25 resultados para routes of administration
Resumo:
Ethylene-propylene diene terpolymer (EPDM) was functionalized with glycidyl methacrylate (GMA) during melt processing by free radical grafting with peroxide initiation in the presence and absence of a reactive comonomer trimethylolpropane triacrylate (Tris). Increasing the peroxide concentration resulted in an increase in the GMA grafting yield, albeit the overall grafting level was low and was accompanied by higher degree of crosslinking of EPDM which was found to be the major competing reaction. The presence of Tris in the grafting system gave rise to higher grafting yield produced at a much lower peroxide concentration though the crosslinking reactions remained high but without the formation of GMA-homopolymer in either of the two systems. The use of these functionalized EPDM (f-EPDM) samples with PET as compatibilisers in binary and ternary blends of PET/EPDM/f-EPDM was evaluated. The influence of the different functionalisation routes of the rubber phase (in presence and absence of Tris) and the effect of the level of functionality and microstructure of the resultant f-EPDM on the extent of the interfacial reaction, morphology and mechanical properties was also investigated. It is suggested that the mechanical properties of the blends are strongly influenced by the performance of the graft copolymer, which is in turn, determined by the level of functionality, molecular structure of the functionalized rubber and the interfacial concentration of the graft copolymer across the interface. The cumulative evidence obtained from torque rheometry, scanning electron microscopy, SEM, dynamic mechanical analysis (DMA), tensile mechanical tests and Fourier transform infrared (FTIR) supports this. It was shown that binary and ternary blends prepared with f-EPDM in the absence of Tris and containing lower levels of g-GMA effected a significant improvement in mechanical properties. This increase, particularly in elongation to break, could be accounted for by the occurrence of a reaction between the epoxy groups of GMA and the hydroxyl/carboxyl end groups of PET that would result in a graft copolymer which could, most probably, preferentially locate at the interface, thereby acting as an 'emulsifier' responsible for decreasing the interfacial tension between the otherwise two immiscible phases. This is supported by results from FTIR analysis of the fractionated PET phase of these blends which confirm the formation of an interfacial reaction, DMA results which show a clear shift in the T s of the blend components and SEM results which reveal very fine morphology, suggesting effective compatibilisation that is concomitant with the improvement observed in their tensile properties. Although Tris has given rise to highest amount of g-GMA, it resulted in lower mechanical properties than the optimized blends produced in the absence of Tris. This was attributed to the difference in the microstructure of the graft and the level of functionality in these samples resulting in less favourable structure responsible for the coarser dispersion of the rubber phase observed by SEM, the lower extent of T shift of the PET phase (DMA), the lower height of the torque curve during reactive blending and FTIR analysis of the separated PET phase that has indicated a lower extent of the interfacial chemical reaction between the phases in this Tris-containing blend sample. © 2005 Elsevier Ltd. All rights reserved.
Resumo:
The brewing industry produces large amounts of by-products and wastes like brewers' spent grain (BSG). In Germany, each year approximately 2.1 million tonnes of BSG are generated. During the last years conventional routes of BSG utilization face a remarkable change, such as the decline in the demand as animal feed. Due to its high content of organic matter energetic utilization may create an additional economic value for breweries. Furthermore, in the recent past breweries tend to shift their energy supply towards more sustainable concepts. Although, a decent number of research projects were carried out already, still no mature strategy is available. However, one possible solution can be the mechanical pretreatment of BSG. This step allows optimized energy utilization by the fractionation of BSG. Due to the transfer of digestible components, such as protein, to the liquid phase, the solid phase will largely consist of combustible components. That represents an opportunity to produce a solid biofuel with lower fuelnitrogen content compared to only thermal dried BSG. Therefore, two main purposes for the mechanical pre-treatment were determined, (1) to reduce the moisture content to at least 60 % (w/w) and (2) to diminish the protein content of the solid phase by 30 %. Moreover, the combustion trials should demonstrate whether stable processes and flue gas emissions within the legal limits in Germany are feasible. The results of the mechanical pre-treatment trials showed that a decrease of the moisture and protein content has been achieved. With regard to the combustion trials inconsistent outcomes were found. On the one hand a stable combustion was realized. On the other hand the legal emission levels of NOx (500 mgm -3) and dust (50 mgm-3) could not be kept during all trials. The further research steps will focus on the optimization of the air/fuel ratio by reducing the primary and secondary air conditions. Copyright © 2014,AIDIC Servizi S.r.l.
Resumo:
Introduction: Methotrexate (MTX) is a cornerstone of treatment in a wide variety of inflammatory conditions, including juvenile idiopathic arthritis (JIA) and juvenile dermatomyositis (JDM). However, owing to its narrow therapeutic index and the considerable interpatient variability in clinical response, monitoring of adherence to MTX is important. The present study demonstrates the feasibility of using methotrexate polyglutamates (MTXPGs) as a biomarker to measure adherence to MTX treatment in children with JIA and JDM. Methods: Data were collected prospectively from a cohort of 48 children (median age 11.5 years) who received oral or subcutaneous (SC) MTX therapy for JIA or JDM. Dried blood spot samples were obtained from children by finger pick at the clinic or via self- or parent-led sampling at home, and they were analysed to determine the variability in MTXPG concentrations and assess adherence to MTX therapy. Results: Wide fluctuations in MTXPG total concentrations (>2.0-fold variations) were found in 17 patients receiving stable weekly doses of MTX, which is indicative of nonadherence or partial adherence to MTX therapy. Age (P = 0.026) and route of administration (P = 0.005) were the most important predictors of nonadherence to MTX treatment. In addition, the study showed that MTX dose and route of administration were significantly associated with variations in the distribution of MTXPG subtypes. Higher doses and SC administration of MTX produced higher levels of total MTXPGs and selective accumulation of longer-chain MTXPGs (P < 0.001 and P < 0.0001, respectively). Conclusions: Nonadherence to MTX therapy is a significant problem in children with JIA and JDM. The present study suggests that patients with inadequate adherence and/or intolerance to oral MTX may benefit from SC administration of the drug. The clinical utility of MTXPG levels to monitor and optimise adherence to MTX in children has been demonstrated. Trial registration: ISRCTN Registry identifier: ISRCTN93945409. Registered 2 December 2011.
Resumo:
To investigate the neurotoxic effects of aluminium (Al) Al was administered: 1) in the diet of the rat (30 mg Al/kg body weight for 6 weeks); 2) as a suspension of aluminium acetate in drinking water of the rat for 3 months and 3) in a long-term study in the mouse in which aluminosilicates were incorporated into a pelleted diet (1035 mg/kg of food over 23 months). In the latter treatment, increased Al was combined with a reduction in calcium and magnesium; a treatment designed to increase absorption of Al into the body. Administration of Al in the drinking water significantly reduced total brain biopterins and BH4 synthesis. However, no significant affect of Al in the diet on total biopterins or BH4 synthesis was found either in the rat or in the long-term study in the mouse. In addition, in the mouse no significant effects of the Al diet on levels of noradrenaline, serotonin, dopamine, 5-HIAA or CAT could be demonstrated. Hence, the occurrence of brain alterations may depend on the Al species present and the method of administration. Al salts in drinking water may increase brain tissue levels compared with the administration of a more insoluble species. Since alterations in biopterin metabolism are also a feature of Alzheimer's disease (AD) these results support the hypothesis that Al in the water supply may be a factor in AD.
Resumo:
Powders for inhalation are traditionally prepared using a destructive micronization process such as jet milling to reduce the particle size of the drug to 2-5 μm. The resultant particles are typically highly cohesive and display poor aerosolization properties, necessitating the addition of a coarse carrier particle to the micronized drug to improve powder flowability. Spray-drying technology offers an alternative, constructive particle production technique to the traditional destructive approach, which may be particularly useful when processing biotechnology products that could be adversely affected by high-energy micronization processes. Advantages of spray drying include the ability to incorporate a wide range of excipients into the spray-drying feedstock, which could modify the aerosolization and stability characterizations of the resultant powders, as well as modify the drug release and absorption profiles following inhalation. This review discusses some of the reasons why pulmonary drug delivery is becoming an increasingly popular route of administration and describes the various investigations that have been undertaken in the preparation of spray-dried powders for pulmonary drug delivery. © 2007 by Begell House, Inc.
Resumo:
Introduction: The requirement of adjuvants in subunit protein vaccination is well known yet their mechanisms of action remain elusive. Of the numerous mechanisms suggested, cationic liposomes appear to fulfil at least three: the antigen depot effect, the delivery of antigen to antigen presenting cells (APCs) and finally the danger signal. We have investigated the role of antigen depot effect with the use of dual radiolabelling whereby adjuvant and antigen presence in tissues can be quantified. In our studies a range of cationic liposomes and different antigens were studied to determine the importance of physical properties such as liposome surface charge, antigen association and inherent lipid immunogenicity. More recently we have investigated the role of liposome size with the cationic liposome formulation DDA:TDB, composed of the cationic lipid dimethyldioctadecylammonium (DDA) and the synthetic mycobacterial glycolipid trehalose 6,6’-dibehenate (TDB). Vesicle size is a frequently investigated parameter which is known to result in different routes of endocytosis. It has been postulated that targeting different routes leads to different intracellular signaling pathway activation and it is certainly true that numerous studies have shown vesicle size to have an effect on the resulting immune responses (e.g. Th1 vs. Th2). Aim: To determine the effect of cationic liposome size on the biodistribution of adjuvant and antigen, the ensuing humoral and cell-mediated immune responses and the uptake and activation of antigen by APCs including macrophages and dendritic cells. Methods: DDA:TDB liposomes were made to three different sizes (~ 0.2, 0.5 and 2 µm) followed by the addition of tuberculosis antigen Ag85B-ESAT-6 therefore resulting in surface adsorption. Liposome formulations were injected into Balb/c or C57Bl/6 mice via the intramuscular route. The biodistribution of the liposome formulations was followed using dual radiolabelling. Tissues including muscle from the site of injection and local draining lymph nodes were removed and liposome and antigen presence quantified. Mice were also immunized with the different vaccine formulations and cytokine production (from Ag85B-ESAT-6 restimulated splenocytes) and antibody presence in blood assayed. Furthermore, splenocyte proliferation after restimulating with Ag85B-ESAT-6 was measured. Finally, APCs were compared for their ability to endocytose vaccine formulations and the effect this had on the maturation status of the cell populations was compared. Flow cytometry and fluorescence labelling was used to investigate maturation marker up-regulation and efficacy of phagocytosis. Results: Our results show that for an efficient Ag85B-ESAT-6 antigen depot at the injection site, liposomes composed of DDA and TDB are required. There is no significant change in the presence of liposome or antigen at 6hrs or 24hrs p.i, nor does liposome size have an effect. Approximately 0.05% of the injected liposome dose is detected in the local draining lymph node 24hrs p.i however protein presence is low (<0.005% dose). Preliminary in vitro data shows liposome and antigen endocytosis by macrophages; further studies on this will be presented in addition to the results of the immunisation study.
Resumo:
here is an increasing number of reports of propylene glycol (PG) toxicity in the literature, regardless of its inclusion on the Generally Recognized as Safe List (GRAS).1 PG is an excipient used in many medications as a solvent for water-insoluble drugs. Polypharmacy may increase PG exposure in vulnerable PICU patients who may accumulate PG due to compromised liver and renal function. The study aim was to quantify PG intake in PICU patients and attitudes of clinicians towards PG. Method A snapshot of 50 PICU patients oral or intravenous medication intake was collected. Other data collected included age, weight, diagnosis, lactate levels and renal function. Manufacturers were contacted for PG content and then converted to mg/kg. Excipients in formulations that compete with the PG metabolism pathway were recorded. The Intensivists' opinions on PG intake was sought via e-survey. Results The 50 patients were prescribed 62 drugs and 83 formulations, 43/83 (52%) were parenteral formulations. Median weight of the patients was 5.5 kg (range 2–50 kg), ages ranged from 1 day to 13 years of age. Eleven of the patients were classed as renally impaired (defined as 1.5 times the baseline creatinine). Sixteen formulations contained PG, 2/16 were parenteral, 6/16 unlicensed preparations. Thirty-eight patients received at least one prescription containing PG and 29/38 of these patients were receiving formulations that contained excipients that may have competed with the metabolic pathways of PG. PG intake ranged from 0.002 mg/kg/day to 250 mg/kg/day. Total intake was inconclusive for 2 patients due to a of lack of availability of information from the manufacturer; these formulations were licensed but used in for off-label indications. Five commonly used formulations contributed to higher intakes of PG, namely co-trimoxazole, dexamethasone, potassium chloride, dipyridamole and phenobarbitone. Lactate levels were difficult to interpret due to the underlying conditions of the patients. One of the sixteen intensivist was aware of PG content in drugs, 16/16 would actively change therapy if intake was above European Medicines Agency recommendations. Conclusions Certain formulations used on PICU can considerably increase PG exposure to patients. Due to a lack of awareness of PG content, these should be highlighted to the clinician to assist with making informed decisions regarding risks versus benefits in continuing that drug, route of administration or formulation.
Resumo:
There is an increasing number of reports of propylene glycol (PG) toxicity in the literature, regardless of its inclusion on the Generally Recognized as Safe List (GRAS).1 PG is an excipient used in many medications as a solvent for water-insoluble drugs. Polypharmacy may increase PG exposure in vulnerable PICU patients who may accumulate PG due to compromised liver and renal function. The study aim was to quantify PG intake in PICU patients and attitudes of clinicians towards PG. Method A snapshot of 50 PICU patients oral or intravenous medication intake was collected. Other data collected included age, weight, diagnosis, lactate levels and renal function. Manufacturers were contacted for PG content and then converted to mg/kg. Excipients in formulations that compete with the PG metabolism pathway were recorded. The Intensivists' opinions on PG intake was sought via e-survey. Results The 50 patients were prescribed 62 drugs and 83 formulations, 43/83 (52%) were parenteral formulations. Median weight of the patients was 5.5 kg (range 2–50 kg), ages ranged from 1 day to 13 years of age. Eleven of the patients were classed as renally impaired (defined as 1.5 times the baseline creatinine). Sixteen formulations contained PG, 2/16 were parenteral, 6/16 unlicensed preparations. Thirty-eight patients received at least one prescription containing PG and 29/38 of these patients were receiving formulations that contained excipients that may have competed with the metabolic pathways of PG. PG intake ranged from 0.002 mg/kg/day to 250 mg/kg/day. Total intake was inconclusive for 2 patients due to a of lack of availability of information from the manufacturer; these formulations were licensed but used in for off-label indications. Five commonly used formulations contributed to higher intakes of PG, namely co-trimoxazole, dexamethasone, potassium chloride, dipyridamole and phenobarbitone. Lactate levels were difficult to interpret due to the underlying conditions of the patients. One of the sixteen intensivist was aware of PG content in drugs, 16/16 would actively change therapy if intake was above European Medicines Agency recommendations. Conclusions Certain formulations used on PICU can considerably increase PG exposure to patients. Due to a lack of awareness of PG content, these should be highlighted to the clinician to assist with making informed decisions regarding risks versus benefits in continuing that drug, route of administration or formulation.
Resumo:
The frequency, time and places of charging have large impact on the Quality of Experience (QoE) of EV drivers. It is critical to design effective EV charging scheduling system to improve the QoE of EV drivers. In order to improve EV charging QoE and utilization of CSs, we develop an innovative travel plan aware charging scheduling scheme for moving EVs to be charged at Charging Stations (CS). In the design of the proposed charging scheduling scheme for moving EVs, the travel routes of EVs and the utility of CSs are taken into consideration. The assignment of EVs to CSs is modeled as a two-sided many-to-one matching game with the objective of maximizing the system utility which reflects the satisfactory degrees of EVs and the profits of CSs. A Stable Matching Algorithm (SMA) is proposed to seek stable matching between charging EVs and CSs. Furthermore, an improved Learning based On-LiNe scheduling Algorithm (LONA) is proposed to be executed by each CS in a distributed manner. The performance gain of the average system utility by the SMA is up to 38.2% comparing to the Random Charging Scheduling (RCS) algorithm, and 4.67% comparing to Only utility of Electric Vehicle Concerned (OEVC) scheme. The effectiveness of the proposed SMA and LONA is also demonstrated by simulations in terms of the satisfactory ratio of charging EVs and the the convergence speed of iteration.
Resumo:
A prerequisite for vaccine-mediated induction of CD8+ T-cell responses is the targeting of dendritic cell (DC) subsets specifically capable of cross-presenting antigen epitopes to CD8+ T cells. Administration of a number of cationic adjuvants via the intraperitoneal (i.p.) route has been shown to result in strong CD8+ T-cell responses, whereas immunization via e.g. the intramuscular (i.m.) or subcutaneous (s.c.) routes often stimulate weak CD8+ T-cell responses. The hypothesis for this is that self-drainage of the adjuvant/antigen to the lymphoid organs, which takes place upon i.p. immunization, is required for the subsequent activation of cross-presenting lymphoid organ-resident CD8α+ DCs. In contrast, s.c. or i.m. immunization usually results in the formation of a depot at the site of injection (SOI), which hinders the self-drainage and targeting of the vaccine to cross-presenting CD8α+ DCs. We investigated this hypothesis by correlating the biodistribution pattern and the adjuvanticity of the strong CD8+ T-cell inducing liposomal cationic adjuvant formulation 09 (CAF09), which is composed of dimethyldioctadecylammonium bromide/monomycoloyl glycerol liposomes with polyinosinic:polycytidylic acid electrostatically adsorbed to the surface. Biodistribution studies with radiolabeled CAF09 and a surface-adsorbed model antigen [ovalbumin (OVA)] showed that a significantly larger fraction of the vaccine dose localized in the draining lymph nodes (dLNs) and the spleen 6 h after i.p. immunization, as compared to after i.m. immunization. Studies with fluorescently labelled OVA + CAF09 demonstrated a preferential association of OVA + CAF09 to DCs/monocytes, as compared to macrophages and B cells, following i.p. immunization. Administration of OVA + CAF09 via the i.p. route did also result in DC activation, whereas no DC activation could be measured within the same period with unadjuvanted OVA and OVA + CAF09 administered via the s.c. or i.m. routes. In the dLNs, the highest level of activated, cross-presenting CD8α+ DCs was detected at 24 h post immunization, whereas an influx of activated, migrating and cross-presenting CD103+ DCs to the dLNs could be measured after 48 h. This suggests that the CD8α+ DCs are activated by self-draining OVA + CAF09 in the lymphoid organs, whereas the CD103+ DCs are stimulated by the OVA + CAF09 at the SOI. These results support the hypothesis that the self-drainage of OVA + CAF09 to the draining LNs is required for the activation of CD8α+ DCs, while the migratory CD103+ DCs may play a role in sustaining the subsequent induction of strong CD8+ T-cell responses.