PRE- AND POST- SHUNT CEREBRAL PERFUSION MEASURED BY DYNAMIC SUSCEPTIBILITY CONTRAST MRI IN PATIENTS WITH NORMAL PRESSURE HYDROCEPHALUS.

Background: NPH-related dementia is the only surgically manageable dementia. Response to ventricular shunting in NPH is variable. This study aims to establish a possible correlation between the changes in cerebral perfusion with clinical response to shunting. The study group consisted of 20 patients with NPH Methods: diagnoses who underwent ventricular shunting. Pre- and 3-month post- shunt DSC-MRI was done to assess the change in relative cerebral blood ?ow (rCBF). Mean ± SD values of rCBF in frontal grey matter, frontal periventricular white Results: matter, parietal periventricular white matter and hippocampus were 0.91 ± 0.11, 0.61 ± 0.09, 0.47 ± 0.11 and 0.93 ± 0.06 before shunt surgery and 0.98 ± 0.06, 0.70 ± 0.07, 0.54 ± 0.07 and 0.98 ± 0.06 after shunt surgery in NPH patients who responded to shunt surgery; and 0.78 ± 0.17, 0.37 ± 0.14, 0.41 ± 0.11 and 0.89 ± 0.10 before shunt surgery and 0.79 ± 0.14, 0.37 ± 0.19, 0.38 ± 0.09 and 0.84 ± 0.07 after shunt surgery in NPH patients who did not respond to shunt surgery. Therefore, regional rCBF in these regions increased in responders after shunt surgery, with a signi?cant statistical difference (p-value < 0.05) while no signi?cant change was seen in shunt non-responders (p-value > 0.05). There is a correlation between a signi?cant increase in Conclusion: regional rCBF and clinical improvement after shunt surgery

Evaluation of Tumor Blood Flow Using Alternate Ascending/Descending Directional Navigation in Primary Brain Tumors: A Comparison Study with Dynamic Susceptibility Contrast Magnetic Resonance Imaging

OBJECTIVE: Alternate ascending/descending directional navigation (ALADDIN) is a novel arterial spin labeling technique that does not require a separate spin preparation pulse. We sought to compare the normalized cerebral blood flow (nCBF) values obtained by ALADDIN and dynamic susceptibility contrast (DSC) perfusion magnetic resonance imaging (MRI) in patients with primary brain tumors. MATERIALS AND METHODS: Sixteen patients with primary brain tumors underwent MRI scans including contrast-enhanced T1-weighted imaging, DSC perfusion MRI, and ALADDIN. The nCBF values of normal gray matter (GM) and tumor areas were measured by both DSC perfusion MRI and ALADDIN, which were compared by the Wilcoxon signed rank test. Subgroup analyses according to pathology were performed with the Wilcoxon signed rank test. RESULTS: Higher mean nCBF values of GM regions in the bilateral frontal lobe, temporal lobe, and caudate were detected by ALADDIN than by DSC perfusion MRI (p <0.05). In terms of the mean or median nCBF values and the mean of the top 10% nCBF values from tumors, DSC perfusion MRI and ALADDIN did not statistically significantly differ either overall or in each tumor group. CONCLUSION: ALADDIN tended to detect higher nCBF values in normal GM, as well as higher perfusion portions of primary brain tumors, than did DSC perfusion MRI. We believe that the high perfusion signal on ALADDIN can be beneficial in lesion detection and characterization.

Effects of artepillin C on model membranes displaying liquid immiscibility

It has been hypothesized that the therapeutic effects of artepillin C, a natural compound derived from Brazilian green propolis, are likely related to its partition in the lipid bilayer component of biological membranes. To test this hypothesis, we investigated the effects of the major compound of green propolis, artepillin C, on model membranes (small and giant unilamelar vesicles) composed of ternary lipid mixtures containing cholesterol, which display liquid-ordered (lo) and liquid-disordered (ld) phase coexistence. Specifically, we explored potential changes in relevant membrane parameters upon addition of artepillin C presenting both neutral and deprotonated states by means of small angle X-ray scattering (SAXS), differential scanning calorimetry (DSC), and confocal and multiphoton excitation fluorescence microscopy. Thermotropic analysis obtained from DSC experiments indicated a loss in the lipid cooperativity of lo phase at equilibrium conditions, while at similar conditions spontaneous formation of unilamellar vesicles from SAXS experiments showed that deprotonated artepillin C preferentially located at the surface of the membrane. Time-resolved experiments using fluorescence microscopy showed that at doses above 100 µM, artepillin C in its neutral state interacted with both liquid-ordered and liquid-disordered phases, inducing curvature stress and promoting dehydration at the membrane interface.

Physicochemical and technological characteristics of arrowroot flour modified by ultrasound and low-temperature heat treatment / Características físico-químicas e tecnológicas da farinha de araruta modificada por ultrassom e por tratamento térmico de baixa umidade

ABSTRACT: Arrowroot is a plant abundant in starch content, and because it does not possess gluten proteins in its composition, its utilization is of great interest in the production of food for people who are intolerant to these proteins. The substitution of gluten involves the use of thickening agents, such as pre-gelatinized starches or flours, which can be obtained by physical processes. In this context, the aim of this study was to evaluate the physicochemical and technological characteristics of arrowroot flour (AFU) modified by ultrasound, in the functioning of intensity and time, and modified by low humidity heat treatment (LHHT) as a function of temperature and time. Besides characterizing AFU and AFLHHT, we aimed their future application in products without gluten. All independent variables affected (P<0.05) water absorption index (WAI) and water solubility index (WSI) at 28 °C; WSI was at 80 °C, peak viscosity, final viscosity, setback and enthalpy of gelatinization (ΔH). The selected AFU was processed in 15 min at an ultrasound intensity of 43.5%, while AFLHHT was at 105 °C for 15 min. Neither of them presented significant differences in relation to their proximal composition. It is concluded that the modification of AF by both methods is feasible, and it is possible to predict its use in the formulation of foods without gluten, due to their physicochemical and technological characteristics which are more appropriate than those of AF.

RESUMO: A araruta é uma planta que apresenta conteúdo abundante de amido, e por não apresentar as proteínas do glúten em sua composição desperta o interesse da sua utilização na produção de alimentos para pessoas intolerantes a essas proteínas. A substituição do glúten envolve a utilização de agentes espessantes, como amidos ou farinhas pré-gelatinizados, que podem ser obtidos por meio de processos físicos. Neste contexto, o objetivo deste estudo foi avaliar as características físico-químicas e tecnológicas da farinha de araruta (FA), FA modificada por ultrassom (FAU) em função da intensidade e tempo, e FA modificada por tratamento térmico de baixa umidade (FATTBU) em função da temperatura e tempo, além de caracterizar FAU e FATTBU selecionadas, visando sua futura aplicação em produtos sem glúten. Todas as variáveis independentes afetaram (P<0.05): índice de absorção de água (IAA) e o índice de solubilidade em água (ISA) a 28 °C, ISA a 80 °C, viscosidade de pico, viscosidade final, tendência a retrogradação e entalpia de gelatinização (ΔH). A FAU selecionada foi processada em 15 min em intensidade do ultrassom de 43,5%, enquanto FATTBU a 105 ºC por 15 min. Ambas não apresentaram diferenças significativas em relação à composição proximal. A modificação da FA tanto por ultrassom como por tratamento térmico com baixa umidade é viável, e é possível prever a sua utilização na formulação de alimentos sem glúten, devido as suas características físico-químicas serem mais apropriadas que a da FA.

Desenvolvimento, caracterização e avaliação da formação de complexos de inclusão de rutina, avobenzona e ρ-metoxicinamato de octila na presença de ciclodextrinas / Development, characterization and evaluation of inclusion complexes between rutin, avobenzone and octyl ρ-methoxycinnamate with cyclodextrins

A radiação UV pode causar danos à pele humana, e, evitar estes danos, é uma preocupação crescente para a população e um desafio à comunidade científica. Para uma ação efetiva de fotoproteção, a associação de filtros, como avobenzona (BMBM) e ρ-metoxicinamato de octila (EHMC), são empregados. Devido à semelhança estrutural com os filtros solares químicos, a rutina (RUT), tal como outros flavonoides, apresenta atividade fotoprotetora. Apesar da disponibilidade de diferentes classes de filtros solares, o desenvolvimento de fotoprotetores contendo filtros químicos é um desafio, devido à instabilidade inerente a certos filtros orgânicos. As ciclodextrinas (CDs) são oligossacarídeos cíclicos, de formato tronco-cônico, cuja estrutura externa é hidrófilica e sua cavidade interna central hidrofóbica, com a capacidade de acomodar substâncias lipofílicas, formando complexos de inclusão. A formação dos complexos de inclusão pode levar à alterações de propriedades físico-químicas da molécula hóspede, tais como, solubilidade, fotoestabilidade e biodisponibilidade. O objetivo deste trabalho foi desenvolver, caracterizar e avaliar a formação de complexos de inclusão entre RUT, BMBM e EHMC e as CDs (HPßCD e SBEßCD). Os complexos de inclusão (RUT:HPßCD, RUT:SBEßCD, BMBM:HPßCD, BMBM:SBEßCD, EHMC:HPßCD e EHMC:SBEßCD) foram obtidos pelo método de liofilização e quantificados por cromatografia líquida de alta eficiência (CLAE). Os sistemas binários foram caracterizados em solução, pelo método de equilíbrio de solubilidade, e, no estado sólido, empregando calorimetria exploratória diferencial (DSC), termogravimetria (TG/DTG) e difração de raios-X de pó (PDRX). As substâncias isoladas e os complexos binários foram avaliados quanto à fotoestabilidade em estado sólido, e, em solução. Incremento na solubilidade (X mcg mL-1) foi observado para os complexo RUT:HPßCD (4,13x); RUT:SBEßCD (4,38x); BMBM:HPßCD (43,3x); BMBM:SBEßCD (53,3x); EHMC:HPßCD (12,7x); e EHMC:SBEßCD (70,0x). Os ensaios de DSC, TG/DTG, e P-DRX indicaram a formação de complexos de inclusão para os todos os sistemas, onde a supressão dos eventos endotérmicos característicos das substâncias isoladas foram observados; porém, nos complexos de BMBM, a presença de avobenzona livre no meio foi detectada, sugerindo, que a complexação não foi completa. A formação dos complexos de inclusão promoveu o aumento da fotoestabilidade em todos os sistemas avaliados, tanto no estado sólido, como em solução. Os resultados reportados neste estudo, indicaram que a complexação de substâncias fotoprotetoras com HPßCD e SBEßCD, pode representar, uma estratégia promissora quanto ao aumento da solubilidade e da fotoestabilidade

UV radiation may cause demage on human skin, and preventing it, is an increasing worry for the population and a challenge to the scientific community. For an effective action of photoprotection, the association of filters, like avobention (BMBM) and octyl ρ-methoxycinnamate (EHMC), are used. Due to the structural similarity with the chemical solar filters, the rutin (RUT), like other flavonoids, shows photoprotective activity. Despite the availability of different classes of sunscreens, the development of photoprotectors containing chemical filters is a challenge, due to the inherent instability of certain organic filters. The cyclodextrins (CD) are cyclic oligosaccharides of truncated conical structure, which external structure is hydrophilic and its internal central hydrophobic cavity, with capacity to accommodate lipophilic substances, forming inclusion complexes. The formation of the inclusion complexes can lead to changes in physicalchemical properties of the host molecule, such as, solubility, photostability and bioavailability. The objective of this work was to develop, characterize and evaluate the formation of the inclusion complexes between RUT, BMBM and EHMC and the CDs (HPßCD and SBEßCD). The inclusion complexes (RUT:HPßCD, RUT:SBEßCD, BMBM:HPßCD, BMBM:SBEßCD, EHMC:HPßCD and EHMC:SBEßCD) were obtained by the lyophilization method and quantified by high performance liquid chromatography (HPLC). The binary systems were characterized in solution, by solubility equilibrium method and in solid state, using differential scanning calorimetry (DSC), thermogravimetry (TG/DTG) and powder X-ray diffraction (P-XRD). The isolated substances and binary complexes were evaluated the photostability in solid state, and in solution. The increase in solubility (X mcg mL-1) was observed for the complexes RUT:HPßCD (4.13x); RUT:SBEßCD (4.38x); BMBM:HPßCD (43.3x); BMBM:SBEßCD (53.3x); EHMC:HPßCD (12.7x); and EHMC:SBEßCD (70.0x). The analysis of DSC, TG/DTG, and P-DRX indicated the formation of inclusion complexes for all systems, where the suppression of the endothermic events characteristic of the isolated substances were observed; however, in the BMBM complexes, the presence of free avobenzone was detected, suggesting that the complexation was not complete. The formation of inclusion complexes promoted the increase of photostability in all evaluated systems, as in solid state as in solution. The results reported in this study indicated that the complexation of photoprotective substances with (HPßCD e SBEßCD). may represent a promising strategy for increasing solubility and photostability

Equivalence Studies of Different Methods for Drug Melting Point Determination / 中国药学杂志

OBJECTIVE: To evaluate the equivalence among three different methods for drug melting point determination:①method A1 by glass liquid thermometer, ②method A2 by digital display,and ③ method B by instrumental method. METHODS: Five chemical reference substances with different melting points were selected as the target drugs, and different brands of melting point apparatus were used to determine melting point. The apparatus used by method A consists of a glass container for a liquid bath and fitted with a suitable means of heating.The obtained results of the melting point by method A1, A2 and B were evaluated by equivalence testing referring to the data of Proficiency Testing Scheme for the melting point determination of chemical drugs organized by NIFDC in 2015 and 2016. RESULTS: Method A1, A2 and B were equivalent,and no significant difference were observed for the melting point values determined by the three methods. CONCLUSION: There is no significant difference between the melting point determination method A and method B in the Chinese Pharmacopoeia(Ch.P), and the obtained melting point values are equivalent either by glass liquid thermometer or digital display while using method A. This experiment provides scientific data support for potential adoption of digital display in melting point apparatus by Ch.P.

Determination of Phase-transition Temperature of White Vaseline Produced by Different Processes by DSC / 中国药师

Objective:To determine the phase-transition temperature of white vaseline produced by different processes by differen-tial scanning calorimetry ( DSC) in order to analyze the relevance between the melting point and the phase-transition temperature and the relevance between different production processes and the phase-transition temperature. Methods: Hermertic aluminum pans were used to encapsulate the samples, and the testing conditions were optimized. The sample weight was about 10 mg, and the range of measuring temperature was -20-100℃. The heating rate was 5℃·min-1 and the flow rate of nitrogen was 30 ml·min-1 . Results:The phase-transition temperature and the melting point were significantly different. The phase-transition temperature of white vaseline samples produced by different processes was quite different. Conclusion:Melting point determination in the current standard method of white vaseline exists defects, and the composition of white vaseline produced by various processes is quite different.

Determination of Mannityl Nicotinate API by DSC / 中国药师

Objective:To establish a DSC method for the determination of mannityl nicotinate. Methods:Indium was used to cor-rect the instrument including temperature correction and heat flow correction. The atmosphere was nitrogen and the flow rate was 20 ml ·min-1 . The sample volume was 1-3. 5 mg with precision reached to 0. 01mg. The initial temperature was 30 ℃, raised to 120 ℃ at the rate of 10℃·min-1 , maintaining for 1 min at 120℃, and raised to 280℃ at the rate of 2. 5℃·min-1 . The results of DSC and HPLC were compared. Results:Mannityl nicotinate had a good linear relationship between the heat absorption and the amount of sam-ple within the range of 1. 05-3. 44 mg (r=0. 9990). The average recovery was 98. 86％ (RSD=1. 59％,n=9). The content of nia-cin detected by HPLC and DSC was 97. 77％ and 97. 80％, respectively, and the relative mean deviation of the two values was 0. 015％. Conclusion:The DSC method is accurate and rapid, and can be used for the determination of mannityl nicotinate like HPLC.

Differentiation between Glioblastoma and Primary Central Nervous System Lymphoma Using Dynamic Susceptibility Contrast-Enhanced Perfusion MR Imaging: Comparison Study of the Manual versus Semiautomatic Segmentation Method

BACKGROUND: Normalized cerebral blood volume (nCBV) can be measured using manual or semiautomatic segmentation method. However, the difference in diagnostic performance on brain tumor differentiation between differently measured nCBV has not been evaluated. PURPOSE: To compare the diagnostic performance of manually obtained nCBV to that of semiautomatically obtained nCBV on glioblastoma (GBM) and primary central nervous system lymphoma (PCNSL) differentiation. MATERIALS AND METHODS: Histopathologically confirmed forty GBM and eleven PCNSL patients underwent 3T MR imaging with dynamic susceptibility contrast-enhanced perfusion MR imaging before any treatment or biopsy. Based on the contrast-enhanced T1-weighted imaging, the mean nCBV (mCBV) was measured using the manual method (manual mCBV), random regions of interest (ROIs) placement by the observer, or the semiautomatic segmentation method (semiautomatic mCBV). The volume of enhancing portion of the tumor was also measured during semiautomatic segmentation process. T-test, ROC curve analysis, Fisher's exact test and multivariate regression analysis were performed to compare the value and evaluate the diagnostic performance of each parameter. RESULTS: GBM showed a higher enhancing volume (P = 0.0307), a higher manual mCBV (P = 0.018) and a higher semiautomatic mCBV (P = 0.0111) than that of the PCNSL. Semiautomatic mCBV had the highest value (0.815) for the area under the curve (AUC), however, the AUCs of the three parameters were not significantly different from each other. The semiautomatic mCBV was the best independent predictor for the GBM and PCNSL differential diagnosis according to the stepwise multiple regression analysis. CONCLUSION: We found that the semiautomatic mCBV could be a better predictor than the manual mCBV for the GBM and PCNSL differentiation. We believe that the semiautomatic segmentation method can contribute to the advancement of perfusion based brain tumor evaluation.

Análisis químico elemental y de fases por medio de PIXE, DSC, TGA y DRX en MTA Angelus® y un cemento Portland blanco / Elemental chemical composition and phase analysis by means of PIXE, DSC, TGA, and DRX of MTA Angelus® and a white Portland cement

Resumen: El mineral trióxido agregado (MTA) es un cemento usado principalmente para sellar perforaciones en órganos dentales debido a que endurece en presencia de humedad, está compuesto por cemento Portland y trióxido de bismuto. Objetivo: Analizar y comparar por medio de PIXE, DSC, TGA y DRX la composición química elemental y de fases del cemento MTA Angelus® y de un cemento Portland blanco (CPB-CA). Material y métodos: MTA Angelus® blanco y un cemento Portland blanco fueron analizados con PIXE en un acelerador de partículas; el análisis de fases cristalinas se realizó por medio de DRX y contrastado los picos con los de base de datos del ICDD, el DSC se realizó en un calorímetro hasta 900 °C. Resultados: PIXE detectó como elementos de mayor porcentaje fueron aluminio, silicio y calcio para ambos cementos; habiendo diferencias en los porcentajes de azufre; el bismuto sólo se detectó en MTA Angelus®. Se detectaron como elementos traza cobre y estroncio en el MTA Angelus®, además de zirconio en CPB-CA. La relación entre silicio-calcio y silicio-aluminio en los dos cementos es similar. Se identificaron tres fases cristalinas en ambos cementos, silicato dicálcico, silicato tricálcico y aluminato tricálcico; sin embargo, se identificó Bismita en el MTA Angelus® y sulfato de calcio en forma de yeso en CPB-CA, que se logró corroborar con la ayuda de la técnica DSC. Conclusiones: Se logró observar la baja cantidad de yeso en MTA Angelus® por medio de la calorimetría. Tanto las fases cristalinas como la composición química elemental son similares en ambos cementos.

Abstract: Mineral trioxide aggregate (MTA) is a cement mainly used to seal tooth perforations; this is due to the fact that it hardens when in presence of humidity. It is composed of Portland cement and Bismuth trioxide. Objective: To analyze and compare with PIXE, DSC, TGA and DRX elementary chemical and phase composition of MTA Angelus® cement with a white Portland cement (WPC). Material and methods: MTA Angelus® white and a white Portland cement were analyzed with PIXE in a particle accelerator, phase analyses were conducted with XRD contrasting peaks with those in the ICDD database. DSC was conducted in a calorimeter up to 900 oC. Results: PIXE detected the following as greater percentage elements: aluminum, silica and calcium for both cements. Differences were found with sulfur percentages; Bismuth was only detected in MTA Angelus®. Trace elements of copper and strontium were detected in MTA Angelus® and zirconium in WPC. Relationship between silica-calcium and silica-aluminum was similar in both cements. In both cements, three crystalline phases were detected: dicalcium silicate, tricalcium silicate and tricalcium aluminate. Nevertheless, Bismite was identified in MTA Angelus® and calcium sulfate in the form of gypsum in WPC, this was corroborated with DSC technique. Conclusions: In MTA Angelus®, low gypsum amounts were observed by means of calorimetry. In both cements, crystalline phases and elemental chemical composition were similar.

Development, Characterization and In Vitro Evaluation of Flurbiprofen Solid Dispersions using Polyethylene Glycols as Carrier.

The purpose of the present investigation was to increase the solubility and dissolution rate of flurbiprofen (FLB) by the preparation of its solid dispersion with polyethylene glycol 4000 and 6000 as carriers using solvent evaporation method (SM) and kneading method (KM). Drug polymer interactions were investigated using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), x-ray diffraction (XRD). The prepared solid dispersions were characterized by IR spectroscopy, which suggests no interaction of drug with carriers. XRD and DSC study indicates reduction in drug crystallinity. Drug solubility was more and also the dissolution was rapid for Flurbiprofen solid dispersions compared to pure drug.

Preparation of Genistein Solid Dispersion and Its Properties Study / 中国药房

OBJECTIVE:To prepare Geinstein (GEN) solid dispersion,and improve the dissolution rate of GEN in vitro. METHODS:Using PVP K30,PEG6000,and PEG4000 as carriers,GEN solid dispersion was prepared by solvent melting meth-od,and its dissolution in vitro was investigated. The structure of the solid dispersion was characterized by FTIR and DSC. RE-SULTS:GEN solid dispersion prepared with PEG4000 as carrier was better than those with other carriers in dissolution,and drug-carrier ratio (1:5) was the best. The results of DSC and FTIR showed that GEN in solid dispersion took amorphous form. CONCLUSIONS:GEN solid dispersion is prepared successfully and significantly improve the dissolution of GEN in vitro.

Effect of Formulation Variables on the Release of Letrozole from Natural Biodegradable Polymeric Implants.

Aim: Letrozole, a non-steroidal aromatase inhibitor, prevents the body from producing its own estrogen. The objective of the present study was to explore the fabrication and evaluation of natural biodegradable polymeric Letrozole implant for long term drug release targeting postmenopausal women with metastatic breast cancer. Methodology: The effect of different formulation variables i.e. different types of excipients and different hardening times (6 hrs, 12 hrs and 24 hrs) with exposure to formaldehyde vapour was investigated on drug loading efficiency and drug release profile. The result of in-vitro dissolution study was fitted to different kinetic models to evaluate the kinetic data. Results: Letrozole release was studied for 10 to 19 days with some excipients. The in vitro Letrozole release from Gelatin-Sodium Alginate biodegradable polymeric implant was maximum, about 19 days, where Cetyl alcohol was incorporated as excipient. The release kinetics was explored and explained using Higuchi, zero and first order while the mechanism of release was confirmed with Korsmeyer-peppas model. Implants were found to follow Higuchi model the best in most cases. Good correlations were also obtained with Korsmeyere-Peppas model. According to these models, the drug released from implants were of diffusion controlled, where the drug was found to leave the matrix through pores and channels formed by entry of dissolution medium. Conclusion: The addition of different excipients and variation in hardening times were found to influence the drug loading efficiency and drug release significantly. Further investigation would confirm its potential in breast cancer therapy.

Thermal analysis on phase sensitive granisetron in situ forming implants.

In this study effect of gamma irradiation sterilization and storage conditions on thermal properties of phase sensitive granisetron in situ forming implant (ISFI) was investigated. ISFI was prepared by mixing Poly (DLlactide- co-glycolide) (PLGA) with dimethylsulfoxide (DMSO) : propylene carbonate (PC) (1:1) solvent combination then granisetron HCl was added and homogenized. Following application of gamma irradiation, ISFI was stored at 25 °C for 4 months. Differential Scanning Calorimeter (DSC) measurements and Thermogravimetric Analysis-Differential Thermal Analysis (TGA-DTA) were carried out on fresh, irradiated and aged forms of granisetron ISFI. According to DSC, TGA and TGA-DTA thermograms and mass loss results application of gamma irradiation and storage of irradiated ISFI at 25 °C for 4 months have not significant effect on thermal stability of ISFI.

Formulation and In vitro Evaluation of Fluconazole Topical Gels.

Aims: Topical drug delivery of fluconazole, an antifungal drug, in gel form was formulated to avoid the side effect of the oral route. Study Design: In this study I prepare different formulation from different polymers and select the best formulation to undergo further antifungal and stability studies. Place and Duration of Study: Faculty of Pharmacy, Department of Pharmaceutics, Assiut University, between May 2010 and July 2011. Methodology: Different polymers; Sodium carboxymethyl cellulose, Sodium alginate, Carbopol 934P, Hydroxypropylmethyl cellulose, Pluronic F-127 and hydroxypropyl cellulose, were used. The compatibility of fluconazole and different gelling polymer was assessed through differential scanning calorimetry and infrared absorption spectroscopy. The influence of polymer type and concentration on fluconazole release from the prepared gels were studied. The prepared gel formulations were evaluated for pH, drug content, rheology, spreadability and in vitro drug release Results: The rheological behavior of all the prepared gels showed a pseudoplastic flow (shear thinning) which is a good characteristic in the pharmaceutical gels. With the increase of the polymer concentration in the formulation, viscosity increased and in vitro release of fluconazole decreased. Among all the prepared formulations, 0.5% Carbopol 934P gel showed desired properties and exhibited the best fluconazole in vitro release that reaches 77% over a 3-hr period. This gel showed a good inhibition to the fungal growth against Candida albicans and Trichophyton mentagrophyte using cup plate method and also, showed good stability. Conclusion: 0.5% Carbopol 934P / Fluconazole gel is a promising dosage form for the treatment of superficial fungal infections and could be used for further clinical studies.

The effect of acrylamide incorporation on the thermal and physical properties of denture resins

PURPOSE: Polymethyl methacrylate (PMMA) is the most commonly used denture base material despite typically low in strength. The purpose of this study was to improve the physical properties of the PMMA based denture base resins (QC-20, Dentsply Ltd., Addlestone, UK; Stellon, AD International Ltd, Dentsply, Switzerland; Acron MC; GC Lab Technologies Inc., Alsip, Japan) by copolymerization mechanism. MATERIALS AND METHODS: Control group specimens were prepared according to the manufacturer recommendations. In the copolymer groups; resins were prepared with 5%, 10%, 15% and 20% acrylamide (AAm) (Merck, Hohenbrunn, Germany) content according to the moleculer weight ratio, respectively. Chemical structure was characterized by a Bruker Vertex-70 Fourier transform infrared spectroscopy (FTIR) (Bruker Optics Inc., Ettlingen, Germany). Hardness was determined using an universal hardness tester (Struers Duramin, Struers A/S, Ballerup, Denmark) equipped with a Vickers diamond penetrator. The glass transition temperature (Tg) of control and copolymers were evaluated by Perkin Elmer Diamond DSC (Perkin Elmer, Massachusetts,USA). Statistical analyses were carried out using the statistical package SPSS for Windows, version 15.0 (SPSS, Chicago, IL, USA). The results were tested regarding the normality of distribution with the Shapiro Wilk test. Data were analyzed using ANOVA with post-hoc Tukey test (P<.01). RESULTS: The copolymer synthesis was confirmed by FTIR spectroscopy. Glass transition temperature of the copolymer groups were higher than the control groups of the resins. The 10%, 15% and 20% copolymer groups of Stellon presented significantly higher than the control group in terms of hardness. 15% and 20% copolymer groups of Acron MC showed significantly higher hardness values when compared to the control group of the resin. Acrylamide addition did not affect the hardness of the QC-20 resin significantly. CONCLUSION: Within the limitation of this study, it can be concluded that copolymerization of PMMA with AAm increased the hardness value and glass transition temperature of PMMA denture base resins.

Propriedades micromeríticas e análise físico-química de matérias-primas de alopurinol / Micromeritic properties and physicochemical analysisof allopurinol raw materials

O controle de qualidade de matérias-primas é imprescindível, pois visa assegurar a qualidade do produto acabado. O objetivo do trabalho foi avaliar a qualidade físico-química e farmacotécnica de matérias-primas de alopurinol, fármaco utilizado para a prevenção e o tratamento de crises de gota, amplamente prescrito e produzido por indústrias e farmácias magistrais. As amostras (A, B, C e D) de alopurinol oriundas de diferentes fornecedores foram submetidas a ensaios farmacopeicos (características organolépticas; solubilidade; ensaios de identificação: teste de precipitação e varredura no UV; ensaios de pureza: limpidez de solução, perda por dessecação, cinzas sulfatadas; doseamento), análise térmica (DSC, TG), análise granulométrica e determinação das propriedades de fluxo (ângulo de repouso, densidade bruta e de compactação, fator de Hausner, índice de compressibilidade e compactabilidade). As amostras foram aprovadas em todos os ensaios farmacopeicos. Nas curvas de DSC, o ponto de fusão foi de cerca de 380 °C para todas as amostras e, após a fusão houve a degradação, confirmada pelas curvas TG, com uma perda de massa de aproximadamente 100 %. A partir da distribuição granulométrica as amostras A e B foram classificadas como pós finos e as C e D como finíssimos. Os valores de ângulo de repouso caracterizaram as amostras A, B, C e D como de fluxo fraco e, o fator de Hausner e índice de compressibilidade caracterizaram as amostras como amostras de fluxo bastante deficiente. Os ensaios demonstraram-se úteis para avaliar a qualidade das amostras. A adição de adjuvantes apropriados durante o preparo das formulações de alopurinol é essencial para melhoramento do fluxo.

The quality control of raw materials is intended to ensure the quality of the finished product. The objective of this study was to carry out physicochemical and pharmacotechnical assessments of allopurinol raw materials. This drug is widely prescribed for the prevention and treatment of gout and is produced both by drug manufacturers and compounding pharmacies. Samples (A, B, C and D) from 4 different suppliers were subjected to pharmacopoeial testing (organoleptic characteristics; solubility; identification tests: precipitation and scanning UV; purity tests: clarity of solution, loss on drying, sulphated ash; assay), thermal analysis (DSC, TG), particle size analysis and flow property tests (angle of repose, bulk density and tapped density, Hausner ratio, compressibility and compactibility). The samples were approved in all the pharmacopoeial tests. In the DSC curves, the melting point was about 380 °C for all samples and after fusion there was degradation, confirmed by TG, with a weight loss of approximately 100%. From the particle size distributions, samples A and B were classified as fine powders and C and D as very fine powders. The angles of repose characterized the samples A, B, C and D as having weak flow, while the Hausner ratio and compressibility index indicated that they had very, very poor flow. The tests proved useful for assessing the quality of the samples and showed that appropriate adjuvants need to be added to the allopurinol formulations to improve the flow.

Biofilm formation and binding specificities of CFA/I, CFA/II and CS2 adhesions of Enterotoxigenic Escherichia coli and CfaE-R181A mutant

Enterotoxigenic Escherichia coli (ETEC) strains are leading causes of childhood diarrhea in developing countries. Adhesion is the first step in pathogenesis of ETEC infections and ETEC pili designated colonization factor antigens (CFAs) are believed to be important in the biofim formation, colonization and host cell adhesions. As a first step, we have determined the biofilm capability of ETEC expressing various types of pili (CFA/I, CfaE-R181A mutant/ CfaE tip mutant, CFA/II and CS2). Further, enzyme-linked immunosorbent assay (ELISA) assay were developed to compare the binding specificity of CFA/I, CFA/II (CS1 - CS3) and CS2 of ETEC, using extracted pili and piliated bacteria. CFA/II strain (E24377a) as well as extracted pili exhibited significantly higher binding both in biofilm and ELISA assays compared to non piliated wild type E24377a, CFA/I and CS2 strains. This indicates that co-expression of two or more CS2 in same strain is more efficient in increasing adherence. Significant decrease in binding specificity of DH5αF'lacIq/∆cotD (CS2) strain and MC4100/pEU2124 (CfaE-R181A) mutant strain indicated the important contribution of tip proteins in adherence assays. However, CS2 tip mutant strain (DH5αF'lacIq/pEU5881) showed that this specific residue may not be important as adhesions in these strains. In summary, our data suggest that pili, their minor subunits are important for biofilm formation and adherence mechanisms. Overall, the functional reactivity of strains co expressing various antigens, particularly minor subunit antigen observed in this study suggest that fewer antibodies may be required to elicit immunity to ETEC expressing a wider array of related pili.

Thermal behavior of direct resin composites: glass transition temperature and initial degradation analyses / Comportamento térmico de resinas compostas de uso direto: temperatura de transição vítrea e temperatura de degradação inicial

PURPOSE: The association of direct resin composites with simple thermal treatments may improve the mechanical properties of these materials. However, the ideal temperature for heat application depends on the thermal behavior of each material, such as glass transition (Tg) and initial degradation temperatures. To propose a heat treatment methodology, this study evaluated the thermal behavior of five commercial direct resin composites using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). METHODS: Photo-irradiation was achieved in cylindrical specimens (3×2 mm) using a photo-activator source (600 mW/cm² for 40 s). Thermal analyses were performed by DSC and TGA using a temperature range from 25 ºC to 900 ºC. RESULTS: Tg values obtained by DSC were 130.6 ºC for FillMagic, 129 ºC for Glacier, 143.5 ºC for Te-Econom, 147.5 ºC for Prisma APH and 143.7 ºC for Natural Look. A moderate weight loss began at around 270 ºC for all materials, which represented the initial degradation temperature. Conclusion: Regarding the heat treatment itself, it was concluded that the effective temperature for heat treatment is material dependent.

OBJETIVO: A associação de resinas compostas de uso direto com tratamentos térmicos pode melhorar as propriedades mecânicas destes materiais. No entanto, a temperatura ideal de aplicação está na dependência do comportamento térmico individual, como a temperatura de transição vítrea (Tg) e a temperatura inicial de degradação. Com o objetivo de propor uma metodologia de aplicação do tratamento térmico, o objetivo deste trabalho foi caracterizar cinco resinas compostas de uso direto usando calorimetria exploratória diferencial (DSC) e termogravimetria (TGA). METODOLOGIA: Corpos-de-prova cilíndricos (3×2 mm) foram fotoirradiados utilizando um aparelho de fotopolimerização (600 mW/cm² - 40s). As análises térmicas foram realizadas nas temperaturas de 25 ºC a 900 ºC. RESULTADOS: Os valores de Tg após análise de DSC foram: 130,6 ºC para FillMagic, 129 ºC para Glacier, 143,5 ºC para Te-Econom, 147,5 ºC para Prisma APH e 143,7 ºC para Natural Look. Para todos os materiais estudados a degradação iniciou-se por volta de 270 ºC. CONCLUSÃO: Considerando a aplicação do tratamento térmico em resinas compostas de uso direto, é possível sugerir que a temperatura efetiva é dependente do material em uso.

Rheological characterization of thermoplasticized injectable gutta percha and resilon / 대한치과보존학회지

OBJECTIVES: The purpose of this study was to observe the change in the viscoelastic properties of thermoplasticized injectable root canal filling materials as a function of temperature and to compare the handling characteristics of these materials. MATERIALS AND METHODS: Three commercial gutta perchas and Resilon (Pentron Clinical Technologies) in a pellet form were heated in the Obtura-II system (Obtura Spartan) at 140degrees C and 200degrees C, and the extrusion temperature of the thermoplasticized materials was measured. The viscoelastic properties of the materials as a function of temperature were evaluated using a rheometer. The elastic modulus G', viscous modulus G", loss tangent tandelta, and complex viscosity eta* were determined. The phase transition temperature was determined by both the rheometer and a differential scanning calorimeter (DSC). The consistency of the materials was compared under compacting pressure at 60degrees C and 40degrees C by a squeeze test. RESULTS: The three gutta perchas had dissimilar profiles in viscoelastic properties with varying temperature. The phase transition of softened materials into solidification occurred at 40degrees C to 50degrees C, and the onset temperatures obtained by a rheometer and a DSC were similar to each other. The onset temperature of phase transition and the consistency upon compaction pressure were different among the materials (p < 0.05). Resilon had a rheologically similar pattern to the gutta perchas, and was featured between high and low-flow gutta perchas. CONCLUSIONS: The rheological characteristics of the thermoplasticized root canal filling materials changed under a cooling process. The dissimilar viscoelastic properties among the materials require different handling characteristics during an injecting and compacting procedure.