delivery of timolol maleate. Anodal iontophoresis with silver-silver chloride electrode significantly increased the timolol maleate skin permeation as compared with the passive permeation study. The amount of timolol maleate transported during iontophoresis was significantly different among the different skins. However, iontophoretic gel formulations provided required flux of drug through human cadaver skin.
New screening methodology for selection of polymeric matrices for transdermal drug delivery devices
Authors: Falcone R. , Jaffe M. , Ravindra N. M.
Published: February 2013

Transdermal drug delivery systems, such as patches, are viewed as one the best technologies that enhance greater patient compliance thus providing the desired therapeutic results. However, one of the main challenges is to find the right polymeric matrix that will provide the desired active therapeutic concentration. This is usually accomplished empirically and is not always the effective approach. In this study, the authors describe a predictive screening methodology based on material parameters to identify materials that will accomplish therapeutic targets.
Design of cross-girders and slabs in ladder deck bridges
Authors: Hendy Chris R. , Sandberg Jessica , Iles David
Published: February 2013

Deck slabs in ladder decks span longitudinally between transverse cross-girders and the primary function of these cross-girders is to support the deck slab. The girders may, however, need to perform the secondary function of preventing the slab from buckling in compression. The concrete deck slab of a ladder deck can have a very large transverse span between main girders. This large unsupported width can lead to buckling of the slab in compression unless it is prevented from doing so by transverse girders. If the spacing of the cross-girders is large, it is still possible for second-order bending moments to develop in the slab under the effects of global compression. This paper sets out guidance on the limiting spacing of main girders and cross-girders to avoid consideration of second-order effects and also the means of determining second-order effects in slabs and cross-girders when this becomes necessary.
The role of plasma treatment on electrochemical capacitance of undoped and nitrogen doped carbon nanotubes
Authors: Shi W. , Venkatachalam K. , Gavalas V. , Qian D. , Andrews R. , Bachas L. G. , Chopra N.
Published: February 2013

Carbon nanotubes (undoped CNTs) and nitrogen-doped CNTs (N-CNTs, 2·6 and 5 at.%) were synthesized using a floating catalyst chemical vapor deposition (CVD) method with ferrocene and xylene, pyridine, or acetonitrile. The CNTs were further treated in acid (3:1 HNO3:H2SO4 mixture for 24 h) or in oxygen plasma for 10, 30, or 50 min. The as-produced and acid/plasma treated CNTs were characterized by microscopic and spectroscopic techniques to understand the modification of structures by different treatment procedures. Electrochemical surface areas of the doped and undoped CNTs before and after acid/plasma treatment were studied. It was observed that the electrochemical surface area was significantly low (∼10-5 to 10-6 m2) due to limited exposure and wettability of the CNTs on the exposed electrode area. Cyclic voltammetry was also performed to evaluate the effects of these treatments on the capacitance behavior of electrodes. The specific capacitance of CNTs based on the electrochemical surface area was in the order of ∼0·3–8·0 F/g or ∼2000–18000 F/m2, which could be attributed to double layer or Faradaic reactions. It was observed that optimized plasma oxidation or surface modification conditions are necessary to achieve maximum specific capacitances. Plasma duration of 10, 30 and 10 min led to maximum specific capacitance for undoped CNTs, 2·6% N-doped CNTs and 5% N-doped CNTs, respectively. Further improvements in specific ca-pacitances necessitate suitable electrode design, selection of electrolyte and charging/discharging conditions. Overall, such low specific capacitances of CNTs in a physiological electrolyte are of critical importance for applications in energy storage in low-powered microreactors or implantable biomedical devices. Supplementary information is available at http://www.icevirtuallibrary.com/upload/10.1680nme.12.00033_SupplementaryInformation.pdf
Multiscale laser materials engineering: energy-efficient processing and materials performance
Authors: Dahotre Narendra B.
Published: February 2013

The article attempts to provide a brief overview of laser material interactions at various scales and associated effects in the materials. The utility of lasers as an advanced materials processing and manufacturing tool has been explained. Several unique characteristics associated with the lasers bring about the physical, chemical and microstructural evolutions and host of properties such as but not limited to mechanical, chemical, electrical and magnetic at multiple scales and in precision manner that are usually not possible by the conventional techniques. Furthermore, the article discusses three specific examples to elucidate the laser-based energy-efficient processing for high-performance materials and its potential as advanced manufacturing tool of the next generation.
Superoleophobic surfaces: design criteria and recent studies
Authors: Kota Arun K. , Mabry Joseph M. , Tuteja Anish
Published: February 2013

Surfaces that display contact angles greater than 150° along with a low contact angle hysteresis for low surface tension liquids such as oils and alcohols are known as superoleophobic surfaces. Such surfaces are of interest for a diverse array of applications including self-cleaning, nonfouling, stain-free clothing and spill-resistant protective wear, drag reduction, microrobots for aqueous and chemical environments and icephobicity. Recently, significant advances have been made in understanding the criteria required to design superoleophobic surfaces. In this article, the authors discuss the roles of surface energy and roughness, the critical role of re-entrant texture and the role of hierarchical structure in fabricating superoleophobic surfaces. On the basis of this understanding, the authors also discuss two design parameters that allow for the systematic design of superoleophobic surfaces. The authors also summarize the recent studies on superoleophobic surfaces and emphasize the need for careful and diligent characterization. Finally, the authors conclude with the major challenges and opportunities for research on superoleophobic surfaces.
A Study of Online Misrepresentation, Self-Disclosure, Cyber-Relationship Motives, and Loneliness among Teenagers in Taiwan
Authors: Huang Chiao Ling , Yang Shu Ching
Published: February 2013

The purpose of this study was to investigate the relationships between online misrepresentation (OM), self-disclosure (SD), cyber-relationship motives (CRM), and loneliness in teenagers. A survey was conducted using a sample of 608 Taiwanese teenagers (13 to 18 years of age). The instruments used include scales of loneliness, OM, and SD in real life (SD-R) and in cyberspace (SD-C). The findings show that 70.23% of teenagers report engaging in OM, indicating that it is a universal phenomenon. This study found no gender differences in reported OM and found that teenagers with online dating experiences exhibited different SD behavior online and offline. A multiple regression analysis showed that a lower valence of SD-R and an increase in the depth of control and accuracy of both SD-C and OM were predictive of teenagers' CRM with an overall middle level of explanatory power; further, lower accuracy and increased intent of SD-R, as well as increases in intentions of easier communication and sexual partners of CRM, were predictive of teenagers' OM, with overall low levels of explanatory power. Recommendations for future research are suggested.
Using Second Life as a Virtual Collaborative Tool for Preservice Teachers Seeking English for Speakers of other Languages Endorsement
Authors: Kim Deoksoon , Blankenship Rebecca J.
Published: February 2013

This study evaluated preservice teachers' professional-knowledge transformation while they participated in simulated professional-development activities via a Second Life virtual classroom—an Internet-based multiuser virtual environment (MUVE). While a cohort of preservice teachers experienced the MUVE environment, the instrumental exploratory case study highlighted how 2 preservice teachers among the 12 internalized professional knowledge, as well as how that knowledge transferred into active teaching practice. The study was framed around sociocultural theory as it pertains to enabling intramental functioning through co-constructed activities. The preservice teachers' debriefings and reflective statements suggest that they entered the Zone of Proximal Development (ZPD)—the range of potential an individual has for learning, with that learning being shaped by the social environment—indicating the positive potential of using an MUVE to promote self-regulatory pedagogic behaviors.
Self-Regulated Learning: A Key of a Successful Learner in Online Learning Environments in Thailand
Authors: Samruayruen Buncha , Enriquez Judith , Natakuatoong Onjaree , Samruayruen Kingkaew
Published: February 2013

This study identified five effective self-regulated learning (SRL), investigated the correlation of demographic information and SRL, and measured significant predictor of prior experiences on SRL. Eighty-eight Thai learners participated in the SRL survey, which was adapted from the MSLQ. The findings indicated that Intrinsic Goal and Self-Efficacy were correlated with Cognitive Strategy and Study Management, but Test Anxiety was not significantly related with any component. Multiple regressions indicated that Internet and Hybrid-course experiences were significant predictors of Study Management. The same results indicated that learners who had more Internet experience reported a significantly higher level of Self-Efficacy and Cognitive Strategy.
Modeling Key Drivers of E-Learning Satisfaction among Student Teachers
Authors: Teo Timothy , Wong Su Luan
Published: February 2013

This study explored the key drivers of student teachers' e-learning satisfaction. Three hundred and eighty-seven participants completed a survey questionnaire measuring their self-reported responses to six constructs (tutor quality, perceived usefulness, perceived ease of use, course delivery, facilitating conditions, and course satisfaction). Data analysis was performed using structural equation modeling. The results of this study showed that, apart from facilitating conditions, all constructs were significant predictors of e-learning satisfaction. However, facilitating conditions was found to be a significant mediator of perceived ease of use and satisfaction. Some implications for e-learning and teacher education were discussed.
Constructs of Student-Centered Online Learning on Learning Satisfaction of a Diverse Online Student Body: A Structural Equation Modeling Approach
Authors: Ke Fengfeng , Kwak Dean
Published: February 2013

The present study investigated the relationships between constructs of web-based student-centered learning and the learning satisfaction of a diverse online student body. Hypotheses on the constructs of student-centered learning were tested using structural equation modeling. The results indicated that five key constructs of student-centered learning in online courses—learner relevance, active learning, authentic learning, learner autonomy, and computer technology competence—predicted students' perceived satisfaction with online courses and web-based distance education at a statistically significant level.