Science.gov

Sample records for delivery system design

  1. Designing Bioactive Delivery Systems for Tissue Regeneration

    PubMed Central

    Davis, Hillary E.

    2010-01-01

    The direct infusion of macromolecules into defect sites generally does not impart adequate physiological responses. Without the protection of delivery systems, inductive molecules may likely redistribute away from their desired locale and are vulnerable to degradation. In order to achieve efficacy, large doses supplied at interval time periods are necessary, often at great expense and ensuing detrimental side effects. The selection of a delivery system plays an important role in the rate of re-growth and functionality of regenerating tissue: not only do the release kinetics of inductive molecules and their consequent bioactivities need to be considered, but also how the delivery system interacts and integrates with its surrounding host environment. In the current review, we describe the means of release of macromolecules from hydrogels, polymeric microspheres, and porous scaffolds along with the selection and utilization of bioactive delivery systems in a variety of tissue-engineering strategies. PMID:20676773

  2. MAST Propellant and Delivery System Design Methods

    NASA Technical Reports Server (NTRS)

    Nadeem, Uzair; Mc Cleskey, Carey M.

    2015-01-01

    A Mars Aerospace Taxi (MAST) concept and propellant storage and delivery case study is undergoing investigation by NASA's Element Design and Architectural Impact (EDAI) design and analysis forum. The MAST lander concept envisions landing with its ascent propellant storage tanks empty and supplying these reusable Mars landers with propellant that is generated and transferred while on the Mars surface. The report provides an overview of the data derived from modeling between different methods of propellant line routing (or "lining") and differentiate the resulting design and operations complexity of fluid and gaseous paths based on a given set of fluid sources and destinations. The EDAI team desires a rough-order-magnitude algorithm for estimating the lining characteristics (i.e., the plumbing mass and complexity) associated different numbers of vehicle propellant sources and destinations. This paper explored the feasibility of preparing a mathematically sound algorithm for this purpose, and offers a method for the EDAI team to implement.

  3. The Design of Environmental Education Delivery Systems: A Procedural Guide.

    ERIC Educational Resources Information Center

    Mills, Stephen R.; And Others

    This guide is intended to facilitate implementation and infusion of environmental education (EE) programs by presenting guidelines for design of a system. The operations leading to the system and its evaluation are discussed. Two components of the design of the system are specifically treated: (1) EE delivery concerns, and (2) levels of planning.…

  4. Design and Biological Evaluation of Delivery Systems Containing Bisphosphonates

    PubMed Central

    Aderibigbe, Blessing; Aderibigbe, Isiaka; Popoola, Patricia

    2016-01-01

    Bisphosphonates have found application in the treatment of reoccurrence of bone diseases, breast cancer, etc. They have also been found to exhibit antimicrobial, anticancer and antimalarial activities. However, they suffer from pharmacological deficiencies such as toxicity, poor bioavailability and low intestinal adsorption. These shortcomings have resulted in several researchers developing delivery systems that can enhance their overall therapeutic effectiveness. This review provides a detailed overview of the published studies on delivery systems designed for the delivery of bisphosphonates and the corresponding in vitro/in vivo results. PMID:28035945

  5. Amorphous drug delivery systems: molecular aspects, design, and performance.

    PubMed

    Kaushal, Aditya Mohan; Gupta, Piyush; Bansal, Arvind Kumar

    2004-01-01

    The biopharmaceutical properties-especially the solubility and permeability-of a molecule contribute to its overall therapeutic efficacy. The newer tools of drug discovery have caused a shift in the properties of drug-like compounds, resulting in drugs with poor aqueous solubility and permeability, which offer delivery challenges, thus requiring considerable pharmaceutical manning. The modulation of solubility is a more viable option for enhancing bioavailability than permeability, because of the lack of "safe" approaches to enhance the latter. Solid-state manipulation in general, and amorphization in particular, are preferred ways of enhancing solubility and optimizing delivery of poorly soluble drugs. This review attempts to address the diverse issues pertaining to amorphous drug delivery systems. We discuss the various thermodynamic phenomenon such as glass transition, fragility, molecular mobility, devitrification kinetics, and molecular-level chemical interactions that contribute to the ease of formation, the solubility advantage, and the stability of amorphous drugs. The engineering of pharmaceutical alloys by solubilizing and stabilizing carriers, commonly termed solid dispersions, provide avenues for exploiting the benefits of amorphous systems. Carrier properties, mechanisms of drug release, and study of release kinetics help to improve the predictability of performance. The review also addresses the various barriers in the design of amorphous delivery systems, use of amorphous form in controlled release delivery systems, and their in vivo performance.

  6. Designing a fiber-optic beam delivery system

    SciTech Connect

    Hunter, B.V. |; Leong, K.H.; Sanders, P.G.

    1997-03-01

    One of the advantages offered by visible and NIR lasers over CO and CO{sub 2} lasers is that they can be delivered through optical fibers. Fiber-optic beam delivery is ideal when the beam must be delivered along a complex path or processing requires complicated manipulation of the beam delivery optics. Harnessing the power of a high-power laser requires that knowledgeable and prudent choices be made when selecting the laser and its beam delivery system. The purpose of this paper is to discuss a variety of issues important when designing a beam delivery system-data obtained with high power Nd:YAG lasers will be used as illustrative examples. (1) Multimode optical fibers are used for high-power applications. The fiber imposes, to varying degrees, a structure on the beam that is different from the laser output. Fibers degrade the beam quality, although the degree of degradation is dependent on the fiber length, diameter and type. Smaller fibers tend to produce less degradation to beam quality, but the minimum usable fiber size is limited by the quality of the laser beam, focusing optic and the numerical aperture of the fiber. (2) The performance of the beam delivery system is ultimately determined by the quality of the optics. Therefore, well-corrected optics are required to realize the best possible performance. Tests with both homogeneous and GRADIUM{trademark} lenses provide insights into evaluating the benefits offered by improvements in the output optics from gradient-index, aspheric and multi-element lens systems. Additionally, these tests illustrate the origins of variable focused spot size and position with increasing laser power. (3) The physical hardware used in the beam delivery system will have several characteristics which enhance its functionality and ease of use, in addition to facilitating the use of advanced diagnostics and monitoring techniques.

  7. Intelligent system design for bionanorobots in drug delivery.

    PubMed

    Fletcher, Mark; Biglarbegian, Mohammad; Neethirajan, Suresh

    A nanorobot is defined as any smart structure which is capable of actuation, sensing, manipulation, intelligence, and swarm behavior at the nanoscale. In this study, we designed an intelligent system using fuzzy logic for diagnosis and treatment of tumors inside the human body using bionanorobots. We utilize fuzzy logic and a combination of thermal, magnetic, optical, and chemical nanosensors to interpret the uncertainty associated with the sensory information. Two different fuzzy logic structures, for diagnosis (Mamdani structure) and for cure (Takagi-Sugeno structure), were developed to efficiently identify the tumors and treat them through delivery of effective dosages of a drug. Validation of the designed system with simulated conditions proved that the drug delivery of bionanorobots was robust to reasonable noise that may occur in the bionanorobot sensors during navigation, diagnosis, and curing of the cancer cells. Bionanorobots represent a great hope for successful cancer therapy in the near future.

  8. Systems approaches to design of targeted therapeutic delivery.

    PubMed

    Myerson, Jacob W; Brenner, Jacob S; Greineder, Colin F; Muzykantov, Vladimir R

    2015-01-01

    Targeted drug delivery aims to improve therapeutic effects and enable mechanisms that are not feasible for untargeted agents (e.g., due to impermeable biological barriers). To achieve targeting, a drug or its carrier should possess properties providing specific accumulation from circulation at the desired site. There are several examples of systems-inspired approaches that have been applied to achieve this goal. First, proteomics analysis of plasma membrane fraction of the vascular endothelium has identified a series of target molecules and their ligands (e.g., antibodies) that deliver conjugated cargoes to well-defined vascular cells and subcellular compartments. Second, selection of ligands binding to cells of interest using phage display libraries in vitro and in vivo has provided peptides and polypeptides that bind to normal and pathologically altered cells. Finally, large-scale high-throughput combinatorial synthesis and selection of lipid- and polymer-based nanocarriers varying their chemical components has yielded a series of carriers accumulating in diverse organs and delivering RNA interference agents to diverse cells. Together, these approaches offer a basis for systems-based design and selection of targets, targeting molecules, and targeting vehicles. Current studies focus on expanding the arsenal of these and alternative targeting strategies, devising drug delivery systems capitalizing on these strategies and evaluation of their benefit/risk ratio in adequate animal models of human diseases. These efforts, combined with better understanding of mechanisms and unintended consequences of these targeted interventions, need to be ultimately translated into industrial development and the clinical domain.

  9. Designing and assessing a sustainable networked delivery (SND) system: hybrid business-to-consumer book delivery case study.

    PubMed

    Kim, Junbeum; Xu, Ming; Kahhat, Ramzy; Allenby, Braden; Williams, Eric

    2009-01-01

    We attempted to design and assess an example of a sustainable networked delivery (SND) system: a hybrid business-to-consumer book delivery system. This system is intended to reduce costs, achieve significant reductions in energy consumption, and reduce environmental emissions of critical local pollutants and greenhouse gases. The energy consumption and concomitant emissions of this delivery system compared with existing alternative delivery systems were estimated. We found that regarding energy consumption, an emerging hybrid delivery system which is a sustainable networked delivery system (SND) would consume 47 and 7 times less than the traditional networked delivery system (TND) and e-commerce networked delivery system (END). Regarding concomitant emissions, in the case of CO2, the SND system produced 32 and 7 times fewer emissions than the TND and END systems. Also the SND system offer meaningful economic benefit such as the costs of delivery and packaging, to the online retailer, grocery, and consumer. Our research results show that the SND system has a lot of possibilities to save local transportation energy consumption and delivery costs, and reduce environmental emissions in delivery system.

  10. Systems approaches to design of targeted therapeutic delivery

    PubMed Central

    Myerson, Jacob W.; Brenner, Jacob S.; Greineder, Colin F.; Muzykantov, Vladimir R.

    2016-01-01

    Targeted drug delivery aims to improve therapeutic effects and enable mechanisms that are not feasible for untargeted agents (e.g., due to impermeable biological barriers). To achieve targeting, a drug or its carrier should possess properties providing specific accumulation from circulation at the desired site. There are several examples of systems-inspired approaches that have been applied to achieve this goal. First, proteomics analysis of plasma membrane fraction of the vascular endothelium has identified a series of target molecules and their ligands (e.g., antibodies) that deliver conjugated cargoes to well-defined vascular cells and subcellular compartments. Second, selection of ligands binding to cells of interest using phage display libraries in vitro and in vivo has provided peptides and polypeptides that bind to normal and pathologically altered cells. Finally, large-scale high-throughput combinatorial synthesis and selection of lipid- and polymer-based nanocarriers varying their chemical components has yielded a series of carriers accumulating in diverse organs and delivering RNA interference agents to diverse cells. Together, these approaches offer a basis for systems-based design and selection of targets, targeting molecules, and targeting vehicles. Current studies focus on expanding the arsenal of these and alternative targeting strategies, devising drug delivery systems capitalizing on these strategies and evaluation of their benefit/risk ratio in adequate animal models of human diseases. These efforts, combined with better understanding of mechanisms and unintended consequences of these targeted interventions, need to be ultimately translated into industrial development and the clinical domain. PMID:25946066

  11. Healthcare delivery systems: designing quality into health information systems.

    PubMed

    Joyce, Phil; Green, Rosamund; Winch, Graham

    2007-01-01

    To ensure that quality is 'engineered in' a holistic, integrated and quality approach is required, and Total Quality Management (TQM) principles are the obvious foundations for this. This paper describes a novel approach to viewing the operations of a healthcare provider where electronic means could be used to distribute information (including electronic fund settlements), building around the Full Service Provider core. Specifically, an approach called the "triple pair flow" model is used to provide a view of healthcare delivery that is integrated, yet detailed, and that combines the strategic enterprise view with a business process view.

  12. NimbleTools: A Universally Designed Test Delivery System

    ERIC Educational Resources Information Center

    Russell, Michael; Hoffmann, Thomas; Higgins, Jennifer

    2009-01-01

    Students with disabilities and special needs have faced challenges in accessing educational content, and in taking traditional pen-and-paper tests. How might technology improve the process, while making statewide tests truly accessible to all students? NimbleTools is the first computer-based test delivery system that incorporates principles of…

  13. NimbleTools: A Universally Designed Test Delivery System

    ERIC Educational Resources Information Center

    Russell, Michael; Hoffmann, Thomas; Higgins, Jennifer

    2009-01-01

    Students with disabilities and special needs have faced challenges in accessing educational content, and in taking traditional pen-and-paper tests. How might technology improve the process, while making statewide tests truly accessible to all students? NimbleTools is the first computer-based test delivery system that incorporates principles of…

  14. Unsteady jet in designing innovative drug delivery system

    NASA Astrophysics Data System (ADS)

    Wang, Cong; Mazur, Paul; Cosse, Julia; Rider, Stephanie; Gharib, Morteza

    2014-11-01

    Micro-needle injections, a promising pain-free drug delivery method, is constrained by its limited penetration depth. This deficiency can be overcome by implementing fast unsteady jet that can penetrate sub-dermally. The development of a faster liquid jet would increase the penetration depth and delivery volume of micro-needles. In this preliminary work, the nonlinear transient behavior of an elastic tube balloon in providing fast discharge is analyzed. A physical model that combines the Mooney Rivlin Material model and Young-Lapalce's Law was developed and used to investigate the fast discharging dynamic phenomenon. A proof of concept prototype was constructed to demonstrate the feasibility of a simple thumb-sized delivery system to generate liquid jet with desired speed in the range of 5-10 m/s. This work is supported by ZCUBE Corporation.

  15. Leishmaniasis: focus on the design of nanoparticulate vaccine delivery systems.

    PubMed

    Doroud, Delaram; Rafati, Sima

    2012-01-01

    Although mass vaccination of the entire population of an endemic area would be the most cost-effective tool to diminish Leishmania burden, an effective vaccine is not yet commercially available. Practically, vaccines have failed to achieve the required level of protection, possibly owing to the lack of an appropriate adjuvant and/or delivery system. Therefore, there is still an imperative demand for an improved, safe and efficient delivery system to enhance the immunogenicity of available vaccine candidates. Nanoparticles are proficient in boosting the quality and magnitude of immune responses in a predictable fashion. Herein, we discuss how nanoparticulate vaccine delivery systems can be used to induce appropriate immune responses against leishmaniasis by controlling physicochemical properties of the vaccine. Stability, production reproducibility, low cost per dose and low risk-benefit ratios are desirable characteristics of an ideal vaccine formulation and solid lipid nanoparticles may serve as one of the most promising practical strategies to help to achieve such a leishmanial vaccine, at least in canine species in the developing world.

  16. Design of a multiple drug delivery system directed at periodontitis.

    PubMed

    Sundararaj, Sharath C; Thomas, Mark V; Peyyala, Rebecca; Dziubla, Thomas D; Puleo, David A

    2013-11-01

    Periodontal disease is highly prevalent, with 90% of the world population affected by either periodontitis or its preceding condition, gingivitis. These conditions are caused by bacterial biofilms on teeth, which stimulate a chronic inflammatory response that leads to loss of alveolar bone and, ultimately, the tooth. Current treatment methods for periodontitis address specific parts of the disease, with no individual treatment serving as a complete therapy. The present research sought to demonstrate development of a multiple drug delivery system for stepwise treatment of different stages of periodontal disease. More specifically, multilayered films were fabricated from an association polymer comprising cellulose acetate phthalate and Pluronic F-127 to achieve sequential release of drugs. The four types of drugs used were metronidazole, ketoprofen, doxycycline, and simvastatin to eliminate infection, inhibit inflammation, prevent tissue destruction, and aid bone regeneration, respectively. Different erosion times and adjustable sequential release profiles were achieved by modifying the number of layers or by inclusion of a slower-eroding polymer layer. Analysis of antibiotic and anti-inflammatory bioactivity showed that drugs released from the devices retained 100% bioactivity. The multilayered CAPP delivery system offers a versatile approach for releasing different drugs based on the pathogenesis of periodontitis and other conditions. © 2013 Elsevier Ltd. All rights reserved.

  17. Design of a Multiple Drug Delivery System Directed at Periodontitis

    PubMed Central

    Sundararaj, Sharath C.; Thomas, Mark V.; Peyyala, Rebecca; Dziubla, Thomas D.; Puleo, David A.

    2013-01-01

    Periodontal disease is highly prevalent, with 90% of the world population affected by either periodontitis or its preceding condition, gingivitis. These conditions are caused by bacterial biofilms on teeth, which stimulate a chronic inflammatory response that leads to loss of alveolar bone and, ultimately, the tooth. Current treatment methods for periodontitis address specific parts of the disease, with no individual treatment serving as a complete therapy. The present research sought to demonstrate development of a multiple drug delivery system for stepwise treatment of different stages of periodontal disease. More specifically, multilayered films were fabricated from an association polymer comprising cellulose acetate phthalate and Pluronic F-127 to achieve sequential release of drugs. The four types of drugs used were metronidazole, ketoprofen, doxycycline, and simvastatin to eliminate infection, inhibit inflammation, prevent tissue destruction, and aid bone regeneration, respectively. Different erosion times and adjustable sequential release profiles were achieved by modifying the number of layers or by inclusion of a slower-eroding polymer layer. Analysis of antibiotic and anti-inflammatory bioactivity showed that drugs released from the devices retained 100% bioactivity. The multilayered CAPP delivery system offers a versatile approach for releasing different drugs based on the pathogenesis of periodontitis and other conditions. PMID:23948165

  18. Design, fabrication, delivery, operation and maintenance of a geothermal power conversion system

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The design, fabrication, delivery, operation and maintenance of an Hydrothermal Power Company 1250 KVA geothermal power conversion system using a helical screw expander as the prime mover is described. Hydrostatic and acceptance testing are discussed.

  19. Rational design and engineering of delivery systems for therapeutics: biomedical exercises in colloid and surface science.

    PubMed

    Kostarelos, Kostas

    2003-12-01

    Engineering delivery systems of therapeutic agents has grown into an independent field, transcending the scope of traditional disciplines and capturing the interest of both academic and industrial research. At the same time, the acceleration in the discovery of new therapeutic moieties (chemical, biological, genetic and radiological) has led to an increasing demand for delivery systems capable of protecting, transporting, and selectively depositing those therapeutic agents to desired sites. The vast majority of delivery systems physically reside in the colloidal domain, while their surface properties and interfacial interactions with the biological milieu critically determine the pharmacological profiles of the delivered therapeutic agents. Interestingly though, the colloidal and surface properties of delivery systems are commonly overlooked in view of the predominant attention placed on the therapeutic effectiveness achieved. Moreover, the development and evaluation of novel delivery systems towards clinical use is often progressed by serendipity rather than a systematic design process, often leading to failure. The present article will attempt to illustrate the colloid and interfacial perspective of a delivery event, as well as exemplify the vast opportunities offered by treating, analysing and manipulating delivery systems as colloidal systems. Exploring and defining the colloid and surface nature of the interactions taking place between the biological moieties in the body and an administered delivery vehicle will allow for the rational engineering of effective delivery systems. A design scheme is also proposed on the way in which the engineering of advanced delivery systems should be practiced towards their transformation from laboratory inventions to clinically viable therapeutics. Lastly, three case studies are presented, demonstrating how rational manipulation of the colloidal and surface properties of delivery systems can lead to newly engineered systems

  20. Design strategies and applications of circulating cell-mediated drug delivery systems

    PubMed Central

    Kim, Gloria B.; Dong, Cheng; Yang, Jian

    2015-01-01

    Drug delivery systems, particularly nanomaterial-based drug delivery systems, possess a tremendous amount of potential to improve diagnostic and therapeutic effects of drugs. Controlled drug delivery targeted to a specific disease is designed to significantly improve the pharmaceutical effects of drugs and reduce their side effects. Unfortunately, only a few targeted drug delivery systems can achieve high targeting efficiency after intravenous injection, even with the development of numerous surface markers and targeting modalities. Thus, alternative drug and nanomedicine targeting approaches are desired. Circulating cells, such as erythrocytes, leukocytes, and stem cells, present innate disease sensing and homing properties. Hence, using living cells as drug delivery carriers has gained increasing interest in recent years. This review highlights the recent advances in the design of cell-mediated drug delivery systems and targeting mechanisms. The approaches of drug encapsulation/conjugation to cell-carriers, cell-mediated targeting mechanisms, and the methods of controlled drug release are elaborated here. Cell-based “live” targeting and delivery could be used to facilitate a more specific, robust, and smart payload distribution for the next-generation drug delivery systems. PMID:25984572

  1. Development and Application of a Systems Engineering Framework to Support Online Course Design and Delivery

    ERIC Educational Resources Information Center

    Bozkurt, Ipek; Helm, James

    2013-01-01

    This paper develops a systems engineering-based framework to assist in the design of an online engineering course. Specifically, the purpose of the framework is to provide a structured methodology for the design, development and delivery of a fully online course, either brand new or modified from an existing face-to-face course. The main strength…

  2. Expanding Alternative Delivery Systems.

    ERIC Educational Resources Information Center

    Baltzer, Jan A.

    Alternative educational delivery systems that might be useful to community colleges are considered. The following categories of delivery systems are covered: broadcast delivery systems; copy delivery systems, print delivery systems, computer delivery systems, telephone delivery systems, and satellites. Among the applications for broadcast…

  3. Chemical delivery systems and soft drugs: Retrometabolic approaches of drug design.

    PubMed

    Bhardwaj, Yashumati Ratan; Pareek, Ashutosh; Jain, Vivek; Kishore, Dharma

    2014-09-01

    Inclusion of metabolic considerations in the drug design process leads to significant development in the field of chemical drug targeting and the design of safer drugs during past few years which is a part of an approach now designated as Retro metabolic drug design (RMDD). This approach represents systematic methodologies that integrate structure-activity and structure-metabolism relationships and are aimed to design safe, locally active compounds with an improved therapeutic index. It embraces two distinct methods, chemical delivery systems and a soft drug approach. Present review recapitulates an impression of RMDD giving reflections on the chemical delivery system and the soft drug approach and provides a variety of examples to embody its concepts. Successful application of such design principles has already been applied to a number of marketed drugs like esmolol; loteprednol etc., and many other candidates like beta blockers, ACE inhibitors, alkylating agents, antimicrobials etc., are also under investigation.

  4. Integrating SAP to Information Systems Curriculum: Design and Delivery

    ERIC Educational Resources Information Center

    Wang, Ming

    2011-01-01

    Information Systems (IS) education is being transformed from the segmented applications toward the integrated enterprise-wide system software Enterprise Resource Planning (ERP). ERP is a platform that integrates all business functions with its centralized data repository shared by all the business operations in the enterprise. This tremendous…

  5. Computational design of nanoparticle drug delivery systems for selective targeting

    NASA Astrophysics Data System (ADS)

    Duncan, Gregg A.; Bevan, Michael A.

    2015-09-01

    Ligand-functionalized nanoparticles capable of selectively binding to diseased versus healthy cell populations are attractive for improved efficacy of nanoparticle-based drug and gene therapies. However, nanoparticles functionalized with high affinity targeting ligands may lead to undesired off-target binding to healthy cells. In this work, Monte Carlo simulations were used to quantitatively determine net surface interactions, binding valency, and selectivity between targeted nanoparticles and cell surfaces. Dissociation constant, KD, and target membrane protein density, ρR, are explored over a range representative of healthy and cancerous cell surfaces. Our findings show highly selective binding to diseased cell surfaces can be achieved with multiple, weaker affinity targeting ligands that can be further optimized by varying the targeting ligand density, ρL. Using the approach developed in this work, nanomedicines can be optimally designed for exclusively targeting diseased cells and tissues.Ligand-functionalized nanoparticles capable of selectively binding to diseased versus healthy cell populations are attractive for improved efficacy of nanoparticle-based drug and gene therapies. However, nanoparticles functionalized with high affinity targeting ligands may lead to undesired off-target binding to healthy cells. In this work, Monte Carlo simulations were used to quantitatively determine net surface interactions, binding valency, and selectivity between targeted nanoparticles and cell surfaces. Dissociation constant, KD, and target membrane protein density, ρR, are explored over a range representative of healthy and cancerous cell surfaces. Our findings show highly selective binding to diseased cell surfaces can be achieved with multiple, weaker affinity targeting ligands that can be further optimized by varying the targeting ligand density, ρL. Using the approach developed in this work, nanomedicines can be optimally designed for exclusively targeting

  6. Conceptual design report for the University of Rochester cryogenic target delivery system

    SciTech Connect

    Fagaly, R.L.; Alexander, N.B.; Bourque, R.F.; Dahms, C.F.; Lindgren, J.R.; Miller, W.J.; Bittner, D.N.; Hendricks, C.D.

    1993-05-01

    The upgrade of the Omega laser at the University of Rochester`s Laboratory for Laser Energetics (UR/LLE) will result in a need for large targets filled with D{sub 2} or Dt and maintained at cryogenic temperatures. This mandates a cryogenic target delivery system capable of filling, layering, characterizing and delivering cryogenic targets to the Omega Upgrade target chamber. The program goal is to design, construct, and test the entire target delivery system by June 1996. When completed (including an operational demonstration), the system will be shipped to Rochester for reassembly and commissioning in time for the Omega Upgrade cryogenic campaign, scheduled to start in 1998. General Atomics has been assigned the task of developing the conceptual design for the cryogenic target delivery system. Design and fabrication activities will be closely coordinated with the University of Rochester, Lawrence Livermore National laboratory (LLNL) and Los Alamos National Laboratory (LANL), drawing upon their knowledge base in fuel layering and cryogenic characterization. The development of a target delivery system for Omega could also benefit experiments at Lawrence Livermore National Laboratory and the other ICF Laboratories in that the same technologies could be applied to NOVA, the National Ignition Facility or the future Laboratory Microfusion Facility.

  7. Conceptual design report for the University of Rochester cryogenic target delivery system

    SciTech Connect

    Fagaly, R.L.; Alexander, N.B.; Bourque, R.F.; Dahms, C.F.; Lindgren, J.R.; Miller, W.J. ); Bittner, D.N.; Hendricks, C.D. )

    1993-05-01

    The upgrade of the Omega laser at the University of Rochester's Laboratory for Laser Energetics (UR/LLE) will result in a need for large targets filled with D[sub 2] or Dt and maintained at cryogenic temperatures. This mandates a cryogenic target delivery system capable of filling, layering, characterizing and delivering cryogenic targets to the Omega Upgrade target chamber. The program goal is to design, construct, and test the entire target delivery system by June 1996. When completed (including an operational demonstration), the system will be shipped to Rochester for reassembly and commissioning in time for the Omega Upgrade cryogenic campaign, scheduled to start in 1998. General Atomics has been assigned the task of developing the conceptual design for the cryogenic target delivery system. Design and fabrication activities will be closely coordinated with the University of Rochester, Lawrence Livermore National laboratory (LLNL) and Los Alamos National Laboratory (LANL), drawing upon their knowledge base in fuel layering and cryogenic characterization. The development of a target delivery system for Omega could also benefit experiments at Lawrence Livermore National Laboratory and the other ICF Laboratories in that the same technologies could be applied to NOVA, the National Ignition Facility or the future Laboratory Microfusion Facility.

  8. Design of the beam delivery system for the international linear collider.

    SciTech Connect

    Seryi, A.; Amann, J.; Arnold, R.; Asiri, F.; Bane, K.; Carwardine, J.; Saunders, C.; Accelerator Systems Division; SLAC; FNAL

    2008-01-01

    The beam delivery system for the linear collider focuses beams to nanometer sizes at its interaction point, collimates the beam halo to provide acceptable background in the detector and has a provision for state-of-the art beam instrumentation in order to reach the ILCs physics goals. This paper describes the design details and status of the baseline configuration considered for the reference design and also lists alternatives.

  9. Design, Characterization, and Optimization of Controlled Drug Delivery System Containing Antibiotic Drug/s

    PubMed Central

    Shelate, Pragna; Dave, Divyang

    2016-01-01

    The objective of this work was design, characterization, and optimization of controlled drug delivery system containing antibiotic drug/s. Osmotic drug delivery system was chosen as controlled drug delivery system. The porous osmotic pump tablets were designed using Plackett-Burman and Box-Behnken factorial design to find out the best formulation. For screening of three categories of polymers, six independent variables were chosen for Plackett-Burman design. Osmotic agent sodium chloride and microcrystalline cellulose, pore forming agent sodium lauryl sulphate and sucrose, and coating agent ethyl cellulose and cellulose acetate were chosen as independent variables. Optimization of osmotic tablets was done by Box-Behnken design by selecting three independent variables. Osmotic agent sodium chloride, pore forming agent sodium lauryl sulphate, and coating agent cellulose acetate were chosen as independent variables. The result of Plackett-Burman and Box-Behnken design and ANOVA studies revealed that osmotic agent and pore former had significant effect on the drug release up to 12 hr. The observed independent variables were found to be very close to predicted values of most satisfactory formulation which demonstrates the feasibility of the optimization procedure in successful development of porous osmotic pump tablets containing antibiotic drug/s by using sodium chloride, sodium lauryl sulphate, and cellulose acetate as key excipients. PMID:27610247

  10. Design optimization of a novel pMDI actuator for systemic drug delivery.

    PubMed

    Kakade, Prashant P; Versteeg, Henk K; Hargrave, Graham K; Genova, Perry; Williams Iii, Robert C; Deaton, Daniel

    2007-01-01

    Pressurized metered dose inhalers (pMDIs) are the most widely prescribed and economical respiratory drug delivery systems. Conventional pMDI actuators-those based on "two-orifice-and-sump" designs-produce an aerosol with a reasonable respirable fraction, but with high aerosol velocity. The latter is responsible for high oropharyngeal deposition, and consequently low drug delivery efficiency. Kos' pMDI technology is based on a proprietary vortex nozzle actuator (VNA), an innovative actuator configuration that seeks to reduce aerosol plume velocity, thereby promoting deep lung deposition. Using VNA development as a case study, this paper presents a systematic design optimization process to improve the actuator performance through use of advanced optical characterization tools. The optimization effort mainly relied on laser-based optical diagnostics to provide an improved understanding of the fundamentals of aerosol formation and interplay of various geometrical factors. The performance of the optimized VNA design thus evolved was characterized using phase Doppler anemometry and cascade impaction. The aerosol velocities for both standard and optimized VNA designs were found to be comparable, with both notably less than conventional actuators. The optimized VNA design also significantly reduces drug deposition in the actuator as well as USP throat adapter, which in turn, leads to a significantly higher fine particle fraction than the standard design (78 +/- 3% vs. 63 +/- 2% on an ex valve basis). This improved drug delivery efficiency makes VNA technology a practical proposition as a systemic drug delivery platform. Thus, this paper demonstrates how advanced optical diagnostic and characterization tools can be used in the development of high efficiency aerosol drug delivery devices.

  11. Design and construction of a magnetic resonance compatible multi-injector gas jet delivery system

    NASA Astrophysics Data System (ADS)

    Megias-Alguacil, David; Keller, Thierry; Lutz, Kai; Barlow, Ashley P.; Ettlin, Dominik A.

    2008-01-01

    We present the design, construction, and performance of a novel multi-injector gas jet delivery capable of operating in a magnetic resonance imaging environment. This apparatus is computer controlled and built with two separate pneumatic circuits enabling gas jet applications at variable sites through four independently activated injectors. Gas jet delivery is fully controllable in terms of pressure, flow rate, gas temperature, application time, and duration of interstimulus interval. We characterized these parameters, considering effects such as pressure drop by flow transport, transient effects, and delays in activation. The system offers new possibilities for use in various biomedical contexts such as, e.g., quantitative sensory testing or dental hypersensitivity assessment.

  12. Design, fabrication and characterization of drug delivery systems based on lab-on-a-chip technology.

    PubMed

    Nguyen, Nam-Trung; Shaegh, Seyed Ali Mousavi; Kashaninejad, Navid; Phan, Dinh-Tuan

    2013-11-01

    Lab-on-a-chip technology is an emerging field evolving from the recent advances of micro- and nanotechnologies. The technology allows the integration of various components into a single microdevice. Microfluidics, the science and engineering of fluid flow in microscale, is the enabling underlying concept for lab-on-a-chip technology. The present paper reviews the design, fabrication and characterization of drug delivery systems based on this amazing technology. The systems are categorized and discussed according to the scales at which the drug is administered. Starting with the fundamentals on scaling laws of mass transfer and basic fabrication techniques, the paper reviews and discusses drug delivery devices for cellular, tissue and organism levels. At the cellular level, a concentration gradient generator integrated with a cell culture platform is the main drug delivery scheme of interest. At the tissue level, the synthesis of smart particles as drug carriers using lab-on-a-chip technology is the main focus of recent developments. At the organism level, microneedles and implantable devices with fluid-handling components are the main drug delivery systems. For drug delivery to a small organism that can fit into a microchip, devices similar to those of cellular level can be used. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Colon-targeted oral drug delivery systems: design trends and approaches.

    PubMed

    Amidon, Seth; Brown, Jack E; Dave, Vivek S

    2015-08-01

    Colon-specific drug delivery systems (CDDS) are desirable for the treatment of a range of local diseases such as ulcerative colitis, Crohn's disease, irritable bowel syndrome, chronic pancreatitis, and colonic cancer. In addition, the colon can be a potential site for the systemic absorption of several drugs to treat non-colonic conditions. Drugs such as proteins and peptides that are known to degrade in the extreme gastric pH, if delivered to the colon intact, can be systemically absorbed by colonic mucosa. In order to achieve effective therapeutic outcomes, it is imperative that the designed delivery system specifically targets the drugs into the colon. Several formulation approaches have been explored in the development colon-targeted drug delivery systems. These approaches involve the use of formulation components that interact with one or more aspects of gastrointestinal (GI) physiology, such as the difference in the pH along the GI tract, the presence of colonic microflora, and enzymes, to achieve colon targeting. This article highlights the factors influencing colon-specific drug delivery and colonic bioavailability, and the limitations associated with CDDS. Further, the review provides a systematic discussion of various conventional, as well as relatively newer formulation approaches/technologies currently being utilized for the development of CDDS.

  14. Systems Analysis and Structural Design of an Unpressurized Cargo Delivery Vehicle

    NASA Technical Reports Server (NTRS)

    Wu, K. Chauncey; Cruz, Jonathan N.; Antol, Jeffrey; Sasamoto, Washito A.

    2007-01-01

    The International Space Station will require a continuous supply of replacement parts for ongoing maintenance and repair after the planned retirement of the Space Shuttle in 2010. These parts are existing line-replaceable items collectively called Orbital Replacement Units, and include heavy and oversized items such as Control Moment Gyroscopes and stowed radiator arrays originally intended for delivery aboard the Space Shuttle. Current resupply spacecraft have limited to no capability to deliver these external logistics. In support of NASA's Exploration Systems Architecture Study, a team at Langley Research Center designed an Unpressurized Cargo Delivery Vehicle to deliver bulk cargo to the Space Station. The Unpressurized Cargo Delivery Vehicle was required to deliver at least 13,200 lbs of cargo mounted on at least 18 Flight Releasable Attachment Mechanisms. The Crew Launch Vehicle design recommended in the Exploration Systems Architecture Study would be used to launch one annual resupply flight to the International Space Station. The baseline vehicle design developed here has a cargo capacity of 16,000 lbs mounted on up to 20 Flight Releasable Attachment Mechanisms. Major vehicle components are a 5.5m-diameter cargo module containing two detachable cargo pallets with the payload, a Service Module to provide propulsion and power, and an aerodynamic nose cone. To reduce cost and risk, the Service Module is identical to the one used for the Crew Exploration Vehicle design.

  15. Experimental design and desirability function approach for development of novel anticancer nanocarrier delivery systems.

    PubMed

    Rafati, H; Mirzajani, F

    2011-01-01

    The therapeutic effects of anticancer drugs would highly improve if problems with low water solubility and toxic adverse reactions could be solved. In this work, a full factorial experimental design was used to develop a polymeric nanoparticulate delivery system as an alternative technique for anticancer drug delivery. Nanoparticles containing tamoxifen citrate were prepared and characterized using an O/W emulsification-solvent evaporation technique and different analytical methods. Scanning Electron Microscopy (SEM), particle size analysis and High Pressure Liquid Chromatography (HPLC) were used for characterization of nanoparticles. Nanoparticles' characteristics including size, size distribution, drug loading and the efficiency of encapsulation were optimized by means of a full factorial experimental design over the influence of four different independent variables and desirability function using Design-Expert software. The resulting tamoxifen loaded nanoparticles showed the best response with particle sizes less than 200 nm, improved encapsulation efficiency of more than 80% and the optimum loading of above 30%. The overall results demonstrate the implication of desirability functionin experimental design as a beneficial approach in nanoparticle drug delivery design.

  16. Polycaprolactone Thin-Film Drug Delivery Systems: Empirical and Predictive Models for Device Design

    PubMed Central

    Schlesinger, Erica; Ciaccio, Natalie; Desai, Tejal A.

    2015-01-01

    Purpose To define empirical models and parameters based on theoretical equations to describe drug release profiles from two polycaprolactone thin-film drug delivery systems. Additionally, to develop a predictive model for empirical parameters based on drugs’ physicochemical properties. Methods Release profiles from a selection of drugs representing the standard pharmaceutical space in both polycaprolactone matrix and reservoir systems were determined experimentally. The proposed models were used to calculate empirical parameters describing drug diffusion and release. Observed correlations between empirical parameters and drug properties were used to develop equations to predict parameters based on drug properties. Predictive and empirical models were evaluated in the design of three prototype devices: a levonorgestrel matrix system for on-demand locally administered contraception, a timolol-maleate reservoir system for glaucoma treatment, and a primaquine-bisphosphate reservoir system for malaria prophylaxis. Results Proposed empirical equations accurately fit experimental data. Experimentally derived empirical parameters show significant correlations with logP, molecular weight, and solubility. Empirical models based on predicted parameters accurately predict experimental release data for three prototype systems, demonstrating the accuracy and utility of these models. Conclusion The proposed empirical models can be used to design polycaprolactone thin-film devices for target geometries and release rates. Empirical parameters can be predicted based on drug properties. Together, these models provide tools for preliminary evaluation and design of controlled-release delivery systems. PMID:26354259

  17. Transducer design for a portable ultrasound enhanced transdermal drug-delivery system.

    PubMed

    Maione, Emiliano; Shung, K Kirk; Meyer, Richard J; Hughes, Jack W; Newnham, Robert E; Smith, Nadine Barrie

    2002-10-01

    For application in a portable transdermal drug-delivery system, novel transducers have been designed to enhance insulin transmission across skin using ultrasound. Previous research has shown transdermal delivery of insulin across skin using commercial sonicators operating at 20 kHz with intensities ranging from 12.5 to 225 mW/cm2. The goal of this research was to design and construct a small, lightweight transducer or array that could operate with a similar frequency and intensity range as a commercial sonicator used in previous transdermal ultrasound insulin experiments, but without the weight and mass of a sonicator probe. To obtain this intensity range, a cymbal transducer design was chosen because of its light, compact structure and low resonance frequency in water. To increase the spatial ultrasound field for drug delivery across skin, two arrays, each comprising of four cymbal transducers, were constructed. The first array, designated the standard array, used four cymbals transducer elements in parallel. A second array (named the stack array) used four cymbal transducers that used stacked piezoelectric discs to drive the titanium flextensional caps. Under similar driving conditions, the standard array produced intensities comparable to those achieved using a commercial sonicator.

  18. Design and performance of feed delivery systems for simulated radioactive waste slurries

    SciTech Connect

    Perez, J.M. Jr.

    1983-02-01

    Processes for vitrifying simulated high-level radioactive waste have been developed at the Pacific Northwest Laboratory (PNL) over the last several years. Paralleling this effort, several feed systems used to deliver the simulated waste slurry to the melter have been tested. Because there had been little industrial experience in delivering abrasive slurries at feed rates of less than 10 L/min, early experience helped direct the design of more-dependable systems. Also, as feed delivery requirements changed, the feed system was modified to meet these new requirements. The various feed systems discussed in this document are part of this evolutionary process, so they have not been ranked against each other. The four slurry feed systems discussed are: (1) vertical-cantilevered centrifugal pump system; (2) airlift feed systems; (3) pressurized-loop systems; and (4) positive-displacement pump system. 20 figures, 11 tables.

  19. Phospholipid-based nonlamellar mesophases for delivery systems: bridging the gap between empirical and rational design.

    PubMed

    Martiel, Isabelle; Sagalowicz, Laurent; Mezzenga, Raffaele

    2014-07-01

    Phospholipids are ubiquitous cell membrane components and relatively well-accepted ingredients due to their natural origin. Phosphatidylcholine (PC) in particular offers a promising alternative to monoglycerides for lyotropic liquid crystalline (LLC) delivery system applications in the food, cosmetics and pharmaceutical industries, provided its strong tendency to form zero-mean curvature lamellar mesophases in water can be overcome. Higher negative curvatures are usually reached through the addition of a third lipid component, forming a ternary diagram phospholipid/water/oil. The initial part of this work summarizes the potential advantages and the challenges of phospholipid-based delivery system applications. In the next part, various ternary PC/water/oil systems are discussed, with a special emphasis on the PC/water/cyclohexane and PC/water/α-tocopherol systems. We report that R-(+)-limonene has a quantitatively similar effect as cyclohexane. The last part is devoted to the theoretical interpretation of the observed phase behaviors. A fruitful parallel is drawn with PC polymer-like reverse micelles, leading to a thermodynamic description in terms of interfacial bending energy. Investigations at the molecular level are reviewed to help in bridging the empirical and theoretical approaches. Predictive rules are finally derived from this wide-ranging overview, thereby opening the way to a future rational design of PC-based LLC delivery systems.

  20. The design and performance of the exubera pulmonary insulin delivery system.

    PubMed

    Harper, Nancy J; Gray, Steven; De Groot, Jennifer; Parker, Joann M; Sadrzadeh, Negar; Schuler, Carlos; Schumacher, Jacqueline D; Seshadri, Sangita; Smith, Adrian E; Steeno, Gregory S; Stevenson, Cynthia L; Taniere, Romain; Wang, May; Bennett, David B

    2007-06-01

    The Exubera system (Pfizer, New York, NY/Nektar Therapeutics, San Carlos, CA) is an integration of five major new technologies: protein formulation, powder processing, powder filling, drug packaging, and delivery device. The product provides a simple interface, where the patient interacts only with the delivery device and powder packaging. These components were designed together to assure repeatable dosing when used by a wide range of patients under real-world life-style and handling conditions. The device design is purely mechanical, using patient-generated compressed air as the energy source. Upon actuation, a sonic discharge of air through the novel release unit reproducibly extracts, de-agglomerates, and disperses the inhalation powder into a respirable aerosol. A clear holding chamber allows for patient feedback via dose visualization and separates aerosol cloud generation from the inspiratory effort. The Exubera product was tested under a wide range of typical use conditions and potential misuse scenarios and following long-term usage in clinical trials. These comprehensive characterization programs demonstrated robust aerosol and mechanical performance, confirming the design intent of the inhaler. These studies provide assurance of consistent and reliable dose delivery in a real-world use of the product.

  1. Design of nanoemulsion-based delivery systems of natural antimicrobials: effect of the emulsifier.

    PubMed

    Donsì, Francesco; Annunziata, Marianna; Vincensi, Mariarosaria; Ferrari, Giovanna

    2012-06-30

    This work aims at investigating the effect of the nanoemulsion delivery systems on the antimicrobial activity of different essential oil components. Carvacrol, limonene and cinnamaldehyde were encapsulated in the sunflower oil droplets of nanoemulsions prepared by high pressure homogenization and stabilized by different emulsifiers: (a) lecithin, (b) pea proteins, (c) sugar ester and (d) a combination of Tween 20 and glycerol monooleate. The antimicrobial activity was measured against three different microorganisms, such as Escherichia coli, Lactobacillus delbrueckii and Saccharomyces cerevisiae. The measured antimicrobial activity was significantly affected by the formulation of the nanoemulsion, where the different bioactive compounds were encapsulated. In particular, the effect of the delivery systems on the antimicrobial activity was correlated to the concentration of the essential oil components in the aqueous phase in equilibrium with the nanoemulsion droplets, suggesting that the ability of the active molecules to interact with cell membranes is associated to their dissolution in the aqueous phase. These considerations can lead to a more rational design of the nanoemulsion-based delivery systems for essential oils, based on the opportune choice of the emulsifiers in dependence of the desired function of the antimicrobials within the food system. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Design and optimization of resonance-based efficient wireless power delivery systems for biomedical implants.

    PubMed

    Ramrakhyani, A K; Mirabbasi, S; Mu Chiao

    2011-02-01

    Resonance-based wireless power delivery is an efficient technique to transfer power over a relatively long distance. This technique typically uses four coils as opposed to two coils used in conventional inductive links. In the four-coil system, the adverse effects of a low coupling coefficient between primary and secondary coils are compensated by using high-quality (Q) factor coils, and the efficiency of the system is improved. Unlike its two-coil counterpart, the efficiency profile of the power transfer is not a monotonically decreasing function of the operating distance and is less sensitive to changes in the distance between the primary and secondary coils. A four-coil energy transfer system can be optimized to provide maximum efficiency at a given operating distance. We have analyzed the four-coil energy transfer systems and outlined the effect of design parameters on power-transfer efficiency. Design steps to obtain the efficient power-transfer system are presented and a design example is provided. A proof-of-concept prototype system is implemented and confirms the validity of the proposed analysis and design techniques. In the prototype system, for a power-link frequency of 700 kHz and a coil distance range of 10 to 20 mm, using a 22-mm diameter implantable coil resonance-based system shows a power-transfer efficiency of more than 80% with an enhanced operating range compared to ~40% efficiency achieved by a conventional two-coil system.

  3. Design and evaluation of an oral multiparticulate system for dual delivery of amoxicillin and Lactobacillus acidophilus.

    PubMed

    Govender, Mershen; Choonara, Yahya E; van Vuuren, Sandy; Kumar, Pradeep; du Toit, Lisa C; Pillay, Viness

    2016-09-01

    A delayed-release dual delivery system for amoxicillin and the probiotic Lactobacillus acidophilus was developed and evaluated. Statistical optimization of a cross-linked denatured ovalbumin protective matrix was first synthesized using a Box-Behnken experimental design prior to encapsulation with glyceryl monostereate. The encapsulated ovalbumin matrix was thereafter incorporated with amoxicillin in a gastro-resistant capsule. In vitro characterization and stability analysis of the ovalbumin and encapsulated components were also performed Results: Protection of L. acidophilus probiotic against the bactericidal effects of amoxicillin within the dual formulation was determined. The dual formulation in this study proved effective and provides insight into current microbiome research to identify, classify and use functional healthy bacteria to develop novel probiotic delivery technologies.

  4. Design and Characterization of Silicone and Surfactant Based Systems for Topical Drug Delivery.

    PubMed

    Oyafuso, Márcia Helena; Carvalho, Flávia Chiva; Chiavacci, Leila Aparecida; Gremião, Maria Palmira Daflon; Chorilli, Marlus

    2015-01-01

    Nanotechnology offers advantages for new drug delivery design by providing drug targeting while minimizing the side effects. Polyoxyethylene 20 cetyl alcohol (CETETH-20) is a surfactant that may form nanostructured systems, such as liquid crystals, when in contact with water/oil, which are structurally similar to biological membranes and may improve skin interaction. The aim of this study was to develop and characterize CETETH 20-based nanostructured systems by combining CETETH-20 with water and different oily phases, including PEG-12-dimethicone for topical drug administration. The systems were characterized by polarized light microscopy (PLM), small-angle X-ray scattering (SAXS), rheology, texture profile analyses (TPA), in vitro cytotoxicity and histopathological analyses of rabbits' skin. Lamellar, hexagonal and cubic phases were identified and their viscoelastic moduli varied according to each phase. The stiffness of the cubic phase was 3-fold higher and twice more adhesive than the hexagonal phase. The formulations did not affect the normal macrophages cells, neither promoted skin irritation. They were spontaneously obtained by simply mixing the components, which corroborates for an ease scaled-up. These results suggest that systems composed of CETETH 20, PEG-12-dimethicone and water are a promising new approach for designing nanostructured topical drug delivery systems.

  5. Self-nanoemulsifying drug delivery systems of tamoxifen citrate: design and optimization.

    PubMed

    Elnaggar, Yosra S R; El-Massik, Magda A; Abdallah, Ossama Y

    2009-10-01

    Tamoxifen citrate is an antiestrogen for peroral breast cancer treatment. The drug delivery encounters problems of poor water solubility and vulnerability to enzymatic degradation in both intestine and liver. In the current study, tamoxifen citrate self-nanoemulsifying drug delivery systems (SNEDDS) were prepared in an attempt to circumvent such obstacles. Preliminary screening was carried out to select proper ingredient combinations. All surfactants screened were recognized for their bioactive aspects. Ternary phase diagrams were then constructed and an optimum system was designated. Three tamoxifen SNEDDS were then compared for optimization. The systems were assessed for robustness to dilution, globule size, cloud point, surface morphology and drug release. An optimum system composed of tamoxifen citrate (1.6%), Maisine 35-1 (16.4%), Caproyl 90 (32.8%), Cremophor RH40 (32.8%) and propylene glycol (16.4%) was selected. The system was robust to different dilution volumes and types. It possessed a mean globule size of 150 nm and a cloud point of 80 degrees C. Transmission electron microscopy demonstrated spherical particle morphology. The drug release from the selected formulation was significantly higher than other SNEDDS and drug suspension, as well. Realizing drug incorporation into an optimized nano-sized SNEDD system that encompasses a bioactive surfactant, our results proposed that the prepared system could be promising to improve oral efficacy of the tamoxifen citrate.

  6. Formulation development of smart gel periodontal drug delivery system for local delivery of chemotherapeutic agents with application of experimental design.

    PubMed

    Dabhi, Mahesh R; Nagori, Stavan A; Gohel, Mukesh C; Parikh, Rajesh K; Sheth, Navin R

    2010-01-01

    Smart gel periodontal drug delivery systems (SGPDDS) containing gellan gum (0.1-0.8% w/v), lutrol F127 (14, 16, and 18% w/v), and ornidazole (1% w/v) were designed for the treatment of periodontal diseases. Each formulation was characterized in terms of in vitro gelling capacity, viscosity, rheology, content uniformity, in vitro drug release, and syringeability. In vitro gelation time and the nature of the gel formed in simulated saliva for prepared formulations showed polymeric concentration dependency. Drug release data from all formulations was fitted to different kinetic models and the Korsemeyer-Peppas model was the best fit model. Drug release was significantly decreased as the concentration of each polymer component was increased. Increasing the concentration of each polymeric component significantly increased viscosity, syringeability, and time for 50%, 70%, and 90% drug release. In conclusion, the formulations described offer a wide range of physical and drug release characteristics. The formulation containing 0.8% w/v of gellan gum and 16% w/v of lutrol F127 exhibited superior physical characteristics.

  7. Design of Drug Delivery Methods for the Brain and Central Nervous System

    NASA Astrophysics Data System (ADS)

    Lueshen, Eric

    Due to the impermeability of the blood-brain barrier (BBB) to macromolecules delivered systemically, drug delivery to the brain and central nervous system (CNS) is quite difficult and has become an area of intense research. Techniques such as convection-enhanced intraparenchymal delivery and intrathecal magnetic drug targeting offer a means of circumventing the blood-brain barrier for targeted delivery of therapeutics. This dissertation focuses on three aspects of drug delivery: pharmacokinetics, convection-enhanced delivery, and intrathecal magnetic drug targeting. Classical pharmacokinetics mainly uses black-box curve fitting techniques without biochemical or biological basis. This dissertation advances the state-of-the-art of pharmacokinetics and pharmacodynamics by incorporating first principles and biochemical/biotransport mechanisms in the prediction of drug fate in vivo. A whole body physiologically-based pharmacokinetics (PBPK) modeling framework is engineered which creates multiscale mathematical models for entire organisms composed of organs, tissues, and a detailed vasculature network to predict drug bioaccumulation and to rigorously determine kinetic parameters. These models can be specialized to account for species, weight, gender, age, and pathology. Systematic individual therapy design using the proposed mechanistic PBPK modeling framework is also a possibility. Biochemical, anatomical, and physiological scaling laws are also developed to accurately project drug kinetics in humans from small animal experiments. Our promising results demonstrate that the whole-body mechanistic PBPK modeling approach not only elucidates drug mechanisms from a biochemical standpoint, but offers better scaling precision. Better models can substantially accelerate the introduction of drug leads to clinical trials and eventually to the market by offering more understanding of the drug mechanisms, aiding in therapy design, and serving as an accurate dosing tool. Convection

  8. Optimizing drug delivery systems using systematic "design of experiments." Part I: fundamental aspects.

    PubMed

    Singh, Bhupinder; Kumar, Rajiv; Ahuja, Naveen

    2005-01-01

    Design of an impeccable drug delivery product normally encompasses multiple objectives. For decades, this task has been attempted through trial and error, supplemented with the previous experience, knowledge, and wisdom of the formulator. Optimization of a pharmaceutical formulation or process using this traditional approach involves changing one variable at a time. Using this methodology, the solution of a specific problematic formulation characteristic can certainly be achieved, but attainment of the true optimal composition is never guaranteed. And for improvement in one characteristic, one has to trade off for degeneration in another. This customary approach of developing a drug product or process has been proved to be not only uneconomical in terms of time, money, and effort, but also unfavorable to fix errors, unpredictable, and at times even unsuccessful. On the other hand, the modern formulation optimization approaches, employing systematic Design of Experiments (DoE), are extensively practiced in the development of diverse kinds of drug delivery devices to improve such irregularities. Such systematic approaches are far more advantageous, because they require fewer experiments to achieve an optimum formulation, make problem tracing and rectification quite easier, reveal drug/polymer interactions, simulate the product performance, and comprehend the process to assist in better formulation development and subsequent scale-up. Optimization techniques using DoE represent effective and cost-effective analytical tools to yield the "best solution" to a particular "problem." Through quantification of drug delivery systems, these approaches provide a depth of understanding as well as an ability to explore and defend ranges for formulation factors, where experimentation is completed before optimization is attempted. The key elements of a DoE optimization methodology encompass planning the study objectives, screening of influential variables, experimental designs

  9. Systems modelling and simulation in health service design, delivery and decision making.

    PubMed

    Pitt, Martin; Monks, Thomas; Crowe, Sonya; Vasilakis, Christos

    2016-01-01

    The ever increasing pressures to ensure the most efficient and effective use of limited health service resources will, over time, encourage policy makers to turn to system modelling solutions. Such techniques have been available for decades, but despite ample research which demonstrates potential, their application in health services to date is limited. This article surveys the breadth of approaches available to support delivery and design across many areas and levels of healthcare planning. A case study in emergency stroke care is presented as an exemplar of an impactful application of health system modelling. This is followed by a discussion of the key issues surrounding the application of these methods in health, what barriers need to be overcome to ensure more effective implementation, as well as likely developments in the future.

  10. Optimization and characterization of gastroretentive floating drug delivery system using Box-Behnken design.

    PubMed

    Rapolu, Kishore; Sanka, Krishna; Vemula, Praveen Kumar; Aatipamula, Vinaydas; Mohd, Abdul Bari; Diwan, Prakash V

    2013-12-01

    One among many strategies to prolong gastric residence time and improve local effect of the metronidazole in stomach to eradicate Helicobacter pylori in the treatment of peptic ulcer was floating drug delivery system particularly effervescent gastroretentive tablets. The objective of this study was to prepare and evaluate, effervescent floating drug delivery system of a model drug, metronidazole. Effervescent floating drug delivery tablets were prepared by wet granulation method. A three-factor, three levels Box-Behnken design was adopted for the optimization. The selected independent variables were amount of hydroxypropyl methylcellulose K 15M (X1), sodium carboxy methylcellulose (X2) and NaHCO3 (X3). The dependent variables were floating lag time (YFLT), cumulative percentage of metronidazole released at 6th h (Y6) and cumulative percentage of metronidazole released at 12th h (Y12). Physical properties, drug content, in vitro floating lag time, total floating time and drug release behavior were assessed. YFLT range was found to be from 1.02 to 12.07 min. The ranges of other responses, Y6 and Y12 were 25.72 ± 2.85 to 77.14 ± 3.42 % and 65.47 ± 1.25 to 99.65 ± 2.28 %, respectively. Stability studies revealed that no significant change in in vitro floating lag time, total floating time and drug release behavior before and after storage. It can be concluded that a combination of hydroxypropyl methylcellulose K 15M, sodium carboxy methylcellulose and NaHCO3 can be used to increase the gastric residence time of the dosage form to improve local effect of metronidazole.

  11. Design and evaluation of colon specific drug delivery system containing flurbiprofen microsponges.

    PubMed

    Orlu, Mine; Cevher, Erdal; Araman, Ahmet

    2006-08-02

    The purpose of this study was to design novel colon specific drug delivery system containing flurbiprofen (FLB) microsponges. Microsponges containing FLB and Eudragit RS 100 were prepared by quasi-emulsion solvent diffusion method. Additionally, FLB was entrapped into a commercial Microsponge 5640 system using entrapment method. Afterwards, the effects of drug:polymer ratio, inner phase solvent amount, stirring time and speed and stirrer type on the physical characteristics of microsponges were investigated. The thermal behaviour, surface morphology, particle size and pore structure of microsponges were examined. The colon specific formulations were prepared by compression coating and also pore plugging of microsponges with pectin:hydroxypropylmethyl cellulose (HPMC) mixture followed by tabletting. In vitro dissolution studies were done on all formulations and the results were kinetically and statistically evaluated. The microsponges were spherical in shape, between 30.7 and 94.5microm in diameter and showed high porosity values (61-72%). The pore shapes of microsponges prepared by quasi-emulsion solvent diffusion method and entrapment method were found as spherical and cylindrical holes, respectively. Mechanically strong tablets prepared for colon specific drug delivery were obtained owing to the plastic deformation of sponge-like structure of microsponges. In vitro studies exhibited that compression coated colon specific tablet formulations started to release the drug at the 8th hour corresponding to the proximal colon arrival time due to the addition of enzyme, following a modified release pattern while the drug release from the colon specific formulations prepared by pore plugging the microsponges showed an increase at the 8th hour which was the time point that the enzyme addition made. This study presents a new approach based on microsponges for colon specific drug delivery.

  12. Nanoparticle Drug Delivery Systems Designed to Improve Cancer Vaccines and Immunotherapy

    PubMed Central

    Fan, Yuchen; Moon, James J.

    2015-01-01

    Recent studies have demonstrated great therapeutic potential of educating and unleashing our own immune system for cancer treatment. However, there are still major challenges in cancer immunotherapy, including poor immunogenicity of cancer vaccines, off-target side effects of immunotherapeutics, as well as suboptimal outcomes of adoptive T cell transfer-based therapies. Nanomaterials with defined physico-biochemical properties are versatile drug delivery platforms that may address these key technical challenges facing cancer vaccines and immunotherapy. Nanoparticle systems have been shown to improve targeted delivery of tumor antigens and therapeutics against immune checkpoint molecules, amplify immune activation via the use of new stimuli-responsive or immunostimulatory materials, and augment the efficacy of adoptive cell therapies. Here, we review the current state-of-the-art in nanoparticle-based strategies designed to potentiate cancer immunotherapies, including cancer vaccines with subunit antigens (e.g., oncoproteins, mutated neo-antigens, DNA and mRNA antigens) and whole-cell tumor antigens, dendritic cell-based vaccines, artificial antigen-presenting cells, and immunotherapeutics based on immunogenic cell death, immune checkpoint blockade, and adoptive T-cell therapy. PMID:26350600

  13. 3D printing in pharmaceutics: A new tool for designing customized drug delivery systems.

    PubMed

    Goole, Jonathan; Amighi, Karim

    2016-02-29

    Three-dimensional printing includes a wide variety of manufacturing techniques, which are all based on digitally-controlled depositing of materials (layer-by-layer) to create freeform geometries. Therefore, three-dimensional printing processes are commonly associated with freeform fabrication techniques. For years, these methods were extensively used in the field of biomanufacturing (especially for bone and tissue engineering) to produce sophisticated and tailor-made scaffolds from patient scans. This paper aims to review the processes that can be used in pharmaceutics, including the parameters to be controlled. In practice, it not straightforward for a formulator to be aware of the various technical advances made in this field, which is gaining more and more interest. Thus, a particular aim of this review is to give an overview on the pragmatic tools, which can be used for designing customized drug delivery systems using 3D printing. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. The design and scale-up of spray dried particle delivery systems.

    PubMed

    Al-Khattawi, Ali; Bayly, Andrew; Phillips, Andrew; Wilson, David

    2017-05-04

    The rising demand for pharmaceutical particles with tailored physicochemical properties has opened new markets for spray drying especially for solubility enhancement, improving inhalation medicines and stabilization of biopharmaceuticals. Despite this, the spray drying literature is scattered and often does not address the principles underpinning robust development of pharmaceuticals. It is therefore necessary to present clearer picture of the field and highlight the factors influencing particle design and scale-up. Areas covered: The review presents a systematic analysis of the trends in development of particle delivery systems using spray drying. This is followed by exploring the mechanisms governing particle formation in the process stages. Particle design factors including those of equipment configurations and feed/process attributes were highlighted. Finally, the review summarises the current industrial approaches for upscaling pharmaceutical spray drying. Expert opinion: Spray drying provides the ability to design particles of the desired functionality. This greatly benefits the pharmaceutical sector especially as product specifications are becoming more encompassing and exacting. One of the biggest barriers to product translation remains one of scale-up/scale-down. A shift from trial and error approaches to model-based particle design helps to enhance control over product properties. To this end, process innovations and advanced manufacturing technologies are particularly welcomed.

  15. Design and evaluation of an innovative floating and bioadhesive multiparticulate drug delivery system based on hollow structure.

    PubMed

    Zhang, Chungang; Tang, Jingya; Liu, Dechun; Li, Xuetao; Cheng, Lan; Tang, Xing

    2016-04-30

    In this study a gastric-retentive delivery system was prepared by a novel method which is reported here for the first time. An innovative floating and bioadhesive drug delivery system with a hollow structure was designed and prepared. The floating and bioadhesive drug delivery system was composed of a hollow spherical shell, a waterproof layer (Stearic acid), a drug layer (Ofloxacin), a release retarding film (the novel blended coating materials) and a bioadhesive layer (Carbomer 934P) prepared by using a liquid multi-layering process. A novel blended coating material was designed and investigated to solve the problem of the initial burst release of the formulation and the release mechanism of the novel material was analyzed in this study. The optimized formulation provided the sustained release characteristic and was able to float for 24h. The SEM cross-section images showed that the particulates were hollow with a spherical shell. X-ray images and pharmacokinetic studies (Frel = 124.1 ± 28.9%) in vivo showed that the gastric-retentive delivery system can be retained in the stomach for more than 6h. The floating and bioadhesive particulate drug delivery system based on a hollow structure with a dual function presented here is a viable alternative to other for gastroretentive drug delivery system. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Design of a platform technology for systemic delivery of siRNA to tumours using rolling circle transcription

    NASA Astrophysics Data System (ADS)

    Jang, Mihue; Kim, Jong Hwan; Nam, Hae Yun; Kwon, Ick Chan; Ahn, Hyung Jun

    2015-08-01

    For therapeutic applications of siRNA, there are technical challenges with respect to targeted and systemic delivery. We here report a new siRNA carrier, RNAtr NPs, in a way that multiple tandem copies of RNA hairpins as a result of rolling circle transcription (RCT) can be readily adapted in tumour-targeted and systemic siRNA delivery. RNAtr NPs provide a means of condensing large amounts of multimeric RNA transcripts into the compact nanoparticles, especially without the aid of polycationic agents, and thus reduce the risk of immunogenicity and cytotoxicity by avoiding the use of synthetic polycationic reagents. This strategy allows the design of a platform technology for systemic delivery of siRNA to tumour sites, because RCT reaction, which enzymatically generates RNA polymers in multiple copy numbers at low cost, can lead to directly accessible routes to targeted and systemic delivery. Therefore, RNAtr NPs suggest great potentials as the siRNA therapeutics for cancer treatment.

  17. Design and optimization of self-nanoemulsifying drug delivery systems (SNEDDS) for enhanced dissolution of gemfibrozil.

    PubMed

    Villar, Ana Maria Sierra; Naveros, Beatriz Clares; Campmany, Ana Cristina Calpena; Trenchs, Monserrat Aróztegui; Rocabert, Coloma Barbé; Bellowa, Lyda Halbaut

    2012-07-15

    Self-nanoemulsifying drug delivery systems of gemfibrozil were developed under Quality by Design approach for improvement of dissolution and oral absorption. Preliminary screening was performed to select proper components combination. Box-Behnken experimental design was employed as statistical tool to optimize the formulation variables, X(1) (Cremophor(®) EL), X(2) (Capmul(®) MCM-C8), and X(3) (lemon essential oil). Systems were assessed for visual characteristics (emulsification efficacy), turbidity, droplet size, polydispersity index and drug release. Different pH media were also assayed for optimization. Following optimization, the values of formulation components (X(1), X(2), and X(3)) were 32.43%, 29.73% and 21.62%, respectively (16.22% of gemfibrozil). Transmission electron microscopy demonstrated spherical droplet morphology. SNEEDS release study was compared to commercial tablets. Optimized SNEDDS formulation of gemfibrozil showed a significant increase in dissolution rate compared to conventional tablets. Both formulations followed Weibull mathematical model release with a significant difference in t(d) parameter in favor of the SNEDDS. Equally amodelistic parameters were calculated being the dissolution efficiency significantly higher for SNEDDS, confirming that the developed SNEDDS formulation was superior to commercial formulation with respect to in vitro dissolution profile. This paper provides an overview of the SNEDDS of the gemfibrozil as a promising alternative to improve oral absorption.

  18. 20 CFR 662.430 - Under what conditions may One-Stop operators designated to operate in a One-Stop delivery system...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... designated to operate in a One-Stop delivery system established prior to the enactment of WIA be designated... DESCRIPTION OF THE ONE-STOP SYSTEM UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT One-Stop Operators § 662.430 Under what conditions may One-Stop operators designated to operate in a One-Stop delivery system...

  19. 20 CFR 662.430 - Under what conditions may One-Stop operators designated to operate in a One-Stop delivery system...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... designated to operate in a One-Stop delivery system established prior to the enactment of WIA be designated... DESCRIPTION OF THE ONE-STOP SYSTEM UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT One-Stop Operators § 662.430 Under what conditions may One-Stop operators designated to operate in a One-Stop delivery system...

  20. Design and construction of a DNA origami drug delivery system based on MPT64 antibody aptamer for tuberculosis treatment

    PubMed Central

    Ranjbar, Reza; Hafezi-Moghadam, Mohammad Sadegh

    2016-01-01

    Introduction With all of the developments on infectious diseases, tuberculosis (TB) remains a cause of death among people. One of the most promising assembly techniques in nano-technology is “scaffolded DNA origami” to design and construct a nano-scale drug delivery system. Because of the global health problems of tuberculosis, the development of potent new anti-tuberculosis drug delivery system without cross-resistance with known anti-mycobacterial agents is urgently needed. The aim of this study was to design a nano-scale drug delivery system for TB treatment using the DNA origami method Methods In this study, we presented an experimental research on a DNA drug delivery system for treating Tuberculosis. TEM images were visualized with an FEI Tecnai T12 BioTWIN at 120 kV. The model was designed by caDNAno software and computational prediction of the 3D solution shape and its flexibility was calculated with a CanDo server. Results Synthesizing the product was imaged using transmission electron microscopy after negative-staining by uranyl formate. Conclusion We constructed a multilayer 3D DNA nanostructure system by designing square lattice geometry with the scaffolded-DNA-origami method. With changes in the lock and key sequences, we recommend that this system be used for other infectious diseases to target the pathogenic bacteria. PMID:27053991

  1. Design challenges in nanoparticle-based platforms: Implications for targeted drug delivery systems

    NASA Astrophysics Data System (ADS)

    Mullen, Douglas Gurnett

    Characterization and control of heterogeneous distributions of nanoparticle-ligand components are major design challenges for nanoparticle-based platforms. This dissertation begins with an examination of poly(amidoamine) (PAMAM) dendrimer-based targeted delivery platform. A folic acid targeted modular platform was developed to target human epithelial cancer cells. Although active targeting was observed in vitro, active targeting was not found in vivo using a mouse tumor model. A major flaw of this platform design was that it did not provide for characterization or control of the component distribution. Motivated by the problems experienced with the modular design, the actual composition of nanoparticle-ligand distributions were examined using a model dendrimer-ligand system. High Pressure Liquid Chromatography (HPLC) resolved the distribution of components in samples with mean ligand/dendrimer ratios ranging from 0.4 to 13. A peak fitting analysis enabled the quantification of the component distribution. Quantified distributions were found to be significantly more heterogeneous than commonly expected and standard analytical parameters, namely the mean ligand/nanoparticle ratio, failed to adequately represent the component heterogeneity. The distribution of components was also found to be sensitive to particle modifications that preceded the ligand conjugation. With the knowledge gained from this detailed distribution analysis, a new platform design was developed to provide a system with dramatically improved control over the number of components and with improved batch reproducibility. Using semi-preparative HPLC, individual dendrimer-ligand components were isolated. The isolated dendrimer with precise numbers of ligands were characterized by NMR and analytical HPLC. In total, nine different dendrimer-ligand components were obtained with degrees of purity ≥80%. This system has the potential to serve as a platform to which a precise number of functional molecules

  2. Systems and Components Fuel Delivery System, Water Delivery System, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Systems and Components - Fuel Delivery System, Water Delivery System, Derrick Crane System, and Crane System Details - Marshall Space Flight Center, F-1 Engine Static Test Stand, On Route 565 between Huntsville and Decatur, Huntsville, Madison County, AL

  3. Mucoadhesive drug delivery systems

    PubMed Central

    Shaikh, Rahamatullah; Raj Singh, Thakur Raghu; Garland, Martin James; Woolfson, A David; Donnelly, Ryan F.

    2011-01-01

    Mucoadhesion is commonly defined as the adhesion between two materials, at least one of which is a mucosal surface. Over the past few decades, mucosal drug delivery has received a great deal of attention. Mucoadhesive dosage forms may be designed to enable prolonged retention at the site of application, providing a controlled rate of drug release for improved therapeutic outcome. Application of dosage forms to mucosal surfaces may be of benefit to drug molecules not amenable to the oral route, such as those that undergo acid degradation or extensive first-pass metabolism. The mucoadhesive ability of a dosage form is dependent upon a variety of factors, including the nature of the mucosal tissue and the physicochemical properties of the polymeric formulation. This review article aims to provide an overview of the various aspects of mucoadhesion, mucoadhesive materials, factors affecting mucoadhesion, evaluating methods, and finally various mucoadhesive drug delivery systems (buccal, nasal, ocular, gastro, vaginal, and rectal). PMID:21430958

  4. Drug delivery system design and development for boron neutron capture therapy on cancer treatment.

    PubMed

    Sherlock Huang, Lin-Chiang; Hsieh, Wen-Yuan; Chen, Jiun-Yu; Huang, Su-Chin; Chen, Jen-Kun; Hsu, Ming-Hua

    2014-06-01

    We have already synthesized a boron-containing polymeric micellar drug delivery system for boron neutron capture therapy (BNCT). The synthesized diblock copolymer, boron-terminated copolymers (Bpin-PLA-PEOz), consisted of biodegradable poly(D,l-lactide) (PLA) block and water-soluble polyelectrolyte poly(2-ethyl-2-oxazoline) (PEOz) block, and a cap of pinacol boronate ester (Bpin). In this study, we have demonstrated that synthesized Bpin-PLA-PEOz micelle has great potential to be boron drug delivery system with preliminary evaluation of biocompatibility and boron content.

  5. Modeling hospital surgical delivery process design using system simulation: optimizing patient flow and bed capacity as an illustration.

    PubMed

    Kumar, Sameer

    2011-01-01

    It is increasingly recognized that hospital operation is an intricate system with limited resources and many interacting sources of both positive and negative feedback. The purpose of this study is to design a surgical delivery process in a county hospital in the U.S where patient flow through a surgical ward is optimized. The system simulation modeling is used to address questions of capacity planning, throughput management and interacting resources which constitute the constantly changing complexity that characterizes designing a contemporary surgical delivery process in a hospital. The steps in building a system simulation model is demonstrated using an example of building a county hospital in a small city in the US. It is used to illustrate a modular system simulation modeling of patient surgery process flows. The system simulation model development will enable planners and designers how they can build in overall efficiencies in a healthcare facility through optimal bed capacity for peak patient flow of emergency and routine patients.

  6. Capsaicin-loaded vesicular systems designed for enhancing localized delivery for psoriasis therapy.

    PubMed

    Gupta, Ruchi; Gupta, Madhu; Mangal, Sharad; Agrawal, Udita; Vyas, Suresh Prasad

    2016-05-01

    The aim of the current investigation is to evaluate the potential of capsaicin (CAP)-containing liposomes, niosomes and emulsomes in providing localized and controlled delivery, to improve the topical delivery of drug. CAP-bearing systems were prepared by the film hydration method and compared through various in vitro and in vivo parameters. The TEM photographs suggested that the carrier systems were spherical in shape and nanometric in size range. Skin retention studies of CAP from in vitro and in vivo experiments revealed significantly higher accumulation of drug in the case of the emul-gel formulation. Based on the results, we concluded that the emul-gel may be a potential approach for the topical delivery of CAP, for an effective therapy for psoriasis.

  7. Intracochlear Drug Delivery Systems

    PubMed Central

    Borenstein, Jeffrey T.

    2011-01-01

    Introduction Advances in molecular biology and in the basic understanding of the mechanisms associated with sensorineural hearing loss and other diseases of the inner ear, are paving the way towards new approaches for treatments for millions of patients. However, the cochlea is a particularly challenging target for drug therapy, and new technologies will be required to provide safe and efficacious delivery of these compounds. Emerging delivery systems based on microfluidic technologies are showing promise as a means for direct intracochlear delivery. Ultimately, these systems may serve as a means for extended delivery of regenerative compounds to restore hearing in patients suffering from a host of auditory diseases. Areas covered in this review Recent progress in the development of drug delivery systems capable of direct intracochlear delivery is reviewed, including passive systems such as osmotic pumps, active microfluidic devices, and systems combined with currently available devices such as cochlear implants. The aim of this article is to provide a concise review of intracochlear drug delivery systems currently under development, and ultimately capable of being combined with emerging therapeutic compounds for the treatment of inner ear diseases. Expert Opinion Safe and efficacious treatment of auditory diseases will require the development of microscale delivery devices, capable of extended operation and direct application to the inner ear. These advances will require miniaturization and integration of multiple functions, including drug storage, delivery, power management and sensing, ultimately enabling closed-loop control and timed-sequence delivery devices for treatment of these diseases. PMID:21615213

  8. Polymers for Drug Delivery Systems

    PubMed Central

    Liechty, William B.; Kryscio, David R.; Slaughter, Brandon V.; Peppas, Nicholas A.

    2012-01-01

    Polymers have played an integral role in the advancement of drug delivery technology by providing controlled release of therapeutic agents in constant doses over long periods, cyclic dosage, and tunable release of both hydrophilic and hydrophobic drugs. From early beginnings using off-the-shelf materials, the field has grown tremendously, driven in part by the innovations of chemical engineers. Modern advances in drug delivery are now predicated upon the rational design of polymers tailored for specific cargo and engineered to exert distinct biological functions. In this review, we highlight the fundamental drug delivery systems and their mathematical foundations and discuss the physiological barriers to drug delivery. We review the origins and applications of stimuli-responsive polymer systems and polymer therapeutics such as polymer-protein and polymer-drug conjugates. The latest developments in polymers capable of molecular recognition or directing intracellular delivery are surveyed to illustrate areas of research advancing the frontiers of drug delivery. PMID:22432577

  9. Design of a novel curcumin-soybean phosphatidylcholine complex-based targeted drug delivery systems.

    PubMed

    Xie, Jiajiang; Li, Yanxiu; Song, Liang; Pan, Zhou; Ye, Shefang; Hou, Zhenqing

    2017-11-01

    Recently, the global trend in the field of nanomedicine has been toward the design of combination of nature active constituents and phospholipid (PC) to form a therapeutic drug-phospholipid complex. As a particular amphiphilic molecular complex, it can be a unique bridge of traditional dosage-form and novel drug delivery system. In thisarticle, on the basis of drug-phospholipid complex technique and self-assembly technique, we chose a pharmacologically safe and low toxic drug curcumin (CUR) to increase drug-loading ability, achieve controlled/sustained drug release and improve anticancer activity. A novel CUR-soybean phosphatidylcholine (SPC) complex and CUR-SPC complex self-assembled nanoparticles (CUR-SPC NPs) were prepared by a co-solvent method and a nanoprecipitation method. DSPE-PEG-FA was further functionalized on the surface of PEG-CUR-SPC NPs (designed as FA-PEG-CUR-SPC NPs) to specifically increase cellular uptake and targetability. The FA-PEG-CUR-SPC NPs showed a spherical shape, a mean diameter of about 180 nm, an excellent physiological stability and pH-triggered drug release. The drug entrapment efficiency and drug-loading content was up to 92.5 and 16.3%, respectively. In vitro cellular uptake and cytotoxicity studies demonstrated that FA-PEG-CUR-SPC NPs and CUR-SPC NPs presented significantly stronger cellular uptake efficacy and anticancer activity against HeLa cells and Caco-2 cells compared to free CUR, CUR-SPC NPs and PEG-CUR-SPC NPs. More importantly, FA-PEG-CUR-SPC NPs showed the prolonged systemic circulation lifetime and enhanced tumor accumulation compared with free CUR and PEG-CUR-SPC NPs. These results suggest that the FA targeted PEGylated CUR-SPC complex self-assembled NPs might be a promising candidate in cancer therapy.

  10. An Information Push-Delivery System Design for Personal Information Service on the Internet.

    ERIC Educational Resources Information Center

    Chen, Chen-Tung; Tai, Wei-Shen

    2003-01-01

    Discussion of information overload from the Internet focuses on an information push-delivery system, which applies fuzzy information retrieval and fuzzy similarity measurement to avoid the information overload problem. Describes an empirical investigation conducted with students at Da-Yeh University (Taiwan) that investigated satisfaction with a…

  11. An Information Push-Delivery System Design for Personal Information Service on the Internet.

    ERIC Educational Resources Information Center

    Chen, Chen-Tung; Tai, Wei-Shen

    2003-01-01

    Discussion of information overload from the Internet focuses on an information push-delivery system, which applies fuzzy information retrieval and fuzzy similarity measurement to avoid the information overload problem. Describes an empirical investigation conducted with students at Da-Yeh University (Taiwan) that investigated satisfaction with a…

  12. Role of particle size, shape, and stiffness in design of intravascular drug delivery systems: insights from computations, experiments, and nature.

    PubMed

    Sen Gupta, Anirban

    2016-01-01

    Packaging of drug molecules within microparticles and nanoparticles has become an important strategy in intravascular drug delivery, where the particles are designed to protect the drugs from plasma effects, increase drug residence time in circulation, and often facilitate drug delivery specifically at disease sites. To this end, over the past few decades, interdisciplinary research has focused on developing biocompatible materials for particle fabrication, technologies for particle manufacture, drug formulation within the particles for efficient loading, and controlled release and refinement of particle surface chemistries to render selectivity toward disease site for site-selective action. Majority of the particle systems developed for such purposes are spherical nano and microparticles and they have had low-to-moderate success in clinical translation. To refine the design of delivery systems for enhanced performance, in recent years, researchers have started focusing on the physicomechanical aspects of carrier particles, especially their shape, size, and stiffness, as new design parameters. Recent computational modeling studies, as well as, experimental studies using microfluidic devices are indicating that these design parameters greatly influence the particles' behavior in hemodynamic circulation, as well as cell-particle interactions for targeted payload delivery. Certain cellular components of circulation are also providing interesting natural cues for refining the design of drug carrier systems. Based on such findings, new benefits and challenges are being realized for the next generation of drug carriers. The current article will provide a comprehensive review of these findings and discuss the emerging design paradigm of incorporating physicomechanical components in fabrication of particulate drug delivery systems.

  13. Design and optimization of self-nanoemulsifying drug delivery systems for improved bioavailability of cyclovirobuxine D

    PubMed Central

    Ke, Zhongcheng; Hou, Xuefeng; Jia, Xiao-bin

    2016-01-01

    Background The main purpose of this research was to design a self-nanoemulsifying drug delivery system (SNEDDS) for improving the bioavailability of cyclovirobuxine D as a poorly water-soluble drug. Materials and methods Solubility trials, emulsifying studies, and pseudo-ternary phase diagrams were used to screen the SNEDDS formulations. The optimized drug-loaded SNEDDS was prepared at a mass ratio of 3:24:38:38 for cyclovirobuxine D, oleic acid, Solutol SH15, and propylene glycol, respectively. The optimized formulation was characterized in terms of physicochemical and pharmacokinetic parameters compared with marketed cyclovirobuxine D tablets. Results The optimized cyclovirobuxine-D-loaded SNEDDS was spontaneously dispersed to form a nanoemulsion with a globule size of 64.80±3.58 nm, which exhibited significant improvement of drug solubility, rapid absorption rate, and enhanced area under the curve, together with increased permeation and decreased efflux. Fortunately, there was a nonsignificant cytotoxic effect toward Caco-2 cells. The relative bioavailability of SNEDDS was 200.22% in comparison with market tablets, in rabbits. Conclusion SNEDDS could be a potential candidate for an oral dosage form of cyclovirobuxine D with improved bioavailability. PMID:27418807

  14. Emerging hydrogel designs for controlled protein delivery.

    PubMed

    Bae, Ki Hyun; Kurisawa, Motoichi

    2016-08-19

    Hydrogels have evolved into indispensable biomaterials in the fields of drug delivery and regenerative medicine. This minireview aims to highlight the recent advances in the hydrogel design for controlled release of bioactive proteins. The latest developments of enzyme-responsive and externally regulated drug delivery systems are summarized. The design strategies and applications of phase-separated hydrogel systems are also described. We expect that these emerging approaches will enable expanded use of hydrogels in biomedicine and healthcare.

  15. Optical fiber diffusive tip designs for medical laser-lightguide delivery systems

    NASA Astrophysics Data System (ADS)

    Spigulis, Janis; Pfafrods, Daumants; Stafeckis, Maris

    1994-12-01

    Medical laser radiation delivery instruments with diffusive tips on the distal ends of plastic-clad silica optical fibers have been designed, tested, and manufactured. The instruments are optimized for endoscopic, therapeutic, dermatologic and surgical laser treatment. The diffusive tips provide radial, cylindrical and aside-conical spatial distributions of the output radiation. Optical schemes concerning each type of the tip and the corresponding spatial distribution functions of the output radiation are presented and analyzed. Designs of the lightguide instruments for surgical and dermatological procedures demanding local high-power laser irradiation are also discussed.

  16. Pathogen-mimicking vaccine delivery system designed with a bioactive polymer (inulin acetate) for robust humoral and cellular immune responses.

    PubMed

    Kumar, Sunny; Kesharwani, Siddharth S; Kuppast, Bhimanna; Bakkari, Mohammed Ali; Tummala, Hemachand

    2017-09-10

    New and improved vaccines are needed against challenging diseases such as malaria, tuberculosis, Ebola, influenza, AIDS, and cancer. The majority of existing vaccine adjuvants lack the ability to significantly stimulate the cellular immune response, which is required to prevent the aforementioned diseases. This study designed a novel particulate based pathogen-mimicking vaccine delivery system (PMVDS) to target antigen-presenting-cells (APCs) such as dendritic cells. The uniqueness of PMVDS is that the polymer used to prepare the delivery system, Inulin Acetate (InAc), activates the innate immune system. InAc was synthesized from the plant polysaccharide, inulin. PMVDS provided improved and persistent antigen delivery to APCs as an efficient vaccine delivery system, and simultaneously, activated Toll-Like Receptor-4 (TLR-4) on APCs to release chemokine's/cytokines as an immune-adjuvant. Through this dual mechanism, PMVDS robustly stimulated both the humoral (>32 times of IgG1 levels vs alum) and the cell-mediated immune responses against the encapsulated antigen (ovalbumin) in mice. More importantly, PMVDS stimulated both cytotoxic T cells and natural killer cells of cell-mediated immunity to provide tumor (B16-ova-Melanoma) protection in around 40% of vaccinated mice and significantly delayed tumor progression in rest of the mice. PMVDS is a unique bio-active vaccine delivery technology with broader applications for vaccines against cancer and several intracellular pathogens, where both humoral and cellular immune responses are desired. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Novel antigen delivery systems

    PubMed Central

    Trovato, Maria; Berardinis, Piergiuseppe De

    2015-01-01

    Vaccines represent the most relevant contribution of immunology to human health. However, despite the remarkable success achieved in the past years, many vaccines are still missing in order to fight important human pathologies and to prevent emerging and re-emerging diseases. For these pathogens the known strategies for making vaccines have been unsuccessful and thus, new avenues should be investigated to overcome the failure of clinical trials and other important issues including safety concerns related to live vaccines or viral vectors, the weak immunogenicity of subunit vaccines and side effects associated with the use of adjuvants. A major hurdle of developing successful and effective vaccines is to design antigen delivery systems in such a way that optimizes antigen presentation and induces broad protective immune responses. Recent advances in vector delivery technologies, immunology, vaccinology and system biology, have led to a deeper understanding of the molecular and cellular mechanisms by which vaccines should stimulate both arms of the adaptive immune responses, offering new strategies of vaccinations. This review is an update of current strategies with respect to live attenuated and inactivated vaccines, DNA vaccines, viral vectors, lipid-based carrier systems such as liposomes and virosomes as well as polymeric nanoparticle vaccines and virus-like particles. In addition, this article will describe our work on a versatile and immunogenic delivery system which we have studied in the past decade and which is derived from a non-pathogenic prokaryotic organism: the “E2 scaffold” of the pyruvate dehydrogenase complex from Geobacillus stearothermophilus. PMID:26279977

  18. Recent Advances on Cellulose-Based Nano-Drug Delivery Systems: Design of Prodrugs and Nanoparticles.

    PubMed

    Dai, Lin; Si, Chuanling

    2017-07-11

    Cellulose being the first abundant biopolymers in nature is playing an increasing role as a carrier material in the biomedicine field. Compared with other materials, cellulose has its own advantages, including rich in resources, good thermal and chemical stability, high hydrophilicity, and excellent biocompatibility, etc. These fascinating properties have made cellulose a real potential material to create nano-drug delivery systems. However, the structure of pure cellulose caused some inherent shortcomings, for instance, bad plasticity and dimensional stability, poor solubility in ordinary solvents, and lack of antibacterial activity. Therefore, it is indispensable to modify the morphology and microstructure of cellulose. This review presents some remarkable recent advances on the drug delivery applications of cellulose-based prodrugs and nanoparticles. Various methods employed for the functionalization, pharmacodynamic actions and applications are covered. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  19. Design and synthesis of novel polyglycerol hybrid nanomaterials for potential applications in drug delivery systems.

    PubMed

    Zarrabi, Ali; Adeli, Mohsen; Vossoughi, Manouchehr; Shokrgozar, Mohammad Ali

    2011-03-10

    The synthesis of a new drug delivery system based on hybrid nanomaterials containing a β-CD core and hyperbranched PG is described. Conjugating PG branches onto β-CD not only increases its water solubility but also affects its host/guest properties deeply. It can form molecular inclusion complexes with small hydrophobic guest molecules such as ferrocene or FITC with reasonable release. In addition, the achievable payloads are significantly higher as for carriers such as hyperbranched PGs. Short-term in vitro cytotoxicity and hemocompatibility tests on L929 cell lines show that the hybrid nanomaterial is highly biocompatible. Due to their outstanding properties, β-CD-g-PG hybrid nanomaterials are introduced as promising materials for nanomedicine, e.g., for drug delivery issues.

  20. Design and evaluation of oral nanoemulsion drug delivery system of mebudipine.

    PubMed

    Khani, Samira; Keyhanfar, Fariborz; Amani, Amir

    2016-07-01

    A nanoemulsion drug delivery system was developed to increase the oral bioavailability of mebudipine as a calcium channel blocker with very low bioavailability profile. The impact of nano-formulation on the pharmacokinetic parameters of mebudipine in rats was investigated. Nanoemulsion formulations containing ethyl oleate, Tween 80, Span 80, polyethylene glycol 400, ethanol and deionized water were prepared using probe sonicator. The optimum formulation was evaluated for physicochemical properties, such as particle size, morphology and stability. The particle size of optimum formulation was 22.8 ± 4.0 nm. Based on the results of this study, the relative bioavailability of mebudipine nanoemulsion was enhanced by about 2.6-, 2.0- and 1.9-fold, respectively, compared with suspension, ethyl oleate solution and micellar solution. In conclusion, nanoemulsion is an interesting option for the delivery of poorly water soluble molecules, such as mebudipine.

  1. Building Student and Family-Centered Care Coordination Through Ongoing Delivery System Design.

    PubMed

    Baker, Dian; Anderson, Lori; Johnson, Jody

    2017-01-01

    In 2016 the National Association of School Nurses released an updated framework for school nurse practice. One highlight of the new framework is 21st century care coordination. That is, moving beyond basic case management to a systems-level approach for delivery of school health services. The framework broadly applies the term care coordination to include direct care and communication across systems. School nurses are often engaged in efforts to create school health care homes that serve as an axis of coordination for students and families between primary care offices and the schools. Effective care coordination requires that the school nurses not only know the principles of traditional case management but also understand complex systems that drive effective care coordination. The outcome of a system-level approach is enhanced access to services in an integrated health care delivery system that includes the school nurse as an integral member of the school's health care team. This article presents a comprehensive, system-level model of care coordination for school nurse leadership and practice.

  2. The Marine Corps Enlisted Personnel Information Delivery System (MC-EPIDS): Prototype design

    SciTech Connect

    Truett, L.F.; Bowman, C.S.; Rascoll, R.P.; Flanagan, D.M.

    1989-03-01

    The Marine Corps Enlisted Personnel Information Delivery System (MC-EPIDS) provides Marine Corps manpower analysts with computer-based tools for retrieving, displaying, and analyzing historical enlisted manpower statistics. This report describes the prototype version of MC-EPIDS. The prototype is implemented using the Statistical Analysis System (SAS) language. Data are stored in SAS datasets; procedural programming is in Base SAS; menu generation is supported by SAS/AF; and graphic displays are produced by SAS/GRAPH. The development of MC-EPIDS required extensive research to overcome restraints caused by hardware, telecommunications, and SAS language limitations. 7 figs.

  3. Conceptual design of a closed loop nutrient solution delivery system for CELSS implementation in a micro-gravity environment

    NASA Technical Reports Server (NTRS)

    Schwartzkopf, Steven H.; Oleson, Mel W.; Cullingford, Hatice S.

    1990-01-01

    Described here are the results of a study to develop a conceptual design for an experimental closed loop fluid handling system capable of monitoring, controlling, and supplying nutrient solution to higher plants. The Plant Feeder Experiment (PFE) is designed to be flight tested in a microgravity environment. When flown, the PFX will provide information on both the generic problems of microgravity fluid handling and the specific problems associated with the delivery of the nutrient solution in a microgravity environment. The experimental hardware is designed to fit into two middeck lockers on the Space Shuttle, and incorporates several components that have previously been flight tested.

  4. Design of a light delivery system for the photodynamic treatment of the Crohn's disease

    NASA Astrophysics Data System (ADS)

    Gabrecht, Tanja; Borle, Francois; van den Bergh, Hubert; Michetti, Pierre; Ortner, Maria-Anna; Wagnières, Georges

    2007-07-01

    Crohn's disease is an inflammatory bowel disease originating from an overwhelming response of the mucosal immune system. Low dose photodynamic therapy (PDT) may modify the mucosal immune response and thus serve as a therapy for Crohn's disease. Most patients with Crohn's disease show inflammatory reactions in the terminal ileum or colon where PDT treatment is feasible by low-invasive endoscopic techniques. However, the tube like geometry of the colon, it's folding, and the presences of multiple foci of Crohn's lesions along the colon require the development of adequate light delivery techniques. We present a prototype light delivery system for endoscopic clinical PDT in patients with Crohn's disease. The system is based on a cylindrical light diffuser inserted into a diffusing balloon catheter. Homogenous irradiation is performed with a 4 W diode laser at 635 nm. Light dosimetry is performed using a calibrated integrating sphere. The system can be used with conventional colonoscopes and colonovideoscopes having a 3.8 mm diameter working channel. The feasibility of PDT in colon with our prototype was demonstrated in first clinical trials.

  5. Design of a multifiber light delivery system for photoacoustic-guided surgery

    NASA Astrophysics Data System (ADS)

    Eddins, Blackberrie; Bell, Muyinatu A. Lediju

    2017-04-01

    This work explores light delivery optimization for photoacoustic-guided minimally invasive surgeries, such as the endonasal transsphenoidal approach. Monte Carlo simulations were employed to study three-dimensional light propagation in tissue, comprising one or two 4-mm diameter arteries located 3 mm below bone, an absorbing metallic drill contacting the bone surface, and a single light source placed next to the 2.4-mm diameter drill shaft with a 2.9-mm diameter spherical drill tip. The optimal fiber distance from the drill shaft was determined from the maximum normalized fluence to the underlying artery. Using this optimal fiber-to-drill shaft distance, Zemax simulations were employed to propagate Gaussian beams through one or more 600 micron-core diameter optical fibers for detection on the bone surface. When the number of equally spaced fibers surrounding the drill increased, a single merged optical profile formed with seven or more fibers, determined by thresholding the resulting light profile images at 1/e times the maximum intensity. We used these simulations to inform design requirements, build a one to seven multifiber light delivery prototype to surround a surgical drill, and demonstrate its ability to simultaneously visualize the tool tip and blood vessel targets in the absence and presence of bone. The results and methodology are generalizable to multiple interventional photoacoustic applications.

  6. Design, fabrication, testing, and delivery of a solar energy collector system for residential heating and cooling

    NASA Technical Reports Server (NTRS)

    Holland, T. H.; Borzoni, J. T.

    1976-01-01

    A low cost flat plate solar energy collector was designed for the heating and cooling of residential buildings. The system meets specified performance requirements, at the desired system operating levels, for a useful life of 15 to 20 years, at minimum cost and uses state-of-the-art materials and technology. The rationale for the design method was based on identifying possible material candidates for various collector components and then selecting the components which best meet the solar collector design requirements. The criteria used to eliminate certain materials were: performance and durability test results, cost analysis, and prior solar collector fabrication experience.

  7. The design and performance of a portable handheld (11)CO2 delivery system.

    PubMed

    Kim, Dohyun; Alexoff, David L; Schueller, Mike; Babst, Ben; Ferrieri, Richard; Fowler, Joanna S; Schlyer, David J

    2014-12-01

    We constructed a hand-held device to efficiently trap [(11)C]CO2 from the cyclotron target, safely transport up to 3.7GBq (100mCi) doses to remote sites and release it without the need for a liquid cryogen. The system consists of a 180W furnace and a miniature molecular sieve trap (80-100mg; 80-100mesh 13×) placed inside a lead pig weighing 11.1kg. The overall [(11)C]CO2 delivery efficiency of the device is ~82% (> 99% trapping efficiency). Radiation dose rates measured at 30cm from the surface of the pig are <43.5µSv/h (5mR/h) up to 2.59GBq (70mCi).

  8. Design and characterization of calcium alginate microparticles coated with polycations as protein delivery system.

    PubMed

    Zarate, J; Virdis, L; Orive, G; Igartua, M; Hernández, R M; Pedraz, J L

    2011-01-01

    Bovine serum albumin (BSA) loaded calcium alginate microparticles (MPs) produced in this study by a w/o emulsification and external gelation method exhibited spherical and fairly smooth and porous morphology with 1.052 ± 0.057 µm modal particle size. The high permeability of the calcium alginate hydrogel lead to a potent burst effect and too fast protein release. To overcome these problems, MPs were coated with polycations, such as chitosan, poly-L-lysine and DEAE-dextran. Our results demonstrated that coated MPs showed slower release and were able to significantly reduce the release of BSA in the first hour. Therefore, this method can be applied to prepare coated alginate MPs which could be an optimal system for the controlled release of biotherapeutic molecules. Nevertheless, further studies are needed to optimize delivery properties which could provide a sustained release of proteins.

  9. Design and Evaluation of Novel Solid Self-Nanodispersion Delivery System for Andrographolide.

    PubMed

    Xu, Junnan; Ma, Yueqin; Xie, Yuanbiao; Chen, Yingchong; Liu, Yang; Yue, Pengfei; Yang, Ming

    2016-09-12

    Poorly water-soluble drugs offer challenges in developing a formulation product with adequate bioavailability. This study took advantage of the features of nanocrystals and direct compression technologies to develop a novel solid self-nanodispersion delivery system for andrographolide (Andro) in order to increase its dissolution rate for enhancing bioavailability. Andro nanosuspensions (Andro-NS) with a particle size of about 500 nm were prepared by homogenization technology and further converted into dried nanocrystal particles (Andro-NP) via spray-drying. The solid self-nanodispersion delivery system (Andro-SNDS)-loaded Andro-NP was prepared via direct compression technology. The DSC and PXRD results demonstrated that the Andro nanocrystals retained its original crystallinity. The dissolution of the Andro-SNDS formulation was 85.87% in pure water over 30 min, better than those of the coarse Andro and physical mixture of Andro and stabilizer. And the C max (299.32 ± 78.54 ng/mL) and AUC0-∞ (4440.55 ± 764.13 mg/L · h) of the Andro-SNDS formulation were significantly higher (p < 0.05) than those of the crude Andro (77.52 ± 31.73 ng/mL and 1437.79 ± 354.25 mg/L · h). The AUC of the Andro-SNDS was 3.09 times as high as that of the crude Andro. This study illustrated a novel approach to combine the features of nanocrystals and composite particles used to improve oral bioavailability of poorly soluble drug.

  10. Custom fractional factorial designs to develop atorvastatin self-nanoemulsifying and nanosuspension delivery systems – enhancement of oral bioavailability

    PubMed Central

    Hashem, Fahima M; Al-Sawahli, Majid M; Nasr, Mohamed; Ahmed, Osama AA

    2015-01-01

    Poor water solubility of a drug is a major challenge in drug delivery research and a main cause for limited bioavailability and pharmacokinetic parameters. This work aims to utilize custom fractional factorial design to assess the development of self-nanoemulsifying drug delivery systems (SNEDDS) and solid nanosuspensions (NS) in order to enhance the oral delivery of atorvastatin (ATR). According to the design, 14 experimental runs of ATR SNEDDS were formulated utilizing the highly ATR solubilizing SNEDDS components: oleic acid, Tween 80, and propylene glycol. In addition, 12 runs of NS were formulated by the antisolvent precipitation–ultrasonication method. Optimized formulations of SNEDDS and solid NS, deduced from the design, were characterized. Optimized SNEDDS formula exhibited mean globule size of 73.5 nm, zeta potential magnitude of −24.1 mV, and 13.5 μs/cm of electrical conductivity. Optimized solid NS formula exhibited mean particle size of 260.3 nm, 7.4 mV of zeta potential, and 93.2% of yield percentage. Transmission electron microscopy showed SNEDDS droplets formula as discrete spheres. The solid NS morphology showed flaky nanoparticles with irregular shapes using scanning electron microscopy. The release behavior of the optimized SNEDDS formula showed 56.78% of cumulative ATR release after 10 minutes. Solid NS formula showed lower rate of release in the first 30 minutes. Bioavailability estimation in Wistar albino rats revealed an augmentation in ATR bioavailability, relative to ATR suspension and the commercial tablets, from optimized ATR SNEDDS and NS formulations by 193.81% and 155.31%, respectively. The findings of this work showed that the optimized nanocarriers enhance the oral delivery and pharmacokinetic profile of ATR. PMID:26150693

  11. Design, fabrication and delivery of a miniature Cassegrainian concentrator solar array system

    NASA Technical Reports Server (NTRS)

    Kruer, Mark A.

    1987-01-01

    The optical design of the miniature Cassegrainian concentrator (MCC) element was improved for both offpoint and onpoint power capability. The cell stack design has shown no losses under the high short term thermal stresses imposed by component level test and is projected to be capable of greater than five years thermal cycle life in low Earth orbit. The structural design met all requirements for stiffness and flatness and requires adjustable inserts for fine tuning of the GFRP structure to meet flatness goals. The completed, fully populated small and large MCC panels deliverable under this contract perform electrically as expected. A solid acceptance inspection program to guarantee quality of all purchased parts, and continued manufacturing process improvements will make the MCC design a viable low cost alternative to standard flat panel technology. Minor improvements to the cell stack design of the MCC element can make significant improvements in both the performance and manufacturability of the MCC system.

  12. Design, fabrication and delivery of a miniature Cassegrainian concentrator solar array system. Final technical report

    SciTech Connect

    Kruer, M.A.

    1987-10-01

    The optical design of the miniature Cassegrainian concentrator (MCC) element was improved for both offpoint and onpoint power capability. The cell stack design has shown no losses under the high short term thermal stresses imposed by component level test and is projected to be capable of greater than five years thermal cycle life in low Earth orbit. The structural design met all requirements for stiffness and flatness and requires adjustable inserts for fine tuning of the GFRP structure to meet flatness goals. The completed, fully populated small and large MCC panels deliverable under this contract perform electrically as expected. A solid acceptance inspection program to guarantee quality of all purchased parts, and continued manufacturing process improvements will make the MCC design a viable low cost alternative to standard flat panel technology. Minor improvements to the cell stack design of the MCC element can make significant improvements in both the performance and manufacturability of the MCC system.

  13. Large amino acid transporter 1 (LAT1) prodrugs of valproic acid: new prodrug design ideas for central nervous system delivery.

    PubMed

    Peura, Lauri; Malmioja, Kalle; Laine, Krista; Leppänen, Jukka; Gynther, Mikko; Isotalo, Antti; Rautio, Jarkko

    2011-10-03

    Central nervous system (CNS) drug delivery is a major challenge in drug development because the blood-brain barrier (BBB) efficiently restricts the entry of drug molecules into the CNS at sufficient amounts. The brain uptake of poorly penetrating drugs could be improved by utilizing the transporters at the BBB with a prodrug approach. In this study, we designed four phenylalanine derivatives of valproic acid and studied their ability to utilize a large amino acid transporter 1 (LAT1) in CNS delivery with an aim to show that the meta-substituted phenylalanine prodrugs bind to LAT1 with a higher affinity compared with the affinity of the para-substituted derivatives. All of the prodrugs crossed the BBB carrier mediatedly via LAT1 in in situ rat brain perfusion. For the first time, we introduced a novel meta-substituted phenylalanine analogue promoiety which improved the LAT1 affinity 10-fold and more importantly the rat brain uptake of the prodrug 2-fold compared with those of the para-substituted derivatives. Therefore, we have characterized a new prodrug design idea for CNS drug delivery utilizing a transporter-mediated prodrug approach.

  14. Design and characterization of an ultrasonic lamb-wave power delivery system.

    PubMed

    Kural, Aleksander; Pullin, Rhys; Holford, Karen; Lees, Jonathan; Naylon, Jack; Paget, Christophe; Featherston, Carol

    2013-06-01

    In this paper, a novel design for an ultrasonic power transmission system designed for use in aircraft structural monitoring systems is described. The prototype system uses ultrasonic Lamb waves to carry energy along plates, such as those used in aircraft structures, and commercially available piezoelectric patch transducers as the transmitter and receiver. This sets it apart from other acoustic power transmission systems reported to date. The optimum configuration transmitted 12.7 mW of power across a distance of 54 cm in a 1.5-mm-thick aluminum plate, while being driven by a 20-Vpp, 35-kHz sinusoidal electric signal. This is in the same order of magnitude as the power required by the wireless sensors nodes of a structural health monitoring system currently being developed by Cardiff University and its partners. Thus, the power transmission system can be considered a viable component of the power source combination considered for the sensor nodes, which will also include vibration and thermal energy harvesting. The paper describes the design and optimization of the transmission and reception circuits with the use of inductive compensation. The use of laser vibrometry to characterize the transducers and to understand the signal propagation between them is also reported.

  15. Cognitive Models of Scientific Work and Their Implications for the Design of Knowledge Delivery Systems.

    ERIC Educational Resources Information Center

    Mavor, A. S.; And Others

    Part of a sustained program that has involved the design of personally tailored information systems responsive to the needs of scientists performing common research and teaching tasks, this project focuses on the procedural and content requirements for accomplishing need diagnosis and presents these requirements as specifications for an…

  16. Technological Delivery Systems.

    ERIC Educational Resources Information Center

    Kennedy, Don; And Others

    A section on technological delivery systems, presented as part of the second Australian National Workshop on Distance Education (Perth, 1983), contains four papers on using technological resources to provide educational services to persons in isolated locations. The first paper, by Don Kennedy, covers the use of satellite broadcasting of course…

  17. Educational Telecommunications Delivery Systems.

    ERIC Educational Resources Information Center

    Curtis, John A., Ed.; Biedenbach, Joseph M., Ed.

    This monograph is a single volume reference manual providing an overall review of the current status and likely near future application of six major educational telecommunications delivery technologies. The introduction provides an overview to the usage and potential for these systems in the context of the major educational issues involved. Each…

  18. Electronic Nicotine Delivery Systems.

    PubMed

    Walley, Susan C; Jenssen, Brian P

    2015-11-01

    Electronic nicotine delivery systems (ENDS) are rapidly growing in popularity among youth. ENDS are handheld devices that produce an aerosolized mixture from a solution typically containing concentrated nicotine, flavoring chemicals, and propylene glycol to be inhaled by the user. ENDS are marketed under a variety of names, most commonly electronic cigarettes and e-cigarettes. In 2014, more youth reported using ENDS than any other tobacco product. ENDS pose health risks to both users and nonusers. Nicotine, the major psychoactive ingredient in ENDS solutions, is both highly addictive and toxic. In addition to nicotine, other toxicants, carcinogens, and metal particles have been detected in solutions and aerosols of ENDS. Nonusers are involuntarily exposed to the emissions of these devices with secondhand and thirdhand aerosol. The concentrated and often flavored nicotine in ENDS solutions poses a poisoning risk for young children. Reports of acute nicotine toxicity from US poison control centers have been increasing, with at least 1 child death reported from unintentional exposure to a nicotine-containing ENDS solution. With flavors, design, and marketing that appeal to youth, ENDS threaten to renormalize and glamorize nicotine and tobacco product use. There is a critical need for ENDS regulation, legislative action, and counter promotion to protect youth. ENDS have the potential to addict a new generation of youth to nicotine and reverse more than 50 years of progress in tobacco control.

  19. Conceptual design of a closed loop nutrient solution delivery system for CELSS implementation in a micro-gravity environment

    NASA Technical Reports Server (NTRS)

    Schwartzkopf, Steven H.; Oleson, Mel W.; Cullingford, Hatice S.

    1989-01-01

    This paper describes the results of a study to develop a conceptual design for an experimental, closed-loop fluid handling system capable of monitoring, controlling, and supplying nutrient solution to higher plants. The Plant Feeder Experiment (PFX) is designed to be flight tested in a micro-gravity (micro-g) environment and was developed under NASA's In-Space Technology Experiments Program (INSTEP). When flown, PFX will provide information on both the generic problems of micro-g fluid handling and the specific problems associated with the delivery of nutrient solution in a micro-g environment. The experimental hardware is designed to fit into two middeck lockers on the Space Shuttle, and incorporates several components that have previously been flight tested.

  20. Conceptual design of a closed loop nutrient solution delivery system for CELSS implementation in a micro-gravity environment

    NASA Technical Reports Server (NTRS)

    Schwartzkopf, Steven H.; Oleson, Mel W.; Cullingford, Hatice S.

    1989-01-01

    This paper describes the results of a study to develop a conceptual design for an experimental, closed-loop fluid handling system capable of monitoring, controlling, and supplying nutrient solution to higher plants. The Plant Feeder Experiment (PFX) is designed to be flight tested in a micro-gravity (micro-g) environment and was developed under NASA's In-Space Technology Experiments Program (INSTEP). When flown, PFX will provide information on both the generic problems of micro-g fluid handling and the specific problems associated with the delivery of nutrient solution in a micro-g environment. The experimental hardware is designed to fit into two middeck lockers on the Space Shuttle, and incorporates several components that have previously been flight tested.

  1. Design, in vitro stability, and ocular hypotensive activity of t-butalone chemical delivery systems.

    PubMed

    Reddy, I K; Vaithiyalingam, S R; Khan, M A; Bodor, N S

    2001-08-01

    The objective of this work was to synthesize two bioreversible diacyl derivatives of t-butalone (chemical delivery systems), determine their chemical and in vitro stability, and investigate their potential use as topical antiglaucoma agents. The stability of these compounds was determined in isotonic phosphate buffers (pH range 5-8) and in selected biological media, including human whole blood, rabbit and rat blood, and the anterior segment tissues of rabbit. The ocular hypotensive activity of these compounds in unrestrained, normotensive albino rabbits was determined with a pneumatonometer. The two compounds were stable at lower pH. The stability decreased as the pH increased, suggesting their lability to base-catalyzed hydrolysis. These compounds exhibited significant differences in the hydrolytic rates in the whole blood among species examined (rat > rabbit > human). The observed rates of disappearance in different ocular tissues were indicative of relative enzyme activity in these media (iris-ciliary body > cornea > aqueous humor). The two compounds exhibited a significant ocular hypotensive activity (P < 0.01) at 2% dose level. The peak activity was found between 2 and 4 h, and the activity was maintained for 4.5 to 7 h. The dipivalyl derivative of t-butalone exhibited more pronounced decrease in intraocular pressure than that of diisovaleryl derivative. The present study suggests the possible use of diacyl derivatives of t-butalone as ocular hypotensive agents.

  2. Systems modelling approaches to the design of safe healthcare delivery: ease of use and usefulness perceived by healthcare workers.

    PubMed

    Jun, Gyuchan Thomas; Ward, James; Clarkson, P John

    2010-07-01

    The UK health service, which had been diagnosed to be seriously out of step with good design practice, has been recommended to obtain knowledge of design and risk management practice from other safety-critical industries. While these other industries have benefited from a broad range of systems modelling approaches, healthcare remains a long way behind. In order to investigate the healthcare-specific applicability of systems modelling approaches, this study identified 10 distinct methods through meta-model analysis. Healthcare workers' perception on 'ease of use' and 'usefulness' was then evaluated. The characterisation of the systems modelling methods showed that each method had particular capabilities to describe specific aspects of a complex system. However, the healthcare workers found that some of the methods, although potentially very useful, would be difficult to understand, particularly without prior experience. This study provides valuable insights into a better use of the systems modelling methods in healthcare. STATEMENT OF RELEVANCE: The findings in this study provide insights into how to make a better use of various systems modelling approaches to the design and risk management of healthcare delivery systems, which have been a growing research interest among ergonomists and human factor professionals.

  3. The Diels-Alder reaction: A powerful tool for the design of drug delivery systems and biomaterials.

    PubMed

    Gregoritza, Manuel; Brandl, Ferdinand P

    2015-11-01

    Click reactions have the potential to greatly facilitate the development of drug delivery systems and biomaterials. These reactions proceed under mild conditions, give high yields, and form only inoffensive by-products. The Diels-Alder cycloaddition is one of the click reactions that do not require any metal catalyst; it is one of the most useful reactions in synthetic organic chemistry and material design. Herein, we highlight possible applications of the Diels-Alder reaction in pharmaceutics and biomedical engineering. Particular focus is placed on the synthesis of polymers and dendrimers for drug delivery, the preparation of functionalized surfaces, bioconjugation techniques, and applications of the Diels-Alder reaction in nanotechnology. Moreover, applications of the reaction for the preparation of hydrogels for drug delivery and tissue engineering are reviewed. A general introduction to the Diels-Alder reaction is presented, along with a discussion of potential pitfalls and challenges. At the end of the article, we provide a set of tools that may facilitate the application of the Diels-Alder reaction to solve important pharmaceutical or biomedical problems. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Design, fabrication and analysis of silicon hollow microneedles for transdermal drug delivery system for treatment of hemodynamic dysfunctions.

    PubMed

    Ashraf, M W; Tayyaba, S; Nisar, A; Afzulpurkar, N; Bodhale, D W; Lomas, T; Poyai, A; Tuantranont, A

    2010-09-01

    In this paper, we present design, fabrication and coupled multifield analysis of hollow out-of-plane silicon microneedles with piezoelectrically actuated microfluidic device for transdermal drug delivery (TDD) system for treatment of cardiovascular or hemodynamic disorders such as hypertension. The mask layout design and fabrication process of silicon microneedles and reservoir involving deep reactive ion etching (DRIE) is first presented. This is followed by actual fabrication of silicon hollow microneedles by a series of combined isotropic and anisotropic etching processes using inductively coupled plasma (ICP) etching technology. Then coupled multifield analysis of a MEMS based piezoelectrically actuated device with integrated silicon microneedles is presented. The coupledfield analysis of hollow silicon microneedle array integrated with piezoelectric micropump has involved structural and fluid field couplings in a sequential structural-fluid analysis on a three-dimensional model of the microfluidic device. The effect of voltage and frequency on silicon membrane deflection and flow rate through the microneedle is investigated in the coupled field analysis using multiple code coupling method. The results of the present study provide valuable benchmark and prediction data to fabricate optimized designs of the silicon hollow microneedle based microfluidic devices for transdermal drug delivery applications.

  5. Colloidal drug delivery systems in vaccine delivery.

    PubMed

    Beg, Sarwar; Samad, Abdus; Nazish, Iram; Sultana, Ruksar; Rahman, Mahfoozur; Ahmad, Md Zaki; Akbar, Md

    2013-01-01

    Vaccines play a vital role in the field of community medicine to combat against several diseases of human existence. Vaccines primarily trigger the acquired immune system to develop long-lasting immunity against pathogens. Conventional approaches for vaccine delivery lacks potential to target a particular antigen to develop acquired immunity by specific antibodies. Recent advancements in vaccine delivery showed that inclusion of adjuvants in vaccine formulations or delivery of them in a carrier helps in achieving desired targeting ability, reducing the immunogenicity and significant augmentation in the immune response. Colloidal carriers (liposomes, niosomes, microspheres, proteosomes, virosomes and virus like particles (VLPs), antigen cochleates, dendrimers and carbon nanotubes) have been widely explored for vaccine delivery. Further, surface engineering of these carriers with ligands, functional moieties and monoclonal antibodies tend to enhance the immune recognition potential of vaccines by differentiation of antigen specific memory T-cells. The current review, therefore, provides an updated account on the recent advancements in various colloidal delivery systems in vaccine delivery, outlining the mechanism of immune response initiated by them along with potential applications and marketed instances in an explicit manner.

  6. Electronic Delivery Systems: A Selection Model.

    ERIC Educational Resources Information Center

    Pallesen, Peter J.; Haley, Paul; Jones, Edward S.; Moore, Bobbie; Widlake, Dina E.; Medsker, Karen L.

    1999-01-01

    Discussion of electronic learning delivery systems focuses on a delivery system selection model that is designed for use by performance improvement professionals who are choosing between satellite networks, teleconferencing, Internet/Intranet networks, desktop multimedia, electronic performance support systems, transportable audio/video, and the…

  7. Evaluating Learning Management System (LMS)-facilitated Delivery of Universal Design for Learning (UDL)

    NASA Astrophysics Data System (ADS)

    Bryans Bongey, Sarah

    This quantitative study involved 157 students in two sections of an undergraduate class in general biology, as well as one instructor who taught both sections of the course. It used resources from the Center for Applied Special Technologies (CAST) to evaluate the viability of a Learning Management System (LMS) to provide Universal Design for Learning (UDL). It also measured and tracked the instructor's level of efficacy in sustaining UDL approaches throughout the semester. In an effort to identify the UDL's specific outcomes or benefits to students, this study used a pre- and post- test to identify the treatment's impact on student engagement. Findings indicated that the LMS could be designed to comply with UDL guidelines, and the instructor was able to establish a high level of efficacy in maintaining that UDL design. However, based on the statistical analysis of pre- and post-test responses from control vs. treatment groups of students, the treatment was seen to have no significant effect in the area of student engagement. Overall, the study added to the literature by suggesting (a) the viability of the LMS as a means of providing UDL approaches, (b) the promise of the LMS as a tool faculty can use to deliver UDL with a high level of efficacy, and (c) the design's lack of effect in the area of student engagement. The fact that this study was limited to a single brand of LMS (Blackboard), a single instructor, and a single group of students underscores the need for further research.

  8. Engineering Design and Molecular Dynamics of Mucoadhesive Drug Delivery Systems as Targeting Agents

    PubMed Central

    Serra, Laura; Doménech, Josep; Peppas, Nicholas

    2009-01-01

    The goal of this critical review is to provide a critical analysis of the chain dynamics responsible for the action of micro- and nanoparticles of mucoadhesive biomaterials. The objective of using bioadhesive controlled drug delivery devices is to prolong their residence at a specific site of delivery, thus enhancing the drug absorption process. These mucoadhesive devices can protect the drug during the absorption process in addition to protecting it on its route to the delivery site. The major emphasis of recent research on mucoadhesive biomaterials has been on the use of adhesion promoters, which would enhance the adhesion between synthetic polymers and mucus. The use of adhesion promoters such as linear or tethered polymer chains is a natural result of the diffusional characteristics of adhesion. Mucoadhesion depends largely on the structure of the synthetic polymer gels used in controlled release applications. PMID:18976706

  9. AcademyHealth's Delivery System Science Fellowship: Training Embedded Researchers to Design, Implement, and Evaluate New Models of Care.

    PubMed

    Kanani, Nisha; Hahn, Erin; Gould, Michael; Brunisholz, Kimberly; Savitz, Lucy; Holve, Erin

    2017-07-01

    AcademyHealth's Delivery System Science Fellowship (DSSF) provides a paid postdoctoral pragmatic learning experience to build capacity within learning healthcare systems to conduct research in applied settings. The fellowship provides hands-on training and professional leadership opportunities for researchers. Since its inception in 2012, the program has grown rapidly, with 16 health systems participating in the DSSF to date. In addition to specific projects conducted within health systems (and numerous publications associated with those initiatives), the DSSF has made several broader contributions to the field, including defining delivery system science, identifying a set of training objectives for researchers working in delivery systems, and developing a national collaborative network of care delivery organizations, operational leaders, and trainees. The DSSF is one promising approach to support higher-value care by promoting continuous learning and improvement in health systems. © 2017 Society of Hospital Medicine.

  10. Designing hydrogels for controlled drug delivery

    NASA Astrophysics Data System (ADS)

    Li, Jianyu; Mooney, David J.

    2016-12-01

    Hydrogel delivery systems can leverage therapeutically beneficial outcomes of drug delivery and have found clinical use. Hydrogels can provide spatial and temporal control over the release of various therapeutic agents, including small-molecule drugs, macromolecular drugs and cells. Owing to their tunable physical properties, controllable degradability and capability to protect labile drugs from degradation, hydrogels serve as a platform on which various physiochemical interactions with the encapsulated drugs occur to control drug release. In this Review, we cover multiscale mechanisms underlying the design of hydrogel drug delivery systems, focusing on physical and chemical properties of the hydrogel network and the hydrogel-drug interactions across the network, mesh and molecular (or atomistic) scales. We discuss how different mechanisms interact and can be integrated to exert fine control in time and space over drug presentation. We also collect experimental release data from the literature, review clinical translation to date of these systems and present quantitative comparisons between different systems to provide guidelines for the rational design of hydrogel delivery systems.

  11. Design and Development of Immunomodulatory Antigen Delivery Systems Based on Peptide/PEG-PLA Conjugate for Tuning Immunity.

    PubMed

    Coumes, Fanny; Huang, Chiung-Yi; Huang, Chung-Hsiung; Coudane, Jean; Domurado, Dominique; Li, Suming; Darcos, Vincent; Huang, Ming-Hsi

    2015-11-09

    Cancer vaccines are considered to be a promising tool for cancer immunotherapy. However, a well-designed cancer vaccine should combine a tumor-associated antigen (TAA) with the most effective immunomodulatory agents and/or delivery system to provoke intense immune responses against the TAA. In the present study, we introduced a new approach by conjugating the immunomodulatory molecule LD-indolicidin to the hydrophilic chain end of the polymeric emulsifier poly(ethylene glycol)-polylactide (PEG-PLA), allowing the molecule to be located close to the surface of the resulting emulsion. A peptide/polymer conjugate, named LD-indolicidin-PEG-PLA, was synthesized by conjugation of the amine end-group of LD-indolicidin to the N-hydroxysuccinimide-activated carboxyl end-group of PEG. As an adjuvant for cancer immunotherapeutic use, TAA vaccine candidate formulated with the LD-indolicidin-PEG-PLA-stabilized squalene-in-water emulsion could effectively help to elicit a T helper (Th)1-dominant antigen-specific immune response as well as antitumor ability, using ovalbumin (OVA) protein/EG7 cells as a TAA/tumor cell model. Taken together, these results open up a new approach to the development of immunomodulatory antigen delivery systems for vaccine adjuvants and cancer immunotherapy technologies.

  12. Risk assessment and experimental design in the development of a prolonged release drug delivery system with paliperidone

    PubMed Central

    Iurian, Sonia; Turdean, Luana; Tomuta, Ioan

    2017-01-01

    This study focuses on the development of a drug product based on a risk assessment-based approach, within the quality by design paradigm. A prolonged release system was proposed for paliperidone (Pal) delivery, containing Kollidon® SR as an insoluble matrix agent and hydroxypropyl cellulose, hydroxypropyl methylcellulose (HPMC), or sodium carboxymethyl cellulose as a hydrophilic polymer. The experimental part was preceded by the identification of potential sources of variability through Ishikawa diagrams, and failure mode and effects analysis was used to deliver the critical process parameters that were further optimized by design of experiments. A D-optimal design was used to investigate the effects of Kollidon SR ratio (X1), the type of hydrophilic polymer (X2), and the percentage of hydrophilic polymer (X3) on the percentages of dissolved Pal over 24 h (Y1–Y9). Effects expressed as regression coefficients and response surfaces were generated, along with a design space for the preparation of a target formulation in an experimental area with low error risk. The optimal formulation contained 27.62% Kollidon SR and 8.73% HPMC and achieved the prolonged release of Pal, with low burst effect, at ratios that were very close to the ones predicted by the model. Thus, the parameters with the highest impact on the final product quality were studied, and safe ranges were established for their variations. Finally, a risk mitigation and control strategy was proposed to assure the quality of the system, by constant process monitoring. PMID:28331293

  13. Risk assessment and experimental design in the development of a prolonged release drug delivery system with paliperidone.

    PubMed

    Iurian, Sonia; Turdean, Luana; Tomuta, Ioan

    2017-01-01

    This study focuses on the development of a drug product based on a risk assessment-based approach, within the quality by design paradigm. A prolonged release system was proposed for paliperidone (Pal) delivery, containing Kollidon(®) SR as an insoluble matrix agent and hydroxypropyl cellulose, hydroxypropyl methylcellulose (HPMC), or sodium carboxymethyl cellulose as a hydrophilic polymer. The experimental part was preceded by the identification of potential sources of variability through Ishikawa diagrams, and failure mode and effects analysis was used to deliver the critical process parameters that were further optimized by design of experiments. A D-optimal design was used to investigate the effects of Kollidon SR ratio (X1), the type of hydrophilic polymer (X2), and the percentage of hydrophilic polymer (X3) on the percentages of dissolved Pal over 24 h (Y1-Y9). Effects expressed as regression coefficients and response surfaces were generated, along with a design space for the preparation of a target formulation in an experimental area with low error risk. The optimal formulation contained 27.62% Kollidon SR and 8.73% HPMC and achieved the prolonged release of Pal, with low burst effect, at ratios that were very close to the ones predicted by the model. Thus, the parameters with the highest impact on the final product quality were studied, and safe ranges were established for their variations. Finally, a risk mitigation and control strategy was proposed to assure the quality of the system, by constant process monitoring.

  14. Designer outer membrane vesicles as immunomodulatory systems - Reprogramming bacteria for vaccine delivery.

    PubMed

    Gnopo, Yehou M D; Watkins, Hannah C; Stevenson, Taylor C; DeLisa, Matthew P; Putnam, David

    2017-05-15

    Vaccines often require adjuvants to be effective. Traditional adjuvants, like alum, activate the immune response but in an uncontrolled way. Newer adjuvants help to direct the immune response in a more coordinated fashion. Here, we review the opportunity to use the outer membrane vesicles (OMVs) of bacteria as a way to modulate the immune response toward making more effective vaccines. This review outlines the different types of OMVs that have been investigated for vaccine delivery and how they are produced. Because OMVs are derived from bacteria, they have compositions that may not be compatible with parenteral delivery in humans; therefore, we also review the strategies brought to bear to detoxify OMVs while maintaining an adjuvant profile. OMV-based vaccines can be derived from the pathogens themselves, or can be used as surrogate constructs to mimic a pathogen through the heterologous expression of specific antigens in a desired host source strain, and approaches to doing so are reviewed. Additionally, the emerging area of engineered pathogen-specific carbohydrate sequences, or glycosylated OMVs is reviewed and contrasted with protein antigen delivery. Existing OMV-based vaccines as well as their routes of administration round out the text. Overall, this is an exciting time in the OMV field as it matures and leads to more effective and targeted ways to induce desired pathogen-specific immune responses. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Nanovehicular Intracellular Delivery Systems

    PubMed Central

    PROKOP, ALES; DAVIDSON, JEFFREY M.

    2013-01-01

    This article provides an overview of principles and barriers relevant to intracellular drug and gene transport, accumulation and retention (collectively called as drug delivery) by means of nanovehicles (NV). The aim is to deliver a cargo to a particular intracellular site, if possible, to exert a local action. Some of the principles discussed in this article apply to noncolloidal drugs that are not permeable to the plasma membrane or to the blood–brain barrier. NV are defined as a wide range of nanosized particles leading to colloidal objects which are capable of entering cells and tissues and delivering a cargo intracelullarly. Different localization and targeting means are discussed. Limited discussion on pharmacokinetics and pharmacodynamics is also presented. NVs are contrasted to micro-delivery and current nanotechnologies which are already in commercial use. Newer developments in NV technologies are outlined and future applications are stressed. We also briefly review the existing modeling tools and approaches to quantitatively describe the behavior of targeted NV within the vascular and tumor compartments, an area of particular importance. While we list “elementary” phenomena related to different level of complexity of delivery to cancer, we also stress importance of multi-scale modeling and bottom-up systems biology approach. PMID:18200527

  16. Delivery systems for brachytherapy.

    PubMed

    de la Puente, Pilar; Azab, Abdel Kareem

    2014-10-28

    Brachytherapy is described as the short distance treatment of cancer with a radioactive isotope placed on, in, or near the lesions or tumor to be treated. The main advantage of brachytherapy compared with external beam radiation (EBR) is the improved localized delivery of dose to the target volume of interest, thus normal tissue irradiation is reduced. The precise and targeted nature of brachytherapy provides a number of key benefits for the effective treatment of cancer such as efficacy, minimized risk of side effects, short treatment times, and cost-effectiveness. Brachytherapy devices have yielded promising results in preclinical and clinical studies. However, brachytherapy can only be used in localized and relatively small tumors. Although the introduction of new delivery devices allows the treatment of more complex tumor sites, with wider range of dose rate for improving treatment efficacy and reduction of side effects, a better understanding about the safety, efficacy, and accuracy of these systems is required, and further development of new techniques is warranted. Therefore, this review focuses on the delivery devices for brachytherapy and their application in prostate, breast, brain, and other tumor sites.

  17. Secondary fuel delivery system

    DOEpatents

    Parker, David M.; Cai, Weidong; Garan, Daniel W.; Harris, Arthur J.

    2010-02-23

    A secondary fuel delivery system for delivering a secondary stream of fuel and/or diluent to a secondary combustion zone located in the transition piece of a combustion engine, downstream of the engine primary combustion region is disclosed. The system includes a manifold formed integral to, and surrounding a portion of, the transition piece, a manifold inlet port, and a collection of injection nozzles. A flowsleeve augments fuel/diluent flow velocity and improves the system cooling effectiveness. Passive cooling elements, including effusion cooling holes located within the transition boundary and thermal-stress-dissipating gaps that resist thermal stress accumulation, provide supplemental heat dissipation in key areas. The system delivers a secondary fuel/diluent mixture to a secondary combustion zone located along the length of the transition piece, while reducing the impact of elevated vibration levels found within the transition piece and avoiding the heat dissipation difficulties often associated with traditional vibration reduction methods.

  18. [Site-specific drug delivery systems. I. Colon targeted delivery].

    PubMed

    Szente, Virág; Zelkó, Romána

    2007-01-01

    Colon specific drug delivery has gained increased importance not just for the delivery of the drugs for the treatment of local diseases associated with the colon like Chron's disease, ulcerative colitis, irritable bowel syndrome, cancer or infections, but also for the potential it holds for the systemic delivery of proteins (e.g. insulin) and therapeutic peptides. These systems enable the protection of healthy tissues from the side effects of drugs and the drug intake of targeted cells, as well. The formulation of colon specific drug delivery systems is of great impact in the case of diseases having circadian rhythm (midnight gerd). Such circadian rhythm release drug delivery systems are designed to provide a plasma concentration--time profile, which varies according to physiological need at different times during the dosing period, i.e., mimicking the circadian rhythm and severity/manifestation of gastric acid secretion (and/or midnight gerd). In general four primary approaches have been proposed for colon targeted delivery namely pH-dependent systems, time dependent systems, colonic microflora activated systems and prodrugs.

  19. Design, Development, and Optimization of Polymeric Based-Colonic Drug Delivery System of Naproxen

    PubMed Central

    Sharma, Pooja; Chawla, Anuj; Pawar, Pravin

    2013-01-01

    The aim of present investigation deals with the development of time-dependent and pH sensitive press-coated tablets for colon specific drug delivery of naproxen. The core tablets were prepared by wet granulation method then press coated with hydroxypropyl cellulose (HPC) or Eudragit RSPO : RLPO mixture and further coated with Eudragit S-100 by dip immerse method. The in vitro drug release study was conducted in different dissolution media such as pH 1.2, 6.8, and 7.4 with or without rat caecal content to simulate GIT conditions. Surface morphology and cross-sectional view of the tablets were visualized by scanning electron microscopy (SEM). All prepared batches were in compliance with the pharmacopoeial standards. The tablets which are compression coated with HPC followed by Eudragit S-100 coated showed highest in vitro drug release of 98.10% in presence of rat caecal content. The SEM of tablets suggested that the number of pores got increased in pH 7.4 medium followed by dissolution of coating layer. The tablets coat erosion study suggested that the lag time depends upon the coating concentrations of polymers. A time-dependent hydrophilic polymer and pH sensitive polymer based press-coated tablets of naproxen were promising delivery for colon targeting. PMID:24198725

  20. Power delivery system

    SciTech Connect

    Moroto, S.; Sakakibara, S.

    1987-06-16

    This patent describes a power delivery system for connecting a transmission to an output shaft of an engine, the transmission including a dog clutch for establishing a power transmission route by the engagement of the dog clutch, the power delivery system comprising; a clutch for disconnecting the engagement between an output member of the fluid coupling and the output shaft when the dog clutch is operated in order to switch between an on-state and an off-state. The clutch includes a clutch plate case in the form of a hollow cylinder which is connected to the turbine shell. A clutch disk wheel connected to the output shaft. A first set of clutch plates supports the clutch plate case, and a second set of clutch plates supports the clutch disk wheel. The first and second sets of clutch plates are positioned within the case adjacent the radially inward periphery of the fluid coupling; the clutch is engaged when the first and second sets of clutch plates are selectively pressed; an oil pump for supplying oil into the fluid coupling case; and the oil pump positioned within the case adjacent the radially inward periphery of the clutch.

  1. Drug Delivery Through the Skin: Molecular Simulations of Barrier Lipids to Design more Effective Noninvasive Dermal and Transdermal Delivery Systems for Small Molecules Biologics and Cosmetics

    SciTech Connect

    J Torin Huzil; S Sivaloganathan; M Kohandel; M Foldvari

    2011-12-31

    The delivery of drugs through the skin provides a convenient route of administration that is often preferable to injection because it is noninvasive and can typically be self-administered. These two factors alone result in a significant reduction of medical complications and improvement in patient compliance. Unfortunately, a significant obstacle to dermal and transdermal drug delivery alike is the resilient barrier that the epidermal layers of the skin, primarily the stratum corneum, presents for the diffusion of exogenous chemical agents. Further advancement of transdermal drug delivery requires the development of novel delivery systems that are suitable for modern, macromolecular protein and nucleotide therapeutic agents. Significant effort has already been devoted to obtain a functional understanding of the physical barrier properties imparted by the epidermis, specifically the membrane structures of the stratum corneum. However, structural observations of membrane systems are often hindered by low resolutions, making it difficult to resolve the molecular mechanisms related to interactions between lipids found within the stratum corneum. Several models describing the molecular diffusion of drug molecules through the stratum corneum have now been postulated, where chemical permeation enhancers are thought to disrupt the underlying lipid structure, resulting in enhanced permeability. Recent investigations using biphasic vesicles also suggested a possibility for novel mechanisms involving the formation of complex polymorphic lipid phases. In this review, we discuss the advantages and limitations of permeation-enhancing strategies and how computational simulations, at the atomic scale, coupled with physical observations can provide insight into the mechanisms of diffusion through the stratum corneum.

  2. Use of the Systems Approach to Training Design and Delivery in Japanese Corporations.

    ERIC Educational Resources Information Center

    Keller, John M.; Taguchi, Mina

    1996-01-01

    Surveyed 45 Japanese corporations to determine common training methods and use of systematic design and development processes. Results indicate that overall there was more internal classroom training than on-the-job training and that only two of the companies had a formal, systematic approach to instruction design and development. (JMV)

  3. Novel mucoadhesion tests for polymers and polymer-coated particles to design optimal mucoadhesive drug delivery systems.

    PubMed

    Takeuchi, Hirofumi; Thongborisute, Jringjai; Matsui, Yuji; Sugihara, Hikaru; Yamamoto, Hiromitsu; Kawashima, Yoshiaki

    2005-11-03

    To design an effective particulate drug delivery system having mucoadhesive function, several mucoadhesion tests for polymers and the resultant particulate systems were developed. Mucin particle method is a simple mucoadhesion test for polymers, in which the commercial mucin particles are used. By measuring the change in particle size or zeta potential of the mucin particle in a certain concentration of polymer solution, we could estimate the extent of their mucoadhesive property. BIACORE method is also a novel mucoadhesion test for polymers. On passing through the mucin suspension on the polymer-immobilized chip of BIACORE instrument, the interaction was quantitatively evaluated with the change in its response diagram. By using these mucoadhesion tests, we detected a strong mucoadhesive property of several types of chitosan and Carbopol. Evaluation of mucoadhesive property of polymer-coated particulate systems was demonstrated with the particle counting method developed by us. To detect the mucoadhesive phenomena in the intestinal tract, we observed the rat intestine with the confocal laser scanning microscope (CLSM) after oral administration of the particulate systems. The resultant photographs clearly showed a longer retention of submicron-sized chitosan-coated liposomes (ssCS-Lip) in the intestinal tract than other liposomal particles tested such as non-coated liposomes and chitosan-coated multilamellar one. These observations explained well the superiority of the ssCS-Lip as drug carrier in oral administration of calcitonin in rats than other liposomal particles.

  4. Microfluidic Assembly of a Multifunctional Tailorable Composite System Designed for Site Specific Combined Oral Delivery of Peptide Drugs.

    PubMed

    Araújo, Francisca; Shrestha, Neha; Shahbazi, Mohammad-Ali; Liu, Dongfei; Herranz-Blanco, Bárbara; Mäkilä, Ermei M; Salonen, Jarno J; Hirvonen, Jouni T; Granja, Pedro L; Sarmento, Bruno; Santos, Hélder A

    2015-08-25

    Multifunctional tailorable composite systems, specifically designed for oral dual-delivery of a peptide (glucagon-like peptide-1) and an enzymatic inhibitor (dipeptidyl peptidase 4 (DPP4)), were assembled through the microfluidics technique. Both drugs were coloaded into these systems for a synergistic therapeutic effect. The systems were composed of chitosan and cell-penetrating peptide modified poly(lactide-co-glycolide) and porous silicon nanoparticles as nanomatrices, further encapsulated in an enteric hydroxypropylmethylcellulose acetylsuccinate polymer. The developed multifunctional systems were pH-sensitive, inherited by the enteric polymer, enabling the release of the nanoparticles only in the simulated intestinal conditions. Moreover, the encapsulation into this polymer prevented the degradation of the nanoparticles' modifications. These nanoparticles showed strong and higher interactions with the intestinal cells in comparison with the nonmodified ones. The presence of DPP4 inhibitor enhanced the peptide permeability across intestinal cell monolayers. Overall, this is a promising platform for simultaneously delivering two drugs from a single formulation. Through this approach peptides are expected to increase their bioavailability and efficiency in vivo both by their specific release at the intestinal level and also by the reduced enzymatic activity. The use of this platform, specifically in combination of the two antidiabetic drugs, has clinical potential for the therapy of type 2 diabetes mellitus.

  5. Dynamic modeling, simulation and control design of a parafoil-payload system for ship launched aerial delivery system (SLADS)

    NASA Astrophysics Data System (ADS)

    Puranik, Anand S.

    The objective of this research was to develop a high-fidelity dynamic model of a parafoil-payload system with respect to its application for the Ship Launched Aerial Delivery System (SLADS). SLADS is a concept in which cargo can be transfered from ship to shore using a parafoil-payload system. It is accomplished in two phases: An initial towing phase when the glider follows the towing vessel in a passive lift mode and an autonomous gliding phase when the system is guided to the desired point. While many previous researchers have analyzed the parafoil-payload system when it is released from another airborne vehicle, limited work has been done in the area of towing up the system from ground or sea. One of the main contributions of this research was the development of a nonlinear dynamic model of a towed parafoil-payload system. After performing an extensive literature review of the existing methods of modeling a parafoil-payload system, a five degree-of-freedom model was developed. The inertial and geometric properties of the system were investigated to predict accurate results in the simulation environment. Since extensive research has been done in determining the aerodynamic characteristics of a paraglider, an existing aerodynamic model was chosen to incorporate the effects of air flow around the flexible paraglider wing. During the towing phase, it is essential that the parafoil-payload system follow the line of the towing vessel path to prevent an unstable flight condition called 'lockout'. A detailed study of the causes of lockout, its mathematical representation and the flight conditions and the parameters related to lockout, constitute another contribution of this work. A linearized model of the parafoil-payload system was developed and used to analyze the stability of the system about equilibrium conditions. The relationship between the control surface inputs and the stability was investigated. In addition to stability of flight, one more important objective

  6. Design of Chronomodulated Drug Delivery System of Valsartan: In Vitro Characterization

    PubMed Central

    Sokar, M.; Hanafy, A.; Elkamel, A.; El-Gamal, S.

    2015-01-01

    The aim of the present study was to design and evaluate a chronomodulated time-clock pulsatile tablets of valsartan to release it after a certain lag time, independent of the gastrointestinal pH, in its absorption window to cope with the circadian rhythm of human body for blood pressure elevation. Core tablets were prepared by direct compression of a homogenous mixture of valsartan, Avicel PH101, croscarmellose sodium, magnesium stearate and Aerosil. The core tablets were then sprayed coated with a sealing layer formed of ethyl cellulose that was subsequently coated with a release-controlling layer. Three different aqueous dispersions namely; carnauba wax or beeswax or a mixture in a ratio of 2.5:1, respectively, were used to form five time-clock tablet formulations having the release controlling layer with different thickness {B5, B10, B20, BW5 and CW5}. Quality control testing were carried out to the core tablets. Differential scanning calorimetry was also performed to detect the possible drug excipient interaction in the core tablet formulation. The release was carried out, for the prepared time-clock tablet formulations, in 0.1 N hydrochloric acid for the first 2 h, followed by phosphate buffer (pH 6.8) for 4.5 h. The effect of pH on valsartan release was studied through a release study in 0.1 N hydrochloric acid for 6.5 h. Two phase dissolution study was performed to the selected time-clock tablet formulation to predict the drug permeation through the gastrointestinal tract. Stability study of the selected formula was performed at 25°/60% RH and at 40°/75% RH for 3 months. Results showed that a release-controlling layer composed of a mixture of carnauba wax and beeswax in a ratio of 2.5:1 showed a reasonable release lag time. The release lag time of the tablets increased with the increase of the coat thickness, thus B20>B10>B5 with corresponding lag time values of 4.5, 3 and 2.5 h, respectively. Selected B5 tablet formula exhibited a reasonable lag time

  7. Design of Chronomodulated Drug Delivery System of Valsartan: In Vitro Characterization.

    PubMed

    Sokar, M; Hanafy, A; Elkamel, A; El-Gamal, S

    2015-01-01

    The aim of the present study was to design and evaluate a chronomodulated time-clock pulsatile tablets of valsartan to release it after a certain lag time, independent of the gastrointestinal pH, in its absorption window to cope with the circadian rhythm of human body for blood pressure elevation. Core tablets were prepared by direct compression of a homogenous mixture of valsartan, Avicel PH101, croscarmellose sodium, magnesium stearate and Aerosil. The core tablets were then sprayed coated with a sealing layer formed of ethyl cellulose that was subsequently coated with a release-controlling layer. Three different aqueous dispersions namely; carnauba wax or beeswax or a mixture in a ratio of 2.5:1, respectively, were used to form five time-clock tablet formulations having the release controlling layer with different thickness {B5, B10, B20, BW5 and CW5}. Quality control testing were carried out to the core tablets. Differential scanning calorimetry was also performed to detect the possible drug excipient interaction in the core tablet formulation. The release was carried out, for the prepared time-clock tablet formulations, in 0.1 N hydrochloric acid for the first 2 h, followed by phosphate buffer (pH 6.8) for 4.5 h. The effect of pH on valsartan release was studied through a release study in 0.1 N hydrochloric acid for 6.5 h. Two phase dissolution study was performed to the selected time-clock tablet formulation to predict the drug permeation through the gastrointestinal tract. Stability study of the selected formula was performed at 25°/60% RH and at 40°/75% RH for 3 months. Results showed that a release-controlling layer composed of a mixture of carnauba wax and beeswax in a ratio of 2.5:1 showed a reasonable release lag time. The release lag time of the tablets increased with the increase of the coat thickness, thus B20>B10>B5 with corresponding lag time values of 4.5, 3 and 2.5 h, respectively. Selected B5 tablet formula exhibited a reasonable lag time

  8. Planning and Instruction and the Social Studies Curriculum: A Discourse on Design and Delivery Systems.

    ERIC Educational Resources Information Center

    Peters, Richard

    A model for Continuous-Integrated-Sequential (C/I/S) curricula for social studies education is presented. The design advocated involves ensuring continuity of instruction from grades K-12, an integration of social studies disciplines, and a sequential process of refining and reinforcing concept and skills from grade-to-grade along the K-12…

  9. Engineering strategies for the design of plant nutrient delivery systems for use in space: approaches to countering microbiological contamination

    NASA Astrophysics Data System (ADS)

    Gonzales, A. A.; Schuerger, A. C.; Barford, C.; Mitchell, R.

    Microbiological contamination of crops within space-based plant growth research chambers has been postulated as a potentially significant problem. Microbial infestations; fouling of Nutrient Delivery System (NDS) fluid loops; and the formation of biofilms have been suggested as the most obvious and important manifestations of the problem. Strict sanitation and quarantine procedures will reduce, but not eliminate, microbial species introduced into plant growth systems in space habitats. Microorganisms transported into space most likely will occur as surface contaminants on spacecraft components, equipment, the crew, and plant-propagative materials. Illustrations of the potential magnitude of the microbiological contamination issue will be drawn from the literature and from documentation of laboratory and commercial field experience. Engineering strategies for limiting contamination and for the development of countermeasures will be described. Microbiological control technologies and NDS hardware will be discussed. Configurations appropriate for microgravity research facilities, as well as anticipated bio-regenerative life support system implementations, will be explored. An efficiently designed NDS, capable of adequately meeting the environmental needs of crop plants in space, is considered to be critical in both the research and operational domains. Recommended experiments, tests, and technology developments, structured to allow the development of prudent engineering solutions also will be presented.

  10. Engineering Strategies for the Design of Plant Nutrient Delivery Systems for Use in Space: Approaches to Countering Microbiological Contamination

    NASA Technical Reports Server (NTRS)

    Gonzales, A. A.; Schuerger, A. C.; Mitchell, R.; Harper, Lynn D. (Technical Monitor)

    1994-01-01

    Microbiological contamination of crops within space-based crop growth research chambers has been postulated as a potentially significant problem. Microbial infestations; fouling of Nutrient Delivery System (NDS) fluid loops; and the formation of biofilms, have been suggested as the most obvious and important manifestations of the problem. Strict sanitation and quarantine procedures will reduce, but not eliminate, microbial species introduced into plant growing systems in space habitats. Microorganisms transported into space will most likely occur as contaminants on spacecraft components, equipment, the crew, and plant-propagative materials. Illustrations of the potential magnitude of the microbiological contamination issue will be drawn from the literature and from documentation of laboratory and commercial field experience. Engineering strategies for limiting contamination and for the development of countermeasures will be described. Microbiological control technologies and NDS hardware will be discussed. Configurations appropriate for microgravity research facilities, as well as anticipated bio-regenerative life support system implementations, will be explored. An efficiently designed NDS, capable of adequately meeting the environmental needs of crop plants in space, is considered to be critical in both the research and operational domains. Recommended experiments, tests and technology developments, structured to allow the development of prudent engineering solutions, will also be presented.

  11. Engineering strategies for the design of plant nutrient delivery systems for use in space: approaches to countering microbiological contamination

    NASA Technical Reports Server (NTRS)

    Gonzales, A. A.; Schuerger, A. C.; Barford, C.; Mitchell, R.

    1996-01-01

    Microbiological contamination of crops within space-based plant growth research chambers has been postulated as a potentially significant problem. Microbial infestations; fouling of Nutrient Delivery System (NDS) fluid loops; and the formation of biofilms have been suggested as the most obvious and important manifestations of the problem. Strict sanitation and quarantine procedures will reduce, but not eliminate, microbial species introduced into plant growth systems in space habitats. Microorganisms transported into space most likely will occur as surface contaminants on spacecraft components, equipment, the crew, and plant-propagative materials. Illustrations of the potential magnitude of the microbiological contamination issue will be drawn from the literature and from documentation of laboratory and commercial field experience. Engineering strategies for limiting contamination and for the development of countermeasures will be described. Microbiological control technologies and NDS hardware will be discussed. Configurations appropriate for microgravity research facilities, as well as anticipated bio-regenerative life support system implementations, will be explored. An efficiently designed NDS, capable of adequately meeting the environmental needs of crop plants in space, is considered to be critical in both the research and operational domains. Recommended experiments, tests, and technology developments, structured to allow the development of prudent engineering solutions also will be presented.

  12. Engineering strategies for the design of plant nutrient delivery systems for use in space: approaches to countering microbiological contamination

    NASA Technical Reports Server (NTRS)

    Gonzales, A. A.; Schuerger, A. C.; Barford, C.; Mitchell, R.

    1996-01-01

    Microbiological contamination of crops within space-based plant growth research chambers has been postulated as a potentially significant problem. Microbial infestations; fouling of Nutrient Delivery System (NDS) fluid loops; and the formation of biofilms have been suggested as the most obvious and important manifestations of the problem. Strict sanitation and quarantine procedures will reduce, but not eliminate, microbial species introduced into plant growth systems in space habitats. Microorganisms transported into space most likely will occur as surface contaminants on spacecraft components, equipment, the crew, and plant-propagative materials. Illustrations of the potential magnitude of the microbiological contamination issue will be drawn from the literature and from documentation of laboratory and commercial field experience. Engineering strategies for limiting contamination and for the development of countermeasures will be described. Microbiological control technologies and NDS hardware will be discussed. Configurations appropriate for microgravity research facilities, as well as anticipated bio-regenerative life support system implementations, will be explored. An efficiently designed NDS, capable of adequately meeting the environmental needs of crop plants in space, is considered to be critical in both the research and operational domains. Recommended experiments, tests, and technology developments, structured to allow the development of prudent engineering solutions also will be presented.

  13. Engineering Strategies for the Design of Plant Nutrient Delivery Systems for Use in Space: Approaches to Countering Microbiological Contamination

    NASA Technical Reports Server (NTRS)

    Gonzales, A. A.; Schuerger, A. C.; Mitchell, R.; Harper, Lynn D. (Technical Monitor)

    1994-01-01

    Microbiological contamination of crops within space-based crop growth research chambers has been postulated as a potentially significant problem. Microbial infestations; fouling of Nutrient Delivery System (NDS) fluid loops; and the formation of biofilms, have been suggested as the most obvious and important manifestations of the problem. Strict sanitation and quarantine procedures will reduce, but not eliminate, microbial species introduced into plant growing systems in space habitats. Microorganisms transported into space will most likely occur as contaminants on spacecraft components, equipment, the crew, and plant-propagative materials. Illustrations of the potential magnitude of the microbiological contamination issue will be drawn from the literature and from documentation of laboratory and commercial field experience. Engineering strategies for limiting contamination and for the development of countermeasures will be described. Microbiological control technologies and NDS hardware will be discussed. Configurations appropriate for microgravity research facilities, as well as anticipated bio-regenerative life support system implementations, will be explored. An efficiently designed NDS, capable of adequately meeting the environmental needs of crop plants in space, is considered to be critical in both the research and operational domains. Recommended experiments, tests and technology developments, structured to allow the development of prudent engineering solutions, will also be presented.

  14. Engineering strategies for the design of plant nutrient delivery systems for use in space: approaches to countering microbiological contamination.

    PubMed

    Gonzales, A A; Schuerger, A C; Barford, C; Mitchell, R

    1996-01-01

    Microbiological contamination of crops within space-based plant growth research chambers has been postulated as a potentially significant problem. Microbial infestations; fouling of Nutrient Delivery System (NDS) fluid loops; and the formation of biofilms have been suggested as the most obvious and important manifestations of the problem. Strict sanitation and quarantine procedures will reduce, but not eliminate, microbial species introduced into plant growth systems in space habitats. Microorganisms transported into space most likely will occur as surface contaminants on spacecraft components, equipment, the crew, and plant-propagative materials. Illustrations of the potential magnitude of the microbiological contamination issue will be drawn from the literature and from documentation of laboratory and commercial field experience. Engineering strategies for limiting contamination and for the development of countermeasures will be described. Microbiological control technologies and NDS hardware will be discussed. Configurations appropriate for microgravity research facilities, as well as anticipated bio-regenerative life support system implementations, will be explored. An efficiently designed NDS, capable of adequately meeting the environmental needs of crop plants in space, is considered to be critical in both the research and operational domains. Recommended experiments, tests, and technology developments, structured to allow the development of prudent engineering solutions also will be presented.

  15. Enterprise Systems (ES) Software in Business School Curriculum--Evaluation of Design and Delivery

    ERIC Educational Resources Information Center

    Seethamraju, Ravi

    2007-01-01

    Considering the increasing importance of enterprise systems in business, and their pedagogical value in demonstrating business process orientation and concepts of integration, several universities have incorporated popular enterprise system (ES) software products such as SAP R/3 into their business school curricula. This paper describes an attempt…

  16. Enterprise Systems (ES) Software in Business School Curriculum--Evaluation of Design and Delivery

    ERIC Educational Resources Information Center

    Seethamraju, Ravi

    2007-01-01

    Considering the increasing importance of enterprise systems in business, and their pedagogical value in demonstrating business process orientation and concepts of integration, several universities have incorporated popular enterprise system (ES) software products such as SAP R/3 into their business school curricula. This paper describes an attempt…

  17. Characterization and design of a low-power wireless power delivery system

    NASA Astrophysics Data System (ADS)

    Falkenstein, Erez Avigdor

    There is an increased demand for wireless sensors for data gathering and transmission where running wires to power a device or changing/charging batteries is difficult. Often the data is gathered at locations that are difficult to access, that need to be covert, and/or where the sensors cannot be easily maintained. Some examples are implanted sensors for medical diagnostics and therapy, structural monitoring sensors, sensors inside hazardous manufacturing or other hazardous environments, etc. For any low power sensor that operates at a low duty cycle, and in an environment with low levels of light or vibration, RF wireless powering offers the potential for maintenance-free operation. The thesis focuses on a design methodology for low-power non-directional far-field wireless powering. The power receiver consists of one or more antennae which receive plane waves transmitted by the powering source, and deliver the RF power to a rectifying element. The resulting DC power is optimally transferred to the electronic application via a power management circuit. The powering is independent of the electronic application which can include wireless transmission of sensor data. The design and implementation of an integrated rectifier-antenna at low incident power densities (from 25--200 muW/cm2) is presented. Nonlinear source-pull measurements and harmonic balance simulations are used for finding the optimal rectifying device RF and DC impedances for efficient rectification. Experimental results show that an antenna design with a specific complex impedance reaches the highest rectification efficiency. Several examples of the design methodology will be shown. In specific, characterization of a rectifying patch antenna at frequency of 2.45GHz will be detailed, with an optimal RF impedance of 137+j149O and an optimal DC load of 365O resulting in RF to DC conversion efficiency of 63% for the rectifier alone and 56% for the total rectifying antenna.

  18. Design and development of ethosomal transdermal drug delivery system of valsartan with preclinical assessment in Wistar albino rats.

    PubMed

    Bhosale, Sagar S; Avachat, Amelia M

    2013-06-01

    Valsartan (VLT) is a highly selective and orally active antihypertensive drug. However, its oral administration is associated with drawbacks like low bioavailability. The objective of this study was to design and develop a transdermal delivery system for VLT using ethosomal carriers to investigate their enhanced transdermal delivery potential. VLT ethosomes were prepared by cold method. VLT ethosomes were characterized by scanning electron microscopy. The prepared ethanolic liposomes were characterized to be spherical having low polydispersity of nano-size range with good entrapment efficiency. ETC5 ethosomal suspension with 4% of phospholipon 90H and 40% of ethanol was found to have highest entrapment efficiency, i.e. 80.230 ± 0.8748%. The permeation study of ethosomes was evaluated by ex vivo diffusion study through rat abdominal skin using Franz's diffusion cells and ETC5 ethosomal suspension was found to have highest permeation with flux of 92.819 ± 1.539 µg/cm²/h, when compared to the permeation profiles of drug solutions either in water or in a water-ethanol mixture. Transdermal application of ethosomal VLT on Wistar rats showed better and prolonged antihypertensive activity in comparison to orally administered VLT suspension by virtue of transdermal permeation through Wistar rat skin. Histopathological study of skin applied with ETC5 showed intercellular permeation across skin by dissolving intercellular lipids in epidermis without causing any rigorous changes in the skin cellular structure. In conclusion, ethosomes enabled the transdermal permeation of VLT, which amply proves its superiority over oral administration for antihypertensive treatment.

  19. Changes in Instructional System Design (ISD): Improving Training Product Delivery to United States Army Soldiers

    DTIC Science & Technology

    2005-03-18

    Ulcers Tumors Gastritis Diseases Digestion Role of Teeth in Digestion Digestion in Mouth Role of Tongue in Digestion Role of Saliva Glands in...Design and the Addie Model e-Learning Guru.com,” 2003; available from <http://www.e-learningguru.com/ articles /art2_1.htm. P.2>; Internet; accessed 4...Model. e-Learning Guru.com,” 2003. Available from <http://www.e-learningguru.com/ articles /art2_1.htm>. Internet. Accessed 4 December 2004. Lakein

  20. Conceptual and Preliminary Design of a Low-Cost Precision Aerial Delivery System

    DTIC Science & Technology

    2016-06-01

    fulfillment of the requirements for the degree of MASTER OF SCIENCE IN SYSTEMS ENGINEERING from the NAVAL POSTGRADUATE SCHOOL June 2016 Approved by...55 V. COMPUTER SIMULATIONS AND FLIGHT-TEST RESULTS ..................57 A. FAILURE MODES...38 Figure 16. Pixhawk Flight Computer and Installation in Prototype Snowflake ADS

  1. Delivery Systems Reviewed.

    ERIC Educational Resources Information Center

    Ryan, William J.

    1997-01-01

    Compares classroom, interactive videodisc, and Web-based training, focusing on cost, delivery time, course content, and desktop delivery. Lists the advantages and disadvantages of Web-based training, describes one company's Intranet use for organizational training, and raises questions to consider before implementing a Web or Intranet-based…

  2. Design and In Vivo Anti-Inflammatory Effect of Ketoprofen Delayed Delivery Systems.

    PubMed

    Cerciello, Andrea; Auriemma, Giulia; Morello, Silvana; Pinto, Aldo; Del Gaudio, Pasquale; Russo, Paola; Aquino, Rita P

    2015-10-01

    For the treatment of inflammatory-based diseases affected by circadian rhythms, the development of once-daily dosage forms is required to target early morning symptoms. In this study, Zn-alginate beads containing ketoprofen (K) were developed by a tandem technique prilling/ionotropic gelation. The effect of main critical variables on particles micromeritics, inner structure as well as on drug loading and in vitro drug release was studied. The in vivo anti-inflammatory efficacy was evaluated using a modified protocol of carrageenan-induced edema in rat paw administering beads to rats by oral gavage at 0, 3, or 5 h before edema induction. Good drug loading and desired particle size and morphology were obtained for the optimized formulation F20. In vitro dissolution studies showed that F20 had a gastroresistant behavior and delayed release of the drug in simulated intestinal fluid. The in vitro delayed release pattern was clearly reflected in the prolonged anti-inflammatory effect in vivo of F20, compared to pure ketoprofen; F20, administered 3 h before edema induction, showed a significant anti-inflammatory activity, reducing maximum paw volume in response to carrageenan injection, whereas no response was observed for ketoprofen. The designed beads appear a promising platform suitable for a delayed release of anti-inflammatory drugs. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:3451-3458, 2015.

  3. Rheological and functional characterization of new antiinflammatory delivery systems designed for buccal administration.

    PubMed

    Perioli, Luana; Pagano, Cinzia; Mazzitelli, Stefania; Rossi, Carlo; Nastruzzi, Claudio

    2008-05-22

    The aim of the present paper was to investigate the influence of different formulation parameters on the rheological and functional properties of emulgels (gelified emulsions), intended for the buccal administration of the antiinflammatory drug flurbiprofen. The influence of formulation parameters, such as (a) the amount of gelling polymeric emulsifier (Pemulen 1621 TR-1) used, (b) the oil to water ratio present in the O/W emulgel and finally (c) the pH of the formulation, was studied by a experimental design (DoE) approach. Formulations were analyzed in term of size and morphology of the internal semi-solid oil droplets as well as in term of rheological properties in the presence or in the absence of flurbiprofen by "shear stress vs. shear rate tests" and "frequency sweep tests". Emulgels were also characterized in vitro both by bioadhesion tests and release studies. In particular release studies demonstrated that flurbiprofen is released by the emulgels in a controlled manner, the drug release efficacy within the first 100min was comprised between 50 and 80% of the total amount of the drug. Finally, in vivo tests on healthy volunteers have demonstrated that emulgels were able to remain on buccal mucosa for an average period of 1h, moreover emulgels did not have bad taste and volunteers referred that were agreeable and pleasant.

  4. Optimization of combinational intranasal drug delivery system for the management of migraine by using statistical design.

    PubMed

    Kumar, Animesh; Garg, Tarun; Sarma, Ganti S; Rath, Goutam; Goyal, Amit Kumar

    2015-04-05

    Migraine is a chronic disorder characterized by significant headache and various associated symptoms which worsen with exertion. Zolmitriptan approved for use in the acute treatment of migraine and related vascular headaches but are limited by high pain recurrence due to rapid drug elimination. Combinationalformulationof triptans and a nonsteroidal anti-inflammatory drug may provide a quicker and longer duration of relief from the subsequent pain during the attack. In this study, we formulate a Zolmitriptan (ZT) & ketorolac tromethamine (KT) loaded thermo reversible in-situ mucoadhesive intranasal gel (TMISG) formulation which gels at the nasal mucosal temperature and contains a bioadhesive polymer (Xyloglucan) that lengthens the residence time will enhance the bioavailability of the combinational drugs. This study uses Box-Behnken design for the first time to develop, optimize the TMISG and assess factors affecting the critical quality attributes. Histopathological study of the nasal mucosa suggested that the formulation was safe for nasal administration. The statistical difference in absolute bioavailability between oral and intranasal route suggested that intranasal route had almost 21% increases in bioavailability for ZT and for KT there was 16% increase over oral formulations. Optimized formulation would help mitigate migraine associated symptoms much better over the currently available formulations.

  5. In vitro lipid digestion models in design of drug delivery systems for enhancing oral bioavailability.

    PubMed

    Fatouros, Dimitrios G; Mullertz, Anette

    2008-01-01

    This review focuses on recent progress in the in vitro lipid digestion models and how these models can underpin in vitro-in vivo correlations which are a key element for drug development. A plethora of articles are dealing with development of lipid-based formulations of poorly soluble compounds for oral administration; however, most studies base formulation development and proof of concept on bioavailability studies and do not consider the use of in vitro studies. A major challenge is the development of in vitro models simulating the gastric or intestinal fluids to assess their in vivo performance. The use of in vitro lipolysis models has been proposed as an approach to probe solubilisation in the aqueous phase during the progress of enzymatic degradation of lipid based-formulations. Moreover, the in vitro digestion models, coupled with biophysical methods, offer insights into the mechanisms underlying lipid digestion, by characterising the generated intermediate colloidal phases, and thereby can serve as a screening tool for designing and optimising lipid-based formulations.

  6. Design of an Inflammation-Sensitive Polyelectrolyte-Based Topical Drug Delivery System for Arthritis.

    PubMed

    Bijukumar, Divya; Choonara, Yahya E; Murugan, Karmani; Choonara, Bibi Fatima; Kumar, Pradeep; du Toit, Lisa C; Pillay, Viness

    2016-10-01

    The most successful treatment strategy for arthritis is intra-articular injections that are costly and have reduced patient compliance. The purpose of the current study was to develop an inflammation-sensitive system for topical drug administration. Multi-macromolecular alginate-hyaluronic acid-chitosan (A-H-C) polyelectrolyte complex nanoparticles, loaded with indomethacin were developed employing pre-gel and post-gel techniques in the presence of dodecyl-L-pyroglutamate (DLP). In addition to in vitro studies, in silico simulations were performed to affirm and associate the molecular interactions inherent to the formulation of core all-natural multi-component biopolymeric architectures composed of an anionic (alginate), a cationic (chitosan), and an amphi-ionic polyelectrolytic (hyaluronic acid) macromolecule. The results demonstrated that DLP significantly influenced the size of the synthesized nanoparticles. Drug-content analysis revealed higher encapsulation efficiency (77.3%) in the presence of DLP, irrespective of the techniques used. Moreover, in vitro drug release studies showed that indomethacin release from the nanosystem was significantly improved (98%) in Fenton's reagent. Drug permeation across a cellulose membrane using a Franz diffusion cell system showed an initial surge flux (0.125 mg/cm(-2)/h), followed by sustained release of indomethacin for the post-gel nanoparticles revealing its effective skin permeation efficiency. In conclusion, the study presents novel nanoparticles which could effectively encapsulate and deliver hydrophobic drugs to the target site, particularly for arthritis.

  7. Design and evaluation of transdermal drug delivery system for curcumin as an anti-inflammatory drug.

    PubMed

    Patel, Nikunjana A; Patel, Natvar J; Patel, Rakesh P

    2009-02-01

    The purpose of this research was to develop a matrix-type transdermal therapeutic system containing herbal drug, curcumin (CUR), with different ratios of hydrophilic (hydroxyl propyl methyl cellulose K4M [HPMC K4M]) and hydrophobic (ethyl cellulose [EC]) polymeric systems by the solvent evaporation technique. Different concentrations of oleic acid (OA) were used to enhance the transdermal permeation of CUR. The physicochemical compatibility of the drug and the polymers was also studied by differential scanning calorimetry (DSC) and infrared (IR) spectroscopy. The results suggested no physicochemical incompatibility between the drug and the polymers. Formulated transdermal films were physically evaluated with regard to drug content, tensile strength, folding endurance, thickness, and weight variation. All prepared formulations indicated good physical stability. In vitro permeation studies of formulations were performed by using Franz diffusion cells. The results followed Higuchi kinetics, and the mechanism of release was diffusion-mediated. Formulation prepared with hydrophilic polymer containing permeation enhancer showed best in vitro skin permeation through rat skin as compared with all other formulations. This formulation demonstrated good anti-inflammatory activity against carrageenan-induced oedema in Wistar albino rats similar to standard formulation.

  8. Mucoadhesive microparticulate drug delivery system of curcumin against Helicobacter pylori infection: Design, development and optimization

    PubMed Central

    Ali, Mohd Sajid; Pandit, Vinay; Jain, Mahendra; Dhar, Kanhiya Lal

    2014-01-01

    The purpose of the present research was to develop and characterize mucoadhesive microspheres of curcumin for the potential use of treating gastric adenocarcinoma, gastric and duodenal ulcer associated with Helicobacter pylori. Curcumin mucoadhesive microspheres were prepared using ethyl cellulose as a matrix and carbopol 934P as a mucoadhesive polymer by an emulsion-solvent evaporation technique. Response surface methodology was used for optimization of formulation using central composite design (CCD) for two factors at three levels each was employed to study the effect of independent variables, drug:polymer:polymer ratio (curcumin:ethylcellulose:carbopol 934P)(X1) and surfactant concentration (X2) on dependent variables, namely drug entrapment efficiency (DEE), percentage mucoadhesion (PM), in vitro drug release and particle size (PS). Optimized formulation was obtained using desirability approach of numerical optimization. The experimental values of DEE, PM, % release and PS after 8 h for the optimized formulation were found to be 50.256 ± 1.38%, 66.23%±0.06, 73.564 ± 1.32%, and 139.881 ± 2.56 μm, respectively, which were in close agreement with those predicted by the mathematical models. The drug release was also found to be slow and extended more than 8 h and release rates were fitted to the Power law equation and Higuchi model to compute the diffusional parameters. The prolonged stomach residence time of curcumin mucoadhesive microspheres might make a contribution to H. pylori complete eradication in combination with other antimicrobial agents. PMID:24696817

  9. Optimizing Consulting Delivery Systems.

    ERIC Educational Resources Information Center

    Spottswood, Curran

    1980-01-01

    Summarizes a study of several types of consulting groups in the Bell System and describes characteristics which are associated with high-impact consulting. A strategy which is designed for internal consulting organizations to maximize the likelihood of both initial success and long-term survival of the group is proposed. (Author/MER)

  10. Project Delivery Systems: What's the Difference?

    ERIC Educational Resources Information Center

    Konchar, Mark; Sanvido, Victor

    1998-01-01

    Discusses project-delivery systems in school-construction management and why its important to both scheduling and budgeting to choose the right system. Examines design-build, construction management at-risk, and design-bid/build variations. Also discusses study data of quantitative costs, scheduling, and quality performance involving 351 building…

  11. Systematic development of design of experiments (DoE) optimised self-microemulsifying drug delivery system of Zotepine.

    PubMed

    Dalvadi, Hitesh; Patel, Nikita; Parmar, Komal

    2017-05-01

    The aim of present investigation is to improve dissolution rate of poor soluble drug Zotepine by a self-microemulsifying drug delivery system (SMEDDS). Ternary phase diagram with oil (Oleic acid), surfactant (Tween 80) and co-surfactant (PEG 400) at apex were used to identify the efficient self-microemulsifying region. Box-Behnken design was implemented to study the influence of independent variables. Principal Component Analysis was used for scrutinising critical variables. The liquid SMEDDS were characterised for macroscopic evaluation, % Transmission, emulsification time and in vitro drug release studies. Optimised formulation OL1 was converted in to S-SMEDDS by using Aerosil(®) 200 as an adsorbent in the ratio of 3:1. The S-SMEDDS was characterised by SEM, DSC, globule size (152.1 nm), zeta-potential (-28.1 mV), % transmission study (98.75%), in vitro release (86.57%) at 30 min. The optimised solid SMEDDS formulation showed faster drug release properties as compared to conventional tablet of Zotepine.

  12. Design and optimization of self-nanoemulsifying delivery system to enhance quercetin hepatoprotective activity in paracetamol-induced hepatotoxicity.

    PubMed

    Ahmed, Osama A A; Badr-Eldin, Shaimaa M; Tawfik, Mona K; Ahmed, Tarek A; El-Say, Khalid M; Badr, Jihan M

    2014-02-01

    The present study aimed to develop optimized quercetin (QT)-loaded self-nanoemulsifying drug delivery system (SNEDDS) that offers protective effect against liver damage. Solubility study of QT in different oils, surfactants, and cosurfactants was performed. Ternary phase mixtures of the selected components were constructed to select a suitable range for each component. Experimental mixture design was utilized to optimize SNEDDSs that possess smaller globule size with enhanced emulsification and dissolution rates. QT SNEDDS was compared with QT suspension control and silymarin. In vivo evaluation and histopatholgical study of the selected QT SNEDDSs were achieved after administration of paracetamol over dosage to albino rats. Two optimized formulations were selected; one based on Sefsol and the other based on linoleic acid as an oily phase, Tween(®) 80 and polyethylene glycol 400 as surfactant and cosurfactant, respectively. Both Sefsol and linoleic-acid-optimized SNEDDS formulation showed no symptoms associated with toxicity and offered protective effect against paracetamol-induced hepatotoxicity by scavenging free radicals, attenuating lipid peroxidation, and enhancing the activity of antioxidants. The histopatholgical observations revealed that the inflammatory infiltrations induced by paracetamol were significantly ameliorated.

  13. Design and development of hyaluronan-functionalized polybenzofulvene nanoparticles as CD44 receptor mediated drug delivery system

    NASA Astrophysics Data System (ADS)

    Licciardi, Mariano; Scialabba, Cinzia; Giammona, Gaetano; Paolino, Marco; Razzano, Vincenzo; Grisci, Giorgio; Giuliani, Germano; Makovec, Francesco; Cappelli, Andrea

    2017-06-01

    A tri-component polymer brush (TCPB ), composed of a polybenzofulvene copolymer bearing low molecular weight hyaluronic acid (HA) on the surface of its cylindrical brush-like backbone and oligo-PEG fractions, was employed in the preparation of 350 nm nanostructured drug delivery systems capable of delivering the anticancer drug doxorubicin. The obtained drug delivery systems were characterized on the basis of drug loading and release, dimensions and zeta potential, morphology and in vitro cell activity, and uptake on three different human cell lines, namely the bronchial epithelial 16HBE, the breast adenocarcinoma MCF-7, and the colon cancer HCT116 cells. Finally, the ability of doxorubicin-loaded TCPB nanoparticles (DOXO-TCPB) to be internalized into cancer cells by CD44 receptor mediated uptake was assessed by means of uptake studies in HCT cells. These data were supported by anti-CD44-FITC staining assay. The proposed TCPB nanostructured drug delivery systems have many potential applications in nanomedicine, including cancer targeted drug delivery.

  14. Formulation, characterization and optimization of valsartan self-microemulsifying drug delivery system using statistical design of experiment.

    PubMed

    Poudel, Bijay Kumar; Marasini, Nirmal; Tran, Tuan Hiep; Choi, Han-Gon; Yong, Chul Soon; Kim, Jong Oh

    2012-01-01

    The aim of the present research was to systematically investigate the main, interaction and the quadratic effects of formulation variables on the performance of self-microemulsifying drug delivery system (SMEDDS) of valsartan using design of experiment. A 17-run Box-Behnken design (BBD) with 3-factors and 3-levels, including 5 replicates at the centre point, was used for fitting a 2nd-order response surface. After the preliminary screening, Labrafil M 2125 CS as oil, Tween 20 as surfactant and Capryol 90 as co-surfactant were taken as independent variables. The dependent factors (responses) were particle size, polydispersity index (PDI), dissolution after 15 min and equilibrium solubility. Coefficients were estimated by regression analysis and the model adequacy was checked by an F-test and the determination coefficient (R(2)). All the responses were optimized simultaneously by using desirability function. Our results demonstrated marked main and interaction effects of independent factors on responses. The optimized formulation consisted of 26.8% (w/w) oil, 60.1% (w/w) surfactant and 13.1% (w/w) co-surfactant, and showed average micelle size of 90.7 nm and 0.246 PDI, 91.2% dissolution after 15 min and 226.7 mg/g equilibrium solubility. For the optimized formulation, predicted value and experimental value were in close agreement. After oral administration, the optimized formulation gave more than 2-fold higher area under curve (AUC) and about 6-fold higher C(max) in rats than valsartan powder (p<0.05). The BBD facilitated in the better understanding of inherent relationship of formulation variables with the responses and in the optimization of valsartan SMEDDS in relatively time and labor effective manner.

  15. Hydrogen storage and delivery system development

    SciTech Connect

    Handrock, J.L.; Wally, K.; Raber, T.N.

    1995-09-01

    Hydrogen storage and delivery is an important element in effective hydrogen utilization for energy applications and is an important part of the FY1994-1998 Hydrogen Program Implementation Plan. The purpose of this project is to develop a platform for the engineering evaluation of hydrogen storage and delivery systems with an added focus on lightweight hydride utilization. Hybrid vehicles represent the primary application area of interest, with secondary interests including such items as existing vehicles and stationary uses. The near term goal is the demonstration of an internal combustion engine/storage/delivery subsystem. The long term goal is optimization of storage technologies for both vehicular and industrial stationary uses. In this project an integrated approach is being used to couple system operating characteristics to hardware development. A model has been developed which integrates engine and storage material characteristics into the design of hydride storage and delivery systems. By specifying engine operating parameters, as well as a variety of storage/delivery design features, hydride bed sizing calculations are completed. The model allows engineering trade-off studies to be completed on various hydride material/delivery system configurations. A more generalized model is also being developed to allow the performance characteristics of various hydrogen storage and delivery systems to be compared (liquid, activated carbon, etc.). Many of the features of the hydride storage model are applicable to the development of this more generalized model.

  16. Quality by design: characterization of self-nano-emulsified drug delivery systems (SNEDDs) using ultrasonic resonator technology.

    PubMed

    Shah, R B; Zidan, A S; Funck, T; Tawakkul, M A; Nguyenpho, A; Khan, M A

    2007-08-16

    In the present work, a novel application of ultrasonic measurements is detailed to characterize nano-emulsion formulations as a part of the overall Quality by Design (QbD) goal. Ultrasonic resonator technology (URT) was utilized to measure sound velocity and absorption of self-nanoemulsified drug delivery systems (SNEDDs) consisting of various ratios of oil:surfactant:co-surfactant. A QbD concept was used to create different SNEDDs formulations utilizing sweet orange oil (oil), Emulphor-620 (surfactant), and Capmul (co-surfactant) by dissolving Cyclosporine A in oil. The mixture was emulsified in water and ultrasonic measurements were carried out in an ultrasonic resonator system isothermally for a period of about 15-20min. Compressibility of the individual components in the droplets, hydration of the droplets and the influence of the composition on droplet stability were studied by systematic ultrasonic measurements at a single resonator frequency. The adiabetic compressibilities for the oil, aqueous and interfacial components were 68, 44.6, and 53 [10(-11)Pa(-1)], respectively as calculated using Urick's equation. Also the ultrasonic absorption correlated droplet size of nano-emulsions linearly with R(2) of 0.84 indicating this can be used as an additional technique to measure the droplet size of nano-emulsions. Correlation of ultrasonic data with formulation components indicated that the ultrasonic velocity correlated negatively with increasing oil amount in the formulation as well as surfactant-to-cosurfactant ratios where as droplet diameter correlated positively with these formulation factors. It can be envisioned from the results that the compressibility of the media increases with the addition of the oily component and thus reducing the sound velocity. Thus URT enabled direct and convenient analysis of the physical properties as well as influence of formulation factors of nano-emulsions which is an important indication of stability of these nano-emulsions.

  17. Radiation sterilization of new drug delivery systems

    PubMed Central

    Abuhanoğlu, Gürhan

    2014-01-01

    Radiation sterilization has now become a commonly used method for sterilization of several active ingredients in drugs or drug delivery systems containing these substances. In this context, many applications have been performed on the human products that are required to be sterile, as well as on pharmaceutical products prepared to be developed. The new drug delivery systems designed to deliver the medication to the target tissue or organ, such as microspheres, nanospheres, microemulsion, and liposomal systems, have been sterilized by gamma (γ) and beta (β) rays, and more recently, by e-beam sterilization. In this review, the sterilization of new drug delivery systems was discussed other than conventional drug delivery systems by γ irradiation. PMID:24936306

  18. Radiation sterilization of new drug delivery systems.

    PubMed

    Abuhanoğlu, Gürhan; Ozer, A Yekta

    2014-06-01

    Radiation sterilization has now become a commonly used method for sterilization of several active ingredients in drugs or drug delivery systems containing these substances. In this context, many applications have been performed on the human products that are required to be sterile, as well as on pharmaceutical products prepared to be developed. The new drug delivery systems designed to deliver the medication to the target tissue or organ, such as microspheres, nanospheres, microemulsion, and liposomal systems, have been sterilized by gamma (γ) and beta (β) rays, and more recently, by e-beam sterilization. In this review, the sterilization of new drug delivery systems was discussed other than conventional drug delivery systems by γ irradiation.

  19. Transcutaneous antigen delivery system

    PubMed Central

    Lee, Mi-Young; Shin, Meong-Cheol; Yang, Victor C.

    2013-01-01

    Transcutaneous immunization refers to the topical application of antigens onto the epidermis. Transcutaneous immunization targeting the Langerhans cells of the skin has received much attention due to its safe, needle-free, and noninvasive antigen delivery. The skin has important immunological functions with unique roles for antigen-presenting cells such as epidermal Langerhans cells and dermal dendritic cells. In recent years, novel vaccine delivery strategies have continually been developed; however, transcutaneous immunization has not yet been fully exploited due to the penetration barrier represented by the stratum corneum, which inhibits the transport of antigens and adjuvants. Herein we review recent achievements in transcutaneous immunization, focusing on the various strategies for the enhancement of antigen delivery and vaccination efficacy. [BMB Reports 2013; 46(1): 17-24] PMID:23351379

  20. Radiation delivery system and method

    DOEpatents

    Sorensen, Scott A.; Robison, Thomas W.; Taylor, Craig M. V.

    2002-01-01

    A radiation delivery system and method are described. The system includes a treatment configuration such as a stent, balloon catheter, wire, ribbon, or the like, a portion of which is covered with a gold layer. Chemisorbed to the gold layer is a radiation-emitting self-assembled monolayer or a radiation-emitting polymer. The radiation delivery system is compatible with medical catheter-based technologies to provide a therapeutic dose of radiation to a lesion following an angioplasty procedure.

  1. The application of design principles to innovate clinical care delivery.

    PubMed

    Brennan, Michael D; Duncan, Alan K; Armbruster, Ryan R; Montori, Victor M; Feyereisn, Wayne L; LaRusso, Nicholas F

    2009-01-01

    Clinical research centers that support hypothesis-driven investigation have long been a feature of academic medical centers but facilities in which clinical care delivery can be systematically assessed and evaluated have heretofore been nonexistent. The Institute of Medicine report "Crossing the Quality Chasm" identified six core attributes of an ideal care delivery system that in turn relied heavily on system redesign. Although manufacturing and service industries have leveraged modern design principles in new product development, healthcare has lagged behind. In this article, we describe a methodology utilized by our facility to study the clinical care delivery system that incorporates modern design principles.

  2. Fluid delivery control system

    SciTech Connect

    Hoff, Brian D.; Johnson, Kris William; Algrain, Marcelo C.; Akasam, Sivaprasad

    2006-06-06

    A method of controlling the delivery of fluid to an engine includes receiving a fuel flow rate signal. An electric pump is arranged to deliver fluid to the engine. The speed of the electric pump is controlled based on the fuel flow rate signal.

  3. Formulation considerations in the design of topical, polymeric film-forming systems for sustained drug delivery to the skin.

    PubMed

    Frederiksen, Kit; Guy, Richard H; Petersson, Karsten

    2015-04-01

    Polymeric film-forming systems (FFSs) are potential drug delivery systems for topical application to the skin. The FFSs form thin and transparent polymeric films in situ upon solvent evaporation. Their application convenience and cosmetic attributes, superior to conventional semi-solids, may offer improved patient compliance. This study represents the first phase of an investigation into the use of FFSs for prolonged dermal drug delivery. FFS formulations were distinguished based on their ability to sustain the release of betamethasone 17-valerate (BMV) in vitro over 72 h. The effect of film-forming polymer (hydrophilic: hydroxypropyl cellulose (Klucel™ LF); hydrophobic: polymethacrylate copolymers (Eudragit® NE and Eudragit® RS), and polyacrylate copolymer (Dermacryl® 79) was first determined, and then the impact of incorporation of plasticisers (triethyl citrate, tributyl citrate, and dibutyl sebacate) was examined. The Klucel film released a significantly higher amount of BMV than the hydrophobic FFS, 42 versus 4 μg/cm(2), respectively. The release was increased when a plasticiser was incorporated, and with higher enhancement ratios achieved with the more lipophilic plasticisers. In conclusion, the results show that FFSs can sustain drug release (hence representing useful systems for prolonged dermal therapy) and emphasise the importance of the formulation on drug delivery, with the type of polymer being of greatest significance.

  4. Adenosine-associated delivery systems.

    PubMed

    Kazemzadeh-Narbat, Mehdi; Annabi, Nasim; Tamayol, Ali; Oklu, Rahmi; Ghanem, Amyl; Khademhosseini, Ali

    2015-01-01

    Adenosine is a naturally occurring purine nucleoside in every cell. Many critical treatments such as modulating irregular heartbeat (arrhythmias), regulation of central nervous system (CNS) activity and inhibiting seizural episodes can be carried out using adenosine. Despite the significant potential therapeutic impact of adenosine and its derivatives, the severe side effects caused by their systemic administration have significantly limited their clinical use. In addition, due to adenosine's extremely short half-life in human blood (<10 s), there is an unmet need for sustained delivery systems to enhance efficacy and reduce side effects. In this article, various adenosine delivery techniques, including encapsulation into biodegradable polymers, cell-based delivery, implantable biomaterials and mechanical-based delivery systems, are critically reviewed and the existing challenges are highlighted.

  5. Adenosine-Associated Delivery Systems

    PubMed Central

    Kazemzadeh-Narbat, Mehdi; Annabi, Nasim; Tamayol, Ali; Oklu, Rahmi; Ghanem, Amyl; Khademhosseini, Ali

    2016-01-01

    Adenosine is a naturally occurring purine nucleoside in every cell. Many critical treatments such as modulating irregular heartbeat (arrhythmias), regulation of central nervous system (CNS) activity, and inhibiting seizural episodes can be carried out using adenosine. Despite the significant potential therapeutic impact of adenosine and its derivatives, the severe side effects caused by their systemic administration have significantly limited their clinical use. In addition, due to adenosine’s extremely short half-life in human blood (less than 10 s), there is an unmet need for sustained delivery systems to enhance efficacy and reduce side effects. In this paper, various adenosine delivery techniques, including encapsulation into biodegradable polymers, cell-based delivery, implantable biomaterials, and mechanical-based delivery systems, are critically reviewed and the existing challenges are highlighted. PMID:26453156

  6. Gantries and dose delivery systems

    NASA Astrophysics Data System (ADS)

    Meer, David; Psoroulas, Serena

    2015-06-01

    Particle therapy is a field in remarkable development, with the goal of increasing the number of indications which could benefit from such treatments and the access to the therapy. The therapeutic usage of a particle beam defines the technical requirements of all the elements of the therapy chain: we summarize the main characteristics of accelerators, the beam line, the treatment room, the integrated therapy and imaging systems used in particle therapy. Aiming at a higher flexibility in the choice of treatments, an increasing number of centers around the world have chosen to equip their treatment rooms with gantries, rotating beam line structures that allow a complete flexibility in the choice of the treatment angle. We review the current designs. A particle therapy gantry though is a quite expensive structure, and future development will increasingly consider reducing the cost and the footprint. Increasing the number of indications also means development in the delivery techniques and solving some of the issues which traditionally affected particle therapy, for example the precision of the delivery in presence of motion and the large penumbras for low depths. We show the current strategies in these fields, focusing on pencil beam scanning (PBS), and give some hints about future developments.

  7. Viral and nonviral delivery systems for gene delivery

    PubMed Central

    Nayerossadat, Nouri; Maedeh, Talebi; Ali, Palizban Abas

    2012-01-01

    Gene therapy is the process of introducing foreign genomic materials into host cells to elicit a therapeutic benefit. Although initially the main focus of gene therapy was on special genetic disorders, now diverse diseases with different patterns of inheritance and acquired diseases are targets of gene therapy. There are 2 major categories of gene therapy, including germline gene therapy and somatic gene therapy. Although germline gene therapy may have great potential, because it is currently ethically forbidden, it cannot be used; however, to date human gene therapy has been limited to somatic cells. Although numerous viral and nonviral gene delivery systems have been developed in the last 3 decades, no delivery system has been designed that can be applied in gene therapy of all kinds of cell types in vitro and in vivo with no limitation and side effects. In this review we explain about the history of gene therapy, all types of gene delivery systems for germline (nuclei, egg cells, embryonic stem cells, pronuclear, microinjection, sperm cells) and somatic cells by viral [retroviral, adenoviral, adeno association, helper-dependent adenoviral systems, hybrid adenoviral systems, herpes simplex, pox virus, lentivirus, Epstein–Barr virus)] and nonviral systems (physical: Naked DNA, DNA bombardant, electroporation, hydrodynamic, ultrasound, magnetofection) and (chemical: Cationic lipids, different cationic polymers, lipid polymers). In addition to the above-mentioned, advantages, disadvantages, and practical use of each system are discussed. PMID:23210086

  8. Nanoparticle drug-delivery systems for peritoneal cancers: a case study of the design, characterization and development of the expansile nanoparticle.

    PubMed

    Colby, Aaron H; Oberlies, Nicholas H; Pearce, Cedric J; Herrera, Victoria L M; Colson, Yolonda L; Grinstaff, Mark W

    2017-02-09

    Nanoparticle (NP)-based drug-delivery systems are frequently employed to improve the intravenous administration of chemotherapy; however, few reports explore their application as an intraperitoneal therapy. We developed a pH-responsive expansile nanoparticle (eNP) specifically designed to leverage the intraperitoneal route of administration to treat intraperitoneal malignancies, such as mesothelioma, ovarian, and pancreatic carcinomatoses. This review describes the design, evaluation, and evolution of the eNP technology and, specifically, a Materials-Based Targeting paradigm that is unique among the many active- and passive-targeting strategies currently employed by NP-delivery systems. pH-responsive eNP swelling is responsible for the extended residence at the target tumor site as well as the subsequent improvement in tumoral drug delivery and efficacy observed with paclitaxel-loaded eNPs (PTX-eNPs) compared to the standard clinical formulation of paclitaxel, Taxol®. Superior PTX-eNP efficacy is demonstrated in two different orthotopic models of peritoneal cancer-mesothelioma and ovarian cancer; in a third model-of pancreatic cancer-PTX-eNPs demonstrated comparable efficacy to Taxol with reduced toxicity. Furthermore, the unique structural and responsive characteristics of eNPs enable them to be used in three additional treatment paradigms, including: treatment of lymphatic metastases in breast cancer; use as a highly fluorescent probe to visually guide the resection of peritoneal implants; and, in a two-step delivery paradigm for concentrating separately administered NP and drug at a target site. This case study serves as an important example of using the targeted disease-state's pathophysiology to inform the NP design as well as the method of use of the delivery system. For further resources related to this article, please visit the WIREs website.

  9. Development of insulin delivery systems.

    PubMed

    Siddiqui, N I; Siddiqui, Ni; Rahman, S; Nessa, A

    2008-01-01

    Delivery system of insulin is vital for its acceptance and adherence to therapy for achieving the glycemic targets. Enormous developments have occurred in the delivery system of insulin during the last twenty years and each improvement was aimed at two common goals: patients convenience and better glycemic control. Till to date, the various insulin delivery systems are: syringes/vials, injection aids, jet injectors, transmucosal delivery, transdermal delivery, external insulin infusion pump, implantable insulin pumps, insulin pens and insulin inhalers. Syringe/vial is the oldest and conventional method, still widely used and relatively cheaper. Modern plastic syringes are disposable, light weight with microfine needle for patients convenience and comfort. Oral route could be the most acceptable and viable, if the barriers can be overcome and under extensive trial. Insulin pen device is an important milestone in the delivery system of insulin as it is convenient, discrete, painless, attractive, portable with flexible life style and improved quality of life. More than 80% of European diabetic patients are using insulin pen. Future digital pen will have better memory option, blood glucose monitoring system, insulin dose calculator etc. Insulin infusion pump is a good option for the children, busy patients with flexible lifestyle and those who want to avoid multiple daily injections. Pulmonary route of insulin delivery is a promising, effective, non-invasive and acceptable alternative method. Exubera, the world first insulin inhaler was approved by FDA in 28 January 2006. But due to certain limitations, it has been withdrawn from the market in October 2007. The main concern of inhaled insulin are: long term pulmonary safety issues, cost effectiveness and user friendly device. In future, more acceptable and cost effective insulin inhaler will be introduced. Newer avenues are under extensive trial for better future insulin delivery systems.

  10. Novel drug delivery systems for glaucoma

    PubMed Central

    Lavik, E; Kuehn, M H; Kwon, Y H

    2011-01-01

    Reduction of intraocular pressure (IOP) by pharmaceutical or surgical means has long been the standard treatment for glaucoma. A number of excellent drugs are available that are effective in reducing IOP. These drugs are typically applied as eye drops. However, patient adherence can be poor, thus reducing the clinical efficacy of the drugs. Several novel delivery systems designed to address the issue of adherence and to ensure consistent reduction of IOP are currently under development. These delivery systems include contact lenses-releasing glaucoma medications, injectables such as biodegradable micro- and nanoparticles, and surgically implanted systems. These new technologies are aimed at increasing clinical efficacy by offering multiple delivery options and are capable of managing IOP for several months. There is also a desire to have complementary neuroprotective approaches for those who continue to show progression, despite IOP reduction. Many potential neuroprotective agents are not suitable for traditional oral or drop formulations. Their potential is dependent on developing suitable delivery systems that can provide the drugs in a sustained, local manner to the retina and optic nerve. Drug delivery systems have the potential to improve patient adherence, reduce side effects, increase efficacy, and ultimately, preserve sight for glaucoma patients. In this review, we discuss benefits and limitations of the current systems of delivery and application, as well as those on the horizon. PMID:21475311

  11. A model of awareness to enhance our understanding of interprofessional collaborative care delivery and health information system design to support it.

    PubMed

    Kuziemsky, Craig E; Varpio, Lara

    2011-08-01

    As more healthcare delivery is provided by collaborative teams there is a need for enhanced design of health information systems (HISs) to support collaborative care delivery. The purpose of this study was to develop a model of the different types of awareness that exist in interprofessional collaborative care (ICC) delivery to inform HIS design to support ICC. Qualitative data collection and analysis was done. The data sources consisted of 90 h of non-participant observations and 30 interviews with nurses, physicians, medical residents, volunteers, and personal support workers. Many of the macro-level ICC activities (e.g. morning rounds, shift change) were constituted by micro-level activities that involved different types of awareness. We identified four primary types of ICC awareness: patient, team member, decision making, and environment. Each type of awareness is discussed and supported by study data. We also discuss implication of our findings for enhanced design of existing HISs as well as providing insight on how HISs could be better designed to support ICC awareness. Awareness is a complex yet crucial piece of successful ICC. The information sources that provided and supported ICC awareness were varied. The different types of awareness from the model can help us understand the explicit details of how care providers communicate and exchange information with one another. Increased understanding of ICC awareness can assist with the design and evaluation of HISs to support collaborative activities. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  12. Novel central nervous system drug delivery systems.

    PubMed

    Stockwell, Jocelyn; Abdi, Nabiha; Lu, Xiaofan; Maheshwari, Oshin; Taghibiglou, Changiz

    2014-05-01

    For decades, biomedical and pharmaceutical researchers have worked to devise new and more effective therapeutics to treat diseases affecting the central nervous system. The blood-brain barrier effectively protects the brain, but poses a profound challenge to drug delivery across this barrier. Many traditional drugs cannot cross the blood-brain barrier in appreciable concentrations, with less than 1% of most drugs reaching the central nervous system, leading to a lack of available treatments for many central nervous system diseases, such as stroke, neurodegenerative disorders, and brain tumors. Due to the ineffective nature of most treatments for central nervous system disorders, the development of novel drug delivery systems is an area of great interest and active research. Multiple novel strategies show promise for effective central nervous system drug delivery, giving potential for more effective and safer therapies in the future. This review outlines several novel drug delivery techniques, including intranasal drug delivery, nanoparticles, drug modifications, convection-enhanced infusion, and ultrasound-mediated drug delivery. It also assesses possible clinical applications, limitations, and examples of current clinical and preclinical research for each of these drug delivery approaches. Improved central nervous system drug delivery is extremely important and will allow for improved treatment of central nervous system diseases, causing improved therapies for those who are affected by central nervous system diseases.

  13. Design and evaluation of hydrophobic coated buoyant core as floating drug delivery system for sustained release of cisapride

    PubMed Central

    Jacob, Shery; Nair, Anroop B; Patil, Pandurang N

    2010-01-01

    An inert hydrophobic buoyant coated–core was developed as floating drug delivery system (FDDS) for sustained release of cisapride using direct compression technology. Core contained low density, porous ethyl cellulose, which was coated with an impermeable, insoluble hydrophobic coating polymer such as rosin. It was further seal coated with low viscosity hydroxypropyl methyl cellulose (HPMC E15) to minimize moisture permeation and better adhesion with an outer drug layer. It was found that stable buoyant core was sufficient to float the tablet more than 8 h without the aid of sodium bicarbonate and citric acid. Sustained release of cisapride was achieved with HPMC K4M in the outer drug layer. The floating lag time required for these novel FDDS was found to be zero, however it is likely that the porosity or density of the core is critical for floatability of these tablets. The in vitro release pattern of these tablets in simulated gastric fluid showed the constant and controlled release for prolonged time. It can be concluded that the hydrophobic coated buoyant core could be used as FDDS for gastroretentive delivery system of cisapride or other suitable drugs. PMID:24825997

  14. Design and evaluation of a gastroretentive drug delivery system for metformin HCl using synthetic and semi-synthetic polymers.

    PubMed

    Meka, Venkata Srikanth; Gorajana, Adinaravyana; Dharmanlingam, Senthil Rajan; Kolapalli, Venkata Ramana Murthy

    2013-12-01

    The aim of the present research was to prepare and evaluate a gastroretentive drug delivery system for metformin HCl, using synthetic and semi-synthetic polymers. The floating approach was applied for preparing gastroretentive tablets (GRT) and these tablets were manufactured by the direct compression method. The drug delivery system comprises of synthetic and semi-synthetic polymers such as polyethylene oxide and Carboxymethyl ethyl cellulose (CMEC) as release-retarding polymers. GRT were evaluated for physico-chemical properties like weight variation, hardness, assay friability, in vitro floating behaviour, swelling studies, in vitro dissolution studies and rate order kinetics. Based upon the drug release and floating properties, two formulations (MP04 & MC03) were selected as optimized formulations. The optimized formulations MP04 and MC03 followed zero order rate kinetics, with non-Fickian diffusion and first order rate kinetics with erosion mechanism, respectively. The optimized formulation was characterised with FTIR studies and it was observed that there was no interaction between the drug and polymers.

  15. Alternative propellant aerosol delivery systems.

    PubMed

    Smyth, Hugh D C; Leach, Chet L

    2005-01-01

    The year 2006 represents the 50th anniversary of the pressurized metered dose inhaler. With most technologies, 50 years represents a significant time span for technology evolution and modification, but with propellant-driven metered dose inhalers, the pace of change has been relatively slow. We are now in the era of alternative propellant aerosol delivery systems, but at this 50-year juncture, what are the characteristics of these systems and what are the prospects for future advances? This review will consider alternative propellant aerosol delivery systems broadly from their inception through future opportunities and challenges.

  16. Design of lipid-based delivery systems for improving lymphatic transport and bioavailability of delta-tocopherol and nobiletin

    NASA Astrophysics Data System (ADS)

    Xia, Chunxin

    Lymphatic drug transport can confer bioavailability advantage by avoiding the first-pass metabolism normally observed in the portal vein hepatic route. It was reported that long chain lipid-based delivery systems can stimulate the formation of chylomicron and thus promote the lymphatic transport of drugs. In this study, a novel delta-tocopherol (delta-T) loaded Solid Lipid Nanoparticle (SLN) system was developed to investigate its effect on promoting the lymphatic transport of delta-T. The delta-T SLN was prepared with hot melt emulsification method by using glyceryl behenate (compritol RTM888) as the lipid phase and lecithin (PC75) as the emulsifier. Formula configuration, processing condition and loading capacity were carefully optimized. Physicochemical properties (particle size, surface charge, morphology) were also characterized. Moreover, excellent stability of the developed delta-T SLN in the gastrointestinal environment was observed by using an in vitro digestion model. Further investigations of the SLN in stimulating delta-T lymphatic transport were performed on mice without cannulation. Compared with the control group (delta-T corn oil dispersion), much lower delta-T levels in both blood and liver indicated reduced portal vein and hepatic transport of delta-T in the form of SLN. On the other hand, significantly higher concentrations of delta-T were observed in thymus, a major lymphatic tissue, indicating improved lymphatic transport of delta-T with the SLN delivery system. Finally, the far less excreted delta-T level in feces further confirmed improved lymphatic transport and overall bioavailability of delta-T by using SLN system. Nobiletin (NOB), one of most abundant polymethoxyflavones (PMFs) found in Citrus genus, has a low solubility in both water and oil at ambient temperatures. Thus it tends to form crystals when the loading exceeds its saturation level in the carrier system. This character greatly impaired its bioavailability and application. To

  17. Lipid based nanocarrier system for the potential oral delivery of decitabine: formulation design, characterization, ex vivo, and in vivo assessment.

    PubMed

    Neupane, Yub Raj; Srivastava, Manish; Ahmad, Nafees; Kumar, Neeraj; Bhatnagar, Aseem; Kohli, Kanchan

    2014-12-30

    The aim of this study was to design and fabricate nanostructured lipid carrier (NLC) for the potential oral delivery of decitabine (DCB). NLC was prepared by cold homogenization technique and optimized by the Box-Behnken experimental design. It was further characterized by particle size, zeta potential, transmission electron microscopy (TEM), atomic force microscopy (AFM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), in vitro release study, and stability study. Moreover, ex vivo and in vivo efficacy of the NLC was assessed by gut permeation study, γ scintigraphy imaging, and MTT assay. NLC was found to have particle size (116.64 ± 6.67 nm), zeta potential (-31.8 ± 0.96 mV) and sustained drug release (80.23 ± 4.67%) up to 24h. TEM and AFM proved that the particles were spherical in shape and smooth surface. DSC and XRD studies had demonstrated the reduced crystallinity and stability enhancing effect of the NLC. Stability studies revealed the changes in the observed parameters up to 45 days were not significantly differences (p>0.05). Ex vivo gut permeation study showed 4-folds increment in the permeation of drug compared with the plain drug solution. γ Scintigraphy imaging and MTT assay results inferred that DCB loaded NLC possesses excellent cytotoxic activity against cancer cells. Thus, NLC holds high potential for the oral delivery of DCB to treat cancer cells and future prospects for the industrial purpose. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Development of a generic adenovirus delivery system based on structure-guided design of bispecific trimeric DARPin adapters.

    PubMed

    Dreier, Birgit; Honegger, Annemarie; Hess, Christian; Nagy-Davidescu, Gabriela; Mittl, Peer R E; Grütter, Markus G; Belousova, Natalya; Mikheeva, Galina; Krasnykh, Victor; Plückthun, Andreas

    2013-03-05

    Adenoviruses (Ads) have shown promise as vectors for gene delivery in clinical trials. Efficient viral targeting to a tissue of choice requires both ablation of the virus' original tropism and engineering of an efficient receptor-mediated uptake by a specific cell population. We have developed a series of adapters binding to the virus with such high affinity that they remain fully bound for >10 d, block its natural receptor binding site and mediate interaction with a surface receptor of choice. The adapter contains two fused modules, both consisting of designed ankyrin repeat proteins (DARPins), one binding to the fiber knob of adenovirus serotype 5 and the other binding to various tumor markers. By solving the crystal structure of the complex of the trimeric knob with three bound DARPins at 1.95-Å resolution, we could use computer modeling to design a link to a trimeric protein of extraordinary kinetic stability, the capsid protein SHP from the lambdoid phage 21. We arrived at a module which binds the knob like a trimeric clamp. When this clamp was fused with DARPins of varying specificities, it enabled adenovirus serotype 5-mediated delivery of a transgene in a human epidermal growth factor receptor 2-, epidermal growth factor receptor-, or epithelial cell adhesion molecule-dependent manner with transduction efficiencies comparable to or even exceeding those of Ad itself. With these adapters, efficiently produced in Escherichia coli, Ad can be converted rapidly to new receptor specificities using any ligand as the receptor-binding moiety. Prefabricated Ads with different payloads thus can be retargeted readily to many cell types of choice.

  19. Collagen interactions: Drug design and delivery.

    PubMed

    An, Bo; Lin, Yu-Shan; Brodsky, Barbara

    2016-02-01

    Collagen is a major component in a wide range of drug delivery systems and biomaterial applications. Its basic physical and structural properties, together with its low immunogenicity and natural turnover, are keys to its biocompatibility and effectiveness. In addition to its material properties, the collagen triple-helix interacts with a large number of molecules that trigger biological events. Collagen interactions with cell surface receptors regulate many cellular processes, while interactions with other ECM components are critical for matrix structure and remodeling. Collagen also interacts with enzymes involved in its biosynthesis and degradation, including matrix metalloproteinases. Over the past decade, much information has been gained about the nature and specificity of collagen interactions with its partners. These studies have defined collagen sequences responsible for binding and the high-resolution structures of triple-helical peptides bound to its natural binding partners. Strategies to target collagen interactions are already being developed, including the use of monoclonal antibodies to interfere with collagen fibril formation and the use of triple-helical peptides to direct liposomes to melanoma cells. The molecular information about collagen interactions will further serve as a foundation for computational studies to design small molecules that can interfere with specific interactions or target tumor cells. Intelligent control of collagen biological interactions within a material context will expand the effectiveness of collagen-based drug delivery.

  20. Teleteach Expanded Delivery System: Evaluation.

    ERIC Educational Resources Information Center

    Christopher, G. Ronald; Milam, Alvin L.

    In order to meet the demand for Air Force Institute of Technology (AFIT) professional continuing education (PCE) courses within the School of Systems and Logistics and the School of Engineering, the Teleteach Expanded Delivery System (TEDS) for instruction of Air Force personnel at remote locations was developed and evaluated. TEDS uses a device…

  1. Delivery System, 2003-2004.

    ERIC Educational Resources Information Center

    Office of Federal Student Aid (ED), Washington, DC.

    This workshop guide for financial aid administrators provides training in the federal student financial aid delivery system. An introduction enables the participant to share some information about his or her responsibilities and to reflect on the relevance of the training to the job. Session 1, "Application Systems," identifies methods of applying…

  2. Delivery System, 2003-2004.

    ERIC Educational Resources Information Center

    Office of Federal Student Aid (ED), Washington, DC.

    This workshop guide for financial aid administrators provides training in the federal student financial aid delivery system. An introduction enables the participant to share some information about his or her responsibilities and to reflect on the relevance of the training to the job. Session 1, "Application Systems," identifies methods of applying…

  3. Intelligent, self-powered, drug delivery systems.

    PubMed

    Patra, Debabrata; Sengupta, Samudra; Duan, Wentao; Zhang, Hua; Pavlick, Ryan; Sen, Ayusman

    2013-02-21

    Self-propelled nano/micromotors and pumps are considered to be next generation drug delivery systems since the carriers can either propel themselves ("motor"-based drug delivery) or be delivered ("pump"-based drug delivery) to the target in response to specific biomarkers. Recently, there has been significant advancement towards developing nano/microtransporters into proof-of-concept tools for biomedical applications. This review encompasses the progress made to date on the design of synthetic nano/micromotors and pumps with respect to transportation and delivery of cargo at specific locations. Looking ahead, it is possible to imagine a day when intelligent machines navigate through the human body and perform challenging tasks.

  4. Waste Feed Delivery Transfer System Analysis

    SciTech Connect

    JULYK, L.J.

    2000-05-05

    This document provides a documented basis for the required design pressure rating and pump pressure capacity of the Hanford Site waste-transfer system in support of the waste feed delivery to the privatization contractor for vitrification. The scope of the analysis includes the 200 East Area double-shell tank waste transfer pipeline system and the associated transfer system pumps for a11 Phase 1B and Phase 2 waste transfers from AN, AP, AW, AY, and A2 Tank Farms.

  5. Design, characterization, and biological evaluation of curcumin-loaded surfactant-based systems for topical drug delivery.

    PubMed

    Fonseca-Santos, Bruno; Dos Santos, Aline Martins; Rodero, Camila Fernanda; Gremião, Maria Palmira Daflon; Chorilli, Marlus

    From previous studies, it has been found that curcumin exhibits an anti-inflammatory activity and is being used for the treatment of skin disorders; however, it is hydrophobic and has weak penetrating ability, resulting in poor drug transport through the stratum corneum. The aim of this study was to develop liquid crystalline systems for topical administration of curcumin for the treatment of inflammation. These liquid crystalline systems were developed from oleic acid, polyoxypropylene (5) polyoxyethylene (20) cetyl alcohol, and water as the surfactant, oil phase, and aqueous phase, respectively. These systems were characterized, and polarized light microscopy showed anisotropy with lamellar mesophases (Formulation 1) and hexagonal mesophases (Formulations 2 and 3), which were confirmed by the peak ratio measured using small-angle X-ray scattering. In addition, rheological tests revealed that the formulations exhibited gel-like behavior (G'>G″), as evidenced by the increased G' values that indicate structured systems. Texture profile analysis showed that hexagonal mesophases have high values of hardness, adhesiveness, and compressibility, which indicate structured systems. In vitro studies on bioadhesion revealed that the hexagonal mesophases increased the bioadhesiveness of the systems to the skin of the pig ear. An in vivo inflammation experiment showed that the curcumin-loaded hexagonal mesophase exhibited an anti-inflammatory activity as compared to the positive control (dexamethasone). The results suggest that this system has a potential to be used as a bioadhesive vehicle for the topical administration of curcumin. Therefore, it is possible to conclude that these systems can be used for the optimization of drug delivery systems to the skin.

  6. Design, characterization, and biological evaluation of curcumin-loaded surfactant-based systems for topical drug delivery

    PubMed Central

    Fonseca-Santos, Bruno; dos Santos, Aline Martins; Rodero, Camila Fernanda; Gremião, Maria Palmira Daflon; Chorilli, Marlus

    2016-01-01

    From previous studies, it has been found that curcumin exhibits an anti-inflammatory activity and is being used for the treatment of skin disorders; however, it is hydrophobic and has weak penetrating ability, resulting in poor drug transport through the stratum corneum. The aim of this study was to develop liquid crystalline systems for topical administration of curcumin for the treatment of inflammation. These liquid crystalline systems were developed from oleic acid, polyoxypropylene (5) polyoxyethylene (20) cetyl alcohol, and water as the surfactant, oil phase, and aqueous phase, respectively. These systems were characterized, and polarized light microscopy showed anisotropy with lamellar mesophases (Formulation 1) and hexagonal mesophases (Formulations 2 and 3), which were confirmed by the peak ratio measured using small-angle X-ray scattering. In addition, rheological tests revealed that the formulations exhibited gel-like behavior (G′>G″), as evidenced by the increased G′ values that indicate structured systems. Texture profile analysis showed that hexagonal mesophases have high values of hardness, adhesiveness, and compressibility, which indicate structured systems. In vitro studies on bioadhesion revealed that the hexagonal mesophases increased the bioadhesiveness of the systems to the skin of the pig ear. An in vivo inflammation experiment showed that the curcumin-loaded hexagonal mesophase exhibited an anti-inflammatory activity as compared to the positive control (dexamethasone). The results suggest that this system has a potential to be used as a bioadhesive vehicle for the topical administration of curcumin. Therefore, it is possible to conclude that these systems can be used for the optimization of drug delivery systems to the skin. PMID:27660447

  7. A light-weight compact proton gantry design with a novel dose delivery system for broad-energetic laser-accelerated beams

    NASA Astrophysics Data System (ADS)

    Masood, U.; Cowan, T. E.; Enghardt, W.; Hofmann, K. M.; Karsch, L.; Kroll, F.; Schramm, U.; Wilkens, J. J.; Pawelke, J.

    2017-07-01

    Proton beams may provide superior dose-conformity in radiation therapy. However, the large sizes and costs limit the widespread use of proton therapy (PT). The recent progress in proton acceleration via high-power laser systems has made it a compelling alternative to conventional accelerators, as it could potentially reduce the overall size and cost of the PT facilities. However, the laser-accelerated beams exhibit different characteristics than conventionally accelerated beams, i.e. very intense proton bunches with large divergences and broad-energy spectra. For the application of laser-driven beams in PT, new solutions for beam transport, such as beam capture, integrated energy selection, beam shaping and delivery systems are required due to the specific beam parameters. The generation of these beams are limited by the low repetition rate of high-power lasers and this limitation would require alternative solutions for tumour irradiation which can efficiently utilize the available high proton fluence and broad-energy spectra per proton bunch to keep treatment times short. This demands new dose delivery system and irradiation field formation schemes. In this paper, we present a multi-functional light-weight and compact proton gantry design for laser-driven sources based on iron-less pulsed high-field magnets. This achromatic design includes improved beam capturing and energy selection systems, with a novel beam shaping and dose delivery system, so-called ELPIS. ELPIS system utilizes magnetic fields, instead of physical scatterers, for broadening the spot-size of broad-energetic beams while capable of simultaneously scanning them in lateral directions. To investigate the clinical feasibility of this gantry design, we conducted a treatment planning study with a 3D treatment planning system augmented for the pulsed beams with optimizable broad-energetic widths and selectable beam spot sizes. High quality treatment plans could be achieved with such unconventional beam

  8. A light-weight compact proton gantry design with a novel dose delivery system for broad-energetic laser-accelerated beams.

    PubMed

    Masood, U; Cowan, T E; Enghardt, W; Hofmann, K M; Karsch, L; Kroll, F; Schramm, U; Wilkens, J J; Pawelke, J

    2017-07-07

    Proton beams may provide superior dose-conformity in radiation therapy. However, the large sizes and costs limit the widespread use of proton therapy (PT). The recent progress in proton acceleration via high-power laser systems has made it a compelling alternative to conventional accelerators, as it could potentially reduce the overall size and cost of the PT facilities. However, the laser-accelerated beams exhibit different characteristics than conventionally accelerated beams, i.e. very intense proton bunches with large divergences and broad-energy spectra. For the application of laser-driven beams in PT, new solutions for beam transport, such as beam capture, integrated energy selection, beam shaping and delivery systems are required due to the specific beam parameters. The generation of these beams are limited by the low repetition rate of high-power lasers and this limitation would require alternative solutions for tumour irradiation which can efficiently utilize the available high proton fluence and broad-energy spectra per proton bunch to keep treatment times short. This demands new dose delivery system and irradiation field formation schemes. In this paper, we present a multi-functional light-weight and compact proton gantry design for laser-driven sources based on iron-less pulsed high-field magnets. This achromatic design includes improved beam capturing and energy selection systems, with a novel beam shaping and dose delivery system, so-called ELPIS. ELPIS system utilizes magnetic fields, instead of physical scatterers, for broadening the spot-size of broad-energetic beams while capable of simultaneously scanning them in lateral directions. To investigate the clinical feasibility of this gantry design, we conducted a treatment planning study with a 3D treatment planning system augmented for the pulsed beams with optimizable broad-energetic widths and selectable beam spot sizes. High quality treatment plans could be achieved with such unconventional beam

  9. Novel Solid Self-Nanoemulsifying Drug Delivery System (S-SNEDDS) for Oral Delivery of Olmesartan Medoxomil: Design, Formulation, Pharmacokinetic and Bioavailability Evaluation

    PubMed Central

    Nasr, Ali; Gardouh, Ahmed; Ghorab, Mamdouh

    2016-01-01

    The main purpose of this study was to develop a solid self-nanoemulsifying drug delivery system (S-SNEDDS) of Olmesartan (OLM) for enhancement of its solubility and dissolution rate. In this study, liquid SNEDDS containing Olmesartan was formulated and further developed into a solid form by the spray drying technique using Aerosil 200 as a solid carrier. Based on the preliminary screening of different unloaded SNEDDS formulae, eight formulae of OLM loaded SNEEDS were prepared using Capryol 90, Cremophor RH40 and Transcutol HP as oil, surfactant and cosurfactant, respectively. Results showed that the mean droplet size of all reconstituted SNEDDS was found to be in the nanometric range (14.91–22.97 nm) with optimum PDI values (0.036–0.241). All formulae also showed rapid emulsification time (15.46 ± 1.34–24.17 ± 1.47 s), good optical clarity (98.33% ± 0.16%–99.87% ± 0.31%) and high drug loading efficiency (96.41% ± 1.20%–99.65% ± 1.11%). TEM analysis revealed the formation of spherical and homogeneous droplets with a size smaller than 50 nm. In vitro release of OLM from SNEDDS formulae showed that more than 90% of OLM released in approximately 90 min. Optimized SNEDDS formulae were selected to be developed into S-SNEDDS using the spray drying technique. The prepared S-SNEDDS formulae were evaluated for flow properties, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), reconstitution properties, drug content and in vitro dissolution study. It was found that S-SNEDDS formulae showed good flow properties and high drug content. Reconstitution properties of S-SNEDDS showed spontaneous self-nanoemulsification and no sign of phase separation. DSC thermograms revealed that OLM was in solubilized form and FTIR supported these findings. SEM photographs showed smooth uniform surface of S-SNEDDS with less aggregation. Results of the in vitro drug release showed that there was great enhancement in the dissolution rate of OLM. To clarify

  10. Novel Solid Self-Nanoemulsifying Drug Delivery System (S-SNEDDS) for Oral Delivery of Olmesartan Medoxomil: Design, Formulation, Pharmacokinetic and Bioavailability Evaluation.

    PubMed

    Nasr, Ali; Gardouh, Ahmed; Ghorab, Mamdouh

    2016-06-27

    The main purpose of this study was to develop a solid self-nanoemulsifying drug delivery system (S-SNEDDS) of Olmesartan (OLM) for enhancement of its solubility and dissolution rate. In this study, liquid SNEDDS containing Olmesartan was formulated and further developed into a solid form by the spray drying technique using Aerosil 200 as a solid carrier. Based on the preliminary screening of different unloaded SNEDDS formulae, eight formulae of OLM loaded SNEEDS were prepared using Capryol 90, Cremophor RH40 and Transcutol HP as oil, surfactant and cosurfactant, respectively. Results showed that the mean droplet size of all reconstituted SNEDDS was found to be in the nanometric range (14.91-22.97 nm) with optimum PDI values (0.036-0.241). All formulae also showed rapid emulsification time (15.46 ± 1.34-24.17 ± 1.47 s), good optical clarity (98.33% ± 0.16%-99.87% ± 0.31%) and high drug loading efficiency (96.41% ± 1.20%-99.65% ± 1.11%). TEM analysis revealed the formation of spherical and homogeneous droplets with a size smaller than 50 nm. In vitro release of OLM from SNEDDS formulae showed that more than 90% of OLM released in approximately 90 min. Optimized SNEDDS formulae were selected to be developed into S-SNEDDS using the spray drying technique. The prepared S-SNEDDS formulae were evaluated for flow properties, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), reconstitution properties, drug content and in vitro dissolution study. It was found that S-SNEDDS formulae showed good flow properties and high drug content. Reconstitution properties of S-SNEDDS showed spontaneous self-nanoemulsification and no sign of phase separation. DSC thermograms revealed that OLM was in solubilized form and FTIR supported these findings. SEM photographs showed smooth uniform surface of S-SNEDDS with less aggregation. Results of the in vitro drug release showed that there was great enhancement in the dissolution rate of OLM. To clarify the

  11. Global Positioning System (GPS) and Geographic Information System (GIS) analysis of mobile harvesting equipment and sediment delivery to streams during forest harvest operations on steep terrain: Experimental design

    Treesearch

    Daniel Bowker; Jeff Stringer; Chris Barton; Songlin. Fei

    2011-01-01

    Sediment mobilized by forest harvest machine traffic contributes substantially to the degradation of headwater stream systems. This study monitored forest harvest machine traffic to analyze how it affects sediment delivery to stream channels. Harvest machines were outfitted with global positioning system (GPS) dataloggers, recording machine movements and working status...

  12. Software Build and Delivery Systems

    SciTech Connect

    Robey, Robert W.

    2016-07-10

    This presentation deals with the hierarchy of software build and delivery systems. One of the goals is to maximize the success rate of new users and developers when first trying your software. First impressions are important. Early successes are important. This also reduces critical documentation costs. This is a presentation focused on computer science and goes into detail about code documentation.

  13. Patient and provider perspectives on the design and implementation of an electronic consultation system for kidney care delivery in Canada: a focus group study

    PubMed Central

    Bello, Aminu K; Molzahn, Anita E; Girard, Louis P; Osman, Mohamed A; Okpechi, Ikechi G; Glassford, Jodi; Thompson, Stephanie; Keely, Erin; Liddy, Clare; Manns, Braden; Jinda, Kailash; Klarenbach, Scott; Hemmelgarn, Brenda; Tonelli, Marcello

    2017-01-01

    Objectives We assessed stakeholder perceptions on the use of an electronic consultation system (e-Consult) to improve the delivery of kidney care in Alberta. We aim to identify acceptability, barriers and facilitators to the use of an e-Consult system for ambulatory kidney care delivery. Methods This was a qualitative focus group study using a thematic analysis design. Eight focus groups were held in four locations in the province of Alberta, Canada. In total, there were 72 participants in two broad stakeholder categories: patients (including patients' relatives) and providers (including primary care physicians, nephrologists, other care providers and policymakers). Findings The e-Consult system was generally acceptable across all stakeholder groups. The key barriers identified were length of time required for referring physicians to complete the e-Consult due to lack of integration with current electronic medical records, and concerns that increased numbers of requests might overwhelm nephrologists and lead to a delayed response or an unsustainable system. The key facilitators identified were potential improvement of care coordination, dissemination of best practice through an educational platform, comprehensive data to make decisions without the need for face-to-face consultation, timely feedback to primary care providers, timeliness/reduced delays for patients' rapid triage and identification of cases needing urgent care and improved access to information to facilitate decision-making in patient care. Conclusions Stakeholder perceptions regarding the e-Consult system were favourable, and the key barriers and facilitators identified will be considered in design and implementation of an acceptable and sustainable electronic consultation system for kidney care delivery. PMID:28255097

  14. Starch Applications for Delivery Systems

    NASA Astrophysics Data System (ADS)

    Li, Jason

    2013-03-01

    Starch is one of the most abundant and economical renewable biopolymers in nature. Starch molecules are high molecular weight polymers of D-glucose linked by α-(1,4) and α-(1,6) glycosidic bonds, forming linear (amylose) and branched (amylopectin) structures. Octenyl succinic anhydride modified starches (OSA-starch) are designed by carefully choosing a proper starch source, path and degree of modification. This enables emulsion and micro-encapsulation delivery systems for oil based flavors, micronutrients, fragrance, and pharmaceutical actives. A large percentage of flavors are encapsulated by spray drying in today's industry due to its high throughput. However, spray drying encapsulation faces constant challenges with retention of volatile compounds, oxidation of sensitive compound, and manufacturing yield. Specialty OSA-starches were developed suitable for the complex dynamics in spray drying and to provide high encapsulation efficiency and high microcapsule quality. The OSA starch surface activity, low viscosity and film forming capability contribute to high volatile retention and low active oxidation. OSA starches exhibit superior performance, especially in high solids and high oil load encapsulations compared with other hydrocolloids. The submission is based on research and development of Ingredion

  15. Insulin Delivery System

    NASA Technical Reports Server (NTRS)

    1988-01-01

    When Programmable Implantable Medication System (PIMS) is implanted in human body, it delivers precise programmed amounts of insulin over long periods of time. Mini-Med Technologies has been refining the Technologies since initial development at APL. The size of a hockey puck, and encased in titanium shell, PIMS holds about 2 1/2 teaspoons of insulin at a programmed basal rate. If a change in measured blood sugar level dictates a different dose, the patient can vary the amount of insulin delivered by holding a small radio transceiver over the implanted system and dialing in a specific program held in the PIMS computer memory. Insulin refills are accomplished approximately 4 times a year by hypodermic needle.

  16. Optimal stent design for drug delivery.

    PubMed

    Rogers, Campbell D K

    2004-01-01

    The efficacy and safety of drug-eluting coronary stents might differ depending on the pharmacologic agents and stent delivery systems used. Recent research has focused on the various constituents of drug-delivery stents, including the stent backbone, materials used as drug-delivery vehicles, and the physicochemical properties of the pharmacotherapeutic agents themselves. Metal stents coated with an outer layer of polymer (bioabsorbable or non-bioabsorbable) can be drug-loaded, thus providing more controlled and sustained drug delivery and allowing more optimal drug-tissue interactions. Among the next generation of drug-eluting stents will be a stent that uses the non-bioabsorbable polymer phosphorylcholine to release the sirolimus analogue ABT-578; another stent will use a highly deliverable cobalt-chromium metal alloy stent platform and, for the first time, a bioabsorbable polymeric coating (thin-film polylactic acid) for drug encapsulation and release.

  17. Sterile Product Packaging and Delivery Systems.

    PubMed

    Akers, Michael J

    2015-01-01

    Both conventional and more advanced product container and delivery systems are the focus of this brief article. Six different product container systems will be discussed, plus advances in primary packaging for special delivery systems and needle technology.

  18. Nanofibers based antibacterial drug design, delivery and applications.

    PubMed

    Ulubayram, Kezban; Calamak, Semih; Shahbazi, Reza; Eroglu, Ipek

    2015-01-01

    Infections caused by microorganisms like bacteria, fungi, etc. are the main obstacle in healing processes. Conventional antibacterial administration routes can be listed as oral, intravenous/intramuscular, topical and inhalation. These kinds of drug administrations are faced with critical vital issues such as; more rapid delivery of the drug than intended which can result in bacterial resistance, dose related systemic toxicity, tissue irritation and finally delayed healing process that need to be tackled. Recently, studies have been focused on new drug delivery systems, overcoming resistance and toxicological problems and finally localizing the molecules at the site of action in a proper dose. In this regard, many nanotechnological approaches such as nanoparticulate therapeutic systems have been developed to address accompanying problems mentioned above. Among them, drug loaded electrospun nanofibers propose main advantages like controlled drug delivery, high drug loading capacity, high encapsulation efficiency, simultaneous delivery of multiple drugs, ease of production and cost effectiveness for pharmaceutical and biomedical applications. Therefore, some particular attention has been devoted to the design of electrospun nanofibers as promising antibacterial drug carrier systems. A variety of antibacterials e.g., biocides, antibiotics, quaternary ammonium salts, triclosan, metallic nanoparticles (silver, titanium dioxide, and zinc oxide) and antibacterial polymers (chitosan, polyethyleneimine, etc.) have been impregnated by various techniques into nanofibers that exhibit strong antibacterial activity in standard assays. This review highlights the design and delivery of antibacterial drug loaded nanofibers with particular focus on their function in the fields of drug delivery, wound healing, tissue engineering, cosmetics and other biomedical applications.

  19. Spectroscopic analysis of aluminum chloride phthalocyanine in binary water/ethanol systems for the design of a new drug delivery system for photodynamic therapy cancer treatment

    NASA Astrophysics Data System (ADS)

    Jayme, Cristiano Ceron; Calori, Italo Rodrigo; Tedesco, Antonio Claudio

    2016-01-01

    This study evaluated the behavior of aluminum chloride phthalocyanine in a binary water/ethanol mixture using electronic absorption spectroscopy and static and time-resolved fluorescence spectroscopy. The electronic absorption spectra, resonance light scattering and fluorescence quenching of aluminum chloride phthalocyanine in water/ethanol mixtures were studied at several concentrations. The electronic absorption spectra and fluorescence quenching changed significantly at approximately 50% water (v/v). Below 50% water, the dimerization constant values were negative (- 2609.2 M- 1 and - 506.5 M- 1 at 30% and 40% of water, respectively), indicating that the formation of aggregates under these conditions is not favored. However, at 50% water, the dimerization constant value was estimated to be 559.7 M- 1, which indicates the presence of dimers. Above 60% water, the aggregation process was responsible for the balance between large complexes (such as trimers, tetramers or oligomers) formed in the medium under these conditions. The appearance of new absorption bands at 387 nm and 802 nm and their bathochromic shift relative to the monomer bands suggested that some J-type aggregates form. These results are relevant to understanding the behavior and use of aluminum chloride phthalocyanine in the design of new drug delivery systems for clinical application in photodynamic therapy as a new approach to treat skin cancer.

  20. Spectroscopic analysis of aluminum chloride phthalocyanine in binary water/ethanol systems for the design of a new drug delivery system for photodynamic therapy cancer treatment.

    PubMed

    Jayme, Cristiano Ceron; Calori, Italo Rodrigo; Tedesco, Antonio Claudio

    2016-01-15

    This study evaluated the behavior of aluminum chloride phthalocyanine in a binary water/ethanol mixture using electronic absorption spectroscopy and static and time-resolved fluorescence spectroscopy. The electronic absorption spectra, resonance light scattering and fluorescence quenching of aluminum chloride phthalocyanine in water/ethanol mixtures were studied at several concentrations. The electronic absorption spectra and fluorescence quenching changed significantly at approximately 50% water (v/v). Below 50% water, the dimerization constant values were negative (-2609.2 M(-1) and -506.5 M(-1) at 30% and 40% of water, respectively), indicating that the formation of aggregates under these conditions is not favored. However, at 50% water, the dimerization constant value was estimated to be 559.7 M(-1), which indicates the presence of dimers. Above 60% water, the aggregation process was responsible for the balance between large complexes (such as trimers, tetramers or oligomers) formed in the medium under these conditions. The appearance of new absorption bands at 387 nm and 802 nm and their bathochromic shift relative to the monomer bands suggested that some J-type aggregates form. These results are relevant to understanding the behavior and use of aluminum chloride phthalocyanine in the design of new drug delivery systems for clinical application in photodynamic therapy as a new approach to treat skin cancer.

  1. Mucoadhesive vaginal drug delivery systems.

    PubMed

    Acartürk, Füsun

    2009-11-01

    Vaginal delivery is an important route of drug administration for both local and systemic diseases. The vaginal route has some advantages due to its large surface area, rich blood supply, avoidance of the first-pass effect, relatively high permeability to many drugs and self-insertion. The traditional commercial preparations, such as creams, foams, gels, irrigations and tablets, are known to reside in the vaginal cavity for a relatively short period of time owing to the self-cleaning action of the vaginal tract, and often require multiple daily doses to ensure the desired therapeutic effect. The vaginal route appears to be highly appropriate for bioadhesive drug delivery systems in order to retain drugs for treating largely local conditions, or for use in contraception. In particular, protection against sexually-transmitted diseases is critical. To prolong the residence time in the vaginal cavity, bioadhesive therapeutic systems have been developed in the form of semi-solid and solid dosage forms. The most commonly used mucoadhesive polymers that are capable of forming hydrogels are synthetic polyacrylates, polycarbophil, chitosan, cellulose derivatives (hydroxyethycellulose, hydroxy-propylcellulose and hydroxypropylmethylcellulose), hyaluronic acid derivatives, pectin, tragacanth, carrageenan and sodium alginate. The present article is a comprehensive review of the patents related to mucoadhesive vaginal drug delivery systems.

  2. Connecting drug delivery reality to smart materials design.

    PubMed

    Grainger, David W

    2013-09-15

    Inflated claims to both design and mechanistic novelty in drug delivery and imaging systems, including most nanotechnologies, are not supported by the generally poor translation of these systems to clinical efficacy. The "form begets function" design paradigm is seductive but perhaps over-simplistic in translation to pharmaceutical efficacy. Most innovations show few clinically important distinctions in their therapeutic benefits in relevant preclinical disease and delivery models, despite frequent claims to the contrary. Long-standing challenges in drug delivery issues must enlist more realistic, back-to-basics approaches to address fundamental materials properties in complex biological systems, preclinical test beds, and analytical methods to more reliably determine fundamental pharmaceutical figures of merit, including drug carrier purity and batch-batch variability, agent biodistribution, therapeutic index (safety), and efficacy. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Hydrogen storage and delivery system development: Fabrication

    SciTech Connect

    Handrock, J.L.; Malinowski, M.E.; Wally, K.

    1996-10-01

    Hydrogen storage and delivery is an important element in effective hydrogen utilization for energy applications and is an important part of the FY1994-1998 Hydrogen Program Implementation Plan. This project is part of the Field Work Proposal entitled Hydrogen Utilization in Internal Combustion Engines (ICE). The goal of the Hydrogen Storage and Delivery System Development Project is to expand the state-of-the-art of hydrogen storage and delivery system design and development. At the foundation of this activity is the development of both analytical and experimental evaluation platforms. These tools provide the basis for an integrated approach for coupling hydrogen storage and delivery technology to the operating characteristics of potential hydrogen energy use applications. Analytical models have been developed for internal combustion engine (ICE) hybrid and fuel cell driven vehicles. The dependence of hydride storage system weight and energy use efficiency on engine brake efficiency and exhaust temperature for ICE hybrid vehicle applications is examined. Results show that while storage system weight decreases with increasing engine brake efficiency energy use efficiency remains relatively unchanged. The development, capability, and use of a newly developed fuel cell vehicle hydride storage system model will also be discussed. As an example of model use power distribution and control for a simulated driving cycle is presented. An experimental test facility, the Hydride Bed Testing Laboratory (HBTL) has been designed and fabricated. The development of this facility and its use in storage system development will be reviewed. These two capabilities (analytical and experimental) form the basis of an integrated approach to storage system design and development. The initial focus of these activities has been on hydride utilization for vehicular applications.

  4. Biomaterials for Nanoparticle Vaccine Delivery Systems

    PubMed Central

    Sahdev, Preety; Ochyl, Lukasz J.; Moon, James J.

    2014-01-01

    Subunit vaccination benefits from improved safety over attenuated or inactivated vaccines, but their limited capability to elicit long-lasting, concerted cellular and humoral immune responses is a major challenge. Recent studies have demonstrated that antigen delivery via nanoparticle formulations significantly improve immunogenicity of vaccines due to either intrinsic immunostimulatory properties of the materials or by co-entrapment of molecular adjuvants such as Toll-like receptor agonists. These studies have collectively shown that nanoparticles designed to mimic biophysical and biochemical cues of pathogens offer new exciting opportunities to enhance activation of innate immunity and elicit potent cellular and humoral immunity with minimal cytotoxicity. In this review, we present key research advances that were made within the last 5 years in the field of nanoparticle vaccine delivery systems. In particular, we focus on the impact of biomaterials composition, size, and surface charge of nanoparticles on modulation of particle biodistribution, delivery of antigens and immunostimulatory molecules, trafficking and targeting of antigen presenting cells, and overall immune responses in systemic and mucosal tissues. This review describes recent progresses in the design of nanoparticle vaccine delivery carriers, including liposomes, lipid-based particles, micelles and nanostructures composed of natural or synthetic polymers, and lipid-polymer hybrid nanoparticles. PMID:24848341

  5. The design of contact lens based ocular drug delivery systems for single-day use: Part (I) Structural factors, surrogate ophthalmic dyes and passive diffusion studies.

    PubMed

    Mahomed, Anisa; Tighe, Brian J

    2014-09-01

    The poor retention and efficacy of instilled drops as a means of delivering drugs to the ophthalmic environment is well-recognised. The potential value of contact lenses as a means of ophthalmic drug delivery, and consequent improvement of pre-corneal retention is one obvious route to the development of a more effective ocular delivery system. Furthermore, the increasing availability and clinical use of daily disposable contact lenses provides the platform for the development of viable single-day use drug delivery devices based on existing materials and lenses. In order to provide a basis for the effective design of such devices, a systematic understanding of the factors affecting the interaction of individual drugs with the lens matrix is required. Because a large number of potential structural variables are involved, it is necessary to achieve some rationalisation of the parameters and physicochemical properties (such as molecular weight, charge, partition coefficients) that influence drug interactions. Ophthalmic dyes and structurally related compounds based on the same core structure were used to investigate these various factors and the way in which they can be used in concert to design effective release systems for structurally different drugs. Initial studies of passive diffusional release form a necessary precursor to the investigation of the features of the ocular environment that over-ride this simple behaviour. Commercially available contact lenses of differing structural classifications were used to study factors affecting the uptake of the surrogate actives and their release under 'passive' conditions. The interaction between active and lens material shows considerable and complex structure dependence, which is not simply related to equilibrium water content. The structure of the polymer matrix itself was found to have the dominant controlling influence on active uptake; hydrophobic interaction with the ophthalmic dye playing a major role. © The

  6. A non-invasive, low-cost study design to determine the release profile of colon drug delivery systems: a feasibility study.

    PubMed

    Maurer, Marina J M; Schellekens, Reinout C A; Wutzke, Klaus D; Dijkstra, Gerard; Woerdenbag, Herman J; Frijlink, Henderik W; Kosterink, Jos G W; Stellaard, Frans

    2012-08-01

    Conventional bioavailability testing of dosage forms based on plasma concentration-time graphs of two products in a two-period, crossover-design, is not applicable to topical treatment of intestinal segments. We introduce an isotope dual-label approach ((13)C- and (15)N(2)-urea) for colon drug delivery systems that can be performed in a one-day, non-invasive study-design. Four healthy volunteers took an uncoated or a ColoPulse-capsule containing (13)C-urea and an uncoated capsule containing (15)N(2)-urea. In case of colon-release (13)C-urea is fermented and (13)C detected as breath (13)CO(2). Absorbed (13)C-urea and (15)N-urea are detected in urine. C and (15)N in urine released from uncoated capsules showed a ratio of 1.01 ± 0.06. The (13)C/(15)N-recovery ratio after intake of a ColoPulse-capsule was constant and lower >12 h post-dose (median 0.22, range 0.13-0.48). The (13)C/(15)N-ratio in a single urine sample at t ≥ 12 h predicted the 24 h non-fermented fraction (13)C of <26 %. Breath (13)CO(2) indicated delayed (>3 h) release and a fermented fraction (13)C >54 %. Breath and urine (13)C and (15)N data describe the release-profile and local bioavailability of a colon delivery device. This allows non-invasive bioavailability studies for evaluation of colon-specific drug delivery systems without radioactive exposure and with increased power and strongly reduced costs.

  7. Nanobiotechnology: Cell Membrane-Based Delivery Systems.

    PubMed

    Zhang, Pengfei; Liu, Gang; Chen, Xiaoyuan

    2017-04-01

    The increasingly rapid pace of research in the field of bioinspired drug delivery systems is revealing the promise of cell membrane-based nanovesicles for biomedical applications. Those cell membrane-based nanoparticles combine the natural functionalities of cell plasma membranes and the bioengineering flexibility of synthetic nanomaterials, and such versatility provides a means of designing exciting new drug formulations for personalized treatment in future nanomedicine.

  8. Design and experimental evaluation of a 256-channel dual-frequency ultrasound phased-array system for transcranial blood-brain barrier opening and brain drug delivery.

    PubMed

    Liu, Hao-Li; Jan, Chen-Kai; Chu, Po-Chun; Hong, Jhong-Cing; Lee, Pei-Yun; Hsu, Jyh-Duen; Lin, Chung-Chih; Huang, Chiung-Ying; Chen, Pin-Yuan; Wei, Kuo-Chen

    2014-04-01

    Focused ultrasound (FUS) in the presence of microbubbles can bring about transcranial and local opening of the blood-brain barrier (BBB) for potential noninvasive delivery of drugs to the brain. A phased-array ultrasound system is essential for FUS-BBB opening to enable electronic steering and correction of the focal beam which is distorted by cranial bone. Here, we demonstrate our prototype design of a 256-channel ultrasound phased-array system for large-region transcranial BBB opening in the brains of large animals. One of the unique features of this system is the capability of generating concurrent dual-frequency ultrasound signals from the driving system for potential enhancement of BBB opening. A wide range of signal frequencies can be generated (frequency = 0.2-1.2 MHz) with controllable driving burst patterns. Precise output power can be controlled for individual channels via 8-bit duty-cycle control of transistor-transistor logic signals and the 8-bit microcontroller-controlled buck converter power supply output voltage. The prototype system was found to be in compliance with the electromagnetic compatibility standard. Moreover, large animal experiments confirmed the phase switching effectiveness of this system, and induction of either a precise spot or large region of BBB opening through fast focal-beam switching. We also demonstrated the capability of dual-frequency exposure to potentially enhance the BBB-opening effect. This study contributes to the design of ultrasound phased arrays for future clinical applications, and provides a new direction toward optimizing FUS brain drug delivery.

  9. Vaginal drug delivery systems for HIV prevention.

    PubMed

    Rohan, Lisa Cencia; Sassi, Alexandra B

    2009-03-01

    Microbicides have become a principal focus for HIV prevention strategies. The successful design of drug delivery systems for vaginal microbicide drug candidates brings with it a multitude of challenges. It is imperative that the chemical and physical characteristics of the drug candidate and its mechanism of action be clearly understood and considered to successfully deliver and target drug candidates efficiently. In addition, an understanding of the dynamic nature of the vaginal environment, the tissue and innate barriers present, as well as patient preferences are critical considerations in the design of effective microbicide products. Although the majority of drug candidates clinically evaluated to date have been delivered using conventional semisolid aqueous-based gel dosage forms, drug delivery system design has recently been extended to include advanced delivery systems such as vaginal rings, quick-dissolve films, and tablets. Ultimately, it may be necessary to develop multiple dosage platforms for a single active agent to provide users with options that can be used within the constraints of their social environment, personal choice, and environmental conditions.

  10. Controlled Release Strategies for Bone, Cartilage, and Osteochondral Engineering—Part I: Recapitulation of Native Tissue Healing and Variables for the Design of Delivery Systems

    PubMed Central

    Santo, Vítor E.; Mano, João F.; Reis, Rui L.

    2013-01-01

    The potential of growth factors to stimulate tissue healing through the enhancement of cell proliferation, migration, and differentiation is undeniable. However, critical parameters on the design of adequate carriers, such as uncontrolled spatiotemporal presence of bioactive factors, inadequate release profiles, and supraphysiological dosages of growth factors, have impaired the translation of these systems onto clinical practice. This review describes the healing cascades for bone, cartilage, and osteochondral interface, highlighting the role of specific growth factors for triggering the reactions leading to tissue regeneration. Critical criteria on the design of carriers for controlled release of bioactive factors are also reported, focusing on the need to provide a spatiotemporal control over the delivery and presentation of these molecules. PMID:23268651

  11. 7 CFR 246.12 - Food delivery systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 4 2011-01-01 2011-01-01 false Food delivery systems. 246.12 Section 246.12 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF... State Agency Provisions § 246.12 Food delivery systems. (a) General. This section sets forth design and...

  12. 7 CFR 246.12 - Food delivery systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 4 2010-01-01 2010-01-01 false Food delivery systems. 246.12 Section 246.12 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF... State Agency Provisions § 246.12 Food delivery systems. (a) General. This section sets forth design and...

  13. Regulatory aspects in the pharmaceutical development of nanoparticle drug delivery systems designed to cross the intestinal epithelium and M-cells.

    PubMed

    Hussain, Nasir

    2016-11-30

    This article reviews the field of oral uptake of nanoparticles across the gastrointestinal epithelium for the period 2006-2016. Analysis is conducted from the viewpoint of i) M-cell genetics and model development, ii) drug targeting to Peyer's patches and M-cells, and iii) physicochemical interactions of nanoparticles in the intestinal milieu. In light of these recent developments, regulatory considerations in the development of orally-absorbable nanoparticle drug products are discussed and focused on Module 3.2.P sub-sections of the Common Technical Document. Particular attention is paid to novel excipients, ligands and the non-standard method of manufacture. The novelty of this drug delivery system demands not only a multi-disciplinary scientific and regulatory approach but also a risk-adjusted consideration for a system defined by both processes and specifications. Given the current state of scientific development in the field it is suggested (in the author's personal opinion) that the design of nanoparticulate drug delivery systems should be kept as simple as possible (from a regulatory and manufacturing perspective) and to target the entire gastrointestinal epithelium. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

  14. Lipid-Based Drug Delivery Systems

    PubMed Central

    Shrestha, Hina; Bala, Rajni; Arora, Sandeep

    2014-01-01

    The principle objective of formulation of lipid-based drugs is to enhance their bioavailability. The use of lipids in drug delivery is no more a new trend now but is still the promising concept. Lipid-based drug delivery systems (LBDDS) are one of the emerging technologies designed to address challenges like the solubility and bioavailability of poorly water-soluble drugs. Lipid-based formulations can be tailored to meet a wide range of product requirements dictated by disease indication, route of administration, cost consideration, product stability, toxicity, and efficacy. These formulations are also a commercially viable strategy to formulate pharmaceuticals, for topical, oral, pulmonary, or parenteral delivery. In addition, lipid-based formulations have been shown to reduce the toxicity of various drugs by changing the biodistribution of the drug away from sensitive organs. However, the number of applications for lipid-based formulations has expanded as the nature and type of active drugs under investigation have become more varied. This paper mainly focuses on novel lipid-based formulations, namely, emulsions, vesicular systems, and lipid particulate systems and their subcategories as well as on their prominent applications in pharmaceutical drug delivery. PMID:26556202

  15. Drug delivery systems for differential release in combination therapy.

    PubMed

    Zhang, Hongbin; Wang, Guojie; Yang, Huai

    2011-02-01

    Combination therapy with multiple therapeutic agents has wide applicability in medical and surgical treatment, especially in the treatment of cancer. Thus, new drug delivery systems that can differentially release two or more drugs are desired. Utilizing new techniques to engineer the established drug delivery systems and synthesizing new materials and designing carriers with new structures are feasible ways to fabricate proper multi-agent delivery systems, which are critical to meet requirements in the clinic and improve therapeutic efficacy. This paper aims to give an overview about the multi-agent delivery systems developed in the last decade for differential release in combination therapy. Multi-agent delivery systems from nanoscale to bulk scale, such as liposomes, micelles, polymer conjugates, nano/microparticles and hydrogels, developed over the last 10 years, have been collected and summarized. The characteristics of different delivery systems are described and discussed, including the structure of drug carriers, drug-loading techniques, release behaviors and consequent evaluation in biological assays. The chemical structure of drug delivery systems is the key to controlling the release of therapeutic agents in combination therapy, and the differential release of multiple drugs could be realized by the successful design of a proper delivery system. Besides biological evaluation in vitro and in vivo, it is important to speed up practical application of the resulting delivery systems.

  16. Implantable drug-delivery systems.

    PubMed

    Blackshear, P J

    1979-12-01

    Implantable drug-delivery systems are being developed to release drugs to the bloodstream continuously as well as free patients from being hospitalized to receive intravenous infusions or frequent injections. One technique is implantation of a pellet in the subcutaneous tissue so the pellet may be released by erosion. Drugs are also diffused through silicone rubber capsules but only polyacrylamide is able to release large molecules. Contraceptive rings containing progesterone and placed in the uterus or vagina and implanted silicone-rubber capsules use these principles. Disadvantages to the subcutaneous delivery of drugs include: 1) release of the drug in subcutaneous tissue rather than in the bloodstream directly; 2) entry into the circulatory system is controlled by surrounding blood supplies which vary with fat; 3) diffusion may be difficult due to dense layers of fibrous tissue; and 4) drug amounts cannot be readily regulated. The Ommaya reservoir uses a container with a self-sealing membrane implanted in the scalp and connected to a cerebral ventricle to treat forms of leukemia and fungal meningitis. Another development is an implantable disk-shaped infusion pump with 2 compartments, the outer one containing a propellant and the inner chamber containing the drug, holds 45 milliliters and releases about 1 milliliter/day. In the future these systems may release drugs in response to biochemical feedback or deliver a drug to 1 specific area.

  17. Design of Nanoparticle-Based Carriers for Targeted Drug Delivery

    PubMed Central

    Ren, Muqing; Duval, Kayla; Guo, Xing; Chen, Zi

    2016-01-01

    Nanoparticles have shown promise as both drug delivery vehicles and direct antitumor systems, but they must be properly designed in order to maximize efficacy. Computational modeling is often used both to design new nanoparticles and to better understand existing ones. Modeled processes include the release of drugs at the tumor site and the physical interaction between the nanoparticle and cancer cells. In this article, we provide an overview of three different targeted drug delivery methods (passive targeting, active targeting and physical targeting), compare methods of action, advantages, limitations, and the current stage of research. For the most commonly used nanoparticle carriers, fabrication methods are also reviewed. This is followed by a review of computational simulations and models on nanoparticle-based drug delivery. PMID:27398083

  18. Advanced rapid prototyping by laser beam sintering of metal prototypes: design and development of an optimized laser beam delivery system

    NASA Astrophysics Data System (ADS)

    Geiger, Manfred; Coremans, A.; Neubauer, Norbert; Niebling, F.

    1996-08-01

    Fast technological advances and steadily increasing severe worldwide competition force industry to respond all the time faster to new and chanced customer wishes. Some of the recently emerged processes, commonly referred to as 'rapid prototyping' (RP), have proved to be powerful tools for accelerating product and process development. Early approaches aimed at the automated production of plastic models. These techniques achieved industrial maturity extremely fast and are meanwhile established as standard utilities in the field of development/design processes. So far, their applicability to metal working industry was limited to design studies because the mechanical properties of the prototypes, e.g. modulus of elasticity and mechanical strength were not comparable to the final products they represented. Therefore, RP-processes aimed at the direct production of metallic prototypes gained more and more importance during recent years. A technique belonging to this group is manufacturing of prototypes by using a laser beam sintering machine capable of directly processing metal powders. This so called laser beam sintering process showed a great potential for direct manufacturing of functional tools and prototypes in early feasibility studies. Detailed examinations were performed at several research centers to determine the attainable quality of the parts concerning roughness, dimensional accuracy and mechanical strength. These examinations showed, that there still is a considerable demand for quality improvements of the previously mentioned parameters. The practical application and the potential for improvement of the geometrical accuracy of laser beam sintered parts by using a dual beam concept was proven. An innovative beam guiding and forming concept, similar to the previously mentioned patented beam guiding system, was developed and built with the goal to improve the process parameters governing mechanical properties as well as geometrical accuracy. Further reaching

  19. Designing synthetic RNA for delivery by nanoparticles

    NASA Astrophysics Data System (ADS)

    Jedrzejczyk, Dominika; Gendaszewska-Darmach, Edyta; Pawlowska, Roza; Chworos, Arkadiusz

    2017-03-01

    The rapid development of synthetic biology and nanobiotechnology has led to the construction of various synthetic RNA nanoparticles of different functionalities and potential applications. As they occur naturally, nucleic acids are an attractive construction material for biocompatible nanoscaffold and nanomachine design. In this review, we provide an overview of the types of RNA and nucleic acid’s nanoparticle design, with the focus on relevant nanostructures utilized for gene-expression regulation in cellular models. Structural analysis and modeling is addressed along with the tools available for RNA structural prediction. The functionalization of RNA-based nanoparticles leading to prospective applications of such constructs in potential therapies is shown. The route from the nanoparticle design and modeling through synthesis and functionalization to cellular application is also described. For a better understanding of the fate of targeted RNA after delivery, an overview of RNA processing inside the cell is also provided.

  20. Delivery systems and adjuvants for oral vaccines.

    PubMed

    Lavelle, Ed C; O'Hagan, D T

    2006-11-01

    The oral route is the ideal means of delivering prophylactic and therapeutic vaccines, offering significant advantages over systemic delivery. Most notably, oral delivery is associated with simple administration and improved safety. In addition, unlike systemic immunisation, oral delivery can induce mucosal immune responses. However, the oral route of vaccine delivery is the most difficult because of the numerous barriers posed by the gastrointestinal tract. To facilitate effective immunisation with peptide and protein vaccines, antigens must be protected, uptake enhanced and the innate immune response activated. Numerous delivery systems and adjuvants have been evaluated for oral vaccine delivery, including live vectors, inert particles and bacterial toxins. Although developments in oral vaccines have been disappointing so far, in terms of the generation of products, the availability of a range of novel delivery systems offers much greater hope for the future development of improved oral vaccines.

  1. Design, Synthesis of Novel Lipids as Chemical Permeation Enhancers and Development of Nanoparticle System for Transdermal Drug Delivery

    PubMed Central

    Shah, Punit P.; Etukala, Jagan Reddy; Vemuri, Adithi; Singh, Mandip

    2013-01-01

    In the present study, we designed and developed novel lipids that include (Z)-1-(Octadec-9-en-1-yl)-pyrrolidine (Cy5T), 1, 1-Di-((Z)-octadec-9-en-1-yl)pyrrolidin-1-ium iodide (Cy5), (Z)-1-(Octadec-9-en-1-yl)-piperidine (Cy6T), and 1, 1-Di-((Z)-octadec-9-en-1-yl) piperidin-1-ium iodide (Cy6) to enhance the transdermal permeation of some selected drugs. Firstly, we evaluated the transdermal permeation efficacies of these lipids as chemical permeation enhancers in vehicle formulations for melatonin, ß-estradiol, caffeine, α-MSH, and spantide using franz diffusion cells. Among them Cy5 lipid was determined to be the most efficient by increasing the transdermal permeation of melatonin, ß-estradiol, caffeine, α-MSH, and spantide by 1.5 to 3.26-fold more at the epidermal layer and 1.3 to 2.5-fold more at the dermal layer, in comparison to either NMP or OA. Hence we developed a nanoparticle system (cy5 lipid ethanol drug nanoparticles) to evaluate any further improvement in the drug penetration. Cy5 lipid formed uniformly sized nanoparticles ranging from 150–200 nm depending on the type of drug. Further, Cy5 based nanoparticle system significantly (p<0.05) increased the permeation of all the drugs in comparison to the lipid solution and standard permeation enhancers. There were about 1.54 to 22-fold more of drug retained in the dermis for the Cy5 based nanoparticles compared to OA/NMP standard enhancers and 3.87 to 66.67-fold more than lipid solution. In addition, epifluorescent microscopic analysis in rhodamine-PE permeation studies confirmed the superior permeation enhancement of LEDs (detection of fluorescence up to skin depth of 340 μm) more than lipid solution, which revealed fluorescence up to skin depth of only 260 μm. In summary the present findings demonstrate that i) cationic lipid with 5 membered amine heterocyclic ring has higher permeating efficacy than the 6 membered amine hertocyclic ring. ii) The nanoparticle system prepared with Cy5 showed

  2. Design, synthesis of novel lipids as chemical permeation enhancers and development of nanoparticle system for transdermal drug delivery.

    PubMed

    Marepally, Srujan; Boakye, Cedar H A; Shah, Punit P; Etukala, Jagan Reddy; Vemuri, Adithi; Singh, Mandip

    2013-01-01

    In the present study, we designed and developed novel lipids that include (Z)-1-(Octadec-9-en-1-yl)-pyrrolidine (Cy5T), 1, 1-Di-((Z)-octadec-9-en-1-yl)pyrrolidin-1-ium iodide (Cy5), (Z)-1-(Octadec-9-en-1-yl)-piperidine (Cy6T), and 1, 1-Di-((Z)-octadec-9-en-1-yl) piperidin-1-ium iodide (Cy6) to enhance the transdermal permeation of some selected drugs. Firstly, we evaluated the transdermal permeation efficacies of these lipids as chemical permeation enhancers in vehicle formulations for melatonin, ß-estradiol, caffeine, α-MSH, and spantide using franz diffusion cells. Among them Cy5 lipid was determined to be the most efficient by increasing the transdermal permeation of melatonin, ß-estradiol, caffeine, α-MSH, and spantide by 1.5 to 3.26-fold more at the epidermal layer and 1.3 to 2.5-fold more at the dermal layer, in comparison to either NMP or OA. Hence we developed a nanoparticle system (cy5 lipid ethanol drug nanoparticles) to evaluate any further improvement in the drug penetration. Cy5 lipid formed uniformly sized nanoparticles ranging from 150-200 nm depending on the type of drug. Further, Cy5 based nanoparticle system significantly (p<0.05) increased the permeation of all the drugs in comparison to the lipid solution and standard permeation enhancers. There were about 1.54 to 22-fold more of drug retained in the dermis for the Cy5 based nanoparticles compared to OA/NMP standard enhancers and 3.87 to 66.67-fold more than lipid solution. In addition, epifluorescent microscopic analysis in rhodamine-PE permeation studies confirmed the superior permeation enhancement of LEDs (detection of fluorescence up to skin depth of 340 μm) more than lipid solution, which revealed fluorescence up to skin depth of only 260 μm. In summary the present findings demonstrate that i) cationic lipid with 5 membered amine heterocyclic ring has higher permeating efficacy than the 6 membered amine hertocyclic ring. ii) The nanoparticle system prepared with Cy5 showed

  3. Hydrogen storage and delivery system development: Analysis

    SciTech Connect

    Handrock, J.L.

    1996-10-01

    Hydrogen storage and delivery is an important element in effective hydrogen utilization for energy applications and is an important part of the FY1994-1998 Hydrogen Program Implementation Plan. This project is part of the Field Work Proposal entitled Hydrogen Utilization in Internal Combustion Engines (ICE). The goal of the Hydrogen Storage and Delivery System Development Project is to expand the state-of-the-art of hydrogen storage and delivery system design and development. At the foundation of this activity is the development of both analytical and experimental evaluation platforms. These tools provide the basis for an integrated approach for coupling hydrogen storage and delivery technology to the operating characteristics of potential hydrogen energy use applications. Results of the analytical model development portion of this project will be discussed. Analytical models have been developed for internal combustion engine (ICE) hybrid and fuel cell driven vehicles. The dependence of hydride storage system weight and energy use efficiency on engine brake efficiency and exhaust temperature for ICE hybrid vehicle applications is examined. Results show that while storage system weight decreases with increasing engine brake efficiency energy use efficiency remains relatively unchanged. The development, capability, and use of a recently developed fuel cell vehicle storage system model will also be discussed. As an example of model use, power distribution and control for a simulated driving cycle is presented. Model calibration results of fuel cell fluid inlet and exit temperatures at various fuel cell idle speeds, assumed fuel cell heat capacities, and ambient temperatures are presented. The model predicts general increases in temperature with fuel cell power and differences between inlet and exit temperatures, but under predicts absolute temperature values, especially at higher power levels.

  4. Development of cytarabine prodrugs and delivery systems for leukemia treatment.

    PubMed

    Chhikara, Bhupender S; Parang, Keykavous

    2010-12-01

    Cytarabine is a polar nucleoside drug used for the treatment of myeloid leukemia and non-Hodgkin's lymphoma. The drug has a short plasma half-life, low stability and limited bioavailability. Overdosing of patients with continuous infusions may lead to side effects. Thus, various prodrug strategies and delivery systems have been explored extensively to enhance the half-life, stability and delivery of cytarabine. Among the recent cytarabine prodrugs, amino acid conjugate ValCytarabine and fatty acid derivative CP-4055 (in Phase III trials) have been investigated for the treatment of leukemia and solid tumors, respectively. Alternatively, delivery systems of cytarabine have emerged for the treatment of different cancers. The liposomal-cytarabine formulation (DepoCyt®, Pacira Pharmaceuticals Inc., New Jersey, USA) has been approved for the treatment of lymphomatous meningitis. Various prodrug strategies evaluated for cytarabine are discussed. Then, the review summarizes the drug delivery systems that have been used for more effective cancer therapy. This review provides in-depth discussion of the prodrug strategy and delivery systems of cytarabine derivatives for the treatment of cancer. The design of cytarabine prodrugs and delivery systems provides insights for designing the next generation of more effective anticancer agents with enhanced delivery and stability. Strategies on designing cytarabine prodrug and delivery formulations showed great promise in developing effective anticancer agents with better therapeutic profile. Similar studies with other anticancer nucleosides can be an alternative approach to gaining access to more effective anticancer agents.

  5. Application of proteins in burst delivery systems

    NASA Astrophysics Data System (ADS)

    Freeman, E.; Weiland, L. M.; Meng, W. S.

    2010-09-01

    Biological proteins embedded in either a biological or an engineered membrane will actively maintain electrochemical balance across that membrane. In this study two applications will be examined. First a system of governing equations will be calibrated for a biological endosome. The endocytosis predictions presented then serve to validate the model. In addition, these predictions introduce new insights into endosome burst, which is of interest for advancing DNA vaccine delivery. The calibrated model is subsequently adapted to an analogous engineering scenario for targeted payload delivery. In the presence of a specific external stimulus, burst release of an arbitrary payload encased in a vesicle akin to an endosome is explored. Control of the process through manipulation of vesicle size, stimulus, and transporters is presented. A case is made for application of proteins as building blocks in the design of targeted response materials.

  6. Status of Statewide Career Information Delivery Systems.

    ERIC Educational Resources Information Center

    Dunn, Wynonia L.

    Intended as a resource document as well as a status report on all the statewide career information delivery systems (CIDS) in operation, this report examines the status of 39 statewide information systems. (Career information delivery systems are computer-based systems that provide national, state, and local information to individuals who are in…

  7. Nanogel Carrier Design for Targeted Drug Delivery

    PubMed Central

    Eckmann, D. M.; Composto, R. J.; Tsourkas, A.; Muzykantov, V. R.

    2014-01-01

    Polymer-based nanogel formulations offer features attractive for drug delivery, including ease of synthesis, controllable swelling and viscoelasticity as well as drug loading and release characteristics, passive and active targeting, and the ability to formulate nanogel carriers that can respond to biological stimuli. These unique features and low toxicity make the nanogels a favorable option for vascular drug targeting. In this review, we address key chemical and biological aspects of nanogel drug carrier design. In particular, we highlight published studies of nanogel design, descriptions of nanogel functional characteristics and their behavior in biological models. These studies form a compendium of information that supports the scientific and clinical rationale for development of this carrier for targeted therapeutic interventions. PMID:25485112

  8. Collagen macromolecular drug delivery systems

    SciTech Connect

    Gilbert, D.L.

    1988-01-01

    The objective of this study was to examine collagen for use as a macromolecular drug delivery system by determining the mechanism of release through a matrix. Collagen membranes varying in porosity, crosslinking density, structure and crosslinker were fabricated. Collagen characterized by infrared spectroscopy and solution viscosity was determined to be pure and native. The collagen membranes were determined to possess native vs. non-native quaternary structure and porous vs. dense aggregate membranes by electron microscopy. Collagen monolithic devices containing a model macromolecule (inulin) were fabricated. In vitro release rates were found to be linear with respect to t{sup {1/2}} and were affected by crosslinking density, crosslinker and structure. The biodegradation of the collagen matrix was also examined. In vivo biocompatibility, degradation and {sup 14}C-inulin release rates were evaluated subcutaneously in rats.

  9. Microfabricated injectable drug delivery system

    DOEpatents

    Krulevitch, Peter A.; Wang, Amy W.

    2002-01-01

    A microfabricated, fully integrated drug delivery system capable of secreting controlled dosages of multiple drugs over long periods of time (up to a year). The device includes a long and narrow shaped implant with a sharp leading edge for implantation under the skin of a human in a manner analogous to a sliver. The implant includes: 1) one or more micromachined, integrated, zero power, high and constant pressure generating osmotic engine; 2) low power addressable one-shot shape memory polymer (SMP) valves for switching on the osmotic engine, and for opening drug outlet ports; 3) microfabricated polymer pistons for isolating the pressure source from drug-filled microchannels; 4) multiple drug/multiple dosage capacity, and 5) anisotropically-etched, atomically-sharp silicon leading edge for penetrating the skin during implantation. The device includes an externally mounted controller for controlling on-board electronics which activates the SMP microvalves, etc. of the implant.

  10. Rapid Data Delivery System (RDDS)

    USGS Publications Warehouse

    Cress, Jill J.; Goplen, Susan E.

    2007-01-01

    Since the start of the active 2000 summer fire season, the U. S. Geological Survey (USGS) Rocky Mountain Geographic Science Center (RMGSC) has been actively engaged in providing crucial and timely support to Federal, State, and local natural hazards monitoring, analysis, response, and recovery activities. As part of this support, RMGSC has developed the Rapid Data Delivery System (RDDS) to provide emergency and incident response teams with timely access to geospatial data. The RDDS meets these needs by combining a simple web-enabled data viewer for the selection and preview of vector and raster geospatial data with an easy to use data ordering form. The RDDS viewer also incorporates geospatial locations for current natural hazard incidents, including wildfires, earthquakes, hurricanes, and volcanoes, allowing incident responders to quickly focus on their area of interest for data selection.

  11. Investigation of Need of Natural Bioenhancer for a Metabolism Susceptible Drug-Raloxifene, in a Designed Self-Emulsifying Drug Delivery System.

    PubMed

    Thakur, Poonam Singh; Singh, Narinder; Sangamwar, Abhay T; Bansal, Arvind Kumar

    2017-02-21

    Bioenhancers can increase the bioavailability of metabolism susceptible drugs. The present study was designed to understand the impact of bioenhancer on permeability and bioavailability of a biopharmaceutical drug disposition classification system (BDDCS) class II drug raloxifene (RLX). RLX undergoes extensive first pass metabolism by UGT enzymes in gastrointestinal tract (GIT) and has an oral bioavailability of about 2%. Self-emulsifying drug delivery system (SEDDS) of RLX was developed using a designed approach and this formulation was loaded with reported bioenhancers: quercetin and piperine. These formulations were tested for improvement in permeability and bioavailability of the RLX. The apparent permeability using everted gut sac (P app) for SEDDS (5.26 ± 1.10 × 10(-8) cm/s) was found to be similar to that of SEDDS with bioenhancers (5.11 ± 1.05 × 10(-8) cm/s). In oral bioavailability study in rat, SEDDS demonstrated a 4-fold and 2.5-fold higher AUC0-∞ than RLX suspension (control) and marketed product, respectively. No additional improvement in permeability and bioavailability was offered by inclusion of piperine and quercetin (bioenhancers) in the SEDDS.

  12. Bio-mimetic drug delivery systems designed to help the senior population reconstruct melatonin plasma profiles similar to those of the healthy younger population.

    PubMed

    Li, Ying; Wang, Liuyi; Wu, Li; Zhang, Xueju; Li, Xue; Guo, Zhen; Li, Haiyan; York, Peter; Gui, Shuangying; Zhang, Jiwen

    2014-02-01

    The secretion of melatonin (MT) is obviously different in the younger and the senior sectors of the population, and the maximum plasma concentration of seniors is only half of that in the younger population group. If exogenous MT can be supplied to senior citizens based on the secretion rate and amount of endogenous MT in the younger population by a bio-mimetic drug delivery system (DDS), an improved therapeutic effect and reduced side effects can be expected. Based upon this hypothesis, the pharmacokinetic parameters of MT, namely, the absorption rate constant (k a), the elimination rate constant (k e), and the ratio of absorption rate (F) to the apparent volume of distribution (V) were obtained by a residual method depending on the plasma concentration curve of immediate release preparations in the healthy younger population. The dose-division method was applied to calculate the cumulative release profiles of MT achieved by oral administration of a controlled release drug delivery system (DDS) to generate plasma MT profiles similar to the physiological level-time profiles. The in vivo release of MT deduced from the healthy younger population physiological MT profiles as the pharmacokinetic output of the bio-mimetic DDS showed a two-phase profile with two different zero order release rates, namely, 4.919 μg/h during 0-4 h (r=0.9992), and 11.097 μg/h during 4-12 h (r=0.9886), respectively. Since the osmotic pump type of DDS generally exhibits a good correlation between in vivo and in vitro release behaviors, an osmotic pump controlled delivery system was designed in combination with dry coating technology targeting on the cumulative release characteristics to mimic the physiological MT profiles in the healthy younger population. The high similarity between the experimental drug release profiles and the theoretical profiles (similarity factor f 2>50) and the high correlation between the predicted plasma concentration profiles and the theoretical plasma

  13. Bio-mimetic drug delivery systems designed to help the senior population reconstruct melatonin plasma profiles similar to those of the healthy younger population

    PubMed Central

    Li, Ying; Wang, Liuyi; Wu, Li; Zhang, Xueju; Li, Xue; Guo, Zhen; Li, Haiyan; York, Peter; Gui, Shuangying; Zhang, Jiwen

    2014-01-01

    The secretion of melatonin (MT) is obviously different in the younger and the senior sectors of the population, and the maximum plasma concentration of seniors is only half of that in the younger population group. If exogenous MT can be supplied to senior citizens based on the secretion rate and amount of endogenous MT in the younger population by a bio-mimetic drug delivery system (DDS), an improved therapeutic effect and reduced side effects can be expected. Based upon this hypothesis, the pharmacokinetic parameters of MT, namely, the absorption rate constant (ka), the elimination rate constant (ke), and the ratio of absorption rate (F) to the apparent volume of distribution (V) were obtained by a residual method depending on the plasma concentration curve of immediate release preparations in the healthy younger population. The dose-division method was applied to calculate the cumulative release profiles of MT achieved by oral administration of a controlled release drug delivery system (DDS) to generate plasma MT profiles similar to the physiological level-time profiles. The in vivo release of MT deduced from the healthy younger population physiological MT profiles as the pharmacokinetic output of the bio-mimetic DDS showed a two-phase profile with two different zero order release rates, namely, 4.919 μg/h during 0–4 h (r=0.9992), and 11.097 μg/h during 4–12 h (r=0.9886), respectively. Since the osmotic pump type of DDS generally exhibits a good correlation between in vivo and in vitro release behaviors, an osmotic pump controlled delivery system was designed in combination with dry coating technology targeting on the cumulative release characteristics to mimic the physiological MT profiles in the healthy younger population. The high similarity between the experimental drug release profiles and the theoretical profiles (similarity factor f2>50) and the high correlation between the predicted plasma concentration profiles and the theoretical plasma

  14. Future prospects for gene delivery systems.

    PubMed

    Kuşcu, Lale; Sezer, Ali Demir

    2017-10-01

    Gene therapy is the challenging area of biotechnology. Despite its promise for critical diseases, it has serious safety and efficiency issues, particularly with regards to gene transfer systems. Areas covered: We examined the current situation with gene transfer systems and addressed problems this technology. We then searched patent applications about in the area from the Patentscope online system, the international patent database. We analyzed the data obtained to get a general idea about gene delivery systems designed for future use and assessed approaches for more efficient, safer and valid delivery systems. Expert opinion: When quality assurance terms are fulfilled, some of these issues (genetic changes, mutations) could be minimized during the production process. Modification of vectors for improving their efficiency and safety or development of alternative transfer systems could be the solutions for these problems. Gene transfer technologies are important for gene therapy and should demonstrate effective, target-specific and acceptable safety profiles. For this reason, searching for alternatives to current systems is a necessity.

  15. Cavity Design, Fabrication and Commission Performance of a 750MHz, 4-rod Separator for CEBAF 4-Hall Beam Delivery System

    SciTech Connect

    Wang, Haipeng; Cheng, Guangfeng; Turlington, Larry T.; Wissmann, Mark J.

    2015-09-01

    A short version of the original CEBAF normal conducting 4-rod separator cavity has been developed into a 750MHz one * since the concept of simultaneous 4-hall operation for CEBAF is introduced **. This work has been advanced further based on the EM design optimization, bench measurement and by conducting RF-thermal coupled simulation using CST and ANSYS to confirm the cavity tuning and thermal performance. The cavity fabrication used matured technology like copper plating and machining. The cavity flanges, couplers, tuners and cooling channels adopted consistent/compatible hardware with the existing 500MHz cavities. The electromagnetic and thermal design simulations have greatly reduced the prototyping and bench tuning time of the first prototype. Four production cavities have reached a typical 1.94MV kick voltage or 3.0kW wall loss on each cavity after a minor multipactoring or no processing, 7.5% overhead power than the design specification.

  16. Intelligent hydrogels for drug delivery system.

    PubMed

    He, Liumin; Zuo, Qinhua; Xie, Shasha; Huang, Yuexin; Xue, Wei

    2011-09-01

    Intelligent hydrogel, also known as smart hydrogels, are materials with great potential for development in drug delivery system. Intelligent hydrogel also has the ability to perceive as a signal structure change and stimulation. The review introduces the temperature-, pH-, electric signal-, biochemical molecule-, light- and pressure- sensitive hydrogels. Finally, we described the application of intelligent hydrogel in drug delivery system and the recent patents involved for hydrogel in drug delivery.

  17. Design and synthesis of new cholesterol-conjugated 5-Fluorouracil: a novel potential delivery system for cancer treatment.

    PubMed

    Radwan, Awwad A; Alanazi, Fares K

    2014-08-26

    Cholesterol-conjugated 5-fluorouracil prodrugs were designed to be carried in vivo via low density lipoproteins (LDL) and subsequently undergo LDL-receptor-mediated internalisation into cancer cells. In vivo anti-cancer evaluation was performed using 5-fluorouracil-cholesterol conjugate in a mouse model. The obtained prodrugs were more potent than 5-fluorouracil control drug at the same 5-fluorouracil content (3 mg·kg-1).

  18. High and low energy gamma beam dump designs for the gamma beam delivery system at ELI-NP

    SciTech Connect

    Yasin, Zafar Matei, Catalin; Ur, Calin A.; Mitu, Iani-Octavian; Udup, Emil; Petcu, Cristian

    2016-03-25

    The Extreme Light Infrastructure - Nuclear Physics (ELI-NP) is under construction in Magurele, Bucharest, Romania. The facility will use two 10 PW lasers and a high intensity, narrow bandwidth gamma beam for stand-alone and combined laser-gamma experiments. The accurate estimation of particle doses and their restriction within the limits for both personel and general public is very important in the design phase of any nuclear facility. In the present work, Monte Carlo simulations are performed using FLUKA and MCNPX to design 19.4 and 4 MeV gamma beam dumps along with shielding of experimental areas. Dose rate contour plots from both FLUKA and MCNPX along with numerical values of doses in experimental area E8 of the facility are performed. The calculated doses are within the permissible limits. Furthermore, a reasonable agreement between both codes enhances our confidence in using one or both of them for future calculations in beam dump designs, radiation shielding, radioactive inventory, and other calculations releated to radiation protection. Residual dose rates and residual activity calculations are also performed for high-energy beam dump and their effect is negligible in comparison to contributions from prompt radiation.

  19. High and low energy gamma beam dump designs for the gamma beam delivery system at ELI-NP

    NASA Astrophysics Data System (ADS)

    Yasin, Zafar; Matei, Catalin; Ur, Calin A.; Mitu, Iani-Octavian; Udup, Emil; Petcu, Cristian

    2016-03-01

    The Extreme Light Infrastructure - Nuclear Physics (ELI-NP) is under construction in Magurele, Bucharest, Romania. The facility will use two 10 PW lasers and a high intensity, narrow bandwidth gamma beam for stand-alone and combined laser-gamma experiments. The accurate estimation of particle doses and their restriction within the limits for both personel and general public is very important in the design phase of any nuclear facility. In the present work, Monte Carlo simulations are performed using FLUKA and MCNPX to design 19.4 and 4 MeV gamma beam dumps along with shielding of experimental areas. Dose rate contour plots from both FLUKA and MCNPX along with numerical values of doses in experimental area E8 of the facility are performed. The calculated doses are within the permissible limits. Furthermore, a reasonable agreement between both codes enhances our confidence in using one or both of them for future calculations in beam dump designs, radiation shielding, radioactive inventory, and other calculations releated to radiation protection. Residual dose rates and residual activity calculations are also performed for high-energy beam dump and their effect is negligible in comparison to contributions from prompt radiation.

  20. Development and optimization of a self-microemulsifying drug delivery system for atorvastatin calcium by using D-optimal mixture design.

    PubMed

    Yeom, Dong Woo; Song, Ye Seul; Kim, Sung Rae; Lee, Sang Gon; Kang, Min Hyung; Lee, Sangkil; Choi, Young Wook

    2015-01-01

    In this study, we developed and optimized a self-microemulsifying drug delivery system (SMEDDS) formulation for improving the dissolution and oral absorption of atorvastatin calcium (ATV), a poorly water-soluble drug. Solubility and emulsification tests were performed to select a suitable combination of oil, surfactant, and cosurfactant. A D-optimal mixture design was used to optimize the concentration of components used in the SMEDDS formulation for achieving excellent physicochemical characteristics, such as small droplet size and high dissolution. The optimized ATV-loaded SMEDDS formulation containing 7.16% Capmul MCM (oil), 48.25% Tween 20 (surfactant), and 44.59% Tetraglycol (cosurfactant) significantly enhanced the dissolution rate of ATV in different types of medium, including simulated intestinal fluid, simulated gastric fluid, and distilled water, compared with ATV suspension. Good agreement was observed between predicted and experimental values for mean droplet size and percentage of the drug released in 15 minutes. Further, pharmacokinetic studies in rats showed that the optimized SMEDDS formulation considerably enhanced the oral absorption of ATV, with 3.4-fold and 4.3-fold increases in the area under the concentration-time curve and time taken to reach peak plasma concentration, respectively, when compared with the ATV suspension. Thus, we successfully developed an optimized ATV-loaded SMEDDS formulation by using the D-optimal mixture design, that could potentially be used for improving the oral absorption of poorly water-soluble drugs.

  1. Development and optimization of a self-microemulsifying drug delivery system for ator vastatin calcium by using d-optimal mixture design

    PubMed Central

    Yeom, Dong Woo; Song, Ye Seul; Kim, Sung Rae; Lee, Sang Gon; Kang, Min Hyung; Lee, Sangkil; Choi, Young Wook

    2015-01-01

    In this study, we developed and optimized a self-microemulsifying drug delivery system (SMEDDS) formulation for improving the dissolution and oral absorption of atorvastatin calcium (ATV), a poorly water-soluble drug. Solubility and emulsification tests were performed to select a suitable combination of oil, surfactant, and cosurfactant. A d-optimal mixture design was used to optimize the concentration of components used in the SMEDDS formulation for achieving excellent physicochemical characteristics, such as small droplet size and high dissolution. The optimized ATV-loaded SMEDDS formulation containing 7.16% Capmul MCM (oil), 48.25% Tween 20 (surfactant), and 44.59% Tetraglycol (cosurfactant) significantly enhanced the dissolution rate of ATV in different types of medium, including simulated intestinal fluid, simulated gastric fluid, and distilled water, compared with ATV suspension. Good agreement was observed between predicted and experimental values for mean droplet size and percentage of the drug released in 15 minutes. Further, pharmacokinetic studies in rats showed that the optimized SMEDDS formulation considerably enhanced the oral absorption of ATV, with 3.4-fold and 4.3-fold increases in the area under the concentration-time curve and time taken to reach peak plasma concentration, respectively, when compared with the ATV suspension. Thus, we successfully developed an optimized ATV-loaded SMEDDS formulation by using the d-optimal mixture design, that could potentially be used for improving the oral absorption of poorly water-soluble drugs. PMID:26089663

  2. Preparation of a beta-Cyclodextrin Supramolecular Nanoparticle as a Drug Delivery System The design, preparation and properties

    NASA Astrophysics Data System (ADS)

    Xin, Junjun

    Steam generator unit in nuclear power plant comprise thousands of heat exchange tubes whereby heat from primary coolant is transferred to water circulating on the secondary side. A variety of tube degradation due to mechanical vibration and chemical interactions compromises the integrity of steam generator tubes. The rupture of these tubes may result in leakage of radioactive water to the environment. Periodic inspections aimed at timely detection and characterization of the degradation is a key element for ensuring tube integrity and safe operation of nuclear power plant. Eddy current testing has proved to be an effective technique to detect defects occurring in the tube wall. In the past two decades, three types eddy current probes developed for steam generator tube inspection include bobbin coil probe, rotating probe and array probe. Each of these probes has their own limitations. The bobbin coil probe is insensitive to circumferential cracks, and rotating probe is slow and involves complex mechanical rotation whereas the array probe has poor resolution and high cost of instrumentation. This dissertation presents the design and validation of a new rotating field eddy current probe. The probe is composed of three phase rectangular windings and pickup sensor, that can be chosen to be a simple bobbin coil or a GMR array sensor placed at the probe center. The probe avoids mechanical rotation and has fast scan speed. The rotating field probe is sensitive to all orientation defects. The axial component of magnetic field along the tubing due to a defect is measured by the pickup sensor. The probe design and performance are evaluated using an experimental validated finite element model. A reduced magnetic vector potential formulation is used for simulating the different commercial probe as well as the proposed new probe design. A probe prototype is built to validate the simulation results with respect to different defects. A parametric study is conducted using the model

  3. Biopolymers as transdermal drug delivery systems in dermatology therapy.

    PubMed

    Basavaraj, K H; Johnsy, George; Navya, M A; Rashmi, R; Siddaramaiah

    2010-01-01

    The skin is considered a complex organ for drug delivery because of its structure. Drug delivery systems are designed for the controlled release of drugs through the skin into the systemic circulation, maintaining consistent efficacy and reducing the dose of the drugs and their related side effects. Transdermal drug delivery represents one of the most rapidly advancing areas of novel drug delivery. The excellent impervious nature of the skin is the greatest challenge that must be overcome for successful drug delivery. Today, polymers have been proven to be successful for long-term drug delivery applications as no single polymer can satisfy all of the requirements. Biopolymers in the field of dermal application are rare and the mechanisms that affect skin absorption are almost unknown. Biopolymers are widely used as drug delivery systems, but as such the use of biopolymers as drug delivery systems in dermatologic therapy is still in progress. Commonly used biopolymers include hydrocolloids, alginates, hydrogels, polyurethane, collagen, poly(lactic-co-glycolic acid), chitosan, proteins and peptides, pectin, siRNAs, and hyaluronic acid. These new and exciting methods for drug delivery are already increasing the number and quality of dermal and transdermal therapies. This article reviews current research on biopolymers and focuses on their potential as drug carriers, particularly in relation to the dermatologic aspects of their use.

  4. Controlled drug delivery systems: past forward and future back.

    PubMed

    Park, Kinam

    2014-09-28

    Controlled drug delivery technology has progressed over the last six decades. This progression began in 1952 with the introduction of the first sustained release formulation. The 1st generation of drug delivery (1950-1980) focused on developing oral and transdermal sustained release systems and establishing controlled drug release mechanisms. The 2nd generation (1980-2010) was dedicated to the development of zero-order release systems, self-regulated drug delivery systems, long-term depot formulations, and nanotechnology-based delivery systems. The latter part of the 2nd generation was largely focused on studying nanoparticle formulations. The Journal of Controlled Release (JCR) has played a pivotal role in the 2nd generation of drug delivery technologies, and it will continue playing a leading role in the next generation. The best path towards a productive 3rd generation of drug delivery technology requires an honest, open dialog without any preconceived ideas of the past. The drug delivery field needs to take a bold approach to designing future drug delivery formulations primarily based on today's necessities, to produce the necessary innovations. The JCR provides a forum for sharing the new ideas that will shape the 3rd generation of drug delivery technology. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. The Controlled Drug Delivery Systems: Past Forward and Future Back

    PubMed Central

    Park, Kinam

    2014-01-01

    The controlled drug delivery technology has progressed over the last six decades. It began in 1952 with the introduction of the first sustained release formulation. The 1st generation (1950-1980) of drug delivery was focused on developing oral and transdermal sustained release systems and establishing the controlled drug release mechanisms. Attention of the 2nd generation (1980-2010) was dedicated to development of zero-order release systems, self-regulated drug delivery systems, long-term depot formulations, and nanotechnology-based delivery systems. The latter part of the 2nd generation was consumed mostly for studying nanoparticle formulations. The Journal of Controlled Release (JCR) has played a pivotal role during the 2nd generation of drug delivery technologies, and it will continue playing a leading role for the next generation. Taking the right path towards the productive 3rd generation of drug delivery technologies requires honest open dialogues without any preconceived ideas of the past. The drug delivery field needs to take a bold approach of designing the future drug delivery formulations first, based on today’s necessities, and produce necessary innovations. The JCR will provide the forum for sharing the new ideas that will shape the 3rd generation of drug delivery technologies. PMID:24794901

  6. Fiber coupled optical spark delivery system

    DOEpatents

    Yalin, Azer; Willson, Bryan; Defoort, Morgan

    2008-08-12

    A spark delivery system for generating a spark using a laser beam is provided, the spark delivery system including a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. In addition, the laser delivery assembly includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. In accordance with embodiments of the present invention, the assembly may be used to create a spark in a combustion engine. In accordance with other embodiments of the present invention, a method of using the spark delivery system is provided. In addition, a method of choosing an appropriate fiber for creating a spark using a laser beam is also presented.

  7. Excimer lasers: Applications, beam delivery systems, and laser design; Proceedings of the Meeting, Boston, MA, Nov. 18, 19, 1992

    NASA Astrophysics Data System (ADS)

    Greer, James A.

    1993-04-01

    The papers presented in this volume provide an overview of recent advances in excimer laser design and performance and several related technologies, as well as new excimer applications. Topics discussed include laser ablation as a new tool for material science, excimer laser damage testing of optical materials, improvements in crystal optics for excimer lasers, and excimer laser processing of aerospace alloys. Attention is also given to novel applications of excimer lasers for fabricating biomedical and sensor products, progress in discharge-pumped excimer lasers, and micromachining with waveguide excimer lasers.

  8. Design and development of novel lipid based gastroretentive delivery system: response surface analysis, in-vivo imaging and pharmacokinetic study.

    PubMed

    Ahmed Abdelbary, Aly; Elsayed, Ibrahim; Hassen Elshafeey, Ahmed

    2015-01-01

    Famotidine HCl has low bioavailability (40-45%) due to its narrow absorption window and low solubility in intestinal pH. Lipids were utilized in the formulation of novel gastroretentive dosage forms to increase the availability of famotidine HCl at its absorption site. Novel non-swellable gastroretentive lipid disks (D) and swellable compression coated tablets with a lipid core (T) were prepared. Formulae were characterized by friability testing, in-vitro buoyancy, in-vitro drug release and scanning electron microscopy (SEM). Factorial designs of 2(2 )× 3(1) and 3(2) were planned for the optimization of disks and tablets, respectively, using Design-Expert® software. X-ray imaging was used for the in-vivo visualization of the selected formula in human gastrointestinal tract (GIT). Moreover, a bioavailability study was performed in healthy human volunteers using the optimized disk formula (D10). Results showed that formulae D10 (containing stearyl alcohol and polyethylene glycol in a ratio of 9:1 w/w) and T7 (containing polyethylene oxide only) had highest desirability values (0.684 and 0.842, respectively). Lipids achieved instantaneous floating and sustained the release of famotidine HCl over a prolonged period of time with significant bioavailability enhancement.

  9. Tax exemption and integrated delivery systems.

    PubMed

    Aseltyne, W J; Peters, G R

    1994-01-01

    This chapter discusses tax exemption of integrated delivery systems, including the requirements for exemption, the charitable purposes test, the private inurement and private benefit tests, and an application to integrated delivery systems. It also discusses the structure of the Friendly Hills and Facey Nonprofit Medical Foundations, including the analysis of the Internal Revenue Service. Finally, it discusses the process for obtaining tax exemption.

  10. Enterprise networks. Strategies for integrated delivery systems.

    PubMed

    Siwicki, B

    1997-02-01

    More integrated delivery systems are making progress toward building computer networks that link all their care delivery sites so they can efficiently and economically coordinate care. A growing number of these systems are turning to intranets--private computer networks that use Internet-derived protocols and technologies--to move information that's essential to managing scare health care resources.

  11. Development of the Choctaw Health Delivery System.

    ERIC Educational Resources Information Center

    Nguyen, Binh N.

    The Choctaw Tribe is the first and only tribe to develop a health delivery system to take over an existing Indian Health Service inpatient facility. The takeover was accomplished in January 1984 under the Indian Self-Determination Act through a contract with the Indian Health Service. The Choctaw Health Delivery System includes a 35-bed general…

  12. Development of the Choctaw Health Delivery System.

    ERIC Educational Resources Information Center

    Nguyen, Binh N.

    The Choctaw Tribe is the first and only tribe to develop a health delivery system to take over an existing Indian Health Service inpatient facility. The takeover was accomplished in January 1984 under the Indian Self-Determination Act through a contract with the Indian Health Service. The Choctaw Health Delivery System includes a 35-bed general…

  13. Rational design and engineering of a modified adeno-associated virus (AAV1)-based vector system for enhanced retrograde gene delivery.

    PubMed

    Davis, Adam S; Federici, Thais; Ray, William C; Boulis, Nicholas M; OʼConnor, Deirdre; Clark, K Reed; Bartlett, Jeffrey S

    2015-02-01

    After injection into muscle and peripheral nerves, a variety of viral vectors undergo retrograde transport to lower motor neurons. However, because of its attractive safety profile and durable gene expression, adeno-associated virus (AAV) remains the only vector to have been applied to the human nervous system for the treatment of neurodegenerative disease. Nonetheless, only a very small fraction of intramuscularly injected AAV vector arrives at the spinal cord. To engineer a novel AAV vector by inserting a neuronal targeting peptide (Tet1), with binding properties similar to those of tetanus toxin, into the AAV1 capsid. Integral to this approach was the use of structure-based design to increase the effectiveness of functional capsid engineering. This approach allowed the optimization of scaffolding regions for effective display of the foreign epitope while minimizing disruption of the native capsid structure. We also validated an approach by which low-titer tropism-modified AAV vectors can be rescued by particle mosaicism with unmodified capsid proteins. Importantly, our rationally engineered AAV1-based vectors exhibited markedly enhanced transduction of cultured motor neurons, diminished transduction of nontarget cells, and markedly superior retrograde delivery compared with unmodified AAV1 vector. This approach promises a significant advancement in the rational engineering of AAV vectors for diseases of the nervous system and other organs.

  14. Design and evaluation of San-huang dispersible tablet--an efficient delivery system for Traditional Chinese Medicine.

    PubMed

    Liu, Cuizhe; Liu, Xigang; Tong, Jiming; Chen, Dawei; Bi, Kaishun

    2009-01-01

    San-huang dispersible tablet (SHDT) was designed with a patented technology to enrich the active ingredients in rhubarb and with a wide selection of excipients in the new manufacturing procedure. The total rhubarb anthraquinones were first enriched in the extract by our patented technology. Eudragit L100, S100 and PEG-6000 were used to release a part of the total rhubarb anthraquinones at the colon to induce the cathartic effect of the anthraquinones by another patented technology. Microcrystalline Cellulose (MCC), low-substituted hydroxypropyl cellulose (L-HPC), sodium carboxymethyl starch (CMS-Na), and hydroxypropyl methylcellulose (HPMC) were used to ensure quick release of baicalin and berberine hydrochloride in the stomach. The dissolution of SHDT was evaluated by a method in 2005 Chinese Pharmacopoeia along with San-huang tablet (SHT), and the results demonstrated that the dissolution of baicalin and berberine hydrochloride more than double that of SHT and release of half of the rhubarb anthraquinones in colon.

  15. The design, fabrication and delivery of a spacelab neutral buoyancy Instrument Pointing System (IPS) mockup. [underwater training simulator

    NASA Technical Reports Server (NTRS)

    Vanvalkenburgh, C. N.

    1984-01-01

    Underwater simulations of EVA contingency operations such as manual jettison, payload disconnect, and payload clamp actuation were used to define crew aid needs and mockup pecularities and characteristics to verify the validity of simulation using the trainer. A set of mockup instrument pointing system tests was conducted and minor modifications and refinements were made. Flight configuration struts were tested and verified to be operable by the flight crew. Tasks involved in developing the following end items are described: IPS gimbal system, payload, and payload clamp assembly; the igloos (volumetric); spacelab pallets, experiments, and hardware; experiment, and hardware; experiment 7; and EVA hand tools, support hardware (handrails and foot restraints). The test plan preparation and test support are also covered.

  16. Drug delivery systems: An updated review

    PubMed Central

    Tiwari, Gaurav; Tiwari, Ruchi; Sriwastawa, Birendra; Bhati, L; Pandey, S; Pandey, P; Bannerjee, Saurabh K

    2012-01-01

    Drug delivery is the method or process of administering a pharmaceutical compound to achieve a therapeutic effect in humans or animals. For the treatment of human diseases, nasal and pulmonary routes of drug delivery are gaining increasing importance. These routes provide promising alternatives to parenteral drug delivery particularly for peptide and protein therapeutics. For this purpose, several drug delivery systems have been formulated and are being investigated for nasal and pulmonary delivery. These include liposomes, proliposomes, microspheres, gels, prodrugs, cyclodextrins, among others. Nanoparticles composed of biodegradable polymers show assurance in fulfilling the stringent requirements placed on these delivery systems, such as ability to be transferred into an aerosol, stability against forces generated during aerosolization, biocompatibility, targeting of specific sites or cell populations in the lung, release of the drug in a predetermined manner, and degradation within an acceptable period of time. PMID:23071954

  17. Transdermal testosterone delivery: comparison between scrotal and nonscrotal delivery systems.

    PubMed

    Lin, S; Xing, Q F; Chien, Y W

    1999-08-01

    The purpose of this investigation was to study the bioequivalence of two testosterone transdermal delivery systems (T-TDSs). Testoderm, designed to deliver testosterone through scrotal skin, and Androderm, designed for nonscrotal permeation. In vitro permeation and release kinetics as well as in vivo pharmacokinetics in the castrated Yucatan miniature swine (minipigs) model of both T-TDSs were studied side by side under the same experimental conditions. In vitro skin permeation kinetics studies demonstrated that testosterone permeates through minipig dorsal skin at zero-order kinetics from both T-TDSs. The nonscrotal T-TDS, however, has a permeation rate which is approximately 13 times higher than that for the scrotal T-TDS. The release of testosterone from the nonscrotal T-TDS showed a biphasic release profile between cumulative amount released and time, whereas a monophasic release profile between cumulative amount released and square root of time was observed for the scrotal T-TDS. Pharmacokinetic analysis of plasma testosterone profiles in minipigs indicated a significant difference (p < 0.001) in daily dose of testosterone delivered (1.20 versus 4.83 mg/day), maximum concentration (Cmax) (54.2 versus 218.0 ng/dl), and area under concentration-time curve (AUC0-28)[665 versus 3208 (ng/dl) x hr] between these T-TDSs. However, there is no difference in time to reach Cmax mean residence time, and daily-delivered-dose-normalized Cmax and AUC0-28. The difference in pharmacokinetic profiles resulted from the difference in daily doses delivered, which could be attributed remarkably to the difference in permeation rate (approximately 13-fold) between the nonscrotal and scrotal T-TDSs.

  18. Multiple Lipid Nanoparticles (MLN), a New Generation of Lipid Nanoparticles for Drug Delivery Systems: Lamivudine-MLN Experimental Design.

    PubMed

    Cavalcanti, Suellen M T; Nunes, Cláudia; Lima, Sofia A C; Soares-Sobrinho, José L; Reis, Salette

    2017-06-01

    An optimized methodology for the development of a new generation of lipid nanoparticles, the multiple lipid nanoparticles (MLN) is described. MLN have characteristics between nanostructured lipid carriers (NLC) and multiple emulsions (W/O/W), but without the outer aqueous phase. The production is based on a hot homogenization method combined with high shear and ultrasonication. The antiretroviral agent lamivudine (3TC), was loaded in the MLN. For comparison purposes, NLC-3TC formulation was also developed and physico-chemically characterized by the same parameters as MLN-3TC. The development and optimization of MLN and NLC formulations were supported by a Quality by Design (QbD) approach. The MLN-3TC formulation exhibited a size of about 450 nm, polydispersity <0.3 and negative zeta potential > -20 mV. Furthermore, the morphology assessed by TEM showed a structure with multiples aqueous vacuoles. MLN-3TC was physically stable for at least 45 days, had low cytotoxicity and drug release studies showed a sustained and controlled release of 3TC under gastric and plasma-simulated conditions (at pH 7.4 for about 45 h). The optimized formulations present suitable profiles for oral administration. Overall, the results reveal that MLN present higher loading capacity and storage stability than NLC.

  19. Design and evaluation of baicalin-containing in situ pH-triggered gelling system for sustained ophthalmic drug delivery.

    PubMed

    Wu, Haoyun; Liu, Zhidong; Peng, Junjie; Li, Lin; Li, Nan; Li, Jiawei; Pan, Hao

    2011-05-30

    Baicalin has been reported to have anti-inflammatory and anti-cataract effects on eye tissues, but it has a low bioavailability partly due to its poor stability of baicalin, the special anatomic structure and efficient protective mechanism of eyes. The aim of this study was to investigate the correlation between the stability of baicalin and in situ pH-triggered gelling system. Carbopol(®) 974P (0.3%, w/v) was used as the gelling agent combined with hydroxypropylmethylcellulose E4M (0.6%, w/v) which acted as a viscosity enhancing agent. In vitro and in vivo evaluations were performed using several techniques, namely confocal scanning light microscopy analysis, rheometry, Gamma scintigraphic technique and microdialysis method. The rheological behavior showed a significant enhancement in gel strength under physiological conditions, and the formulation provided sustained release of the drug over an 8-h period. In elimination studies, the radioactivity of formulation was always higher than that of the control solution. Additionally, the AUC and C(max) values were 6.1-fold and 3.6-fold higher than those of the control solution, respectively. The results demonstrated that an in situ pH-triggered gelling system have better ability to keep baicalin stable and retain drug release than marketed baicalin eye drops to enhance the ocular bioavailability. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

  20. Design Project on Controlled-Release Drug Delivery Devices: Implementation, Management, and Learning Experiences

    ERIC Educational Resources Information Center

    Xu, Qingxing; Liang, Youyun; Tong, Yen Wah; Wang, Chi-Hwa

    2010-01-01

    A design project that focuses on the subject of controlled-release drug delivery devices is presented for use in an undergraduate course on mass transfer. The purpose of the project is to introduce students to the various technologies used in the fabrication of drug delivery systems and provide a practical design exercise for understanding the…

  1. Design Project on Controlled-Release Drug Delivery Devices: Implementation, Management, and Learning Experiences

    ERIC Educational Resources Information Center

    Xu, Qingxing; Liang, Youyun; Tong, Yen Wah; Wang, Chi-Hwa

    2010-01-01

    A design project that focuses on the subject of controlled-release drug delivery devices is presented for use in an undergraduate course on mass transfer. The purpose of the project is to introduce students to the various technologies used in the fabrication of drug delivery systems and provide a practical design exercise for understanding the…

  2. Design and development of a safer non-invasive transungual drug delivery system for topical treatment of onychomycosis.

    PubMed

    Pal, Paulami; Thakur, R S; Ray, Subhabrata; Mazumder, Bhaskar

    2015-01-01

    The main objective of this study is to develop a safer non-invasive treatment for nail infections since the current treatment regimen has drawbacks like, incidence of systemic side-effects and higher cost. Proposed topical treatment on the other hand can drastically improve the situation, hence highly desirable. This work was undertaken with a hypothesis to develop a transungual microemulsion gel for topical treatment of onychomycosis. Benzyl alcohol and isopropyl myristate were used as oil, Pluronic F68 as surfactant and ethanol as co surfactant, in double-distilled water and loading itraconazole as the model antifungal drug. Pseudo-ternary phase diagram was developed by titrating different ratios of total oil and water with total surfactant, and Km ratio was fixed at 1:1. Microemulsion formulations were prepared based on the phase diagram and incorporated in gels by adding Carbopol 934P. Nail permeation enhancers like urea and salicylic acid were used to increase drug permeation through the nail plate. Parameters like drug loading, clarity, particle size distribution, drug entrapment efficiency (DEE), drug release profile, release kinetics and nail uptake were checked for the evaluation of the formulations. Complete release of drug from the formulation varied from 60 to 120 min. The optimized formulation had DEE of 92.75%, complete drug release in 60 min and highest nail uptake of 0.386%/mm(2) (39 µg of drug) with 5% urea as nail permeation enhancer. The formulation may prove beneficial in safer treatment of onychomycosis.

  3. Application of Artificial Neural Networks in the Design and Optimization of a Nanoparticulate Fingolimod Delivery System Based on Biodegradable Poly(3-Hydroxybutyrate-Co-3-Hydroxyvalerate).

    PubMed

    Shahsavari, Shadab; Rezaie Shirmard, Leila; Amini, Mohsen; Abedin Dokoosh, Farid

    2017-01-01

    Formulation of a nanoparticulate Fingolimod delivery system based on biodegradable poly(3-hydroxybutyrate-co-3-hydroxyvalerate) was optimized according to artificial neural networks (ANNs). Concentration of poly(3-hydroxybutyrate-co-3-hydroxyvalerate), PVA and amount of Fingolimod is considered as the input value, and the particle size, polydispersity index, loading capacity, and entrapment efficacy as output data in experimental design study. In vitro release study was carried out for best formulation according to statistical analysis. ANNs are employed to generate the best model to determine the relationships between various values. In order to specify the model with the best accuracy and proficiency for the in vitro release, a multilayer percepteron with different training algorithm has been examined. Three training model formulations including Levenberg-Marquardt (LM), gradient descent, and Bayesian regularization were employed for training the ANN models. It is demonstrated that the predictive ability of each training algorithm is in the order of LM > gradient descent > Bayesian regularization. Also, optimum formulation was achieved by LM training function with 15 hidden layers and 20 neurons. The transfer function of the hidden layer for this formulation and the output layer were tansig and purlin, respectively. Also, the optimization process was developed by minimizing the error among the predicted and observed values of training algorithm (about 0.0341).

  4. Micro-porous surfaces in controlled drug delivery systems: design and evaluation of diltiazem hydrochloride controlled porosity osmotic pump using non-ionic surfactants as pore-former.

    PubMed

    Adibkia, Khosro; Ghanbarzadeh, Saeed; Shokri, Mohammad Hosein; Arami, Zahra; Arash, Zeinab; Shokri, Javad

    2014-06-01

    The major problem associated with conventional drug delivery systems is unpredictable plasma concentrations. The aim of this study was to design a controlled porosity osmotic pump (CPOP) of diltiazem hydrochloride to deliver the drug in a controlled manner. CPOP tablets were prepared by incorporation of drug in the core and subsequent coating with cellulose acetate as semi-permeable membrane. Non-ionic surfactants were applied as pore-formers as well. The effect of pore-formers concentration on the in vitro release of diltiazem was also studied. The formulations were compared based on four comparative parameters, namely, total drug released after 24 h (D24 h), lag-time (tL), squared correlation coefficient of zero order equation (RSQzero) and mean percent deviation from zero order kinetic (MPDzero). Results of scanning electron microscopy studies exhibited formation of pores in the membrane from where the drug release occurred. It was revealed that drug release rate was directly proportional to the concentration of the pore-formers. The value of D24 h in the formulations containing Tween 80 (10%) and Brij 35 (5%) were found to be more than 94.9%, and drug release followed zero order kinetic (RSQzero > 0.99 and MPDzero < 8%) with acceptable tL (lower than 1 h).

  5. Formulation and Application of Biodegradable Nanoparticles Based Biopharmaceutical Delivery - An Efficient Delivery System.

    PubMed

    Bhattacharjee, Surajit; Sarkar, Biplab; Sharma, Ashish Ranjan; Gupta, Priya; Sharma, Garima; Lee, Sang-Soo; Chakraborty, Chiranjib

    2016-01-01

    Biodegradable polymer based drug delivery has emerged as a promising and successful clinical tool for specific targeting and controlled drug release delivery system. Various other unique advantages associated with this delivery system include prolonged circulation, biocompatibility, degradation in nontoxic by-products etc. Till date, various biopharmaceutical agents have been successfully encapsulated within biodegradable polymers and used in clinics. However, before the clinical implementation of such nanocarriers different parameters have to be considered which influence the success of these nanocarriers such as drug release profile, size of nanocarrier, degradation mechanism, toxicity profile, type of polymer used, appropriate synthesis method, selection of mode of delivery etc. The following review focuses on such considerations to explore the area of designing and development of biodegradable polymeric nanosystems which when encapsulated with biopharmaceutical agents can be efficient for clinical application.

  6. New delivery systems and propellants.

    PubMed

    Dolovich, M

    1999-01-01

    The removal of chlorofluorocarbon (CFC) propellants from industrial and household products has been agreed to by over 165 countries of which more than 135 are developing countries. The timetable for this process is outlined in the Montreal Protocol on Substances that Deplete the Ozone Layer document and in several subsequent amendments. Pressured metered dose inhalers (pMDIs) for medical use have been granted temporary exemptions until replacement formulations, providing the same medication via the same route, and with the same efficacy and safety profiles, are approved for human use. Hydrofluoroalkanes (HFAs) are the alternative propellants for CFCs-12 and -114. Their potential for damage to the ozone layer is nonexistent, and while they are greenhouse gases, their global warming potential is a fraction (one-tenth) of that of CFCs. Replacement formulations for almost all inhalant respiratory medications have been or are being produced and tested; in Canada, it is anticipated that the transition to these HFA or CFC-free pMDIs will be complete by the year 2005. Initially, an HFA pMDI was to be equivalent to the CFC pMDI being replaced, in terms of aerosol properties and effective clinical dose. However, this will not necessarily be the situation, particularly for some corticosteroid products. Currently, only one CFC-free formulation is available in Canada - Airomir, a HFA salbutamol pMDI. This paper discusses the in vitro aerosol characteristics, in vivo deposition and clinical data for several HFA pMDIs for which there are data available in the literature. Alternative delivery systems to the pMDI, namely, dry powder inhalers and nebulizers, are briefly reviewed.

  7. Multi-channel gas-delivery system

    SciTech Connect

    Rozenzon, Yan; Trujillo, Robert T.; Beese, Steven C.

    2016-09-13

    One embodiment of the present invention provides a gas-delivery system for delivering reaction gas to a reactor chamber. The gas-delivery system includes a main gas-inlet port for receiving reaction gases and a gas-delivery plate that includes a plurality of gas channels. A gas channel includes a plurality of gas holes for allowing the reaction gases to enter the reactor chamber from the gas channel. The gas-delivery system further includes a plurality of sub-gas lines coupling together the main gas-inlet port and the gas-delivery plate, and a respective sub-gas line is configured to deliver a portion of the received reaction gases to a corresponding gas channel.

  8. Fiber laser coupled optical spark delivery system

    DOEpatents

    Yalin, Azer; Willson, Bryan; Defoort, Morgan; Joshi, Sachin; Reynolds, Adam

    2008-03-04

    A spark delivery system for generating a spark using a laser beam is provided, and includes a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. The laser delivery assembly further includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. Other embodiments use a fiber laser to generate a spark. Embodiments of the present invention may be used to create a spark in an engine. Yet other embodiments include collecting light from the spark or a flame resulting from the spark and conveying the light for diagnostics. Methods of using the spark delivery systems and diagnostic systems are provided.

  9. The Research Progress of Targeted Drug Delivery Systems

    NASA Astrophysics Data System (ADS)

    Zhan, Jiayin; Ting, Xizi Liang; Zhu, Junjie

    2017-06-01

    Targeted drug delivery system (DDS) means to selectively transport drugs to targeted tissues, organs, and cells through a variety of drugs carrier. It is usually designed to improve the pharmacological and therapeutic properties of conventional drugs and to overcome problems such as limited solubility, drug aggregation, poor bio distribution and lack of selectivity, controlling drug release carrier and to reduce normal tissue damage. With the characteristics of nontoxic and biodegradable, it can increase the retention of drug in lesion site and the permeability, improve the concentration of the drug in lesion site. at present, there are some kinds of DDS using at test phase, such as slow controlled release drug delivery system, targeted drug delivery systems, transdermal drug delivery system, adhesion dosing system and so on. This paper makes a review for DDS.

  10. Distance Synchronous Information Systems Course Delivery

    ERIC Educational Resources Information Center

    Peslak, Alan R.; Lewis, Griffith R.; Aebli, Fred

    2014-01-01

    Teaching computer information systems via distance education is a challenge for both student and faculty. Much research work has been performed on methods of teaching via distance education. Today we are faced with a variety of options for course delivery. Asynchronous delivery via online or lesson instruction still remains most common. But…

  11. Organized Athletics as a Leisure Delivery System.

    ERIC Educational Resources Information Center

    Kidd, Thomas R.; Mendell, Ron

    1980-01-01

    Athletic programs are leisure time delivery systems for the athletes, spectators, and the local community as long as scholarships and extensive media coverage are not involved. College administration should make sure that sports and athletics do not become a delivery sytem for public relations and finance. (CJ)

  12. Organized Athletics as a Leisure Delivery System.

    ERIC Educational Resources Information Center

    Kidd, Thomas R.; Mendell, Ron

    1980-01-01

    Athletic programs are leisure time delivery systems for the athletes, spectators, and the local community as long as scholarships and extensive media coverage are not involved. College administration should make sure that sports and athletics do not become a delivery sytem for public relations and finance. (CJ)

  13. Design and application of multifunctional DNA nanocarriers for therapeutic delivery.

    PubMed

    Charoenphol, P; Bermudez, H

    2014-04-01

    The unique programmability of nucleic acids offers versatility and flexibility in the creation of self-assembled DNA nanostructures. To date, many three-dimensional DNA architectures of varying sizes and shapes have been precisely formed. Their biocompatibility, biodegradability and high intrinsic stability in physiological environments emphasize their emerging use as carriers for drug and gene delivery. Furthermore, DNA nanocarriers have been shown to enter cells efficiently and without the aid of transfection reagents. A key strength of DNA nanocarriers over other delivery systems is their modularity and their ability to control the spatial distribution of cargoes and ligands. Optimizing DNA nanocarrier properties to dictate their localization, uptake and intracellular trafficking is also possible. This review presents design considerations for DNA nanocarriers and examples of their use in the context of therapeutic delivery applications. The assembly of DNA nanocarriers and approaches for loading and releasing cargo are described. The stability and safety of DNA nanocarriers are also discussed, with particular attention to the in vivo physiological environment. Mechanisms of cellular uptake and intracellular trafficking are examined, and the paper concludes with strategies to enhance the delivery efficiency of DNA nanocarriers. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  14. Design and Application of Multifunctional DNA Nanocarriers for Therapeutic Delivery

    PubMed Central

    Charoenphol, Phapanin; Bermudez, Harry

    2013-01-01

    The unique programmability of nucleic acids offers versatility and flexibility in the creation of self-assembled DNA nanostructures. To date, many three-dimensional DNA architectures have been precisely formed of varying sizes and shapes. Their biocompatibility, biodegradability, and high intrinsic stability in physiological environments emphasize their emerging use as carriers for drug and gene delivery. Furthermore, DNA nanocarriers have been shown to enter cells efficiently and without the aid of transfection reagents. A key strength of DNA nanocarriers over other delivery systems is their modularity and their ability to control the spatial distribution of cargoes and ligands. Optimizing DNA nanocarrier properties to dictate their localization, uptake, and intracellular trafficking is also possible. In this review, we present design considerations for DNA nanocarriers and examples of their use in the context of therapeutic delivery applications. The assembly of DNA nanocarriers and approaches for loading and releasing cargo are described. The stability and safety of DNA nanocarriers is also discussed, with particular attention to the in vivo physiological environment. Mechanisms of cellular uptake and intracellular trafficking are examined, and we conclude with strategies to enhance the delivery efficiency of DNA nanocarriers. PMID:23896566

  15. Quality-by-design based development of a self-microemulsifying drug delivery system to reduce the effect of food on Nelfinavir mesylate.

    PubMed

    Kamboj, Sunil; Rana, Vikas

    2016-03-30

    Poor aqueous solubility and moderate permeability of Nelfinavir mesylate (NFM) leads to high variability in absorption after oral administration. To improve the solubility and bioavailability of NFM, the self microemulsifying drug delivery system (SMEDDS) was developed. For this purpose, Quality by design (QbD) approach employing D-optimal mixture design was used to prepare SMEDDS of NFM. Further, the software generated numerically optimized SMEDDS were developed by utilizing desirability function. Maisine 35-1, Tween 80, and Transcutol HP were identified as oil, surfactant, and co-surfactant that had best solubility for NFM. Ternary phase diagrams were plotted to identify the self-emulsification region. Dissolution of putative NFM in simulated fasted or fed small intestinal conditions, respectively, predicted that there is a positive food effect. However, NFM loaded SMEDDS showed absence of food effect with no significant difference in dissolution performance either in Fasted or fed state simulated intestinal fluid (FaSSIF or FeSSIF) biorelevent dissolution media. The prepared SMEDDS were thermodynamically stable with droplet size (121 nm), poly dispersity index (PDI) (0.198) and emulsification time (<1 min). Transmission electron microscopy (TEM) analysis confirmed the spherical shape of the reconstituted SMEDDS droplets. The ex vivo performance revealed 4.57 fold enhancement in the apparent permeability of NFM as compared to NFM suspension. The animal pharmacokinetic analysis in New Zealand strain rabbits indicated food effect on pure NFM suspension. However, absence of food effect and 3.5-3.6 fold enhancement in the oral bioavailability was observed when NFM was formulated into SMEDDS. Thus, it could be envisaged that development of SMEDDS formulation of NFM could be one of the best alternative to enhance oral bioavailability of NFM. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Design Factors for Applying Cryogen Storage and Delivery Technology to Solar Thermal Propulsion

    NASA Technical Reports Server (NTRS)

    Millis, Marc G.

    1996-01-01

    Thermodynamic Vent System (TVS) and Multilayer Insulation (MLI) technology, originally developed for long term storage of cryogen propellants in microgravity, is ideally suited for propellant storage and delivery systems for solar thermal propulsion. With this technology the heat-induced pressure rise in the tank provides the propellant delivery pressure without the need for an auxiliary pressurant system, and propellant delivery is used to remove the excess heat to control tank pressure. The factors to consider in designing such a balanced system, are presented. An example of a minimum system design is presented along with examples of laboratory-tested hardware.

  17. Design of a peptide-based vector, PepFect6, for efficient delivery of siRNA in cell culture and systemically in vivo

    PubMed Central

    EL Andaloussi, Samir; Lehto, Taavi; Mäger, Imre; Rosenthal-Aizman, Katri; Oprea, Iulian I.; Simonson, Oscar E.; Sork, Helena; Ezzat, Kariem; Copolovici, Dana M.; Kurrikoff, Kaido; Viola, Joana R.; Zaghloul, Eman M.; Sillard, Rannar; Johansson, Henrik J.; Said Hassane, Fatouma; Guterstam, Peter; Suhorutšenko, Julia; Moreno, Pedro M. D.; Oskolkov, Nikita; Hälldin, Jonas; Tedebark, Ulf; Metspalu, Andres; Lebleu, Bernard; Lehtiö, Janne; Smith, C. I. Edvard; Langel, Ülo

    2011-01-01

    While small interfering RNAs (siRNAs) have been rapidly appreciated to silence genes, efficient and non-toxic vectors for primary cells and for systemic in vivo delivery are lacking. Several siRNA-delivery vehicles, including cell-penetrating peptides (CPPs), have been developed but their utility is often restricted by entrapment following endocytosis. Hence, developing CPPs that promote endosomal escape is a prerequisite for successful siRNA implementation. We here present a novel CPP, PepFect 6 (PF6), comprising the previously reported stearyl-TP10 peptide, having pH titratable trifluoromethylquinoline moieties covalently incorporated to facilitate endosomal release. Stable PF6/siRNA nanoparticles enter entire cell populations and rapidly promote endosomal escape, resulting in robust RNAi responses in various cell types (including primary cells), with minimal associated transcriptomic or proteomic changes. Furthermore, PF6-mediated delivery is independent of cell confluence and, in most cases, not significantly hampered by serum proteins. Finally, these nanoparticles promote strong RNAi responses in different organs following systemic delivery in mice without any associated toxicity. Strikingly, similar knockdown in liver is achieved by PF6/siRNA nanoparticles and siRNA injected by hydrodynamic infusion, a golden standard technique for liver transfection. These results imply that the peptide, in addition to having utility for RNAi screens in vitro, displays therapeutic potential. PMID:21245043

  18. Drug delivery systems from nose to brain.

    PubMed

    Misra, Ambikanandan; Kher, Gitanjali

    2012-09-01

    The treatment of brain disorders is particularly challenging due to the presence of a variety of formidable obstacles to deliver drugs selectively and effectively to the brain. Blood-brain-barrier (BBB) constitutes the major obstacle to the uptake of drugs into the brain following systemic administration. Intranasal delivery offers a non-invasive and convenient method to bypass the BBB and delivery of therapeutics directly to the brain. The review discusses the potential of intranasal route to deliver drugs to the brain, the mechanisms and pathways of direct nose to brain drug transport, the various factors influencing transnasal drug absorption, the conventional and novel intranasal drug delivery systems, the various intranasal drug delivery techniques and devices, and examples of brain drug transport that have been feasible in treating various brain disorders. Moreover, products on the market, investigational drugs, and the author's perceptions about the prospect of intranasal delivery for treating brain disorders are also been discussed.

  19. Alternative delivery systems in rural areas.

    PubMed Central

    Christianson, J B

    1989-01-01

    Alternative delivery systems, such as HMOs, PPOs, and primary care case-management programs, have a long history in rural America despite significant impediments to their development. However, little is known about the effect of these systems on rural communities and their medical care delivery systems. Existing studies, which focus on rural HMOs, are qualitative in nature and generally are directed at identifying factors that facilitate or retard HMO development. Despite their limitations, the studies do raise a variety of issues deserving of quantitative analysis. Research is now needed that (1) investigates the effect of rural alternative delivery systems on the cost and quality of care received by rural residents, (2) assesses the effectiveness of different mechanisms used by these systems to contain costs, (3) estimates the effect of alternative delivery systems on rural providers, (4) determines the extent to which the presence or absence of alternative delivery systems influences physician decisions to locate in rural areas, (5) identifies factors that are important in consumer decisions to enroll or not enroll in a rural alternative delivery system, and (6) analyzes the diffusion patterns of these systems in rural areas. PMID:2645250

  20. Design and Concept of Polyzwitterionic Copolymer Microgel Drug Delivery Systems In Situ Loaded with Non-steroidal Anti-inflammatory Ibuprofen.

    PubMed

    Kostova, Bistra; Kamenska, Elena; Georgieva, Dilyana; Balashev, Konstantin; Rachev, Dimitar; Georgiev, George

    2017-01-01

    Nowadays, the modern pharmaceutical investigations are directed toward obtaining of new polymer micro- and nano-sized drug delivery carriers. In this respect, the use of hydrogel carriers based on polyzwitterions (PZIs) is an opportunity in the preparation of polymer drug delivery systems with desired characteristics. This paper describes the synthesis and characterization of micro-structured p(VA-co-DMAPS) systems with different compositions in situ loaded with Ibuprofen by emulsifier-free emulsion copolymerization (EEC) in water. The mean size of the prepared microparticles was measured by SEM and particles have been visualized by AFM. The inclusion of Ibuprofen in the polyzwitterionic copolymer microgel systems was established by using DSC. In vitro drug release experiments were carried out in order to estimate the ability of the obtained microgels to modify the release of water-insoluble Ibuprofen.

  1. Harnessing hospital purchase power to design safe care delivery.

    PubMed

    Ebben, Steven F; Gieras, Izabella A; Gosbee, Laura Lin

    2008-01-01

    Since the Institute of Medicine's well-publicized 1999 report To Err is Human, the healthcare patient safety movement has grown at an exponential pace. However, much more can be done to advance patient safety from a care process design vantage point-improving safety through effective care processes and technology integration. While progress is being made, the chasm between technology developers and caregivers remains a profound void. Why hasn't more been done to expand our view of patient safety to include technology design? Healthcare organizations have not consolidated their purchasing power to expect improved designs. This article will (1) provide an assessment of the present state of healthcare technology management and (2) provide recommendations for collaborative design of safe healthcare delivery systems.

  2. Promoting Quality of Program Delivery via an Internet Message Delivery System

    ERIC Educational Resources Information Center

    Bishop, Dana C.; Dusenbury, Linda; Pankratz, Melinda M.; Hansen, William B.

    2013-01-01

    This article presents results from a study that evaluated an online message system designed to improve the delivery of prevention programs. We conducted a quasi-experimental study with 32 agencies and schools that implemented substance use prevention programs and examined differences between the comparison and intervention groups. We also examined…

  3. A telemedicine health care delivery system

    NASA Technical Reports Server (NTRS)

    Sanders, Jay H.

    1991-01-01

    The Interactive Telemedicine Systems (ITS) system was specifically developed to address the ever widening gap between our medical care expertise and our medical care delivery system. The frustrating reality is that as our knowledge of how to diagnose and treat medical conditions has continued to advance, the system to deliver that care has remained in an embryonic stage. This has resulted in millions of people being denied their most basic health care needs. Telemedicine utilizes an interactive video system integrated with biomedical telemetry that allows a physician at a base station specialty medical complex or teaching hospital to examine and treat a patient at multiple satellite locations, such as rural hospitals, ambulatory health centers, correctional institutions, facilities caring for the elderly, community hospital emergency departments, or international health facilities. Based on the interactive nature of the system design, the consulting physician at the base station can do a complete history and physical examination, as if the patient at the satellite site was sitting in the physician's office. This system is described.

  4. Microneedles: an emerging transdermal drug delivery system.

    PubMed

    Bariya, Shital H; Gohel, Mukesh C; Mehta, Tejal A; Sharma, Om Prakash

    2012-01-01

    One of the thrust areas in drug delivery research is transdermal drug delivery systems (TDDS) due to their characteristic advantages over oral and parenteral drug delivery systems. Researchers have focused their attention on the use of microneedles to overcome the barrier of the stratum corneum. Microneedles deliver the drug into the epidermis without disruption of nerve endings. Recent advances in the development of microneedles are discussed in this review for the benefit of young scientists and to promote research in the area. Microneedles are fabricated using a microelectromechanical system employing silicon, metals, polymers or polysaccharides. Solid coated microneedles can be used to pierce the superficial skin layer followed by delivery of the drug. Advances in microneedle research led to development of dissolvable/degradable and hollow microneedles to deliver drugs at a higher dose and to engineer drug release. Iontophoresis, sonophoresis and electrophoresis can be used to modify drug delivery when used in concern with hollow microneedles. Microneedles can be used to deliver macromolecules such as insulin, growth hormones, immunobiologicals, proteins and peptides. Microneedles containing 'cosmeceuticals' are currently available to treat acne, pigmentation, scars and wrinkles, as well as for skin tone improvement. Literature survey and patents filled revealed that microneedle-based drug delivery system can be explored as a potential tool for the delivery of a variety of macromolecules that are not effectively delivered by conventional transdermal techniques. © 2011 The Authors. JPP © 2011 Royal Pharmaceutical Society.

  5. WEDDS: The WITS Encrypted Data Delivery System

    NASA Technical Reports Server (NTRS)

    Norris, J.; Backes, P.

    1999-01-01

    WEDDS, the WITS Encrypted Data Delivery System, is a framework for supporting distributed mission operations by automatically transferring sensitive mission data in a secure and efficient manner to and from remote mission participants over the internet.

  6. WEDDS: The WITS Encrypted Data Delivery System

    NASA Technical Reports Server (NTRS)

    Norris, J.; Backes, P.

    1999-01-01

    WEDDS, the WITS Encrypted Data Delivery System, is a framework for supporting distributed mission operations by automatically transferring sensitive mission data in a secure and efficient manner to and from remote mission participants over the internet.

  7. Electronic nicotine delivery systems: a research agenda

    PubMed Central

    Etter, Jean-François; Bullen, Chris; Flouris, Andreas D; Laugesen, Murray; Eissenberg, Thomas

    2011-01-01

    Electronic nicotine delivery systems (ENDS, also called electronic cigarettes or e-cigarettes) are marketed to deliver nicotine and sometimes other substances by inhalation. Some tobacco smokers report that they used ENDS as a smoking cessation aid. Whether sold as tobacco products or drug delivery devices, these products need to be regulated, and thus far, across countries and states, there has been a wide range of regulatory responses ranging from no regulation to complete bans. The empirical basis for these regulatory decisions is uncertain, and more research on ENDS must be conducted in order to ensure that the decisions of regulators, health care providers and consumers are based on science. However, there is a dearth of scientific research on these products, including safety, abuse liability and efficacy for smoking cessation. The authors, who cover a broad range of scientific expertise, from basic science to public health, suggest research priorities for non-clinical, clinical and public health studies. They conclude that the first priority is to characterize the safety profile of these products, including in long-term users. If these products are demonstrated to be safe, their efficacy as smoking cessation aids should then be tested in appropriately designed trials. Until these studies are conducted, continued marketing constitutes an uncontrolled experiment and the primary outcome measure, poorly assessed, is user health. Potentially, this research effort, contributing to the safety and efficacy of new smoking cessation devices and to the withdrawal of dangerous products, could save many lives. PMID:21415064

  8. Electronic nicotine delivery systems: a research agenda.

    PubMed

    Etter, Jean-François; Bullen, Chris; Flouris, Andreas D; Laugesen, Murray; Eissenberg, Thomas

    2011-05-01

    Electronic nicotine delivery systems (ENDS, also called electronic cigarettes or e-cigarettes) are marketed to deliver nicotine and sometimes other substances by inhalation. Some tobacco smokers report that they used ENDS as a smoking cessation aid. Whether sold as tobacco products or drug delivery devices, these products need to be regulated, and thus far, across countries and states, there has been a wide range of regulatory responses ranging from no regulation to complete bans. The empirical basis for these regulatory decisions is uncertain, and more research on ENDS must be conducted in order to ensure that the decisions of regulators, health care providers and consumers are based on science. However, there is a dearth of scientific research on these products, including safety, abuse liability and efficacy for smoking cessation. The authors, who cover a broad range of scientific expertise, from basic science to public health, suggest research priorities for non-clinical, clinical and public health studies. They conclude that the first priority is to characterize the safety profile of these products, including in long-term users. If these products are demonstrated to be safe, their efficacy as smoking cessation aids should then be tested in appropriately designed trials. Until these studies are conducted, continued marketing constitutes an uncontrolled experiment and the primary outcome measure, poorly assessed, is user health. Potentially, this research effort, contributing to the safety and efficacy of new smoking cessation devices and to the withdrawal of dangerous products, could save many lives.

  9. Cyclodextrins in delivery systems: Applications

    PubMed Central

    Tiwari, Gaurav; Tiwari, Ruchi; Rai, Awani K.

    2010-01-01

    Cyclodextrins (CDs) are a family of cyclic oligosaccharides with a hydrophilic outer surface and a lipophilic central cavity. CD molecules are relatively large with a number of hydrogen donors and acceptors and, thus in general, they do not permeate lipophilic membranes. In the pharmaceutical industry, CDs have mainly been used as complexing agents to increase aqueous solubility of poorly soluble drugs and to increase their bioavailability and stability. CDs are used in pharmaceutical applications for numerous purposes, including improving the bioavailability of drugs. Current CD-based therapeutics is described and possible future applications are discussed. CD-containing polymers are reviewed and their use in drug delivery is presented. Of specific interest is the use of CD-containing polymers to provide unique capabilities for the delivery of nucleic acids. Studies in both humans and animals have shown that CDs can be used to improve drug delivery from almost any type of drug formulation. Currently, there are approximately 30 different pharmaceutical products worldwide containing drug/CD complexes in the market. PMID:21814436

  10. Engaging Faculty in Telecommunications-Based Instructional Delivery Systems.

    ERIC Educational Resources Information Center

    Swalec, John J.

    In the design and development of telecommunications-based instructional delivery systems, attention to faculty involvement and training is often overlooked until the system is operational. The Waubonsee Telecommunications Instructional Consortium (TIC), in Illinois, is one network that benefited from early faculty input. Even before the first…

  11. Planetary Regolith Delivery Systems for ISRU

    NASA Technical Reports Server (NTRS)

    Mantovani, James G.; Townsend, Ivan I., III

    2012-01-01

    The challenges associated with collecting regolith on a planetary surface and delivering it to an in-situ resource utilization system differ significantly from similar activities conducted on Earth. Since system maintenance on a planetary body can be difficult or impossible to do, high reliability and service life are expected of a regolith delivery system. Mission costs impose upper limits on power and mass. The regolith delivery system must provide a leak-tight interface between the near-vacuum planetary surface and the pressurized ISRU system. Regolith delivery in amounts ranging from a few grams to tens of kilograms may be required. Finally, the spent regolith must be removed from the ISRU chamber and returned to the planetary environment via dust tolerant valves capable of operating and sealing over a large temperature range. This paper will describe pneumatic and auger regolith transfer systems that have already been field tested for ISRU, and discuss other systems that await future field testing.

  12. History of Polymeric Gene Delivery Systems.

    PubMed

    Zhang, Peng; Wagner, Ernst

    2017-04-01

    As an option for genetic disease treatment and an alternative for traditional cancer chemotherapy, gene therapy achieves significant attention. Nucleic acid delivery, however, remains a main challenge in human gene therapy. Polymer-based delivery systems offer a safer and promising route for therapeutic gene delivery. Over the past five decades, various cationic polymers have been optimized for increasingly effective nucleic acid transfer. This resulted in a chemical evolution of cationic polymers from the first-generation polycations towards bioinspired multifunctional sequence-defined polymers and nanocomposites. With the increasing of knowledge in molecular biological processes and rapid progress of macromolecular chemistry, further improvement of polymeric nucleic acid delivery systems will provide effective tool for gene-based therapy in the near future.

  13. Kontrollierte therapeutische Systeme (Controlled drug delivery systems)

    NASA Astrophysics Data System (ADS)

    Ha, Suk-Woo; Wintermantel, Erich

    Es gibt eine grosse Anzahl von Arzneistoffen, die nicht mit der höchsten Effizienz eingesetzt werden können, weil das geeignete therapeutische System (drug delivery system) für die optimale Applikation fehlt. Viele Arzneistoffe setzen eine häufige Anwendung voraus und sind oft mit mehr oder weniger starken Nebenwirkungen oder aber mit Beeinträchtigungen von Arbeits- und Lebensrhythmus der Patienten verbunden. Der therapeutische Erfolg einer medikamentösen Behandlung setzt eine korrekte Diagnose, die Wahl der richtigen Wirksubstanz sowie ihr Vorliegen in geeigneter Darreichungsform voraus. Zudem muss ein genauer Verabreichungsplan erstellt werden, dessen Einhaltung seitens der Patienten eine wesentliche Voraussetzung für die optimale Wirkung des Arzneistoffes ist. Das Mass, mit dem eine Wirksubstanz therapeutisch voll genutzt werden kann, korreliert direkt mit der Darreichungsform, in der sie angewandt wird. Da viele hochwirksame Arzneimittel bereits existieren, hat sich, neben Neuentwicklungen, das Interesse im vergangenen Jahrzehnt der Optimierung von Arzneimittelwirkungen durch neue Darreichungsformen zugewandt.

  14. Hydrogel-Based Controlled Delivery Systems for Articular Cartilage Repair

    PubMed Central

    Madry, Henning

    2016-01-01

    Delivery of bioactive factors is a very valuable strategy for articular cartilage repair. Nevertheless, the direct supply of such biomolecules is limited by several factors including rapid degradation, the need for supraphysiological doses, the occurrence of immune and inflammatory responses, and the possibility of dissemination to nontarget sites that may impair their therapeutic action and raise undesired effects. The use of controlled delivery systems has the potential of overcoming these hurdles by promoting the temporal and spatial presentation of such factors in a defined target. Hydrogels are promising materials to develop delivery systems for cartilage repair as they can be easily loaded with bioactive molecules controlling their release only where required. This review exposes the most recent technologies on the design of hydrogels as controlled delivery platforms of bioactive molecules for cartilage repair. PMID:27642587

  15. Goals for Postsecondary Instructional Delivery Systems.

    ERIC Educational Resources Information Center

    Knapp, Stuart E.; Valentine, Carol A.

    Extrapolating from the trends in postsecondary instructional delivery systems identified by Brown, Lewis and Harcleroad, this report attempts to identify how these trends might be implemented in Oregon. Separating the systems into technology-centered and people-centered, the report proposes future applications of dial access systems, self learning…

  16. Bioengineered Silk Gene Delivery System for Nuclear Targeting

    PubMed Central

    Yigit, Sezin; Tokareva, Olena; Varone, Antonio; Georgakoudi, Irene

    2015-01-01

    Gene delivery research has gained momentum with the use of lipophilic vectors that mimic viral systems to increase transfection efficiency. However, maintaining cell viability with these systems remains a major challenge. Therefore biocompatible and nontoxic biopolymers that are designed by combining non-immunological viral mimicking components with suitable carriers have been explored to address these limitations. In the present study recombinant DNA technology was used to design a multi-functional gene delivery system for nuclear targeting, while also supporting cell viability. Spider dragline silk recombinant proteins were modified with DNA condensing units and the proton sponge endosomal escape pathway was utilized for enhanced delivery. Short-term transfection efficiency in a COS-7 cell line (adherent kidney cells isolated from African green monkey) was enhanced compared to lipofectamine and polyethyleneimine (PEI), as was cell viability with these recombinant bio-polyplexes. Endosomal escape and consequent nuclear targeting were shown with fluorescence microscopy. PMID:24889658

  17. Insertional mutagenesis and development of malignancies induced by integrating gene delivery systems: implications for the design of safer gene-based interventions in patients.

    PubMed

    Romano, Gaetano; Marino, Ignazio R; Pentimalli, Francesca; Adamo, Vincenzo; Giordano, Antonio

    2009-05-01

    Effective gene-based interventions for the treatment of genetic disorders, neurodegenerative diseases and cardiovascular maladies require longterm transgene expression in target cells. Integrating viral vector systems based on the genera of the retroviridae and on adeno-associated virus are suitable tools, as the integration of viral vector genomes into the cellular chromosomal DNA allows for a more stable and long-lasting transgene expression than episomal gene-delivery models. Two nonviral gene-delivery systems with integrating properties have also been developed. These are based on the Sleeping Beauty DNA transposon system and on the Streptomyces bacteriophage integrase phiC31. However, the integration of recombinant vector systems may damage the natural genetic arrangement of the target cell. Such genetic alterations are termed insertional mutagenesis, which might result in malignant cell transformation. Insertional mutagenesis caused leukemia in five patients who participated in clinical trials for the treatment of severe combined immunodeficiency (SCID)-X1; sadly, one of the patients died. Gene therapists had to assess the real risk-versus-benefit ratio for the use of retroviral vectors in patients and devise novel strategies to minimize the occurrence of insertional mutagenesis-related malignancies. In this respect, a particular emphasis was placed on the engineering of enhancer-less self-inactivating retroviridae-based systems.

  18. Delivery systems for gene therapy.

    PubMed

    Mali, Shrikant

    2013-01-01

    The structure of DNA was unraveled by Watson and Crick in 1953, and two decades later Arber, Nathans and Smith discovered DNA restriction enzymes, which led to the rapid growth in the field of recombinant DNA technology. From expressing cloned genes in bacteria to expressing foreign DNA in transgenic animals, DNA is now slated to be used as a therapeutic agent to replace defective genes in patients suffering from genetic disorders or to kill tumor cells in cancer patients. Gene therapy provides modern medicine with new perspectives that were unthinkable two decades ago. Progress in molecular biology and especially, molecular medicine is now changing the basics of clinical medicine. A variety of viral and non-viral possibilities are available for basic and clinical research. This review summarizes the delivery routes and methods for gene transfer used in gene therapy.

  19. [Oxygen-conserving delivery system].

    PubMed

    Ishihara, T; Kumazaki, S; Mishima, H; Sano, K

    1992-12-01

    Three methods for improving oxygen delivery efficiency--transtracheal oxygen therapy (TTO), reservoir cannula, and demand-pulse oxygen delivery--are currently available. We discuss our experiences of TTO and its characteristics compared with the other two methods. Since 1988, we have tried to apply TTO to the candidates for home oxygen therapy (HOT) fulfilling the following criteria: 1) good activity and enthusiasm to daily life, 2) high oxygen flow rate with nasal cannula, 3) complicating nasal disorders such as chronic sinusitis, or 4) suffering complications from nasal cannula therapy. We used a disposable 8-Fr feeding tube for a trnastracheal catheter. Patients were taught to change their catheters themselves every day by simply removing the old and reinserting the new catheter. We have experienced nine patients on HOT with TTO. A half to a third of the flow rate of nasal cannular was required with TTO to achieve an equivalent PaO2 level. In cases with hypercapnea, a persistent significant increase of PaCO2 was not found. We measured arterial blood gases, changing the distance from the tract opening to the catheter tip, and it was suggested that in each case there may be an optimum distance to achieve the highest PaO2 level. Seven cases received TTO for more than 18 months, a mean of 30.2 months (range 19.3-48.9) and HOT for a mean of 26.6 months. They all maintained a high degree of enthusiasm for TTO. Two cases could return to work. Five cases enjoyed active daily lives, such as shopping, going out for recreation, travelling, and attending concerts.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Liposomes as Advanced Delivery Systems for Nutraceuticals

    PubMed Central

    Shade, Christopher W.

    2016-01-01

    Liposomes are delivery vehicles for transporting substances into the body effectively via facilitating absorption directly in the mouth or by preventing breakdown by stomach acid. Since the 1970s, liposomes have been investigated as potential drug delivery systems because of their biocompatibility and ability to incorporate both hydrophilic and hydrophobic therapeutic agents. Despite early promise, it was decades later, in the late 1990s to the present, that liposome technologies could create successful commercial products. Oral deliveries are recently emerging as availability of quality phospholipids and reliable homogenization and sizing equipment have become routinely available. Nutritional industry use of liposomes will grow rapidly in the next 5–10 y. High-quality products with more complex mixtures of pure compounds and complex botanical mixtures will offer clinicians less-invasive options for dosing and delivery of these actives. PMID:27053934

  1. Educational Power Tools: New Instructional Delivery Systems.

    ERIC Educational Resources Information Center

    Van Horn, Royal

    1991-01-01

    New instructional delivery systems are needed to individualize instruction, relieve the teacher's burden as sole information provider, and meet the challenge of student diversity. Microcomputers, optical memory devices, videodiscs, and hypermedia programs are being combined to create integrated learning systems, multimedia work stations, and other…

  2. Synthesis and factorial design applied to a novel chitosan/sodium polyphosphate nanoparticles via ionotropic gelation as an RGD delivery system.

    PubMed

    Kiilll, Charlene Priscila; Barud, Hernane da Silva; Santagneli, Sílvia Helena; Ribeiro, Sidney José Lima; Silva, Amélia M; Tercjak, Agnieszka; Gutierrez, Junkal; Pironi, Andressa Maria; Gremião, Maria Palmira Daflon

    2017-02-10

    Chitosan nanoparticles have been extensively studied for both drug and protein/peptide delivery. The aim of this study was to develop an optimized chitosan nanoparticle, by ionotropic gelation method, using 3(2) full factorial design with a novel polyanion, sodium polyphosphate, well known under the trade name Graham salt. The effects of these parameters on the particle size, zeta potential, and morphology and association efficiency were investigated. The optimized nanoparticles showed an estimated size of 166.20±1.95nm, a zeta potential of 38.7±1.2mV and an efficacy of association of 97.0±2.4%. The Atomic Force Microscopy (AFM) and Scanning Electronic Microscopy (SEM) revealed spherical nanoparticles with uniform size. Molecular interactions among the components of the nanoparticles and peptide were evaluated by Fourier Transform Infrared Spectra (FTIR) and Differential Scanning Calorimetry (DSC). The obtained results indicated that, the developed nanoparticles demonstrated high biocompatible, revealing no or low toxicity in the human cancer cell line (Caco-2). In conclusion, this work provides parameters that contribute to production of chitosan nanoparticles and sodium polyphosphate with desirable size, biocompatible and enabling successful use for protein/peptides delivery.

  3. A Molecular Communication System Model for Particulate Drug Delivery Systems.

    PubMed

    Chahibi, Youssef; Pierobon, Massimiliano; Song, Sang Ok; Akyildiz, Ian F

    2013-12-01

    The goal of a drug delivery system (DDS) is to convey a drug where the medication is needed, while, at the same time, preventing the drug from affecting other healthy parts of the body. Drugs composed of micro- or nano-sized particles (particulate DDS) that are able to cross barriers which prevent large particles from escaping the bloodstream are used in the most advanced solutions. Molecular communication (MC) is used as an abstraction of the propagation of drug particles in the body. MC is a new paradigm in communication research where the exchange of information is achieved through the propagation of molecules. Here, the transmitter is the drug injection, the receiver is the drug delivery, and the channel is realized by the transport of drug particles, thus enabling the analysis and design of a particulate DDS using communication tools. This is achieved by modeling the MC channel as two separate contributions, namely, the cardiovascular network model and the drug propagation network. The cardiovascular network model allows to analytically compute the blood velocity profile in every location of the cardiovascular system given the flow input by the heart. The drug propagation network model allows the analytical expression of the drug delivery rate at the targeted site given the drug injection rate. Numerical results are also presented to assess the flexibility and accuracy of the developed model. The study of novel optimization techniques for a more effective and less invasive drug delivery will be aided by this model, while paving the way for novel communication techniques for Intrabody communication networks.

  4. Lung surfactant as a drug delivery system.

    PubMed

    Vermehren, C; Frokjaer, S; Aurstad, T; Hansen, J

    2006-01-03

    Lung surfactant is a complex mixture of mainly phospholipids and proteins. The composition leads to a unique spreading effect of the surfactant as well as spontaneous vesicle formation, which may be favourable characteristics of a drug delivery system for pulmonary delivery. The aim of study was to investigate the potential use of the surfactant extract, HL10 (LeoPharma, DK) as a drug delivery system. Studies involved incorporation of hydrophilic- and amphipathic model drugs (sucrose and acylated peptides) into HL10 and elucidation of the influence of surfactant proteins on the HL10 behaviour. Results showed that HL10 vesicles did not retain sucrose indicating formation of leaky vesicles. Studying the influence of surfactant proteins on release from DPPC-liposomes showed tendencies toward a protein-induced release. Hence, the surfactant proteins may influence the membrane lipid packing and characteristics resulting in leakiness of the membranes. Incorporation of acylated peptides into HL10 depended on the chain length rendering a successful incorporation of the peptide acylated with C14-acyl chains. This study suggests that HL10 may be a promising drug delivery system for the pulmonary delivery of amphipathic drug substances, e.g. therapeutically active acylated peptides (e.g. acylated insulin).

  5. Renewable energy delivery systems and methods

    DOEpatents

    Walker, Howard Andrew

    2013-12-10

    A system, method and/or apparatus for the delivery of energy at a site, at least a portion of the energy being delivered by at least one or more of a plurality of renewable energy technologies, the system and method including calculating the load required by the site for the period; calculating the amount of renewable energy for the period, including obtaining a capacity and a percentage of the period for the renewable energy to be delivered; comparing the total load to the renewable energy available; and, implementing one or both of additional and alternative renewable energy sources for delivery of energy to the site.

  6. Platelets as delivery systems for disease treatments

    PubMed Central

    Shi, Qizhen; Montgomery, Robert R.

    2010-01-01

    Platelets are small, anucleate, discoid shaped blood cells that play a fundamental role in hemostasis. Platelets contain a large number of biologically active molecules within cytoplasmic granules that are critical to normal platelet function. Because platelets circulate in blood through out the body, release biological molecules and mediators on demand, and participate in hemostasis as well as many other pathophysiologic processes, targeting expression of proteins of interest to platelets and utilizing platelets as delivery systems for disease treatment would be a logical approach. This paper reviews the genetic therapy for inherited bleeding disorders utilizing platelets as delivery system, with a particular focus on platelet-derived FVIII for hemophilia A treatment. PMID:20619307

  7. Design of novel multifunctional targeting nano-carrier drug delivery system based on CD44 receptor and tumor microenvironment pH condition.

    PubMed

    Chen, Daquan; Lian, Shengnan; Sun, Jingfang; Liu, Zongliang; Zhao, Feng; Jiang, Yongtao; Gao, Mingming; Sun, Kaoxiang; Liu, Wanhui; Fu, Fenghua

    2016-01-01

    In this study, to develop a multifunctional targeting nano-carrier drug delivery system for cancer therapy, the novel pH-sensitive ketal based oligosaccharides of hyaluronan (oHA) conjugates were synthesized by chemical conjugation of hydrophobic menthone 1,2-glycerol ketal (MGK) to the backbone of oHA with the histidine as the linker of proton sponge effect. The multifunctional oHA conjugates, oHA-histidine-MGK (oHM) carried the pH-sensitive MGK as hydrophobic moieties and oHA as the target of CD44 receptor. The oHM could self-assemble to nano-sized spherical shape with the average diameters of 128.6 nm at pH 7.4 PBS conditions. The oHM nanoparticles (oHMN) could release encapsulated curcumin (Cur) with 82.6% at pH 5.0 compared with 49.3% at pH 7.4. The results of cytotoxicity assay indicated that encapsulated Cur in oHMN (Cur-oHMN) were stable and have less toxicity compared to Cur suspension. The anti-tumor efficacy in vivo suggested that Cur-oHMN suppressed tumor growth most efficiently. These results present the promising potential of oHMN as a stable and effective nano-sized pH-sensitive drug delivery system for cancer treatment.

  8. Adamantane in Drug Delivery Systems and Surface Recognition.

    PubMed

    Štimac, Adela; Šekutor, Marina; Mlinarić-Majerski, Kata; Frkanec, Leo; Frkanec, Ruža

    2017-02-16

    The adamantane moiety is widely applied in design and synthesis of new drug delivery systems and in surface recognition studies. This review focuses on liposomes, cyclodextrins, and dendrimers based on or incorporating adamantane derivatives. Our recent concept of adamantane as an anchor in the lipid bilayer of liposomes has promising applications in the field of targeted drug delivery and surface recognition. The results reported here encourage the development of novel adamantane-based structures and self-assembled supramolecular systems for basic chemical investigations as well as for biomedical application.

  9. Programmable nanomedicine: synergistic and sequential drug delivery systems

    NASA Astrophysics Data System (ADS)

    Pacardo, Dennis B.; Ligler, Frances S.; Gu, Zhen

    2015-02-01

    Recent developments in nanomedicine for the cancer therapy have enabled programmable delivery of therapeutics by exploiting the stimuli-responsive properties of nanocarriers. These therapeutic systems were designed with the relevant chemical and physical properties that respond to different triggers for enhanced anticancer efficacy, including the reduced development of drug-resistance, lower therapeutic dose, site-specific transport, and spatiotemporally controlled release. This minireview discusses the current advances in programmable nanocarriers for cancer therapy with particular emphasis on synergistic and sequential drug delivery systems.

  10. Deep Space Systems Technology Program Future Deliveries

    NASA Technical Reports Server (NTRS)

    Salvo, Christopher G.; Keuneke, Matthew S.

    2000-01-01

    NASA is in a period of frequent launches of low cost deep space missions with challenging performance needs. The modest budgets of these missions make it impossible for each to develop its own technology, therefore, efficient and effective development and insertion of technology for these missions must be approached at a higher level than has been done in the past. The Deep Space Systems Technology Program (DSST), often referred to as X2000, has been formed to address this need. The program is divided into a series of "Deliveries" that develop and demonstrate a set of spacecraft system capabilities with broad applicability for use by multiple missions. The First Delivery Project, to be completed in 2001, will provide a one MRAD-tolerant flight computer, power switching electronics, efficient radioisotope power source, and a transponder with services at 8.4 GHz and 32 GHz bands. Plans call for a Second Delivery in late 2003 to enable complete deep space systems in the 10 to 50 kg class, and a Third Delivery built around Systems on a Chip (extreme levels of electronic and microsystems integration) around 2006. Formulation of Future Deliveries (past the First Delivery) is ongoing and includes plans for such developments as highly miniaturized digital/analog/power electronics, optical communications, multifunctional structures, miniature lightweight propulsion, advanced thermal control techniques, highly efficient radioisotope power sources, and a unified flight ground software architecture to support the needs of future highly intelligent space systems. All developments are targeted at broad applicability and reuse, and will be commercialized within the US.

  11. Hydrazone linkages in pH responsive drug delivery systems.

    PubMed

    Sonawane, Sandeep J; Kalhapure, Rahul S; Govender, Thirumala

    2017-03-01

    Stimuli-responsive polymeric drug delivery systems using various triggers to release the drug at the sites have become a major focus area. Among various stimuli-responsive materials, pH-responsiveness has been studied extensively. The materials used for fabricating pH-responsive drug delivery systems include a specific chemical functionality in their structure that can respond to changes in the pH of the surrounding environment. Various chemical functionalities, for example, acetal, amine, ortho ester, amine and hydrazone, have been used to design materials that are capable of releasing their payload at the acidic pH conditions of the tumor or infection sites. Hydrazone linkages are significant synthons for numerous transformations and have gained importance in pharmaceutical sciences due to their various biological and clinical applications. These linkages have been employed in various drug delivery vehicles, such as linear polymers, star shaped polymers, dendrimers, micelles, liposomes and inorganic nanoparticles, for pH-responsive drug delivery. This review paper focuses on the synthesis and characterization methods of hydrazone bond containing materials and their applications in pH-responsive drug delivery systems. It provides detailed suggestions as guidelines to materials and formulation scientists for designing biocompatible pH-responsive materials with hydrazone linkages and identifying future studies.

  12. Brain drug delivery systems for neurodegenerative disorders.

    PubMed

    Garbayo, E; Ansorena, E; Blanco-Prieto, M J

    2012-09-01

    Neurodegenerative disorders (NDs) are rapidly increasing as population ages. However, successful treatments for NDs have so far been limited and drug delivery to the brain remains one of the major challenges to overcome. There has recently been growing interest in the development of drug delivery systems (DDS) for local or systemic brain administration. DDS are able to improve the pharmacological and therapeutic properties of conventional drugs and reduce their side effects. The present review provides a concise overview of the recent advances made in the field of brain drug delivery for treating neurodegenerative disorders. Examples include polymeric micro and nanoparticles, lipidic nanoparticles, pegylated liposomes, microemulsions and nanogels that have been tested in experimental models of Parkinson's, Alzheimer's and Huntington's disease. Overall, the results reviewed here show that DDS have great potential for NDs treatment.

  13. Importance of dual delivery systems for bone tissue engineering.

    PubMed

    Farokhi, Mehdi; Mottaghitalab, Fatemeh; Shokrgozar, Mohammad Ali; Ou, Keng-Liang; Mao, Chuanbin; Hosseinkhani, Hossein

    2016-03-10

    Bone formation is a complex process that requires concerted function of multiple growth factors. For this, it is essential to design a delivery system with the ability to load multiple growth factors in order to mimic the natural microenvironment for bone tissue formation. However, the short half-lives of growth factors, their relatively large size, slow tissue penetration, and high toxicity suggest that conventional routes of administration are unlikely to be effective. Therefore, it seems that using multiple bioactive factors in different delivery systems can develop new strategies for improving bone tissue regeneration. Combination of these factors along with biomaterials that permit tunable release profiles would help to achieve truly spatiotemporal regulation during delivery. This review summarizes the various dual-control release systems that are used for bone tissue engineering. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Self-nanoemulsifying drug delivery system (SNEDDS) of the poorly water-soluble grapefruit flavonoid Naringenin: design, characterization, in vitro and in vivo evaluation.

    PubMed

    Khan, Abdul Wadood; Kotta, Sabna; Ansari, Shahid Husain; Sharma, Rakesh Kumar; Ali, Javed

    2015-01-01

    Naringenin (NRG), predominant flavanone in grapefruits, possesses anti-inflammatory, anti-carcinogenic, hepato-protective and anti-lipid peroxidation effects. Slow dissolution after oral ingestion due to its poor solubility in water, as well as low bioavailability following oral administration, restricts its therapeutic application. The study is an attempt to improve the solubility and bioavailability of NRG by employing self-nanoemulsifying drug delivery technique. Preliminary screening was carried out to select oil, surfactant and co-surfactant, based on solubilization and emulsification efficiency of the components. Pseudo ternary phase diagrams were constructed to identify the area of nanoemulsification. The developed self-nanoemulsifying drug delivery systems (SNEDDS) were evaluated in term of goluble size, globule size distribution, zeta potential, and surface morphology of nanoemulsions so obtained. The TEM analysis proves that nanoemulsion shows a droplet size less than 50 nm. Freeze thaw cycling and centrifugation studies were carried out to confirm the stability of the developed SNEDDS. In vitro drug release from SNEDDS was significantly higher (p < 0.005) than pure drug. Furthermore, area under the drug concentration time-curve (AUC(0-24)) of NRG from SNEDDS formulation revealed a significant increase (p < 0.005) in NRG absorption compared to NRG alone. The increase in drug release and bioavailability as compared to drug suspension from SNEDDS formulation may be attributed to the nanosized droplets and enhanced solubility of NRG in the SNEDDS.

  15. Based on 3G and RFID logistic delivery management system application and practice analysis

    NASA Astrophysics Data System (ADS)

    Li, Xiaojun; Peng, Longjun; Zhong, Kaiwen; Huang, Jianming

    2008-10-01

    This article in view of the Logistic Delivery Management characteristic, analysis the logistic delivery management cannot satisfy requests rapid reaction and conformity transportation at present and so on. This article elaborated based on 3G (GIS, GPS, and GPRS) and RFID technology logistic delivery contents and so on management system, system design and architecture design, and its effective integration. The system design mentality uses the systems engineering method, follows the humanist idea, and embarks from user's demand, according to the user demand and the network request, divides according to the laminated structure into the decision-making strata, the service level, the management maintenance level and the technical support level 4 levels. The overall structural design including the system function structural design and the software system design, and take some province logistic delivery management system in management service as an example, introduced the design mentality and the application way.

  16. Kraft black liquor delivery systems

    SciTech Connect

    Adams, T.N.; Empie, H.L.; Obuskovic, N.; Spielbauer, T.M.

    1990-02-01

    Improvement of spray nozzles for black liquor injection into kraft recovery furnaces is expected to result from obtaining a controlled, well-defined droplet size distribution. Work this year has centered on defining the capabilities of commercial black liquor nozzles currently in use. Considerations of the observed mechanism of droplet formation suggest a major revision is needed in the theory of how droplets form from these nozzles. High resolution, high sensitivity video has been shown to be superior to flash x-ray as a technique for measuring the droplet size distribution as well as the formation history. An environmentally sound spray facility capable of spraying black liquor at temperatures up to normal firing conditions is being constructed before data acquisition continues. Preliminary correlations have been developed between liquor properties, nozzle design, and droplet size. Three aspects of nozzle design have been investigated: droplet size distribution, fluid sheet thickness, and flow and pressure drop characteristics. The standard deviation about the median droplet size for black liquor is nearly the same as the for a wide variety of other fluids and nozzle types. Preliminary correlation for fluid sheet thickness on the plate of a splashplate nozzle show the strong similarities of black liquor to other fluids. The flow and pressure drop characteristic of black liquor nozzle, follow a simple two-term relationship similar to other flow devices. This means that in routine mill operation of black liquor nozzles only the fluid acceleration in the nozzle is important, viscous losses are quiet small. 21 refs., 53 figs., 10 tabs.

  17. Marine Origin Polysaccharides in Drug Delivery Systems.

    PubMed

    Cardoso, Matias J; Costa, Rui R; Mano, João F

    2016-02-05

    Oceans are a vast source of natural substances. In them, we find various compounds with wide biotechnological and biomedical applicabilities. The exploitation of the sea as a renewable source of biocompounds can have a positive impact on the development of new systems and devices for biomedical applications. Marine polysaccharides are among the most abundant materials in the seas, which contributes to a decrease of the extraction costs, besides their solubility behavior in aqueous solvents and extraction media, and their interaction with other biocompounds. Polysaccharides such as alginate, carrageenan and fucoidan can be extracted from algae, whereas chitosan and hyaluronan can be obtained from animal sources. Most marine polysaccharides have important biological properties such as biocompatibility, biodegradability, and anti-inflammatory activity, as well as adhesive and antimicrobial actions. Moreover, they can be modified in order to allow processing them into various shapes and sizes and may exhibit response dependence to external stimuli, such as pH and temperature. Due to these properties, these biomaterials have been studied as raw material for the construction of carrier devices for drugs, including particles, capsules and hydrogels. The devices are designed to achieve a controlled release of therapeutic agents in an attempt to fight against serious diseases, and to be used in advanced therapies, such as gene delivery or regenerative medicine.

  18. Marine Origin Polysaccharides in Drug Delivery Systems

    PubMed Central

    Cardoso, Matias J.; Costa, Rui R.; Mano, João F.

    2016-01-01

    Oceans are a vast source of natural substances. In them, we find various compounds with wide biotechnological and biomedical applicabilities. The exploitation of the sea as a renewable source of biocompounds can have a positive impact on the development of new systems and devices for biomedical applications. Marine polysaccharides are among the most abundant materials in the seas, which contributes to a decrease of the extraction costs, besides their solubility behavior in aqueous solvents and extraction media, and their interaction with other biocompounds. Polysaccharides such as alginate, carrageenan and fucoidan can be extracted from algae, whereas chitosan and hyaluronan can be obtained from animal sources. Most marine polysaccharides have important biological properties such as biocompatibility, biodegradability, and anti-inflammatory activity, as well as adhesive and antimicrobial actions. Moreover, they can be modified in order to allow processing them into various shapes and sizes and may exhibit response dependence to external stimuli, such as pH and temperature. Due to these properties, these biomaterials have been studied as raw material for the construction of carrier devices for drugs, including particles, capsules and hydrogels. The devices are designed to achieve a controlled release of therapeutic agents in an attempt to fight against serious diseases, and to be used in advanced therapies, such as gene delivery or regenerative medicine. PMID:26861358

  19. Albumin nanostructures as advanced drug delivery systems.

    PubMed

    Karimi, Mahdi; Bahrami, Sajad; Ravari, Soodeh Baghaee; Zangabad, Parham Sahandi; Mirshekari, Hamed; Bozorgomid, Mahnaz; Shahreza, Somayeh; Sori, Masume; Hamblin, Michael R

    2016-11-01

    One of the biggest impacts that the nanotechnology has made on medicine and biology, has been in the area of drug delivery systems (DDSs). Many drugs suffer from serious problems concerning insolubility, instability in biological environments, poor uptake into cells and tissues, sub-optimal selectivity for targets and unwanted side effects. Nanocarriers can be designed as DDSs to overcome many of these drawbacks. One of the most versatile building blocks to prepare these nanocarriers is the ubiquitous, readily available and inexpensive protein, serum albumin. Areas covered: This review covers the use of different types of albumin (human, bovine, rat, and chicken egg) to prepare nanoparticle and microparticle-based structures to bind drugs. Various methods have been used to modify the albumin structure. A range of targeting ligands can be attached to the albumin that can be recognized by specific cell receptors that are expressed on target cells or tissues. Expert opinion: The particular advantages of albumin used in DDSs include ready availability, ease of chemical modification, good biocompatibility, and low immunogenicity. The regulatory approvals that have been received for several albumin-based therapeutic agents suggest that this approach will continue to be successfully explored.

  20. Niosomes: a controlled and novel drug delivery system.

    PubMed

    Rajera, Rampal; Nagpal, Kalpana; Singh, Shailendra Kumar; Mishra, Dina Nath

    2011-01-01

    During the past decade formulation of vesicles as a tool to improve drug delivery, has created a lot of interest amongst the scientist working in the area of drug delivery systems. Vesicular system such as liposomes, niosomes, transferosomes, pharmacosomes and ethosomes provide an alternative to improve the drug delivery. Niosomes play an important role owing to their nonionic properties, in such drug delivery system. Design and development of novel drug delivery system (NDDS) has two prerequisites. First, it should deliver the drug in accordance with a predetermined rate and second it should release therapeutically effective amount of drug at the site of action. Conventional dosage forms are unable to meet these requisites. Niosomes are essentially non-ionic surfactant based multilamellar or unilamellar vesicles in which an aqueous solution of solute is entirely enclosed by a membrane resulting from the organization of surfactant macromolecules as bilayer. Niosomes are formed on hydration of non-ionic surfactant film which eventually hydrates imbibing or encapsulating the hydrating aqueous solution. The main aim of development of niosomes is to control the release of drug in a sustained way, modification of distribution profile of drug and for targeting the drug to the specific body site. This paper deals with composition, characterization/evaluation, merits, demerits and applications of niosomes.

  1. Transferosomes - A vesicular transdermal delivery system for enhanced drug permeation

    PubMed Central

    Rajan, Reshmy; Jose, Shoma; Mukund, V. P. Biju; Vasudevan, Deepa T.

    2011-01-01

    Transdermal administration of drugs is generally limited by the barrier function of the skin. Vesicular systems are one of the most controversial methods for transdermal delivery of active substances. The interest in designing transdermal delivery systems was relaunched after the discovery of elastic vesicles like transferosomes, ethosomes, cubosomes, phytosomes, etc. This paper presents the composition, mechanisms of penetration, manufacturing and characterization methods of transferosomes as transdermal delivery systems of active substances. For a drug to be absorbed and distributed into organs and tissues and eliminated from the body, it must pass through one or more biological membranes/barriers at various locations. Such a movement of drug across the membrane is called as drug transport. For the drugs to be delivered to the body, they should cross the membranous barrier. The concept of these delivery systems was designed in an attempt to concentrate the drug in the tissues of interest, while reducing the amount of drug in the remaining tissues. Hence, surrounding tissues are not affected by the drug. In addition, loss of drug does not happen due to localization of drug, leading to get maximum efficacy of the medication. Therefore, the phospholipid based carrier systems are of considerable interest in this era. PMID:22171309

  2. Calibrator for microflow delivery systems

    NASA Astrophysics Data System (ADS)

    Marinozzi, Franco; Bini, Fabiano; Cappa, Paolo

    2005-01-01

    An apparatus for calibrating the fluid flow rate down to 3×10-2ml/h is proposed, based on the volumetric pump working principle. Constant flow rate is assured by means of the constant speed at which the plunger of a laboratory syringe is moved. To test effectiveness of the system, a flow sensor, composed by a differential pressure transducer and a needle was calibrated and afterward utilized for characterizing a clinical drug infusion device. The proposed apparatus showed a full scale (FS) uncertainty approximately equal to 3.5% over a range of 6 ml/h. The calibration range starts at 3×10-2ml/h with a 1 ml syringe and at 3×10-3ml/h with a 0.1 ml syringe. The minimum detectable signal (evaluated at 6 dB SNR) was equal to about 1.4×10-2ml/h by using a syringe of 1 ml. The outcomes of the adopted procedure allowed a characterization of the performance of an infusion pump, without the need of the usual but somewhat cumbersome gravimetric calibration standard. Moreover, some issues about the expected resolution and uncertainty, depending on the characteristics of the system, is also reported.

  3. Comparative Health Systems Research among Kaiser Permanente and Other Integrated Delivery Systems: A Systematic Literature Review

    PubMed Central

    Maeda, Jared Lane K; Lee, Karen M; Horberg, Michael

    2014-01-01

    Context: Because of rising health care costs, wide variations in quality, and increased patient complexity, the US health care system is undergoing rapid changes that include payment reform and movement toward integrated delivery systems. Well-established integrated delivery systems, such as Kaiser Permanente (KP), should work to identify the specific system-level factors that result in superior patient outcomes in response to policymakers’ concerns. Comparative health systems research can provide insights into which particular aspects of the integrated delivery system result in improved care delivery. Objective: To provide a baseline understanding of comparative health systems research related to integrated delivery systems and KP. Design: Systematic literature review. Methods: We conducted a literature search on PubMed and the KP Publications Library. Studies that compared KP as a system or organization with other health care systems or across KP facilities internally were included. The literature search identified 1605 articles, of which 65 met the study inclusion criteria and were examined by 3 reviewers. Results: Most comparative health systems studies focused on intra-KP comparisons (n = 42). Fewer studies compared KP with other US (n = 15) or international (n = 12) health care systems. Several themes emerged from the literature as possible factors that may contribute to improved care delivery in integrated delivery systems. Conclusions: Of all studies published by or about KP, only a small proportion of articles (4%) was identified as being comparative health systems research. Additional empirical studies that compare the specific factors of the integrated delivery system model with other systems of care are needed to better understand the “system-level” factors that result in improved and/or diminished care delivery. PMID:24937150

  4. Chitosan Microspheres in Novel Drug Delivery Systems

    PubMed Central

    Mitra, Analava; Dey, Baishakhi

    2011-01-01

    The main aim in the drug therapy of any disease is to attain the desired therapeutic concentration of the drug in plasma or at the site of action and maintain it for the entire duration of treatment. A drug on being used in conventional dosage forms leads to unavoidable fluctuations in the drug concentration leading to under medication or overmedication and increased frequency of dose administration as well as poor patient compliance. To minimize drug degradation and loss, to prevent harmful side effects and to increase drug bioavailability various drug delivery and drug targeting systems are currently under development. Handling the treatment of severe disease conditions has necessitated the development of innovative ideas to modify drug delivery techniques. Drug targeting means delivery of the drug-loaded system to the site of interest. Drug carrier systems include polymers, micelles, microcapsules, liposomes and lipoproteins to name some. Different polymer carriers exert different effects on drug delivery. Synthetic polymers are usually non-biocompatible, non-biodegradable and expensive. Natural polymers such as chitin and chitosan are devoid of such problems. Chitosan comes from the deacetylation of chitin, a natural biopolymer originating from crustacean shells. Chitosan is a biocompatible, biodegradable, and nontoxic natural polymer with excellent film-forming ability. Being of cationic character, chitosan is able to react with polyanions giving rise to polyelectrolyte complexes. Hence chitosan has become a promising natural polymer for the preparation of microspheres/nanospheres and microcapsules. The techniques employed to microencapsulate with chitosan include ionotropic gelation, spray drying, emulsion phase separation, simple and complex coacervation. This review focuses on the preparation, characterization of chitosan microspheres and their role in novel drug delivery systems. PMID:22707817

  5. Smart surface-enhanced Raman scattering traceable drug delivery systems

    NASA Astrophysics Data System (ADS)

    Liu, Lei; Tang, Yonghong; Dai, Sheng; Kleitz, Freddy; Qiao, Shi Zhang

    2016-06-01

    A novel smart nanoparticle-based system has been developed for tracking intracellular drug delivery through surface-enhanced Raman scattering (SERS). This new drug delivery system (DDS) shows targeted cytotoxicity towards cancer cells via pH-cleavable covalent carboxylic hydrazone links and the SERS tracing capability based on gold@silica nanocarriers. Doxorubicin, as a model anticancer drug, was employed to compare SERS with conventional fluorescence tracing approaches. It is evident that SERS demonstrates higher sensitivity and resolution, revealing intracellular details, as the strengths of the original Raman signals can be amplified by SERS. Importantly, non-destructive SERS will provide the designed DDS with great autonomy and potential to study the dynamic procedures of non-fluorescent drug delivery into living cells.A novel smart nanoparticle-based system has been developed for tracking intracellular drug delivery through surface-enhanced Raman scattering (SERS). This new drug delivery system (DDS) shows targeted cytotoxicity towards cancer cells via pH-cleavable covalent carboxylic hydrazone links and the SERS tracing capability based on gold@silica nanocarriers. Doxorubicin, as a model anticancer drug, was employed to compare SERS with conventional fluorescence tracing approaches. It is evident that SERS demonstrates higher sensitivity and resolution, revealing intracellular details, as the strengths of the original Raman signals can be amplified by SERS. Importantly, non-destructive SERS will provide the designed DDS with great autonomy and potential to study the dynamic procedures of non-fluorescent drug delivery into living cells. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr03869g

  6. Noncontact laser fiber delivery system for endoscopic medical applications

    NASA Astrophysics Data System (ADS)

    Denisov, Nikolay A.; Griffin, Stephen E.

    1999-02-01

    The objective of the study was to design and to investigate laser fiber delivery system for treatment of obstructed human internal tubular organs using endoscopic techniques. This system eliminates the main disadvantages of both applied contact and non-contact probes, namely surface contamination with concomitant hydrothermal probe deterioration and large beam divergence with poor energy density, respectively. Proposed silica or sapphire probes produce quasi-collimated beam with specific outside diameter and power distribution. To provide comparative analysis of laser delivery systems' optical properties with non-contact endoscopic probes 'steady beam distance' (SBD) and 'steady beam ratio' (SBR) coefficients are proposed. The calculation results are presented in the form of the plots of the SBR - coefficients and SBDs for a 2.0 mm specific outside beam diameter versus laser wavelength, delivery fiber core diameter and its numerical aperture for both probe material. Additionally, the cross power distributions along the SBD were studied. Results obtained could provide a useful tool to designers of non-contact fiber delivery systems intended for a variety of medical applications, including endoscopic surgery with cw or pulse laser tissue irradiation, skin de-epithelialization, laser-induced fluorescence and photodynamic therapy.

  7. Drug delivery systems for brain tumor therapy.

    PubMed

    Rautioa, Jarkko; Chikhale, Prashant J

    2004-01-01

    Brain tumors are one of the most lethal forms of cancer. They are extremely difficult to treat. Although, the rate of brain tumor incidence is relatively low, the field clearly lacks therapeutic strategies capable of overcoming barriers for effective delivery of drugs to brain tumors. Clinical failure of many potentially effective therapeutics for the treatment of brain tumors is usually not due to a lack of drug potency, but rather can be attributed to shortcomings in the methods by which a drug is delivered to the brain and into brain tumors. In response to the lack of efficacy of conventional drug delivery methods, extensive efforts have been made to develop novel strategies to overcome the obstacles for brain tumor drug delivery. The challenge is to design therapeutic strategies that deliver drugs to brain tumors in a safe and effective manner. This review provides some insight into several potential techniques that have been developed to improve drug delivery to brain tumors, and it should be helpful to clinicians and research scientists as well.

  8. Bioengineered Silk Protein-Based Gene Delivery Systems

    PubMed Central

    Numata, Keiji; Subramanian, Balajikarthick; Currie, Heather A.; Kaplan, David L.

    2009-01-01

    Silk proteins self-assemble into mechanically robust material structures that are also biodegradable and non-cytotoxic, suggesting utility for gene delivery. Since silk proteins can also be tailored in terms of chemistry, molecular weight and other design features via genetic engineering, further control of this system for gene delivery can be considered. In the present study, silk-based block copolymers were bioengineered with poly(l-lysine) domains for gene delivery. Ionic complexes of these silk-polylysine based block copolymers with plasmid DNA (pDNA) were prepared for gene delivery to human embryonic kidney (HEK) cells. The material systems were characterized by agarose gel electrophoresis, atomic force microscopy, and dynamic light scattering. The polymers self-assembled in solution and complexed plasmid DNA through ionic interactions. The pDNA complexes with 30-lysine residues prepared at a polymer/nucleotide ratio of 10 and with a solution diameter of 380 nm, showed the highest efficiency for transfection. The pDNA complexes were also immobilized on silk films and demonstrated direct cell transfection from these surfaces. The results demonstrate the potential of bioengineered silk proteins as a new family of highly tailored gene delivery systems. PMID:19577803

  9. Integrated delivery systems focus on service delivery after capitation efforts stall.

    PubMed

    2005-03-01

    Integrated delivery systems focus on service delivery after capitation efforts stall. Integrated delivery systems are going through changes that are focusing the provider organizations more on delivering care than managing risk, says Dean C. Coddington, one of the leading researchers into capitated organizations and a senior consultant with McManis Consulting in Denver.

  10. Cyclodextrin-based host-guest supramolecular nanoparticles for delivery: from design to applications.

    PubMed

    Hu, Qi-Da; Tang, Gu-Ping; Chu, Paul K

    2014-07-15

    CONSPECTUS: Efficient assembly in host-guest interactions is crucial to supramolecular nanotechnology. Cyclodextrins (CDs), which possess a hydrophilic exterior surface and hydrophobic interior cavity on the truncated cone, improve the biocompatibility of nanodelivery systems, and hence, supramolecular approaches utilizing CDs can improve and expand the design and applications of functional delivery systems. Owing to good inclusion ability, αCD and βCD are commonly used in the design and construction of supramolecular structures. In this Account, we describe the design strategies to adopt CDs in host-guest delivery systems. Modification of CDs with polymers is popular in current research due to the potential benefits rendered by cationic protection and improved capability. While the process has only minor influence on the host characteristics of the CD cavity, the interaction between the CD and the guest moiety imparts new attributes to the nanosystems with guest-decorated functional groups such as adamantyl poly(ethylene glycol) (PEG) for coating protection, hybrid guests for conformational flexibility, and adamantyl prodrugs for drug delivery. Some specific agents form inclusion complexes with the polymerized βCDs directly and core-shell nanoparticles with hydrophobic cores and are usually created to carry insoluble drugs while the hydrophilic shells offer protection. These unique designs provide the means to practically adapt special characteristics for additional functions or co-delivery. In order to be accepted clinically, delivery systems need to possess extra functions such as controlled particle size, biodegradability, controlled release, and targeted delivery to overcome the hurdles in delivery. These features can be added to biomaterials by self-assembly of functional groups facilitated by the host-guest interactions. Size control by hybridization of switchable polymer compartments in supramolecular structures contributes to the biodistribution utility

  11. Design Education Online: Learning Delivery and Evaluation

    ERIC Educational Resources Information Center

    Park, Ji Yong

    2011-01-01

    Online learning has been recognised as an effective pedagogical method and tool, and is broadly integrated into various types of teaching and learning strategies in higher education. In practice, the use of Virtual Learning Environment (VLE) in higher education has become an integral strategy for quality education. The field of design education,…

  12. Structural design principles for delivery of bioactive components in nutraceuticals and functional foods.

    PubMed

    McClements, David Julian; Decker, Eric Andrew; Park, Yeonhwa; Weiss, Jochen

    2009-06-01

    There have been major advances in the design and fabrication of structured delivery systems for the encapsulation of nutraceutical and functional food components. A wide variety of delivery systems is now available, each with its own advantages and disadvantages for particular applications. This review begins by discussing some of the major nutraceutical and functional food components that need to be delivered and highlights the main limitations to their current utilization within the food industry. It then discusses the principles underpinning the rational design of structured delivery systems: the structural characteristics of the building blocks; the nature of the forces holding these building blocks together; and, the different ways of assembling these building blocks into structured delivery systems. Finally, we review the major types of structured delivery systems that are currently available to food scientists: lipid-based (simple, multiple, multilayer, and solid lipid particle emulsions); surfactant-based (simple micelles, mixed micelles, vesicles, and microemulsions) and biopolymer-based (soluble complexes, coacervates, hydrogel droplets, and particles). For each type of delivery system we describe its preparation, properties, advantages, and limitations.

  13. Multilayered materials based on biopolymers as drug delivery systems.

    PubMed

    Vilela, Carla; Figueiredo, Ana R P; Silvestre, Armando J D; Freire, Carmen S R

    2017-02-01

    The design of efficient therapeutic delivery devices has become a tremendously active area of research with a strong contribution from the layer-by-layer (LbL) technology. The application of this simple yet firmly established technique for the design of drug reservoirs originates a multitude of multilayered systems of tailored architecture and with a high level of control of drug administration. Areas covered: This review will focus on the most recent and original research on LbL assemblies based on biopolymers including polysaccharides, polypeptides and proteins, with potential use in drug delivery. Herein, drug reservoirs consisting of multilayered planar films and capsules will be examined with emphasis on the ones benefiting from the non-cytotoxic and biocompatible nature of biopolymers, which are suitable to load, protect and release a high payload of toxic and fragile drugs. Expert opinion: The combination of biopolymers with LbL technology has undergone extensive research, still, there is a multitude of R&D opportunities for the design of smart drug delivery systems with distinct multilayered morphologies, low immunological response, non-invasive drug release devices, as well as the design of theranostic systems combining diagnostics and therapeutic features. Further developments in terms of scaling towards mass production in the pharmaceutical industry are expected in the long-term.

  14. Current Multistage Drug Delivery Systems Based on the Tumor Microenvironment

    PubMed Central

    Chen, Binlong; Dai, Wenbing; He, Bing; Zhang, Hua; Wang, Xueqing; Wang, Yiguang; Zhang, Qiang

    2017-01-01

    The development of traditional tumor-targeted drug delivery systems based on EPR effect and receptor-mediated endocytosis is very challenging probably because of the biological complexity of tumors as well as the limitations in the design of the functional nano-sized delivery systems. Recently, multistage drug delivery systems (Ms-DDS) triggered by various specific tumor microenvironment stimuli have emerged for tumor therapy and imaging. In response to the differences in the physiological blood circulation, tumor microenvironment, and intracellular environment, Ms-DDS can change their physicochemical properties (such as size, hydrophobicity, or zeta potential) to achieve deeper tumor penetration, enhanced cellular uptake, timely drug release, as well as effective endosomal escape. Based on these mechanisms, Ms-DDS could deliver maximum quantity of drugs to the therapeutic targets including tumor tissues, cells, and subcellular organelles and eventually exhibit the highest therapeutic efficacy. In this review, we expatiate on various responsive modes triggered by the tumor microenvironment stimuli, introduce recent advances in multistage nanoparticle systems, especially the multi-stimuli responsive delivery systems, and discuss their functions, effects, and prospects. PMID:28255348

  15. Chitosan magnetic nanoparticles for drug delivery systems.

    PubMed

    Assa, Farnaz; Jafarizadeh-Malmiri, Hoda; Ajamein, Hossein; Vaghari, Hamideh; Anarjan, Navideh; Ahmadi, Omid; Berenjian, Aydin

    2017-06-01

    The potential of magnetic nanoparticles (MNPs) in drug delivery systems (DDSs) is mainly related to its magnetic core and surface coating. These coatings can eliminate or minimize their aggregation under physiological conditions. Also, they can provide functional groups for bioconjugation to anticancer drugs and/or targeted ligands. Chitosan, as a derivative of chitin, is an attractive natural biopolymer from renewable resources with the presence of reactive amino and hydroxyl functional groups in its structure. Chitosan nanoparticles (NPs), due to their huge surface to volume ratio as compared to the chitosan in its bulk form, have outstanding physico-chemical, antimicrobial and biological properties. These unique properties make chitosan NPs a promising biopolymer for the application of DDSs. In this review, the current state and challenges for the application magnetic chitosan NPs in drug delivery systems were investigated. The present review also revisits the limitations and commercial impediments to provide insight for future works.

  16. Regional Multiteam Systems in Cancer Care Delivery

    PubMed Central

    Monson, John R.T.; Rizvi, Irfan; Savastano, Ann; Green, James S.A.; Sevdalis, Nick

    2016-01-01

    Teamwork is essential for addressing many of the challenges that arise in the coordination and delivery of cancer care, especially for the problems that are presented by patients who cross geographic boundaries and enter and exit multiple health care systems at various times during their cancer care journeys. The problem of coordinating the care of patients with cancer is further complicated by the growing number of treatment options and modalities, incompatibilities among the vast variety of technology platforms that have recently been adopted by the health care industry, and competing and misaligned incentives for providers and systems. Here we examine the issue of regional care coordination in cancer through the prism of a real patient journey. This article will synthesize and elaborate on existing knowledge about coordination approaches for complex systems, in particular, in general and cancer care multidisciplinary teams; define elements of coordination derived from organizational psychology and human factors research that are applicable to team-based cancer care delivery; and suggest approaches for improving multidisciplinary team coordination in regional cancer care delivery and avenues for future research. The phenomenon of the mobile, multisystem patient represents a growing challenge in cancer care. Paradoxically, development of high-quality, high-volume centers of excellence and the ease of virtual communication and data sharing by using electronic medical records have introduced significant barriers to effective team-based cancer care. These challenges urgently require solutions. PMID:27650833

  17. Regional Multiteam Systems in Cancer Care Delivery.

    PubMed

    Noyes, Katia; Monson, John R T; Rizvi, Irfan; Savastano, Ann; Green, James S A; Sevdalis, Nick

    2016-11-01

    Teamwork is essential for addressing many of the challenges that arise in the coordination and delivery of cancer care, especially for the problems that are presented by patients who cross geographic boundaries and enter and exit multiple health care systems at various times during their cancer care journeys. The problem of coordinating the care of patients with cancer is further complicated by the growing number of treatment options and modalities, incompatibilities among the vast variety of technology platforms that have recently been adopted by the health care industry, and competing and misaligned incentives for providers and systems. Here we examine the issue of regional care coordination in cancer through the prism of a real patient journey. This article will synthesize and elaborate on existing knowledge about coordination approaches for complex systems, in particular, in general and cancer care multidisciplinary teams; define elements of coordination derived from organizational psychology and human factors research that are applicable to team-based cancer care delivery; and suggest approaches for improving multidisciplinary team coordination in regional cancer care delivery and avenues for future research. The phenomenon of the mobile, multisystem patient represents a growing challenge in cancer care. Paradoxically, development of high-quality, high-volume centers of excellence and the ease of virtual communication and data sharing by using electronic medical records have introduced significant barriers to effective team-based cancer care. These challenges urgently require solutions.

  18. Drug delivery system and breast cancer cells

    NASA Astrophysics Data System (ADS)

    Colone, Marisa; Kaliappan, Subramanian; Calcabrini, Annarica; Tortora, Mariarosaria; Cavalieri, Francesca; Stringaro, Annarita

    2016-06-01

    Recently, nanomedicine has received increasing attention for its ability to improve the efficacy of cancer therapeutics. Nanosized polymer therapeutic agents offer the advantage of prolonged circulation in the blood stream, targeting to specific sites, improved efficacy and reduced side effects. In this way, local, controlled delivery of the drug will be achieved with the advantage of a high concentration of drug release at the target site while keeping the systemic concentration of the drug low, thus reducing side effects due to bioaccumulation. Various drug delivery systems such as nanoparticles, liposomes, microparticles and implants have been demonstrated to significantly enhance the preventive/therapeutic efficacy of many drugs by increasing their bioavailability and targetability. As these carriers significantly increase the therapeutic effect of drugs, their administration would become less cost effective in the near future. The purpose of our research work is to develop a delivery system for breast cancer cells using a microvector of drugs. These results highlight the potential uses of these responsive platforms suited for biomedical and pharmaceutical applications. At the request of all authors of the paper an updated version was published on 12 July 2016. The manuscript was prepared and submitted without Dr. Francesca Cavalieri's contribution and her name was added without her consent. Her name has been removed in the updated and re-published article.

  19. Photocontrolled nanoparticle delivery systems for biomedical applications.

    PubMed

    Bansal, Akshaya; Zhang, Yong

    2014-10-21

    "Smart" stimuli-responsive nanomaterials are becoming popular as targeted delivery systems because they allow the use of internal or external stimuli to achieve spatial or temporal control over the delivery process. Among the stimuli that have been used, light is of special interest because it is not only noninvasive but also controllable both spatially and temporally, thus allowing unprecedented control over the delivery of bioactive molecules such as nucleic acids, proteins, drugs, etc. This is particularly advantageous for biomedical applications where specificity and selectivity are highly desired. Several strategies have evolved under the umbrella of light based delivery systems and can be classified into three main groups. The first strategy involves "caging" of the bioactive molecule using photolabile groups, loading these caged molecules onto a carrier and then "uncaging" or activating them at the targeted site upon irradiation with light of a particular wavelength. The second strategy makes use of nanocarriers that themselves are made photoresponsive either through modification with photosensitive groups or through the attachment of photolinkers on the carrier surface. These nanoparticles upon irradiation dissociate, releasing the cargo encapsulated within, or the photolinkers attaching the cargo to the surface get cleaved, resulting in release. The third approach makes use of the surface plasmon resonance of noble metal based nanoparticles. Upon irradiation with light at the plasmon resonant frequency, the resulting thermal or nonthermal field enhancement effects facilitate the release of bioactive molecules loaded onto the nanoparticles. In addition, other materials, certain metal sulfides, graphene oxide, etc., also exhibit photothermal transduction that can be exploited for targeted delivery. These approaches, though effective, are constrained by their predominant use of UV or visible light to which most photolabile groups are sensitive. Near infrared

  20. Design and evaluation of a novel potential carrier for a hydrophilic antitumor drug: Auricularia auricular polysaccharide-chitosan nanoparticles as a delivery system for doxorubicin hydrochloride.

    PubMed

    Xiong, Wei; Li, Li; Wang, Yingying; Yu, Yibin; Wang, Shenxia; Gao, Yunyun; Liang, Yanyao; Zhang, Guogang; Pan, Weisan; Yang, Xinggang

    2016-09-10

    To improve the low loading content of hydrophilic drugs in nanodrug delivery systems, a natural watersoluble polysaccharide, Auricularia auricular polysaccharide (AAP), was extracted and purified as a vehicle for the hydrophilic drug doxorubicin hydrochloride (Dox·HCl). This involved the preparation of polyelectrolyte complexes nanoparticles (PEC NPs) using the electrostatic interaction between cationic chitosan (CS) and anionic AAP. The formation of AAP-CS-NPs was confirmed by FT-IR and TEM. It was found that Dox-loaded AAP-CS-NPs possessed a spherical morphology with average diameters of 237.6nm and 74.1% Dox·HCl encapsulation efficiency. The stability of Dox AAP-CS-NPs was examined by suspending the nanoparticles in PBS (pH 7.4) at room temperature. The particle size of the nanoparticle samples remained stable and exhibited no obvious variations in drug content after half a month. In addition, in vitro cytotoxicity studies showed that blank AAP-CS-NPs did not exhibit any cytotoxic effects, while Dox AAP-CS-NPs increased the Dox·HCl cytotoxicity against MCF-7 cells as the result of significantly increased cellular uptake, compared with free Dox·HCl. Hence, the overall results obtained suggest that AAP-CS-NPs are very effective in entrapping Dox·HCl and to penetrate into tumor cells, rendering them promising carriers for hydrophilic antitumor drugs. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. THE SUPERCONDUCTION MAGNETS OF THE ILC BEAM DELIVERY SYSTEM.

    SciTech Connect

    PARKER,B.; ANEREELA, M.; ESCALLIE, J.; HE, P.; JAIN, A.; MARONE, A.; NOSOCHKOV, Y.; SERYI, A.

    2007-06-25

    The ILC Reference Design Report was completed early in February 2007. The Magnet Systems Group was formed to translate magnetic field requirements into magnet designs and cost estimates for the Reference Design. As presently configured, the ILC will have more than 13,000 magnetic elements of which more than 2300 will be based on superconducting technology. This paper will describe the major superconducting magnet needs for the ILC as presently determined by the Area Systems Groups, responsible for beam line design, working with the Magnet Systems Group. The superconducting magnet components include Main Linac quadrupoles, Positron Source undulators, Damping Ring wigglers, a complex array of Final Focus superconducting elements in the Beam Delivery System, and large superconducting solenoids in the e{sup +} and e{sup -} Sources, and the Ring to Main Linac lines.

  2. Orally disintegrating films: A modern expansion in drug delivery system.

    PubMed

    Irfan, Muhammad; Rabel, Sumeira; Bukhtar, Quratulain; Qadir, Muhammad Imran; Jabeen, Farhat; Khan, Ahmed

    2016-09-01

    Over the past few decades, tendency toward innovative drug delivery systems has majorly increased attempts to ensure efficacy, safety and patient acceptability. As discovery and development of new chemical agents is a complex, expensive and time consuming process, so recent trends are shifting toward designing and developing innovative drug delivery systems for existing drugs. Out of those, drug delivery system being very eminent among pediatrics and geriatrics is orally disintegrating films (ODFs). These fast disintegrating films have superiority over fast disintegrating tablets as the latter are associated with the risks of choking and friability. This drug delivery system has numerous advantages over conventional fast disintegrating tablets as they can be used for dysphasic and schizophrenic patients and are taken without water due to their ability to disintegrate within a few seconds releasing medication in mouth. Various approaches are employed for formulating ODFs and among which solvent casting and spraying methods are frequently used. Generally, hydrophilic polymers along with other excipients are used for preparing ODFs which allow films to disintegrate quickly releasing incorporated active pharmaceutical ingredient (API) within seconds. Orally disintegrating films have potential for business and market exploitation because of their myriad of benefits over orally disintegrating tablets. This present review attempts to focus on benefits, composition, approaches for formulation and evaluation of ODFs. Additionally, the market prospect of this innovative dosage form is also targeted.

  3. The LITA Drill and Sample Delivery System

    NASA Astrophysics Data System (ADS)

    Paulsen, G.; Yoon, S.; Zacny, K.; Wettergreeng, D.; Cabrol, N. A.

    2013-12-01

    The Life in the Atacama (LITA) project has a goal of demonstrating autonomous roving, sample acquisition, delivery and analysis operations in Atacama, Chile. To enable the sample handling requirement, Honeybee Robotics developed a rover-deployed, rotary-percussive, autonomous drill, called the LITA Drill, capable of penetrating to ~80 cm in various formations, capturing and delivering subsurface samples to a 20 cup carousel. The carousel has a built-in capability to press the samples within each cup, and position target cups underneath instruments for analysis. The drill and sample delivery system had to have mass and power requirements consistent with a flight system. The drill weighs 12 kg and uses less than 100 watt of power to penetrate ~80 cm. The LITA Drill auger has been designed with two distinct stages. The lower part has deep and gently sloping flutes for retaining powdered sample, while the upper section has shallow and steep flutes for preventing borehole collapse and for efficient movement of cuttings and fall back material out of the hole. The drill uses the so called 'bite-sampling' approach that is samples are taken in short, 5-10 cm bites. To take the first bite, the drill is lowered onto the ground and upon drilling of the first bite it is then retracted into an auger tube. The auger with the auger tube are then lifted off the ground and positioned next to the carousel. To deposit the sample, the auger is rotated and retracted above the auger tube. The cuttings retained on the flutes are either gravity fed or are brushed off by a passive side brush into the cup. After the sample from the first bite has been deposited, the drill is lowered back into the same hole to take the next bite. This process is repeated until a target depth is reached. The bite sampling is analogous to peck drilling in the machining process where a bit is periodically retracted to clear chips. If there is some fall back into the hole once the auger has cleared the hole, this

  4. 42 CFR 457.490 - Delivery and utilization control systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Delivery and utilization control systems. 457.490... State Plan Requirements: Coverage and Benefits § 457.490 Delivery and utilization control systems. A... control systems. A State must— (a) Describe the methods of delivery of child health assistance...

  5. 42 CFR 457.490 - Delivery and utilization control systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 4 2011-10-01 2011-10-01 false Delivery and utilization control systems. 457.490... State Plan Requirements: Coverage and Benefits § 457.490 Delivery and utilization control systems. A... control systems. A State must— (a) Describe the methods of delivery of child health assistance...

  6. Drug Design, Development, and Delivery: An Interdisciplinary Course on Pharmaceuticals

    ERIC Educational Resources Information Center

    Prausnitz, Mark R.; Bommarius, Andreas S.

    2011-01-01

    We developed a new interdisciplinary course on pharmaceuticals to address needs of undergraduate and graduate students in chemical engineering and other departments. This course introduces drug design, development, and delivery in an integrated fashion that provides scientific depth in context with broader impacts in business, policy, and ethics.…

  7. Viability, Advantages and Design Methodologies of M-Learning Delivery

    ERIC Educational Resources Information Center

    Zabel, Todd W.

    2010-01-01

    The purpose of this study was to examine the viability and principle design methodologies of Mobile Learning models in developing regions. Demographic and market studies were utilized to determine the viability of M-Learning delivery as well as best uses for such technologies and methods given socioeconomic and political conditions within the…

  8. Drug Design, Development, and Delivery: An Interdisciplinary Course on Pharmaceuticals

    ERIC Educational Resources Information Center

    Prausnitz, Mark R.; Bommarius, Andreas S.

    2011-01-01

    We developed a new interdisciplinary course on pharmaceuticals to address needs of undergraduate and graduate students in chemical engineering and other departments. This course introduces drug design, development, and delivery in an integrated fashion that provides scientific depth in context with broader impacts in business, policy, and ethics.…

  9. Ultrasound-mediated nail drug delivery system.

    PubMed

    Abadi, Danielle; Zderic, Vesna

    2011-12-01

    A novel ultrasound-mediated drug delivery system has been developed for treatment of a nail fungal disorder (onychomycosis) by improving delivery to the nail bed using ultrasound to increase the permeability of the nail. The slip-in device consists of ultrasound transducers and drug delivery compartments above each toenail. The device is connected to a computer, where a software interface allows users to select their preferred course of treatment. In in vitro testing, canine nails were exposed to 3 energy levels (acoustic power of 1.2 W and exposure durations of 30, 60, and 120 seconds). A stereo -microscope was used to determine how much of a drug-mimicking compound was delivered through the nail layers by measuring brightness on the cross section of each nail tested at each condition, where brightness level decreases coincide with increases in permeability. Each of the 3 energy levels tested showed statistical significance when compared to the control (P < .05) with a permeability factor of 1.3 after 30 seconds of exposure, 1.3 after 60 seconds, and 1.5 after 120 seconds, where a permeability factor of 1 shows no increase in permeability. Current treatments for onychomycosis include systemic, topical, and surgical. Even when used all together, these treatments typically take a long time to result in nail healing, thus making this ultrasound-mediated device a promising alternative.

  10. Recent Trends of Polymer Mediated Liposomal Gene Delivery System

    PubMed Central

    Lee, Sang-Soo; George Priya Doss, C.; Yagihara, Shin; Kim, Do-Young

    2014-01-01

    Advancement in the gene delivery system have resulted in clinical successes in gene therapy for patients with several genetic diseases, such as immunodeficiency diseases, X-linked adrenoleukodystrophy (X-ALD) blindness, thalassemia, and many more. Among various delivery systems, liposomal mediated gene delivery route is offering great promises for gene therapy. This review is an attempt to depict a portrait about the polymer based liposomal gene delivery systems and their future applications. Herein, we have discussed in detail the characteristics of liposome, importance of polymer for liposome formulation, gene delivery, and future direction of liposome based gene delivery as a whole. PMID:25250340

  11. Drug Delivery Systems, CNS Protection, and the Blood Brain Barrier

    PubMed Central

    Upadhyay, Ravi Kant

    2014-01-01

    Present review highlights various drug delivery systems used for delivery of pharmaceutical agents mainly antibiotics, antineoplastic agents, neuropeptides, and other therapeutic substances through the endothelial capillaries (BBB) for CNS therapeutics. In addition, the use of ultrasound in delivery of therapeutic agents/biomolecules such as proline rich peptides, prodrugs, radiopharmaceuticals, proteins, immunoglobulins, and chimeric peptides to the target sites in deep tissue locations inside tumor sites of brain has been explained. In addition, therapeutic applications of various types of nanoparticles such as chitosan based nanomers, dendrimers, carbon nanotubes, niosomes, beta cyclodextrin carriers, cholesterol mediated cationic solid lipid nanoparticles, colloidal drug carriers, liposomes, and micelles have been discussed with their recent advancements. Emphasis has been given on the need of physiological and therapeutic optimization of existing drug delivery methods and their carriers to deliver therapeutic amount of drug into the brain for treatment of various neurological diseases and disorders. Further, strong recommendations are being made to develop nanosized drug carriers/vehicles and noninvasive therapeutic alternatives of conventional methods for better therapeutics of CNS related diseases. Hence, there is an urgent need to design nontoxic biocompatible drugs and develop noninvasive delivery methods to check posttreatment clinical fatalities in neuropatients which occur due to existing highly toxic invasive drugs and treatment methods. PMID:25136634

  12. [Thought and application of traditional Chinese medicine multiple drug delivery system based on material basis component].

    PubMed

    Sun, E; Jia, Xiaobin; Huang, Yang; Chen, Bin; Hu, Qin; Xiao, Wei

    2012-07-01

    To aim directly at the research status of Chinese drugs pharmaceutics, this study provides a new research idea "traditional Chinese medicine multiple drug delivery system based on material basis component". This thought according to whole concept, syndrome, and Chinese medicine characteristics of multi-component, multi-target, multi-effect. The premise of designing traditional Chinese medicine multiple drug delivery system is material basis component, and the purpose is to improve bioavailability. The example of multi-drug delivery system of tongmai micro-pellets is expounded for application. This new research model of Chinese drugs pharmaceutics provides new strategies and methods for the development of modern Chinese drug delivery systems.

  13. Continuously charged flywheel type power delivery system

    SciTech Connect

    Frank, A.A.; Omitsu, T.

    1986-04-22

    In a method of controlling the operation of a flywheel-type power delivery system having an energy-storing flywheel, an internal combustion engine is described operatively coupled to the flywheel for delivering power to the flywheel, and a continuously variable ratio transmission operatively coupled to the flywheel for delivering power to an output shaft. The improvement described here consists of: predetermining a desired maximum output shaft speed limit; and adjusting the working displacement of the engine in proportion to the output shaft speed limit, whereby the efficient power output of the engine is tailored to the power requirements of the system.

  14. Advances in the Applications of Polyhydroxyalkanoate Nanoparticles for Novel Drug Delivery System

    PubMed Central

    Shrivastav, Anupama; Kim, Hae-Yeong; Kim, Young-Rok

    2013-01-01

    Drug delivery technology is emerging as an interdisciplinary science aimed at improving human health. The controlled delivery of pharmacologically active agents to the specific site of action at the therapeutically optimal rate and dose regimen has been a major goal in designing drug delivery systems. Over the past few decades, there has been considerable interest in developing biodegradable drug carriers as effective drug delivery systems. Polymeric materials from natural sources play an important role in controlled release of drug at a particular site. Polyhydroxyalkanoates, due to their origin from natural sources, are given attention as candidates for drug delivery materials. Biodegradable and biocompatible polyhydroxyalkanoates are linear polyesters produced by microorganisms under unbalanced growth conditions, which have emerged as potential polymers for use as biomedical materials for drug delivery due to their unique physiochemical and mechanical properties. This review summarizes many of the key findings in the applications of polyhydroxyalkanoates and polyhydroxyalkanoate nanoparticles for drug delivery system. PMID:23984383

  15. Enhancing intestinal drug solubilisation using lipid-based delivery systems.

    PubMed

    Porter, Christopher J H; Pouton, Colin W; Cuine, Jean F; Charman, William N

    2008-03-17

    Lipid-based delivery systems are finding increasing application in the oral delivery of poorly water-soluble, lipophilic drugs. Whilst lipidic dose forms may improve oral bioavailability via several mechanisms, enhancement of gastrointestinal solubilisation remains argueably the most important method of absorption enhancement. This review firstly describes the mechanistic rationale which underpins the use of lipid-based delivery systems to enhance drug solubilisation and briefly reviews the available literature describing increases in oral bioavailability after the administration of lipid solution, suspension and self-emulsifying formulations. The use of in vitro methods including dispersion tests and more complex models of in vitro lipolysis as indicators of potential in vivo performance are subsequently described, with particular focus on recent data which suggests that the digestion of surfactants present in lipid-based formulations may impact on formulation performance. Finally, a series of seven guiding principles for formulation design of lipid-based delivery systems are suggested based on an analysis of recent data generated in our laboratories and elsewhere.

  16. The role of biomaterials in insulin delivery systems.

    PubMed

    Bruck, S D

    1980-09-01

    The control of blood glucose levels in diabetes involving devices are critically reviewed, and the role of blood-contacting biomaterial components analyzed. These include mechanical insulin-delivery systems of the closed-loop type that require an electronic glucose sensor and feedback, and open-loop systems that deliver insulin without a sensor and feedback. Whole pancreatic and islet transplantations, islet encapsulation, and the potential role of polymeric sustained drug delivery systems are discussed. The medical and social impacts of diabetes mellitus are of prime public health concern and of even greater magnitude than those of heart disease in the United States. While future advances in device design, miniaturization, and biomaterials technology will significantly add to the arsenal of therapeutic alternatives, devices capable of controlling blood glucose levels ought to be viewed as mere interim phases rather than as final goals of the problem.

  17. Microemulsions based transdermal drug delivery systems.

    PubMed

    Vadlamudi, Harini C; Narendran, Hyndavi; Nagaswaram, Tejeswari; Yaga, Gowri; Thanniru, Jyotsna; Yalavarthi, Prasanna R

    2014-01-01

    Since the discovery of microemulsions by Jack H Schulman, there has been huge progress made in applying microemulsion systems in plethora of research and industrial process. Microemulsions are optically isotropic systems consisting of water, oil and amphiphile. These systems are beneficial due to their thermodynamic stability, optical clarity, ease of preparation, higher diffusion and absorption rates. Moreover, it has been reported that the ingredients of microemulsion can effectively overcome the diffusion barrier and penetrate through the stratum corneum of the skin. Hence it becomes promising for both transdermal and dermal drug delivery. However, low viscosity of microemulsion restrains its applicability in pharmaceutical industry. To overcome the above drawback, the low viscous microemulsions were added to viscous gel bases to potentiate its applications as topical drug delivery systems so that various drug related toxic effects and erratic drug absorption can be avoided. The present review deals with the microemulsions, various techniques involved in the development of organic nanoparticles. The review emphasized on microemulsion based systems such as hydrogels and organogels. The physicochemical characteristics, mechanical properties, rheological and stability principles involved in microemulsion based viscous gels were also explored.

  18. The new organization of the health care delivery system.

    PubMed

    Shortell, S M; Hull, K E

    1996-01-01

    The U.S. health care system is restructuring at a dizzying pace. In many parts of the country, managed care has moved into third-generation models emphasizing capitated payment for enrolled lives and, in the process, turning most providers and institutions into cost centers to be managed rather than generators of revenue. While the full impact of the new managed care models remains to be seen, most evidence to date suggests that it tends to reduce inpatient use, may be associated with greater use of physician services and preventive care, and appears to result in no net differences either positive or negative with regard to quality or outcomes of care in comparison with fee-for-service plans. Some patients, however, tend to be somewhat less satisfied with scheduling of appointments and the amount of time spent with providers. There is no persuasive evidence that managed care lowers the rate of growth in overall health care costs within a given market. Further, managed care performance varies considerably across the country, and the factors influencing managed care performance are not well understood. Organized delivery systems are a somewhat more recent phenomenon representing various forms of ownership and strategic alliances among hospitals, physicians, and insurers designed to provide more cost-effective care to defined populations by achieving desired levels of functional, physician-system, and clinical integration. Early evidence suggests that organized delivery systems that are more integrated have the potential to provide more accessible coordinated care across the continuum, and appear to be associated with higher levels of inpatient productivity, greater total system revenue, greater total system cash flow, and greater total system operating margin than less integrated delivery forms. Some key success factors for developing organized delivery systems have been identified. Important roles are played by organizational culture, information systems, internal

  19. Drug Delivery Systems for Platinum Drugs

    NASA Astrophysics Data System (ADS)

    Huynh, Vien T.; Scarano, Wei; Stenzel, Martina H.

    2013-09-01

    Since the discovery of cisplatin, drugs based on platinum, have made a significant impact on the treatment of various cancers. The administration of platinum drugs is however accompanied by significant side effects. This chapter discusses the types of drug delivery systems that have been developed in order to enable the targeted delivery while maintaining controlled temporal supply of the drug. The sizes of carriers range from nanometer to micrometer sized particles. The most common types of drug carriers are micelles, liposomes, nanoparticles, and dendrimers, but also a few microspheres have been developed. Most striking aspect of the delivery of platinum drugs is the possibility of physical encapsulation but also the binding of the drug to the polymer carrier coordinate covalent bond. Since platinum drugs have typically two permanent and two leaving ligands, the polymer can be part of either ligand. As the leaving ligand, the platinum drug is released often as cisplatin. If the polymer provides the functionality for the permanent ligand, a new macromolecular drug has been formed. In addition to the attachment of pt(II) drugs, recent offorts are devoted to the conjugation via the Pt((IV) prodrug.

  20. Multiparticulate chitosan-dispersed system for drug delivery.

    PubMed

    Shimono, Norihito; Takatori, Toshihito; Ueda, Masumi; Mori, Masaaki; Nakamura, Yasuhiko

    2003-06-01

    A multiparticulate chitosan-dispersed system (CDS), which is composed of the drug reservoir and the drug release-regulating layer, was developed for drug delivery. The drug release-regulating layer is a mixture of water-insoluble polymer and chitosan powder. The drug is released from CDS pellets in all regions of the gastrointestinal tract (from the stomach to the colon). CDS pellets containing chitosan powder were designed to dissolve chitosan powder partly in the release-regulating layer in the stomach and release part of drug. After passing through the stomach, the drug is released from CDS pellets at a constant speed in the small intestine. In the large intestine, CDS pellets were designed to disintegrate the remaining chitosan powder at an accelerated speed and the remaining drug in CDS pellets is released. The drug release rate can be controlled with the thickness of the chitosan-dispersed water-insoluble layer. Furthermore, for colon-specific drug delivery, an additional outer enteric coating is necessary to prevent drug release from CDS pellets in the stomach, because the chitosan-dispersed water-insoluble layer dissolves gradually under acidic conditions. The resulting enteric-coated CDS (E-CDS) pellets were found to permit colon-specific drug delivery. In this study, the multiparticulate CDS was adopted not only for colon-specific drug delivery but also for sustained drug release.

  1. Limited Efficiency of Drug Delivery to Specific Intracellular Organelles Using Subcellularly "Targeted" Drug Delivery Systems.

    PubMed

    Maity, Amit Ranjan; Stepensky, David

    2016-01-04

    Many drugs have been designed to act on intracellular targets and to affect intracellular processes inside target cells. For the desired effects to be exerted, these drugs should permeate target cells and reach specific intracellular organelles. This subcellular drug targeting approach has been proposed for enhancement of accumulation of these drugs in target organelles and improved efficiency. This approach is based on drug encapsulation in drug delivery systems (DDSs) and/or their decoration with specific targeting moieties that are intended to enhance the drug/DDS accumulation in the intracellular organelle of interest. During recent years, there has been a constant increase in interest in DDSs targeted to specific intracellular organelles, and many different approaches have been proposed for attaining efficient drug delivery to specific organelles of interest. However, it appears that in many studies insufficient efforts have been devoted to quantitative analysis of the major formulation parameters of the DDSs disposition (efficiency of DDS endocytosis and endosomal escape, intracellular trafficking, and efficiency of DDS delivery to the target organelle) and of the resulting pharmacological effects. Thus, in many cases, claims regarding efficient delivery of drug/DDS to a specific organelle and efficient subcellular targeting appear to be exaggerated. On the basis of the available experimental data, it appears that drugs/DDS decoration with specific targeting residues can affect their intracellular fate and result in preferential drug accumulation within an organelle of interest. However, it is not clear whether these approaches will be efficient in in vivo settings and be translated into preclinical and clinical applications. Studies that quantitatively assess the mechanisms, barriers, and efficiencies of subcellular drug delivery and of the associated toxic effects are required to determine the therapeutic potential of subcellular DDS targeting.

  2. Effects of formulation design on niacin therapeutics: mechanism of action, metabolism, and drug delivery.

    PubMed

    Cooper, Dustin L; Murrell, Derek E; Roane, David S; Harirforoosh, Sam

    2015-07-25

    Niacin is a highly effective, lipid regulating drug associated with a number of metabolically induced side effects such as prostaglandin (PG) mediated flushing and hepatic toxicity. In an attempt to reduce the development of these adverse effects, scientists have investigated differing methods of niacin delivery designed to control drug release and alter metabolism. However, despite successful formulation of various orally based capsule and tablet delivery systems, patient adherence to niacin therapy is still compromised by adverse events such as PG-induced flushing. While the primary advantage of orally dosed formulations is ease of use, alternative delivery options such as transdermal delivery or polymeric micro/nanoparticle encapsulation for oral administration have shown promise in niacin reformulation. However, the effectiveness of these alternative delivery options in reducing inimical effects of niacin and maintaining drug efficacy is still largely unknown and requires more in-depth investigation. In this paper, we present an overview of niacin applications, its metabolic pathways, and current drug delivery formulations. Focus is placed on oral immediate, sustained, and extended release niacin delivery as well as combined statin and/or prostaglandin antagonist niacin formulation. We also examine and discuss current findings involving transdermal niacin formulations and polymeric micro/nanoparticle encapsulated niacin delivery.

  3. 42 CFR 457.490 - Delivery and utilization control systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... State Plan Requirements: Coverage and Benefits § 457.490 Delivery and utilization control systems. A... 42 Public Health 4 2013-10-01 2013-10-01 false Delivery and utilization control systems. 457.490... targeted low-income children, including a description of the proposed methods of delivery and...

  4. 42 CFR 457.490 - Delivery and utilization control systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... State Plan Requirements: Coverage and Benefits § 457.490 Delivery and utilization control systems. A... 42 Public Health 4 2012-10-01 2012-10-01 false Delivery and utilization control systems. 457.490... targeted low-income children, including a description of the proposed methods of delivery and...

  5. Modeling the Delivery Physiology of Distributed Learning Systems.

    ERIC Educational Resources Information Center

    Paquette, Gilbert; Rosca, Ioan

    2003-01-01

    Discusses instructional delivery models and their physiology in distributed learning systems. Highlights include building delivery models; types of delivery models, including distributed classroom, self-training on the Web, online training, communities of practice, and performance support systems; and actors (users) involved, including experts,…

  6. Stimuli-Responsive Polymeric Systems for Controlled Protein and Peptide Delivery: Future Implications for Ocular Delivery.

    PubMed

    Mahlumba, Pakama; Choonara, Yahya E; Kumar, Pradeep; du Toit, Lisa C; Pillay, Viness

    2016-07-30

    Therapeutic proteins and peptides have become notable in the drug delivery arena for their compatibility with the human body as well as their high potency. However, their biocompatibility and high potency does not negate the existence of challenges resulting from physicochemical properties of proteins and peptides, including large size, short half-life, capability to provoke immune responses and susceptibility to degradation. Various delivery routes and delivery systems have been utilized to improve bioavailability, patient acceptability and reduce biodegradation. The ocular route remains of great interest, particularly for responsive delivery of macromolecules due to the anatomy and physiology of the eye that makes it a sensitive and complex environment. Research in this field is slowly gaining attention as this could be the breakthrough in ocular drug delivery of macromolecules. This work reviews stimuli-responsive polymeric delivery systems, their use in the delivery of therapeutic proteins and peptides as well as examples of proteins and peptides used in the treatment of ocular disorders. Stimuli reviewed include pH, temperature, enzymes, light, ultrasound and magnetic field. In addition, it discusses the current progress in responsive ocular drug delivery. Furthermore, it explores future prospects in the use of stimuli-responsive polymers for ocular delivery of proteins and peptides. Stimuli-responsive polymers offer great potential in improving the delivery of ocular therapeutics, therefore there is a need to consider them in order to guarantee a local, sustained and ideal delivery of ocular proteins and peptides, evading tissue invasion and systemic side-effects.

  7. Liposomes as delivery systems for antineoplastic drugs

    NASA Astrophysics Data System (ADS)

    Medina, Luis Alberto

    2014-11-01

    Liposome drug formulations are defined as pharmaceutical products containing active drug substances encapsulated within the lipid bilayer or in the interior aqueous space of the liposomes. The main importance of this drug delivery system is based on its drastic reduction in systemic dose and concomitant systemic toxicity that in comparison with the free drug, results in an improvement of patient compliance and in a more effective treatment. There are several therapeutic drugs that are potential candidates to be encapsulated into liposomes; particular interest has been focused in therapeutic and antineoplastic drugs, which are characterized for its low therapeutic index and high systemic toxicity. The use of liposomes as drug carriers has been extensively justified and the importance of the development of different formulations or techniques to encapsulate therapeutic drugs has an enormous value in benefit of patients affected by neoplastic diseases.

  8. Design and Evaluation of Hydrophilic Matrix System Containing Polyethylene Oxides for the Zero-Order Controlled Delivery of Water-Insoluble Drugs.

    PubMed

    Wang, Lijie; Chen, Kai; Wen, Haoyang; Ouyang, Defang; Li, Xue; Gao, Yunyun; Pan, Weisan; Yang, Xinggang

    2017-01-01

    The aim of this study was to design a polyethylene oxide (PEO) binary hydrophilic matrix controlled system and investigate the most important influence(s) on the in vitro water-insoluble drug release behavior of this controlled system. Direct-compressed PEO binary matrix tablets were obtained from a variety of low viscosity hydrophilic materials as a sustained agent, using anhydrous drugs as a model drug. Water uptake rate, swelling rate, and erosion rate of matrices were investigated for the evaluation of the PEO hydrophilic matrix systems. The effect of the dose, the solubility of water-insoluble drug, and the rheology of polymers on in vitro release were also discussed. Based on the in vitro release kinetics study, three optimized PEO binary matrices were selected for further research. And, these PEO binary matrices had shown the similar release behavior that had been evaluated by the similarity factor f 2. Further study indicated that they had identical hydration, swelling, and erosion rate. Moreover, rheology study exhibited the similar rheological equation of Herschel-Bulkley and their viscosity was also within the same magnitude. Therefore, viscosity plays the most important role to control drug release compared to other factors in PEO binary matrix system. This research provides fundamental understanding of in vitro drug release of PEO binary hydrophilic matrix tablets and helps pharmaceutical workers to develop a hydrophilic controlled system, which will effectively shorten the process of formulation development by reducing trial-and-error.

  9. Using DNA nanotechnology to produce a drug delivery system

    NASA Astrophysics Data System (ADS)

    Huyen La, Thi; Thu Thuy Nguyen, Thi; Phuc Pham, Van; Huyen Nguyen, Thi Minh; Huan Le, Quang

    2013-03-01

    Drug delivery to cancer cells in chemotherapy is one of the most advanced research topics. The effectiveness of the current cancer treatment drugs is limited because they are not capable of distinguishing between cancer cells and normal cells so that they kill not only cancer cells but also normal ones. To overcome this disadvantage by profiting from the differences in physical and chemical properties between cancer and normal cells, nanoparticles (NPs) delivering a drug are designed in a specific manner such that they can distinguish the cancer cells from the normal ones and are targeted only to the cancer cells. Currently, there are various drug delivery systems with many advantages, but sharing some common disadvantages such as difficulty with controlling the size, low encapsulation capacity and low stability. With the development and success of DNA nanotechnology, DNA strands are used to create effective drug delivery NPs with precisely controlled size and structure, safety and high stability. This article presents our study on drug encapsulation in DNA nanostructure which loaded docetaxel and curcumin in a desire to create a new and effective drug delivery system with high biological compatibility. Invited talk at the 6th International Workshop on Advanced Materials Science and Nanotechnology, 30 October-2 November, 2012, Ha Long, Vietnam.

  10. Mucoadhesive drug delivery system: An overview

    PubMed Central

    Boddupalli, Bindu M.; Mohammed, Zulkar N. K.; Nath, Ravinder A.; Banji, David

    2010-01-01

    Mucoadhesive drug delivery systems interact with the mucus layer covering the mucosal epithelial surface, and mucin molecules and increase the residence time of the dosage form at the site of absorption. The drugs which have local action or those which have maximum absorption in gastrointestinal tract (GIT) require increased duration of stay in GIT. Thus, mucoadhesive dosage forms are advantageous in increasing the drug plasma concentrations and also therapeutic activity. In this regard, this review covers the areas of mechanisms and theories of mucoadhesion, factors influencing the mucoadhesive devices and also various mucoadhesive dosage forms. PMID:22247877

  11. Fuel delivery system including heat exchanger means

    NASA Technical Reports Server (NTRS)

    Coffinberry, G. A. (Inventor)

    1978-01-01

    A fuel delivery system is presented wherein first and second heat exchanger means are each adapted to provide the transfer of heat between the fuel and a second fluid such as lubricating oil associated with the gas turbine engine. Valve means are included which are operative in a first mode to provide for flow of the second fluid through both first and second heat exchange means and further operative in a second mode for bypassing the second fluid around the second heat exchanger means.

  12. In Situ Forming Polymeric Drug Delivery Systems

    PubMed Central

    Madan, M.; Bajaj, A.; Lewis, S.; Udupa, N.; Baig, J. A.

    2009-01-01

    In situ forming polymeric formulations are drug delivery systems that are in sol form before administration in the body, but once administered, undergo gelation in situ, to form a gel. The formation of gels depends on factors like temperature modulation, pH change, presence of ions and ultra violet irradiation, from which the drug gets released in a sustained and controlled manner. Various polymers that are used for the formulation of in situ gels include gellan gum, alginic acid, xyloglucan, pectin, chitosan, poly(DL-lactic acid), poly(DL-lactide-co-glycolide) and poly-caprolactone. The choice of solvents like water, dimethylsulphoxide, N-methyl pyrrolidone, triacetin and 2-pyrrolidone for these formulations depends on the solubility of polymer used. Mainly in situ gels are administered by oral, ocular, rectal, vaginal, injectable and intraperitoneal routes. The in situ gel forming polymeric formulations offer several advantages like sustained and prolonged action in comparison to conventional drug delivery systems. The article presents a detailed review of these types of polymeric systems, their evaluation, advancements and their commercial formulations. From a manufacturing point of view, the production of such devices is less complex and thus lowers the investment and manufacturing cost. PMID:20490289

  13. Inhaled formulations and pulmonary drug delivery systems for respiratory infections.

    PubMed

    Zhou, Qi Tony; Leung, Sharon Shui Yee; Tang, Patricia; Parumasivam, Thaigarajan; Loh, Zhi Hui; Chan, Hak-Kim

    2015-05-01

    Respiratory infections represent a major global health problem. They are often treated by parenteral administrations of antimicrobials. Unfortunately, systemic therapies of high-dose antimicrobials can lead to severe adverse effects and this calls for a need to develop inhaled formulations that enable targeted drug delivery to the airways with minimal systemic drug exposure. Recent technological advances facilitate the development of inhaled anti-microbial therapies. The newer mesh nebulisers have achieved minimal drug residue, higher aerosolisation efficiencies and rapid administration compared to traditional jet nebulisers. Novel particle engineering and intelligent device design also make dry powder inhalers appealing for the delivery of high-dose antibiotics. In view of the fact that no new antibiotic entities against multi-drug resistant bacteria have come close to commercialisation, advanced formulation strategies are in high demand for combating respiratory 'super bugs'.

  14. Chronopharmaceutical Drug Delivery Systems: Hurdles, Hype or Hope?⊗

    PubMed Central

    Youan, Bi-Botti C.

    2010-01-01

    The current advances in chronobiology and the knowledge gained from chronotherapy of selected diseases strongly suggest that “the one size fits all at all times” approach to drug delivery is no longer substantiated, at least for selected bioactive agents and disease therapy or prevention. Thus, there is a critical and urgent need for chronopharmaceutical research (e.g., design and evaluation of robust, spatially and temporally controlled drug delivery systems that would be clinically intended for chronotherapy by different routes of administration). This review provides a brief overview of current delivery system intended for chronotherapy. In theory, such an ideal “magic pill” preferably with affordable cost, would improve the safety, efficacy and patient compliance of old and new drugs. However, currently, there are three major hurdles for the successful transition of such system from laboratory to patient bedside. These include the challenges to identify adequate (i) rhythmic biomaterials and systems, (ii) rhythm engineering modeling, perhaps using system biology and (iii) regulatory guidance. PMID:20438781

  15. State-of-the-Art in Design Rules for Drug Delivery Platforms: Lessons from FDA-approved Nanomedicines

    PubMed Central

    Dawidczyk, Charlene M.; Kim, Chloe; Park, Jea Ho; Russell, Luisa M.; Lee, Kwan Hyi; Pomper, Martin G.; Searson, Peter C.

    2014-01-01

    The ability to efficiently deliver a drug to a tumor site is dependent on a wide range of physiologically imposed design constraints. Nanotechnology provides the possibility of creating delivery vehicles where these design constraints can be decoupled, allowing new approaches for reducing the unwanted side effects of systemic delivery, increasing targeting efficiency and efficacy. Here we review the design strategies of the two FDA-approved antibody-drug conjugates (Brentuximab vedotin and Trastuzumab emtansine) and the four FDA-approved nanoparticle-based drug delivery platforms (Doxil, DaunoXome, Marqibo, and Abraxane) in the context of the challenges associated with systemic targeted delivery of a drug to a solid tumor. The lessons learned from these nanomedicines provide important insight into the key challenges associated with the development of new platforms for systemic delivery of anti-cancer drugs. PMID:24874289

  16. State-of-the-art in design rules for drug delivery platforms: lessons learned from FDA-approved nanomedicines.

    PubMed

    Dawidczyk, Charlene M; Kim, Chloe; Park, Jea Ho; Russell, Luisa M; Lee, Kwan Hyi; Pomper, Martin G; Searson, Peter C

    2014-08-10

    The ability to efficiently deliver a drug to a tumor site is dependent on a wide range of physiologically imposed design constraints. Nanotechnology provides the possibility of creating delivery vehicles where these design constraints can be decoupled, allowing new approaches for reducing the unwanted side effects of systemic delivery, increasing targeting efficiency and efficacy. Here we review the design strategies of the two FDA-approved antibody-drug conjugates (Brentuximab vedotin and Trastuzumab emtansine) and the four FDA-approved nanoparticle-based drug delivery platforms (Doxil, DaunoXome, Marqibo, and Abraxane) in the context of the challenges associated with systemic targeted delivery of a drug to a solid tumor. The lessons learned from these nanomedicines provide an important insight into the key challenges associated with the development of new platforms for systemic delivery of anti-cancer drugs. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Online Mapping Systems for Climate Data Delivery

    NASA Astrophysics Data System (ADS)

    Gray, S. T.; Nicholson, C. M.; Bergantino, A. R.

    2009-12-01

    Online, map-based applications have experienced an explosion in popularity over the past decade. The success of these systems is largely due to their ability to provide a spatial framework data exploration, and for the visual context (e.g., satellite images) they offer. Here we detail the development of a new online mapping system for Wyoming that will serve as a portal for the delivery of weather, climate, and water-related data for users across the state. While capitalizing on the success of previous online mapping efforts, this new system also highlights the potential for additional applications and functionality. Known as the Wyoming Internet Map Server (WyoIMS), the system brings together real-time observations and summary products from multiple federal agencies (NOAA-NWS, NRCS, USGS) to provide “one-stop-shopping” for key climatic datasets. Likewise this system is providing a platform for data delivery, archiving, and QC/QA as part of a new statewide hydroclimatic monitoring network. Moving beyond the simple transfer of data, this system also allows users to access information from resources that include state libraries and various databases that contain information related to climate and water resources. Users can, for example, select individual counties, watersheds, irrigation districts, or municipalities and download a wide range of documents and reports specific to those locations. On the whole, WyoIMS has become a catalyst for the development of new climate-related products, and a foundation for decision support with applications in water resources, wildlife management, and agriculture.

  18. Strategies For Assessing Delivery System Innovations.

    PubMed

    McGlynn, Elizabeth A; McClellan, Mark

    2017-03-01

    Driven by evidence of continuing gaps in health care quality and efficiency and inspired by the emergence of new value-based payment models, both large and small health care organizations are developing and deploying a wide range of care delivery innovations. But how can decision makers in these organizations determine if the innovations really improve service delivery, patient experience, clinical outcomes, or costs? Organization leaders need appropriate, timely evidence to inform their decision making. In this article we describe a range of approaches to evaluating innovations and pose key questions about the validity of the results. We highlight a specific type of evaluation approach-the stepped wedge design-because it can balance the need for internal and external validity with the ability to generate timely results. We elaborate on three key steps in the innovation assessment phase (identifying the target population, describing baseline performance, and documenting the components of the innovation) that are useful for both organizations that will generate new evidence and those using evidence generated by others. We conclude with a discussion of payer approaches for supporting health care organizations in their efforts to develop new evidence on innovations. Project HOPE—The People-to-People Health Foundation, Inc.

  19. Silk Electrogel Based Gastroretentive Drug Delivery System

    NASA Astrophysics Data System (ADS)

    Wang, Qianrui

    Gastric cancer has become a global pandemic and there is imperative to develop efficient therapies. Oral dosing strategy is the preferred route to deliver drugs for treating the disease. Recent studies suggested silk electro hydrogel, which is pH sensitive and reversible, has potential as a vehicle to deliver the drug in the stomach environment. The aim of this study is to establish in vitro electrogelation e-gel based silk gel as a gastroretentive drug delivery system. We successfully extended the duration of silk e-gel in artificial gastric juice by mixing silk solution with glycerol at different ratios before the electrogelation. Structural analysis indicated the extended duration was due to the change of beta sheet content. The glycerol mixed silk e-gel had good doxorubicin loading capability and could release doxorubicin in a sustained-release profile. Doxorubicin loaded silk e-gels were applied to human gastric cancer cells. Significant cell viability decrease was observed. We believe that with further characterization as well as functional analysis, the silk e-gel system has the potential to become an effective vehicle for gastric drug delivery applications.

  20. Gellified Emulsion of Ofloxacin for Transdermal Drug Delivery System

    PubMed Central

    Jagdale, Swati; Pawar, Saylee

    2017-01-01

    Purpose: Ofloxacin is a fluoroquinolone with broad-spectrum antibacterial action, used in treatment of systemic and local infections. Ofloxacin is BCS class II drug having low solubility, high permeability with short half-life. The present work was aimed to design, develop and optimize gellified emulsion of Ofloxacin to provide site targeted drug delivery. Transdermal drug delivery will enhance the bioavailability of the drug giving controlled drug release. Methods: Transdermal drug delivery system was designed with gelling agent (Carbopol 940 and HPMC K100M), oil phase (oleic acid) and emulsifying agent (Tween 80: Span 80). Effect of concentration of gelling agent on release of drug from transdermal delivery was studied by 32 factorial design. Emulgel was evaluated for physical appearance, pH, drug content, viscosity, spreadability, antimicrobial activity, in- vitro diffusion study and ex-vivo diffusion study. Results: FE-SEM study of the emulsion batch B5 has revealed formation of emulsion globules of approximately size 6-8 µm with -11.2 mV zeta potential showing good stability for the emulsion. Carbopol 940 had shown greater linear effect on drug release and viscosity of the formulations due to its high degree of gelling. In-vitro diffusion study through egg membrane had shown 88.58±1.82 % drug release for optimized batch F4. Ex-vivo diffusion study through goat skin indicated 76.68 ± 2.52% drug release. Conclusion: Controlled release Ofloxacin emulgel exhibiting good in-vitro and ex-vivo drug release proving good antimicrobial property was formulated. PMID:28761825

  1. Gellified Emulsion of Ofloxacin for Transdermal Drug Delivery System.

    PubMed

    Jagdale, Swati; Pawar, Saylee

    2017-06-01

    Purpose: Ofloxacin is a fluoroquinolone with broad-spectrum antibacterial action, used in treatment of systemic and local infections. Ofloxacin is BCS class II drug having low solubility, high permeability with short half-life. The present work was aimed to design, develop and optimize gellified emulsion of Ofloxacin to provide site targeted drug delivery. Transdermal drug delivery will enhance the bioavailability of the drug giving controlled drug release. Methods: Transdermal drug delivery system was designed with gelling agent (Carbopol 940 and HPMC K100M), oil phase (oleic acid) and emulsifying agent (Tween 80: Span 80). Effect of concentration of gelling agent on release of drug from transdermal delivery was studied by 3(2) factorial design. Emulgel was evaluated for physical appearance, pH, drug content, viscosity, spreadability, antimicrobial activity, in- vitro diffusion study and ex-vivo diffusion study. Results: FE-SEM study of the emulsion batch B5 has revealed formation of emulsion globules of approximately size 6-8 µm with -11.2 mV zeta potential showing good stability for the emulsion. Carbopol 940 had shown greater linear effect on drug release and viscosity of the formulations due to its high degree of gelling. In-vitro diffusion study through egg membrane had shown 88.58±1.82 % drug release for optimized batch F4. Ex-vivo diffusion study through goat skin indicated 76.68 ± 2.52% drug release. Conclusion: Controlled release Ofloxacin emulgel exhibiting good in-vitro and ex-vivo drug release proving good antimicrobial property was formulated.

  2. [Studies on market of drug delivery system product and drug delivery system of compound Chinese medicine].

    PubMed

    Feng, Yi; Xu, De-Sheng; Hong, Yan-Long; Zhang, Ning; Ma, Yue-Ming

    2006-10-01

    Based on the progress in the world market of drug delivery system (DDS) product and the research profile of DDS of compound Chinese Medicine, The article puts forward a new method of studies on DDS of compound Chinese Medicine. It is expected that the theory of compatibility of compound Chinese Medicine can be shown and its role can be exerted to the largest extent with the application of pharmaceutics technology to change the mode of drug delivery of activated components of compound Chinese Medicine.

  3. Mental Health of the Rural Elderly Outreach Program: A Unique Health Care Delivery System.

    ERIC Educational Resources Information Center

    Buckwalter, Kathleen C.; And Others

    This article describes a unique health care delivery system, the Mental Health of the Rural Elderly Outreach Program. The project in designed to identify and provide mental health services to an underserved population, the rural elderly, who are suffering from severe and disabling mental illness. Delivery of mental health services to the rural…

  4. Leisure Service Delivery Systems: Are They Adequate

    Treesearch

    Rene Fukuhara Dahl

    1992-01-01

    This presentation explores a model of service delivery ranging from direct service provision to advocacy and reports findings on the delivery mode most prevalent in park and recreation departments that serve Asian groups in their community. The implications of the role of the professional, the range of service delivery, and the manner in which ethnic groups are...

  5. Demonstrated delivery/employment systems for unattended ground sensors

    NASA Astrophysics Data System (ADS)

    Taylor, Robert R.; Bendowski, Michael A.; McFeaters, Ryan C.

    1997-07-01

    This paper describes the payload delivery system developed and proven to deploy an electronic warfare device to specific, predetermined locations on the battlefield. Initially called the Artillery Delivered Expendable Jammer (AD/EXJAM), it is now designated the Air Delivered-Ground (Deployed) Expendable Jammer (AD-G/EXJAM). The initial units were demonstrated from 155 MM artillery; the later units, from UAV's, helicopters and slow moving, fixed wing aircraft. While these two delivery systems were originally designed specifically for the EXJAM system, the concept is directly applicable to unattended ground sensors that require unmanned remote emplacement. Keys to the success of the jammer included design, development and field testing of power supplies, antennas, deployment systems and packaging to allow payloads to withstand high-g impact and other severe environments typically encountered. The artillery deployed systems were designed to be `wooden' rounds needing no special handling and storing. These systems treat the payload as independent elements which are self-ejected from a fired M483A1 or M864 round and are completely automatic upon hitting the ground. The more recent payloads can be delivered from UAV's and include remote control capabilities, increased operating life and increased power output. The present payload is packaged into a cylindrical shape, approximately six inches in diameter and 6.5 inches long and are contained within a carrier, attached to an Unmanned Air Vehicle (UAV) or any other air vehicle. Upon reaching the dispensing point, the release command can be issue by either the UAV or a separate ground control unit in RF contact with the carrier. The carrier then begins a timed dispensing sequence that has been selected for optimum payload emplacement in the target area. New developments include a design and subsystem demonstration of a tactical munitions dispenser variant of the deployment system. Operational characteristics of any specific

  6. Fluid Delivery System For Capillary Electrophoretic Applications.

    DOEpatents

    Li, Qingbo; Liu, Changsheng; Kane, Thomas E.; Kernan, John R.; Sonnenschein, Bernard; Sharer, Michael V.

    2002-04-23

    An automated electrophoretic system is disclosed. The system employs a capillary cartridge having a plurality of capillary tubes. The cartridge has a first array of capillary ends projecting from one side of a plate. The first array of capillary ends are spaced apart in substantially the same manner as the wells of a microtitre tray of standard size. This allows one to simultaneously perform capillary electrophoresis on samples present in each of the wells of the tray. The system includes a stacked, dual carrousel arrangement to eliminate cross-contamination resulting from reuse of the same buffer tray on consecutive executions from electrophoresis. The system also has a gel delivery module containing a gel syringe/a stepper motor or a high pressure chamber with a pump to quickly and uniformly deliver gel through the capillary tubes. The system further includes a multi-wavelength beam generator to generate a laser beam which produces a beam with a wide range of wavelengths. An off-line capillary reconditioner thoroughly cleans a capillary cartridge to enable simultaneous execution of electrophoresis with another capillary cartridge. The streamlined nature of the off-line capillary reconditioner offers the advantage of increased system throughput with a minimal increase in system cost.

  7. Reliability review of the remote tool delivery system locomotor

    SciTech Connect

    Chesser, J.B.

    1999-04-01

    The locomotor being built by RedZone Robotics is designed to serve as a remote tool delivery (RID) system for waste retrieval, tank cleaning, viewing, and inspection inside the high-level waste tanks 8D-1 and 8D-2 at West Valley Nuclear Services (WVNS). The RTD systm is to be deployed through a tank riser. The locomotor portion of the RTD system is designed to be inserted into the tank and is to be capable of moving around the tank by supporting itself and moving on the tank internal structural columns. The locomotor will serve as a mounting platform for a dexterous manipulator arm. The complete RTD system consists of the locomotor, dexterous manipulator arm, cameras, lights, cables, hoses, cable/hose management system, power supply, and operator control station.

  8. Virtual Design of Chemical Penetration Enhancers for Transdermal Drug Delivery

    PubMed Central

    Golla, Sharath; Neely, Brian J.; Whitebay, Eric; Madihally, Sundar; Robinson, Robert L.; Gasem, Khaled A. M.

    2012-01-01

    Traditional drug design is a laborious and expensive process that often challenges the pharmaceutical industries. As a result, researchers have turned to computational methods for computer-assisted molecular design. Recently, genetic and evolutionary algorithms have emerged as efficient methods in solving combinatorial problems associated with computer-aided molecular design. Further, combining genetic algorithms (GAs) with quantitative structure-property relationship (QSPR) analyses has proved effective in drug design. In this work, we have integrated a new genetic algorithm and non-linear QSPR models to develop a reliable virtual screening algorithm for generation of potential chemical penetration enhancers (CPEs). The GA-QSPR algorithm has been implemented successfully to identify potential CPEs for transdermal drug delivery of insulin. Validation of the newly-identified CPE molecular structures was conducted through carefully designed experiments, which elucidated the cytotoxicity and permeability of the CPEs. PMID:22172168

  9. Virtual design of chemical penetration enhancers for transdermal drug delivery.

    PubMed

    Golla, Sharath; Neely, Brian J; Whitebay, Eric; Madihally, Sundar; Robinson, Robert L; Gasem, Khaled A M

    2012-04-01

    Traditional drug design is a laborious and expensive process that often challenges the pharmaceutical industries. As a result, researchers have turned to computational methods for computer-assisted molecular design. Recently, genetic and evolutionary algorithms have emerged as efficient methods in solving combinatorial problems associated with computer-aided molecular design. Further, combining genetic algorithms with quantitative structure-property relationship analyses has proved effective in drug design. In this work, we have integrated a new genetic algorithm and nonlinear quantitative structure-property relationship models to develop a reliable virtual screening algorithm for the generation of potential chemical penetration enhancers. The genetic algorithms-quantitative structure-property relationship algorithm has been implemented successfully to identify potential chemical penetration enhancers for transdermal drug delivery of insulin. Validation of the newly identified chemical penetration enhancer molecular structures was conducted through carefully designed experiments, which elucidated the cytotoxicity and permeability of the chemical penetration enhancers.

  10. Oral Dispersible System: A New Approach in Drug Delivery System

    PubMed Central

    Hannan, P. A.; Khan, J. A.; Khan, A.; Safiullah, S.

    2016-01-01

    Dosage form is a mean used for the delivery of drug to a living body. In order to get the desired effect the drug should be delivered to its site of action at such rate and concentration to achieve the maximum therapeutic effect and minimum adverse effect. Since oral route is still widely accepted route but having a common drawback of difficulty in swallowing of tablets and capsules. Therefore a lot of research has been done on novel drug delivery systems. This review is about oral dispersible tablets a novel approach in drug delivery systems that are now a day's more focused in formulation world, and laid a new path that, helped the patients to build their compliance level with the therapy, also reduced the cost and ease the administration especially in case of pediatrics and geriatrics. Quick absorption, rapid onset of action and reduction in drug loss properties are the basic advantages of this dosage form. PMID:27168675

  11. ILC cryogenic systems reference design

    SciTech Connect

    Peterson, T.J.; Geynisman, M.; Klebaner, A.; Theilacker, J.; Parma, V.; Tavian, L.; /CERN

    2008-01-01

    A Global Design Effort (GDE) began in 2005 to study a TeV scale electron-positron linear accelerator based on superconducting radio-frequency (RF) technology, called the International Linear Collider (ILC). In early 2007, the design effort culminated in a reference design for the ILC, closely based on the earlier TESLA design. The ILC will consist of two 250 GeV linacs, which provide positron-electron collisions for high energy physics research. The particle beams will be accelerated to their final energy in superconducting niobium RF cavities operating at 2 kelvin. At a length of about 12 km each, the main linacs will be the largest cryogenic systems in the ILC. Positron and electron sources, damping rings, and beam delivery systems will also have a large number and variety of other superconducting RF cavities and magnets, which require cooling at liquid helium temperatures. Ten large cryogenic plants with 2 kelvin refrigeration are envisioned to cool the main linacs and the electron and positron sources. Three smaller cryogenic plants will cool the damping rings and beam delivery system components predominately at 4.5 K. This paper describes the cryogenic systems concepts for the ILC.

  12. Ilc Cryogenic Systems Reference Design

    NASA Astrophysics Data System (ADS)

    Peterson, T. J.; Geynisman, M.; Klebaner, A.; Parma, V.; Tavian, L.; Theilacker, J.

    2008-03-01

    A Global Design Effort (GDE) began in 2005 to study a TeV scale electron-positron linear accelerator based on superconducting radio-frequency (RF) technology, called the International Linear Collider (ILC). In early 2007, the design effort culminated in a reference design for the ILC, closely based on the earlier TESLA design. The ILC will consist of two 250 GeV linacs, which provide positron-electron collisions for high energy physics research. The particle beams will be accelerated to their final energy in superconducting niobium RF cavities operating at 2 kelvin. At a length of about 12 km each, the main linacs will be the largest cryogenic systems in the ILC. Positron and electron sources, damping rings, and beam delivery systems will also have a large number and variety of other superconducting RF cavities and magnets, which require cooling at liquid helium temperatures. Ten large cryogenic plants with 2 kelvin refrigeration are envisioned to cool the main linacs and the electron and positron sources. Three smaller cryogenic plants will cool the damping rings and beam delivery system components predominately at 4.5 K. This paper describes the cryogenic systems concepts for the ILC.

  13. Porous tube plant nutrient delivery system development: A device for nutrient delivery in microgravity

    NASA Technical Reports Server (NTRS)

    Dreschel, T. W.; Brown, C. S.; Piastuch, W. C.; Hinkle, C. R.; Knott, W. M.

    1994-01-01

    The Porous Tube Plant Nutrient Delivery Systems or PTPNDS (U.S. Patent #4,926,585) has been under development for the past six years with the goal of providing a means for culturing plants in microgravity, specifically providing water and nutrients to the roots. Direct applications of the PTPNDS include plant space biology investigations on the Space Shuttle and plant research for life support in the Space Station Freedom. In the past, we investigated various configurations, the suitability of different porous materials, and the effects of pressure and pore size on plant growth. Current work is focused on characterizing the physical operation of the system, examining the effects of solution aeration, and developing prototype configurations for the Plant Growth Unit (PGU), the flight system for the Shuttle mid-deck. Future developments will involve testing on KC-135 parabolic flights, the design of flight hardware and testing aboard the Space Shuttle.

  14. Porous Tube Plant Nutrient Delivery System development: a device for nutrient delivery in microgravity.

    PubMed

    Dreschel, T W; Brown, C S; Piastuch, W C; Hinkle, C R; Knott, W M

    1994-11-01

    The Porous Tube Plant Nutrient Delivery System or PTPNDS (U.S. Patent #4,926,585) has been under development for the past six years with the goal of providing a means for culturing plants in microgravity, specifically providing water and nutrients to the roots. Direct applications of the PTPNDS include plant space biology investigations on the Space Shuttle and plant research for life support in Space Station Freedom. In the past, we investigated various configurations, the suitability of different porous materials, and the effects of pressure and pore size on plant growth. Current work is focused on characterizing the physical operation of the system, examining the effects of solution aeration, and developing prototype configurations for the Plant Growth Unit (PGU), the flight system for the Shuttle mid-deck. Future developments will involve testing on KC-135 parabolic flights, the design of flight hardware and testing aboard the Space Shuttle.

  15. Porous tube plant nutrient delivery system development: A device for nutrient delivery in microgravity

    NASA Technical Reports Server (NTRS)

    Dreschel, T. W.; Brown, C. S.; Piastuch, W. C.; Hinkle, C. R.; Knott, W. M.

    1994-01-01

    The Porous Tube Plant Nutrient Delivery Systems or PTPNDS (U.S. Patent #4,926,585) has been under development for the past six years with the goal of providing a means for culturing plants in microgravity, specifically providing water and nutrients to the roots. Direct applications of the PTPNDS include plant space biology investigations on the Space Shuttle and plant research for life support in the Space Station Freedom. In the past, we investigated various configurations, the suitability of different porous materials, and the effects of pressure and pore size on plant growth. Current work is focused on characterizing the physical operation of the system, examining the effects of solution aeration, and developing prototype configurations for the Plant Growth Unit (PGU), the flight system for the Shuttle mid-deck. Future developments will involve testing on KC-135 parabolic flights, the design of flight hardware and testing aboard the Space Shuttle.

  16. Light-sensitive intelligent drug delivery systems.

    PubMed

    Alvarez-Lorenzo, Carmen; Bromberg, Lev; Concheiro, Angel

    2009-01-01

    Drug delivery systems (DDS) capable of releasing an active molecule at the appropriate site and at a rate that adjusts in response to the progression of the disease or to certain functions/biorhythms of the organism are particularly appealing. Biocompatible materials sensitive to certain physiological variables or external physicochemical stimuli (intelligent materials) can be used for achieving this aim. Light-responsiveness is receiving increasing attention owing to the possibility of developing materials sensitive to innocuous electromagnetic radiation (mainly in the UV, visible and near-infrared range), which can be applied on demand at well delimited sites of the body. Some light-responsive DDS are of a single use (i.e. the light triggers an irreversible structural change that provokes the delivery of the entire dose) while others able to undergo reversible structural changes when cycles of light/dark are applied, behave as multi-switchable carriers (releasing the drug in a pulsatile manner). In this review, the mechanisms used to develop polymeric micelles, gels, liposomes and nanocomposites with light-sensitiveness are analyzed. Examples of the capability of some polymeric, lipidic and inorganic structures to regulate the release of small solutes and biomacromolecules are presented and the potential of light-sensitive carriers as functional components of intelligent DDS is discussed.

  17. Phospholipid nanodisc engineering for drug delivery systems.

    PubMed

    Murakami, Tatsuya

    2012-06-01

    Biocompatible mesoscale nanoparticles (5-100 nm in diameter) are attractive tools for drug delivery. Among them are several types of liposomes and polymer micelles already in clinical trial or use. Generally, biocompatibility of such particles is achieved by coating them with polyethylene glycol (PEG). Without PEG coating, particles are quickly trapped in the reticuloendothelial system when intravenously administered. However, recent studies have revealed several potential problems with PEG coating, including antigenicity and restriction of cellular uptake. This has motivated the development of alternative drug and gene delivery vehicles, including chemically and genetically engineered high-density lipoprotein (HDL)-like nanodiscs or "bicelles". HDL is a naturally occurring mesoscale nanoparticle that normally ferries cholesterol around in the body. Its initial "nascent" form is thought to be a simple 10 nm disc of phospholipids in a bilayer, and can be easily synthesized in vitro by mixing recombinant apoA-I proteins with various phospholipids. In this review, the use of synthetic HDL-like phospholipid nanodiscs as biocompatible drug carriers is summarized, focussing on manufacturing, size-control, drug loading and cell targeting. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Turbomachine injection nozzle including a coolant delivery system

    DOEpatents

    Zuo, Baifang [Simpsonville, SC

    2012-02-14

    An injection nozzle for a turbomachine includes a main body having a first end portion that extends to a second end portion defining an exterior wall having an outer surface. A plurality of fluid delivery tubes extend through the main body. Each of the plurality of fluid delivery tubes includes a first fluid inlet for receiving a first fluid, a second fluid inlet for receiving a second fluid and an outlet. The injection nozzle further includes a coolant delivery system arranged within the main body. The coolant delivery system guides a coolant along at least one of a portion of the exterior wall and around the plurality of fluid delivery tubes.

  19. Recent advances in pulsatile oral drug delivery systems.

    PubMed

    Politis, Stavros N; Rekkas, Dimitrios M

    2013-08-01

    It is well established that several diseases exhibit circadian behavior, following the relevant rhythm of the physiological functions of the human body. Their study falls in the fields of chronobiology and chronotherapeutics, the latter being essentially the effort of timely matching the treatment with the disease expression, in order to maximize the therapeutic benefits and minimize side effects. Pulsatile drug delivery is one of the pillars of chronopharmaceutics, achieved through dosage form design that allows programmable release of active pharmaceutical ingredients (APIs) to follow the disease's time profile. Its major characteristic is the presence of lag phases, followed by drug release in a variety of rates, immediate, repeated or controlled. The scope of this review is to summarize the recent literature on pulsatile oral drug delivery systems and provide an overview of the ready to use solutions and early stage technologies, focusing on the awarded and pending patents in this technical field during the last few years.

  20. Development of a Production Ready Automated Wire Delivery System

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The current development effort is a Phase 3 research study entitled "A Production Ready Automated Wire Delivery System", contract number NAS8-39933, awarded to Nichols Research Corporation (NRC). The goals of this research study were to production harden the existing Automated Wire Delivery (AWDS) motion and sensor hardware and test the modified AWDS in a range of welding applications. In addition, the prototype AWDS controller would be moved to the VME bus platform by designing, fabricating and testing a single board VME bus AWDS controller. This effort was to provide an AWDS that could transition from the laboratory environment to production operations. The project was performed in two development steps. Step 1 modified and tested an improved MWG. Step 2 developed and tested the AWDS single board VME bus controller. Step 3 installed the Wire Pilot in a Weld Controller with the imbedded VME bus controller.

  1. Leadership Dynamics Promoting Systemic Reform for Inclusive Service Delivery

    ERIC Educational Resources Information Center

    Scanlan, Martin

    2009-01-01

    This article presents a multicase study of two systems of schools striving to reform service delivery systems for students with special needs. Considering these systems as institutional actors, the study examines what promotes the understanding and implementation of special education service delivery within a system of schools in a manner that…

  2. Protamine-based nanoparticles as new antigen delivery systems.

    PubMed

    González-Aramundiz, José Vicente; Peleteiro Olmedo, Mercedes; González-Fernández, África; Alonso Fernández, María José; Csaba, Noemi Stefánia

    2015-11-01

    The use of biodegradable nanoparticles as antigen delivery vehicles is an attractive approach to overcome the problems associated with the use of Alum-based classical adjuvants. Herein we report, the design and development of protamine-based nanoparticles as novel antigen delivery systems, using recombinant hepatitis B surface antigen as a model viral antigen. The nanoparticles, composed of protamine and a polysaccharide (hyaluronic acid or alginate), were obtained using a mild ionic cross-linking technique. The size and surface charge of the nanoparticles could be modulated by adjusting the ratio of the components. Prototypes with optimal physicochemical characteristics and satisfactory colloidal stability were selected for the assessment of their antigen loading capacity, antigen stability during storage and in vitro and in vivo proof-of-concept studies. In vitro studies showed that antigen-loaded nanoparticles induced the secretion of cytokines by macrophages more efficiently than the antigen in solution, thus indicating a potential adjuvant effect of the nanoparticles. Finally, in vivo studies showed the capacity of these systems to trigger efficient immune responses against the hepatitis B antigen following intramuscular administration, suggesting the potential interest of protamine-polysaccharide nanoparticles as antigen delivery systems. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Peptide/protein vaccine delivery system based on PLGA particles

    PubMed Central

    Allahyari, Mojgan; Mohit, Elham

    2016-01-01

    abstract Due to the excellent safety profile of poly (D,L-lactide-co-glycolide) (PLGA) particles in human, and their biodegradability, many studies have focused on the application of PLGA particles as a controlled-release vaccine delivery system. Antigenic proteins/peptides can be encapsulated into or adsorbed to the surface of PLGA particles. The gradual release of loaded antigens from PLGA particles is necessary for the induction of efficient immunity. Various factors can influence protein release rates from PLGA particles, which can be defined intrinsic features of the polymer, particle characteristics as well as protein and environmental related factors. The use of PLGA particles encapsulating antigens of different diseases such as hepatitis B, tuberculosis, chlamydia, malaria, leishmania, toxoplasma and allergy antigens will be described herein. The co-delivery of antigens and immunostimulants (IS) with PLGA particles can prevent the systemic adverse effects of immunopotentiators and activate both dendritic cells (DCs) and natural killer (NKs) cells, consequently enhancing the therapeutic efficacy of antigen-loaded PLGA particles. We will review co-delivery of different TLR ligands with antigens in various models, highlighting the specific strengths and weaknesses of the system. Strategies to enhance the immunotherapeutic effect of DC-based vaccine using PLGA particles can be designed to target DCs by functionalized PLGA particle encapsulating siRNAs of suppressive gene, and disease specific antigens. Finally, specific examples of cellular targeting where decorating the surface of PLGA particles target orally administrated vaccine to M-cells will be highlighted. PMID:26513024

  4. Structured emulsion-based delivery systems: controlling the digestion and release of lipophilic food components.

    PubMed

    McClements, David Julian; Li, Yan

    2010-09-15

    There is a need for edible delivery systems to encapsulate, protect and release bioactive and functional lipophilic constituents within the food and pharmaceutical industries. These delivery systems could be used for a number of purposes: controlling lipid bioavailability; targeting the delivery of bioactive components within the gastrointestinal tract; and designing food matrices that delay lipid digestion and induce satiety. Emulsion technology is particularly suited for the design and fabrication of delivery systems for lipids. In this article we provide an overview of a number of emulsion-based technologies that can be used as edible delivery systems by the food and other industries, including conventional emulsions, nanoemulsions, multilayer emulsions, solid lipid particles, and filled hydrogel particles. Each of these delivery systems can be produced from food-grade (GRAS) ingredients (e.g., lipids, proteins, polysaccharides, surfactants, and minerals) using relatively simple processing operations (e.g., mixing, homogenizing, and thermal processing). The structure, preparation, and utilization of each type of delivery system for controlling lipid digestion are discussed. This knowledge can be used to select the most appropriate emulsion-based delivery system for specific applications, such as encapsulation, controlled digestion, and targeted release. Copyright 2010 Elsevier B.V. All rights reserved.

  5. Public health delivery systems: evidence, uncertainty, and emerging research needs.

    PubMed

    Mays, Glen P; Smith, Sharla A; Ingram, Richard C; Racster, Laura J; Lamberth, Cynthia D; Lovely, Emma S

    2009-03-01

    The authors review empirical studies published between 1990 and 2007 on the topics of public health organization, financing, staffing, and service delivery. A summary is provided of what is currently known about the attributes of public health delivery systems that influence their performance and outcomes. This review also identifies unanswered questions, highlighting areas where new research is needed. Existing studies suggest that economies of scale and scope exist in the delivery of public health services, and that key organizational and governance characteristics of public health agencies may explain differences in service delivery across communities. Financial resources and staffing characteristics vary widely across public health systems and have expected associations with service delivery and outcomes. Numerous gaps and uncertainties are identified regarding the mechanisms through which organizational, financial, and workforce characteristics influence the effectiveness and efficiency of public health service delivery. This review suggests that new research is needed to evaluate the effects of ongoing changes in delivery system structure, financing, and staffing.

  6. Optimized Delivery System Achieves Enhanced Endomyocardial Stem Cell Retention

    PubMed Central

    Behfar, Atta; Latere, Jean-Pierre; Bartunek, Jozef; Homsy, Christian; Daro, Dorothee; Crespo-Diaz, Ruben J.; Stalboerger, Paul G.; Steenwinckel, Valerie; Seron, Aymeric; Redfield, Margaret M.; Terzic, Andre

    2014-01-01

    Background Regenerative cell-based therapies are associated with limited myocardial retention of delivered stem cells. The objective of this study is to develop an endocardial delivery system for enhanced cell retention. Methods and Results Stem cell retention was simulated in silico using one and three-dimensional models of tissue distortion and compliance associated with delivery. Needle designs, predicted to be optimal, were accordingly engineered using nitinol – a nickel and titanium alloy displaying shape memory and super-elasticity. Biocompatibility was tested with human mesenchymal stem cells. Experimental validation was performed with species-matched cells directly delivered into Langendorff-perfused porcine hearts or administered percutaneously into the endocardium of infarcted pigs. Cell retention was quantified by flow cytometry and real time quantitative polymerase chain reaction methodology. Models, computing optimal distribution of distortion calibrated to favor tissue compliance, predicted that a 75°-curved needle featuring small-to-large graded side holes would ensure the highest cell retention profile. In isolated hearts, the nitinol curved needle catheter (C-Cath) design ensured 3-fold superior stem cell retention compared to a standard needle. In the setting of chronic infarction, percutaneous delivery of stem cells with C-Cath yielded a 37.7±7.1% versus 10.0±2.8% retention achieved with a traditional needle, without impact on biocompatibility or safety. Conclusions Modeling guided development of a nitinol-based curved needle delivery system with incremental side holes achieved enhanced myocardial stem cell retention. PMID:24326777

  7. Biomedical Imaging in Implantable Drug Delivery Systems

    PubMed Central

    Zhou, Haoyan; Hernandez, Christopher; Goss, Monika; Gawlik, Anna; Exner, Agata A.

    2015-01-01

    Implantable drug delivery systems (DDS) provide a platform for sustained release of therapeutic agents over a period of weeks to months and sometimes years. Such strategies are typically used clinically to increase patient compliance by replacing frequent administration of drugs such as contraceptives and hormones to maintain plasma concentration within the therapeutic window. Implantable or injectable systems have also been investigated as a means of local drug administration which favors high drug concentration at a site of interest, such as a tumor, while reducing systemic drug exposure to minimize unwanted side effects. Significant advances in the field of local DDS have led to increasingly sophisticated technology with new challenges including quantification of local and systemic pharmacokinetics and implant-body interactions. Because many of these sought-after parameters are highly dependent on the tissue properties at the implantation site, and rarely represented adequately with in vitro models, new nondestructive techniques that can be used to study implants in situ are highly desirable. Versatile imaging tools can meet this need and provide quantitative data on morphological and functional aspects of implantable systems. The focus of this review article is an overview of current biomedical imaging techniques, including magnetic resonance imaging (MRI), ultrasound imaging, optical imaging, X-ray and computed tomography (CT), and their application in evaluation of implantable DDS. PMID:25418857

  8. Engaging children and parents in service design and delivery.

    PubMed

    Bedford Russell, A R; Passant, M; Kitt, H

    2014-12-01

    The involvement of all user groups, including children, young people (CYP) and their parents, encourages people to take responsibility for healthier lifestyle behaviours, improves treatment compliance and leads to more appropriate use of healthcare resources. Initiatives to engage CYP in the UK are gathering momentum, but significant improvements are still needed. There is a national drive from the department of health (DH) and NHS England, strategic clinical networks, operational delivery networks (including newborn networks), charities, parent groups and a number of other bodies to embed CYP involvement in service design and delivery. User engagement and patient choice, is underpinned by the NHS outcomes framework, and a myriad of other DH and NHS England policies and practice frameworks. It is now everybody's business.

  9. A multiportal compensator system for IMRT delivery.

    PubMed

    Yoda, Kiyoshi; Aoki, Yukimasa

    2003-05-01

    We have developed a multiportal compensator system for IMRT delivery, comprising a rotational compensator mount for a linac head, cylindrical compensator enclosures positioned in the mount, a vacuum-formed thermoplastic sheet with heavy alloy granules inside the enclosure, and a vacuum thermoforming device. The mount rotates like a revolver by a stepping motor, thus allowing automatic multiportal IMRT without exchanging compensators by human operators during treatment. The thermoforming device has servo-motor-driven 10 x 10 metal rod elements to actualize an arbitrary intensity profile. The thermoplastic sheet is preheated by a built-in biplanar heater and then it is placed over the rod elements. Subsequently, vacuum forming is performed through corner cutouts of the rod elements. After forced cooling down, the heavy alloy granules are fed into the formed sheet. Preliminary experiment using solid water phantoms and an x-ray film has shown that the intensity profile on the film agrees reasonably well with the desired profile.

  10. Herbal Excipients in Novel Drug Delivery Systems

    PubMed Central

    Shirwaikar, A.; Shirwaikar, Annie; Prabu, S. Lakshmana; Kumar, G. Aravind

    2008-01-01

    The use of natural excipients to deliver the bioactive agents has been hampered by the synthetic materials. However advantages offered by these natural excipients are their being non-toxic, less expensive and freely available. The performance of the excipients partly determines the quality of the medicines. The traditional concept of the excipients as any component other than the active substance has undergone a substantial evolution from an inert and cheap vehicle to an essential constituent of the formulation. Excipients are any component other than the active substance(s) intentionally added to formulation of a dosage form. This article gives an overview of herbal excipients which are used in conventional dosage forms as well as novel drug delivery systems. PMID:20046764

  11. LNG delivery system for gas powered vehicles

    SciTech Connect

    Nesser, T.A.; Hedegard, K.W.

    1992-07-07

    This patent describes a natural gas delivery system. It comprises a first vehicle mounted tank for storing liquid natural gas and natural gas vapor; a second vehicle mounted tank for storing liquid natural gas and natural gas vapor; a use line connected to the first and second tanks for receiving natural gas from the first and second tanks and delivering natural gas vapor to the use device on the vehicle and means for pressurizing the natural gas in the use line; means for selecting one of the first or second tanks to deliver natural gas to the use line; and means for overriding the selecting means to deliver natural gas vapor to the use line from either of the tanks in response to detecting a pressure rise therein which exceeds a preselected maximum.

  12. Software Design Analyzer System

    NASA Technical Reports Server (NTRS)

    Tausworthe, R. C.

    1985-01-01

    CRISP80 software design analyzer system a set of programs that supports top-down, hierarchic, modular structured design, and programing methodologies. CRISP80 allows for expression of design as picture of program.

  13. Computational and Pharmacological Target of Neurovascular Unit for Drug Design and Delivery

    PubMed Central

    Islam, Md. Mirazul; Mohamed, Zahurin

    2015-01-01

    The blood-brain barrier (BBB) is a dynamic and highly selective permeable interface between central nervous system (CNS) and periphery that regulates the brain homeostasis. Increasing evidences of neurological disorders and restricted drug delivery process in brain make BBB as special target for further study. At present, neurovascular unit (NVU) is a great interest and highlighted topic of pharmaceutical companies for CNS drug design and delivery approaches. Some recent advancement of pharmacology and computational biology makes it convenient to develop drugs within limited time and affordable cost. In this review, we briefly introduce current understanding of the NVU, including molecular and cellular composition, physiology, and regulatory function. We also discuss the recent technology and interaction of pharmacogenomics and bioinformatics for drug design and step towards personalized medicine. Additionally, we develop gene network due to understand NVU associated transporter proteins interactions that might be effective for understanding aetiology of neurological disorders and new target base protective therapies development and delivery. PMID:26579539

  14. Computational and Pharmacological Target of Neurovascular Unit for Drug Design and Delivery.

    PubMed

    Islam, Md Mirazul; Mohamed, Zahurin

    2015-01-01

    The blood-brain barrier (BBB) is a dynamic and highly selective permeable interface between central nervous system (CNS) and periphery that regulates the brain homeostasis. Increasing evidences of neurological disorders and restricted drug delivery process in brain make BBB as special target for further study. At present, neurovascular unit (NVU) is a great interest and highlighted topic of pharmaceutical companies for CNS drug design and delivery approaches. Some recent advancement of pharmacology and computational biology makes it convenient to develop drugs within limited time and affordable cost. In this review, we briefly introduce current understanding of the NVU, including molecular and cellular composition, physiology, and regulatory function. We also discuss the recent technology and interaction of pharmacogenomics and bioinformatics for drug design and step towards personalized medicine. Additionally, we develop gene network due to understand NVU associated transporter proteins interactions that might be effective for understanding aetiology of neurological disorders and new target base protective therapies development and delivery.

  15. Erythrocytes-based synthetic delivery systems: transition from conventional to novel engineering strategies.

    PubMed

    Bhateria, Manisha; Rachumallu, Ramakrishna; Singh, Rajbir; Bhatta, Rabi Sankar

    2014-08-01

    Erythrocytes (red blood cells [RBCs]) and artificial or synthetic delivery systems such as liposomes, nanoparticles (NPs) are the most investigated carrier systems. Herein, progress made from conventional approach of using RBC as delivery systems to novel approach of using synthetic delivery systems based on RBC properties will be reviewed. We aim to highlight both conventional and novel approaches of using RBCs as potential carrier system. Conventional approaches which include two main strategies are: i) directly loading therapeutic moieties in RBCs; and ii) coupling them with RBCs whereas novel approaches exploit structural, mechanical and biological properties of RBCs to design synthetic delivery systems through various engineering strategies. Initial attempts included coupling of antibodies to liposomes to specifically target RBCs. Knowledge obtained from several studies led to the development of RBC membrane derived liposomes (nanoerythrosomes), inspiring future application of RBC or its structural features in other attractive delivery systems (hydrogels, filomicelles, microcapsules, micro- and NPs) for even greater potential. In conclusion, this review dwells upon comparative analysis of various conventional and novel engineering strategies in developing RBC based drug delivery systems, diversifying their applications in arena of drug delivery. Regardless of the challenges in front of us, RBC based delivery systems offer an exciting approach of exploiting biological entities in a multitude of medical applications.

  16. Biocompatibility and characterization of polyglycerol-based thermoresponsive nanogels designed as novel drug-delivery systems and their intracellular localization in keratinocytes.

    PubMed

    Gerecke, Christian; Edlich, Alexander; Giulbudagian, Michael; Schumacher, Fabian; Zhang, Nan; Said, Andre; Yealland, Guy; Lohan, Silke B; Neumann, Falko; Meinke, Martina C; Ma, Nan; Calderón, Marcelo; Hedtrich, Sarah; Schäfer-Korting, Monika; Kleuser, Burkhard

    2017-03-01

    Novel nanogels that possess the capacity to change their physico-chemical properties in response to external stimuli are promising drug-delivery candidates for the treatment of severe skin diseases. As thermoresponsive nanogels (tNGs) are capable of enhancing penetration through biological barriers such as the stratum corneum and are taken up by keratinocytes of human skin, potential adverse consequences of their exposure must be elucidated. In this study, tNGs were synthesized from dendritic polyglycerol (dPG) and two thermoresponsive polymers. tNG_dPG_tPG are the combination of dPG with poly(glycidyl methyl ether-co-ethyl glycidyl ether) (p(GME-co-EGE)) and tNG_dPG_pNIPAM the one with poly(N-isopropylacrylamide) (pNIPAM). Both thermoresponsive nanogels are able to incorporate high amounts of dexamethasone and tacrolimus, drugs used in the treatment of severe skin diseases. Cellular uptake, intracellular localization and the toxicological properties of the tNGs were comprehensively characterized in primary normal human keratinocytes (NHK) and in spontaneously transformed aneuploid immortal keratinocyte cell line from adult human skin (HaCaT). Laser scanning confocal microscopy revealed fluorescently labeled tNGs entered into the cells and localized predominantly within lysosomal compartments. MTT assay, comet assay and carboxy-H2DCFDA assay, demonstrated neither cytotoxic or genotoxic effects, nor any induction of reactive oxygen species of the tNGs in keratinocytes. In addition, both tNGs were devoid of eye irritation potential as shown by bovine corneal opacity and permeability (BCOP) test and red blood cell (RBC) hemolysis assay. Therefore, our study provides evidence that tNGs are locally well tolerated and underlines their potential for cutaneous drug delivery.

  17. Ocular drug delivery systems: An overview

    PubMed Central

    Patel, Ashaben; Cholkar, Kishore; Agrahari, Vibhuti; Mitra, Ashim K

    2014-01-01

    The major challenge faced by today’s pharmacologist and formulation scientist is ocular drug delivery. Topical eye drop is the most convenient and patient compliant route of drug administration, especially for the treatment of anterior segment diseases. Delivery of drugs to the targeted ocular tissues is restricted by various precorneal, dynamic and static ocular barriers. Also, therapeutic drug levels are not maintained for longer duration in target tissues. In the past two decades, ocular drug delivery research acceleratedly advanced towards developing a novel, safe and patient compliant formulation and drug delivery devices/techniques, which may surpass these barriers and maintain drug levels in tissues. Anterior segment drug delivery advances are witnessed by modulation of conventional topical solutions with permeation and viscosity enhancers. Also, it includes development of conventional topical formulations such as suspensions, emulsions and ointments. Various nanoformulations have also been introduced for anterior segment ocular drug delivery. On the other hand, for posterior ocular delivery, research has been immensely focused towards development of drug releasing devices and nanoformulations for treating chronic vitreoretinal diseases. These novel devices and/or formulations may help to surpass ocular barriers and associated side effects with conventional topical drops. Also, these novel devices and/or formulations are easy to formulate, no/negligibly irritating, possess high precorneal residence time, sustain the drug release, and enhance ocular bioavailability of therapeutics. An update of current research advancement in ocular drug delivery necessitates and helps drug delivery scientists to modulate their think process and develop novel and safe drug delivery strategies. Current review intends to summarize the existing conventional formulations for ocular delivery and their advancements followed by current nanotechnology based formulation developments

  18. Humanized docking system for assembly of targeting drug delivery complexes.

    PubMed

    Backer, Marina V; Gaynutdinov, Timur I; Gorshkova, Inna I; Crouch, Robert J; Hu, Tao; Aloise, Renee; Arab, Mohamed; Przekop, Kristen; Backer, Joseph M

    2003-05-20

    Targeted drug delivery requires 'loading' drugs onto targeting proteins. Traditional technologies for loading drugs rely on chemical conjugation of drugs or drug carriers to targeting proteins. An alternative approach might rely on assembly of targeting complexes using a docking system that includes two components: a 'docking' tag fused to a targeting protein, and a 'payload' module containing an adapter protein for non-covalent binding to the docking tag. We describe here a fully humanized adapter/docking tag system based on non-covalent interaction between two fragments of human pancreatic RNase I. A 15 amino acid long N-terminal fragment of RNase I designed to serve as a docking tag, was fused to the N-terminus of human vascular endothelial growth factor that served as a targeting protein. An 18-125 and an 18-127 amino acid long fragments of RNase I were engineered, expressed and refolded into active conformations to serve as adapter proteins. Interactions between the targeting and adapter proteins were characterized using enzymatic analysis and surface plasmon resonance. Targeting DNA delivery complexes were assembled, characterized by dynamic light scattering, and found to be very effective in receptor-mediated DNA delivery.

  19. The Superconducting Magnets of the ILC Beam Delivery System

    SciTech Connect

    Parker, B.; Anerella, M.; Escallier, J.; He, P.; Jain, A.; Marone, A.; Nosochkov, Y.; Seryi, Andrei; /SLAC

    2007-09-28

    The ILC Beam Delivery System (BDS) uses a variety of superconducting magnets to maximize luminosity and minimize background. Compact final focus quadrupoles with multifunction correction coils focus incoming beams to few nanometer spot sizes while focusing outgoing disrupted beams into a separate extraction beam line. Anti-solenoids mitigate effects from overlapping focusing and the detector solenoid field. Far from the interaction point (IP) strong octupoles help minimize IP backgrounds. A low-field but very large aperture dipole is integrated with the detector solenoid to reduce backgrounds from beamstrahlung pairs generated at the IP. Physics requirements and magnetic design solutions for the BDS superconducting magnets are reviewed in this paper.

  20. Description and Documentation of the Dental School Dental Delivery System.

    ERIC Educational Resources Information Center

    Chase, Rosen and Wallace, Inc., Alexandria, VA.

    A study was undertaken to describe and document the dental school dental delivery system using an integrated systems approach. In late 1976 and early 1977, a team of systems analysts and dental consultants visited three dental schools to observe the delivery of dental services and patient flow and to interview administrative staff and faculty.…

  1. Implantable microchip: the futuristic controlled drug delivery system.

    PubMed

    Sutradhar, Kumar Bishwajit; Sumi, Chandra Datta

    2016-01-01

    There is no doubt that controlled and pulsatile drug delivery system is an important challenge in medicine over the conventional drug delivery system in case of therapeutic efficacy. However, the conventional drug delivery systems often offer a limited by their inability to drug delivery which consists of systemic toxicity, narrow therapeutic window, complex dosing schedule for long term treatment etc. Therefore, there has been a search for the drug delivery system that exhibit broad enhancing activity for more drugs with less complication. More recently, some elegant study has noted that, a new type of micro-electrochemical system or MEMS-based drug delivery systems called microchip has been improved to overcome the problems related to conventional drug delivery. Moreover, micro-fabrication technology has enabled to develop the implantable controlled released microchip devices with improved drug administration and patient compliance. In this article, we have presented an overview of the investigations on the feasibility and application of microchip as an advanced drug delivery system. Commercial manufacturing materials and methods, related other research works and current advancement of the microchips for controlled drug delivery have also been summarized.

  2. Designer lipids for drug delivery: from heads to tails

    PubMed Central

    Kohli, Aditya G.; Kierstead, Paul H.; Venditto, Vincent J.; Walsh, Colin L.; Szoka, Francis C.

    2014-01-01

    For four decades, liposomes composed of both naturally occurring and synthetic lipids have been investigated as delivery vehicles for low molecular weight and macromolecular drugs. These studies paved the way for the clinical and commercial success of a number of liposomal drugs, each of which required a tailored formulation; one liposome size does not fit all drugs! Instead, the physicochemical properties of the liposome must be matched to the pharmacology of the drug. An extensive biophysical literature demonstrates that varying lipid composition can influence the size, membrane stability, in vivo interactions, and drug release properties of a liposome. In this review we focus on recently described synthetic lipid headgroups, linkers and hydrophobic domains that can provide control over the intermolecular forces, phase preference, and macroscopic behavior of liposomes. These synthetic lipids further our understanding of lipid biophysics, promote targeted drug delivery, and improve liposome stability. We further highlight the immune reactivity of novel synthetic headgroups as a key design consideration. For instance it was originally thought that synthetic PEGylated lipids were immunologically inert; however, it’s been observed that under certain conditions PEGylated lipids induce humoral immunity. Such immune activation may be a limitation to the use of other engineered lipid headgroups for drug delivery. In addition to the potential immunogenicity of engineered lipids, future investigations on liposome drugs in vivo should pay particular attention to the location and dynamics of payload release. PMID:24816069

  3. Rational design of protamine nanocapsules as antigen delivery carriers.

    PubMed

    González-Aramundiz, José Vicente; Presas, Elena; Dalmau-Mena, Inmaculada; Martínez-Pulgarín, Susana; Alonso, Covadonga; Escribano, José M; Alonso, María J; Csaba, Noemi Stefánia

    2017-01-10

    Current challenges in global immunization indicate the demand for new delivery strategies, which could be applied to the development of new vaccines against emerging diseases, as well as to improve safety and efficacy of currently existing vaccine formulations. Here, we report a novel antigen nanocarrier consisting of an oily core and a protamine shell, further stabilized with pegylated surfactants. These nanocarriers, named protamine nanocapsules, were rationally designed to promote the intracellular delivery of antigens to immunocompetent cells and to trigger an efficient and long-lasting immune response. Protamine nanocapsules have nanometric size, positive zeta potential and high association capacity for H1N1 influenza hemagglutinin, a protein that was used here as a model antigen. The new formulation shows an attractive stability profile both, as an aqueous suspension or a freeze-dried powder formulation. In vitro studies showed that protamine nanocapsules were efficiently internalized by macrophages without eliciting significant toxicity. In vivo studies indicate that antigen-loaded nanocapsules trigger immune responses comparable to those achieved with alum, even when using significantly lower antigen doses, thus indicating their adjuvant properties. These promising in vivo data, alongside with their versatility for the loading of different antigens and oily immunomodulators and their excellent stability profile, make these nanocapsules a promising platform for the delivery of antigens.

  4. Importance of novel drug delivery systems in herbal medicines

    PubMed Central

    Devi, V. Kusum; Jain, Nimisha; Valli, Kusum S.

    2010-01-01

    Novel drug delivery system is a novel approach to drug delivery that addresses the limitations of the traditional drug delivery systems. Our country has a vast knowledge base of Ayurveda whose potential is only being realized in the recent years. However, the drug delivery system used for administering the herbal medicine to the patient is traditional and out-of-date, resulting in reduced efficacy of the drug. If the novel drug delivery technology is applied in herbal medicine, it may help in increasing the efficacy and reducing the side effects of various herbal compounds and herbs. This is the basic idea behind incorporating novel method of drug delivery in herbal medicines. Thus it is important to integrate novel drug delivery system and Indian Ayurvedic medicines to combat more serious diseases. For a long time herbal medicines were not considered for development as novel formulations owing to lack of scientific justification and processing difficulties, such as standardization, extraction and identification of individual drug components in complex polyherbal systems. However, modern phytopharmaceutical research can solve the scientific needs (such as determination of pharmacokinetics, mechanism of action, site of action, accurate dose required etc.) of herbal medicines to be incorporated in novel drug delivery system, such as nanoparticles, microemulsions, matrix systems, solid dispersions, liposomes, solid lipid nanoparticles and so on. This article summarizes various drug delivery technologies, which can be used for herbal actives together with some examples. PMID:22228938

  5. Importance of novel drug delivery systems in herbal medicines.

    PubMed

    Devi, V Kusum; Jain, Nimisha; Valli, Kusum S

    2010-01-01

    Novel drug delivery system is a novel approach to drug delivery that addresses the limitations of the traditional drug delivery systems. Our country has a vast knowledge base of Ayurveda whose potential is only being realized in the recent years. However, the drug delivery system used for administering the herbal medicine to the patient is traditional and out-of-date, resulting in reduced efficacy of the drug. If the novel drug delivery technology is applied in herbal medicine, it may help in increasing the efficacy and reducing the side effects of various herbal compounds and herbs. This is the basic idea behind incorporating novel method of drug delivery in herbal medicines. Thus it is important to integrate novel drug delivery system and Indian Ayurvedic medicines to combat more serious diseases. For a long time herbal medicines were not considered for development as novel formulations owing to lack of scientific justification and processing difficulties, such as standardization, extraction and identification of individual drug components in complex polyherbal systems. However, modern phytopharmaceutical research can solve the scientific needs (such as determination of pharmacokinetics, mechanism of action, site of action, accurate dose required etc.) of herbal medicines to be incorporated in novel drug delivery system, such as nanoparticles, microemulsions, matrix systems, solid dispersions, liposomes, solid lipid nanoparticles and so on. This article summarizes various drug delivery technologies, which can be used for herbal actives together with some examples.

  6. An overview of Ball Aerospace cryogen storage and delivery systems

    NASA Astrophysics Data System (ADS)

    Marquardt, J.; Keller, J.; Mills, G.; Schmidt, J.

    2015-12-01

    Starting on the Gemini program in the 1960s, Beech Aircraft (now Ball Aerospace) has been designing and manufacturing dewars for a variety of cryogens including liquid hydrogen and oxygen. These dewars flew on the Apollo, Skylab and Space Shuttle spacecraft providing fuel cell reactants resulting in over 150 manned spaceflights. Since Space Shuttle, Ball has also built the liquid hydrogen fuel tanks for the Boeing Phantom Eye unmanned aerial vehicle. Returning back to its fuel cell days, Ball has designed, built and tested a volume-constrained liquid hydrogen and oxygen tank system for reactant delivery to fuel cells on unmanned undersea vehicles (UUVs). Herein past history of Ball technology is described. Testing has been completed on the UUV specific design, which will be described.

  7. Control system design guide

    SciTech Connect

    Sellers, David; Friedman, Hannah; Haasl, Tudi; Bourassa, Norman; Piette, Mary Ann

    2003-05-01

    The ''Control System Design Guide'' (Design Guide) provides methods and recommendations for the control system design process and control point selection and installation. Control systems are often the most problematic system in a building. A good design process that takes into account maintenance, operation, and commissioning can lead to a smoothly operating and efficient building. To this end, the Design Guide provides a toolbox of templates for improving control system design and specification. HVAC designers are the primary audience for the Design Guide. The control design process it presents will help produce well-designed control systems that achieve efficient and robust operation. The spreadsheet examples for control valve schedules, damper schedules, and points lists can streamline the use of the control system design concepts set forth in the Design Guide by providing convenient starting points from which designers can build. Although each reader brings their own unique questions to the text, the Design Guide contains information that designers, commissioning providers, operators, and owners will find useful.

  8. ICS-283: a system for targeted intravenous delivery of siRNA.

    PubMed

    Schiffelers, Raymond M; Storm, Gert

    2006-05-01

    ICS-283 was developed within Intradigm Corporation as a system that is designed for the systemic delivery of therapeutic small interfering (siRNA) to sites of pathological angiogenesis. The non-viral siRNA delivery system is based on synthetic nanoparticles, known as Targe (Intradigm Corporation), which functions as a broad-platform technology to deliver siRNA to specific target cells in diseased tissues. The system is constructed to incorporate different functionalities that address critical needs for successful nucleic acid delivery. The TargeTran synthetic vector is a self-assembling, layered nanoparticle that protects and targets siRNA to specific cell types in pathological tissues. At present, ICS-283 is the only antiangiogenic siRNA delivery system that is designed for intravenous administration to treat angiogenesis-driven diseases.

  9. Simulated respiratory system for in vitro evaluation of two inhalation delivery systems using selected steroids.

    PubMed

    Sciarra, J J; Cutie, A

    1978-10-01

    A simulated respiratory system was developed for the in vitro evaluation of two differently designed oral inhalation delivery systems. The deposition properties of a newly designed delivery system used for triamcinolone acetonide were compared to the more conventional, commercially available adapter utilized for an aerosol containing beclomethasone dipropionate. The simulated respiratory system was constructed so that the delivered dose of active ingredient could be classified into two fractions: the fraction that would be deposited in the oral cavity and throat and the fraction that would reach the desired site of activity in the respiratory tract. Based on this method, the newly designed system delivered more than 95% of the labeled dose to the desired site. The beclomethasone dipropionate aerosol system, which was observed to discharge the active ingredient with a greater intensity, delivered approximately 40% of the labeled dose. The particle-size distribution of the dose dispensed from the newly designed delivery system attached to the triamcinolone acetonide aerosol was determined using an impactor technique. No effort was made to correlate these results with an in vivo response.

  10. Programmable open-loop micropump insulin delivery system.

    PubMed

    Clemens, A H

    1980-01-01

    The application of "closed-loop" glucose-controlled insulin infusion in metabolic research and in the management of diabetic patients in acute emergency situations has stimulated the development of portable insulin infusion devices intended for the long-term stabilization of glucose levels. Since in vivo glucose sensors with long-term accuracy and reliability are not yet available, the currently projected portable insulin infusion systems are the "open-loop" type. Such systems should be reliable, safe, programmable, lightweight, and small in size. In addition, the power requirements should be as low as possible to avoid the need for heavy batteries and/or periodic recharging. In turn, these requirements govern the design criteria for the most essential component of such an instrument, the insulin delivery pump. A micropump has been developed in an attempt to meet all desirable design features. Evaluation data are presented.

  11. Design of serum compatible tetrary complexes for gene delivery.

    PubMed

    Bahadur K C, Remant; Thapa, Bindu; Xu, Peisheng

    2012-05-01

    A novel gene delivery system, called PoSC, consisting of PEI, PSP, and HA is described. In contrast to the DNA/PEI/HA ternary system whose transfection efficiency decreases significantly with increasing serum concentration, PoSC exhibits a high transfection efficiency of about 51 and 87% for NIH3T3 and HCT116 cells, respectively, at 50% serum concentration. Furthermore, PoSC shows no cytotoxic effect at its working concentration. The overall results suggest that HA adsorption on cationic complexes enhances the transfection efficiency, while PSP is essential for high transfection efficiency at higher serum concentration.

  12. Acrylated chitosan for mucoadhesive drug delivery systems.

    PubMed

    Shitrit, Yulia; Bianco-Peled, Havazelet

    2017-01-30

    A new mucoadhesive polymer was synthesized by conjugating chitosan to poly(ethylene glycol)diacrylate (PEGDA) via the Michael type reaction. The product was characterized using NMR. Higher PEGDA grafting efficacy was observed with low molecular weight PEGDA (0.7kDa), compared to long 10kDa PEGDA. The acrylation percentage was calculated based on the reaction of ninhydrin with chitosan, and supported the qualitative NMR findings. The adhesive properties were studied by tensile test and rotating system involving detachment of polymer tablets from a fresh intestine sample. Chitosan modified with high molecular weight PEGDA presented improvement in mucoadhesive properties compared to both non-modified and thiolated chitosan. On the molecular level, rheology measurements of polymer/mucin mixtures provided additional evidence of strong interaction between modified chitosan and mucin glycoproteins. This new polymer shows promise as a useful polymeric carrier matrix for delivery systems, which could provide prolonged residence time of the vehicle on the mucosa surface. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Micro injector sample delivery system for charged molecules

    DOEpatents

    Davidson, James C.; Balch, Joseph W.

    1999-11-09

    A micro injector sample delivery system for charged molecules. The injector is used for collecting and delivering controlled amounts of charged molecule samples for subsequent analysis. The injector delivery system can be scaled to large numbers (>96) for sample delivery to massively parallel high throughput analysis systems. The essence of the injector system is an electric field controllable loading tip including a section of porous material. By applying the appropriate polarity bias potential to the injector tip, charged molecules will migrate into porous material, and by reversing the polarity bias potential the molecules are ejected or forced away from the tip. The invention has application for uptake of charged biological molecules (e.g. proteins, nucleic acids, polymers, etc.) for delivery to analytical systems, and can be used in automated sample delivery systems.

  14. Reservoir-Based Drug Delivery Systems Utilizing Microtechnology

    PubMed Central

    Stevenson, Cynthia L.; Santini, John T.; Langer, Robert

    2012-01-01

    This review covers reservoir-based drug delivery systems that incorporate microtechnology, with an emphasis on oral, dermal, and implantable systems. Key features of each technology are highlighted such as working principles, fabrication methods, dimensional constraints, and performance criteria. Reservoir-based systems include a subset of microfabricated drug delivery systems and provide unique advantages. Reservoirs, whether external to the body or implanted, provide a well-controlled environment for a drug formulation, allowing increased drug stability and prolonged delivery times. Reservoir systems have the flexibility to accommodate various delivery schemes, including zero order, pulsatile, and on demand dosing, as opposed to a standard sustained release profile. Furthermore, the development of reservoir-based systems for targeted delivery for difficult to treat applications (e.g., ocular) has resulted in potential platforms for patient therapy. PMID:22465783

  15. New Delivery Systems for the 21st Century.

    ERIC Educational Resources Information Center

    Van Patten, James J.

    This paper presents an historical perspective on the development of educational delivery systems, and then turns to the challenges of the information age and the issues of developing new delivery systems in this challenging environment. The paper discusses the fragility of power sources and of the networked world; technological weaknesses; freedom…

  16. Guidelines for Psychological Practice in Health Care Delivery Systems

    ERIC Educational Resources Information Center

    American Psychologist, 2013

    2013-01-01

    Psychologists practice in an increasingly diverse range of health care delivery systems. The following guidelines are intended to assist psychologists, other health care providers, administrators in health care delivery systems, and the public to conceptualize the roles and responsibilities of psychologists in these diverse contexts. These…

  17. Guidelines for Psychological Practice in Health Care Delivery Systems

    ERIC Educational Resources Information Center

    American Psychologist, 2013

    2013-01-01

    Psychologists practice in an increasingly diverse range of health care delivery systems. The following guidelines are intended to assist psychologists, other health care providers, administrators in health care delivery systems, and the public to conceptualize the roles and responsibilities of psychologists in these diverse contexts. These…

  18. Delivery Systems: Meeting the Multiple Needs of Diversified Clientele

    ERIC Educational Resources Information Center

    Field, Hyman F.

    1978-01-01

    Explores a variety of instructional delivery systems available to community-based colleges and the unique capabilities and limitations of each. Also considers variables influencing the selection of a delivery system, such as instructional requirements, learner characteristics, institutional costs, and ease of administration. (AYC)

  19. Applying Systems Engineering Principles in Improving Health Care Delivery

    PubMed Central

    Kopach-Konrad, Renata; Criswell, Mike; Hasan, Imran; Chakraborty, Santanu; Pekny, Joseph; Doebbeling, Bradley N.

    2007-01-01

    Background In a highly publicized joint report, the National Academy of Engineering and the Institute of Medicine recently recommended the systematic application of systems engineering approaches for reforming our health care delivery system. For this to happen, medical professionals and managers need to understand and appreciate the power that systems engineering concepts and tools can bring to redesigning and improving health care environments and practices. Objective To present and discuss fundamental concepts and tools of systems engineering and important parallels between systems engineering, health services, and implementation research as it pertains to the care of complex patients. Design An exploratory, qualitative review of systems engineering concepts and overview of ongoing applications of these concepts in the areas of hemodialysis, radiation therapy, and patient flow modeling. Results In this paper, we describe systems engineering as the process of identifying the system of interest, choosing appropriate performance measures, selecting the best modeling tool, studying model properties and behavior under a variety of scenarios, and making design and operational decisions for implementation. Conclusions We discuss challenges and opportunities for bringing people with systems engineering skills into health care. PMID:18026813

  20. Design and Evaluation of Chronomodulated Drug Delivery of Tramadol Hydrochloride.

    PubMed

    Alekya, Thota; Narendar, Dudhipala; Mahipal, Donthi; Arjun, Narala; Nagaraj, Banala

    2017-09-26

    Rheumatoid arthritis is an auto immune disease which requires chronotherapy as it occurs during early morning. Tramadol hydrochloride (TH) is an analgesic drug, used to treat rheumatoid arthritis. The aim of the present investigation was to develop chronomodulated drug delivery system of tramadol hydrochloride such that it releases the drug early in the morning, during which the symptoms of rheumatoid arthritis worsen. To develop chronomodulated drug delivery system of TH, initially core tablets of TH were prepared using three different supradisintegrants followed by coating with pH dependent polymer of Eudragit S100. The prepared core tablets are evaluated for physical parameters and an optimal system was identified. Further, coating composition of Eudragit S100 was optimized and coating tablets of TH was prepared. The prepared coated tablets were evaluated for weight variation, hardness, drug content and in vitro release studies in 0.1N HCl, pH 6.8 phosphate buffer and pH 7.4 phosphate buffer. Formulation with 7.5% of coating solution (ES2) had shown a significant drug release after a lag time of 3 h (in pH 6.8 medium), 6 h (in pH 6.8 medium) and 8 h (in pH 7.4 medium), respectively. DSC studies revealed that no interaction between core and coated materials with drug was observed. Thus, chronomodulated drug delivery system of TH was formulated and assuming that if a tablet is administered around 9 pm to 10 pm, the drug release starts after a lag time of 6 h i. e., around 3am to 4 am. © Georg Thieme Verlag KG Stuttgart · New York.

  1. Design, preparation and application of nucleic acid delivery carriers.

    PubMed

    Yang, Jun; Liu, Hongmei; Zhang, Xin

    2014-01-01

    Gene delivery vectors must deliver their cargoes into the cytosol or the nucleus, where DNA or siRNA functions in vivo. Therefore it is crucial for the rational design of the nucleic acid delivery carriers. Compared with viral vectors, non-viral vectors have overcome some fatal defections in gene therapy. Whereas the most important issue for the non-viral vectors is the low transfection efficiency, which hinders the progress of non-viral carriers. Sparked by the structures of the virus and understanding of the process of virus infection, various biomimic structures of non-viral carriers were designed and prepared to improve the transfection issues in vitro and in vivo. However, less impressive results are achieved. In this review, we will investigate the evolution of the virus-mimicking carriers of nucleic acids for gene therapy, especially in cancer therapy; explore and discuss the relationship between the structures, materials and functions of the carriers, to provide guidance for establishing safe and highly efficient non-viral carriers for gene therapy. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Vesicular system: Versatile carrier for transdermal delivery of bioactives.

    PubMed

    Singh, Deependra; Pradhan, Madhulika; Nag, Mukesh; Singh, Manju Rawat

    2015-01-01

    The transdermal route of drug delivery has gained immense interest for pharmaceutical researchers. The major hurdle for diffusion of drugs and bioactives through transdermal route is the stratum corneum, the outermost layer of the skin. Currently, various approaches such as physical approach, chemical approach, and delivery carriers have been used to augment the transdermal delivery of bioactives. This review provides a brief overview of mechanism of drug transport across skin, different lipid vesicular systems, with special emphasis on lipid vesicular systems including transfersomes, liposomes, niosomes, ethosomes, virosomes, and pharmacosomes and their application for the delivery of different bioactives.

  3. Delivery system reform tracking: a framework for understanding change.

    PubMed

    Tollen, Laura; Enthoven, Alain; Crosson, Francis J; Taylor, Nancy; Audet, Anne-Marie; Schoen, Cathy; Ross, Murray

    2011-06-01

    The health care delivery system is changing rapidly, with providers forming patient-centered medical homes and exploring the creation of accountable care organizations. Enactment of the Affordable Care Act will likely accelerate these changes. Significant delivery system reforms will simultaneously affect the structures, capabilities, incentives, and outcomes of the delivery system. With so many changes taking place at once, there is a need for a new tool to track progress at the community level. Many of the necessary data elements for a delivery system reform tracking tool are already being collected in various places and by different stakeholders. The authors propose that all elements be brought together in a unified whole to create a detailed picture of delivery system change. This brief provides a rationale for creating such a tool and presents a framework for doing so.

  4. Superparamagnetic Iron Oxide Nanoparticle-Based Delivery Systems for Biotherapeutics

    PubMed Central

    Mok, Hyejung; Zhang, Miqin

    2014-01-01

    Introduction Superparamagnetic iron oxide nanoparticle (SPION)-based carrier systems have many advantages over other nanoparticle-based systems. They are biocompatible, biodegradable, facilely tunable, and superparamagnetic and thus controllable by an external magnetic field. These attributes enable their broad biomedical applications. In particular, magnetically-driven carriers are drawing considerable interest as an emerging therapeutic delivery system because of their superior delivery efficiency. Area covered This article reviews the recent advances in use of SPION-based carrier systems to improve the delivery efficiency and target specificity of biotherapeutics. We examine various formulations of SPION-based delivery systems, including SPION micelles, clusters, hydrogels, liposomes, and micro/nanospheres, as well as their specific applications in delivery of biotherapeutics. Expert opinion Recently, biotherapeutics including therapeutic cells, proteins and genes have been studied as alternative treatments to various diseases. Despite the advantages of high target specificity and low adverse effects, clinical translation of biotherapeutics has been hindered by the poor stability and low delivery efficiency compared to chemical drugs. Accordingly, biotherapeutic delivery systems that can overcome these limitations are actively pursued. SPION-based materials can be ideal candidates for developing such delivery systems because of their excellent biocompatibility and superparamagnetism that enables long-term accumulation/retention at target sites by utilization of a suitable magnet. In addition, synthesis technologies for production of finely-tuned, homogeneous SPIONs have been well developed, which may promise their rapid clinical translation. PMID:23199200

  5. CLIPS: An expert system tool for delivery and training

    NASA Technical Reports Server (NTRS)

    Riley, Gary; Culbert, Chris; Savely, Robert T.; Lopez, Frank

    1987-01-01

    The C Language Integrated Production System (CLIPS) is a forward chaining rule-based language. The requirements necessary for an expert system tool which is used for development, delivery, and training are examined. Because of its high portability, low cost, and ease of integration with external systems, CLIPS has great potential as an expert system tool for delivery and training. In addition, its representation flexibility, debugging aids, and performance, along with its other strengths, make it a viable alternative for expert system development.

  6. Pharmacokinetics of formulated tenoxicam transdermal delivery systems.

    PubMed

    Kim, Taekyung; Kang, Eunyoung; Chun, Inkoo; Gwak, Hyesun

    2008-01-01

    To investigate the feasibility of developing a new tenoxicam transdermal delivery system (TDS), the pharmacokinetics of tenoxicam from various formulated TDS were evaluated and compared with values following oral administration of tenoxicam and with application of a piroxicam plaster (Trast) marketed in Korea. Based on previous in-vitro study results, a mixture of diethylene glycol monoethyl ether (DGME) and propylene glycol monolaurate (PGML) (40:60) was used as a vehicle, and caprylic acid, capric acid, lauric acid, oleic acid or linoleic acid (each at 3%) was added as an enhancer. Triethanolamine (5%) was used as a solubilizer, and Duro-Tak 87-2510 as a pressure-sensitive adhesive. Among these fatty acids used for the formulation of tenoxicam TDS, caprylic acid showed the greatest enhancing effect; the area under the plasma concentration-time profile (AUC) decreased in the order of caprylic acid>linoleic acid>or=oleic acid>lauric acid>capric acid. Compared with oral administration, maximum plasma concentration (Cmax) was significantly lower, and time to reach Cmax (Tmax) delayed with all formulated tenoxicam TDS. All formulated TDS resulted in a lower AUC than with the oral formulation, except for TDS containing caprylic acid, although the difference was statistically significant only with capric acid. The AUC for all the formulated tenoxicam TDS was significantly higher than that of the piroxicam plaster; TDS with caprylic acid increased AUC 8.53-fold compared with the piroxicam plaster. Even though the Tmax of tenoxicam TDS was not significantly different from that of the piroxicam plaster, Cmax was higher; formulations containing caprylic acid and linoleic acid increased Cmax by 7.39- and 8.76-fold, respectively. In conclusion, a formulation containing 1.5 mL DGME-PGML (40:60) with 3% caprylic acid and 5% triethanolamine mixed with 6 g Duro-Tak 87-2510 could be a good candidate for developing a new tenoxicam TDS to maintain a comparable extent of absorption

  7. PET-based dose delivery verification in proton therapy: a GATE based simulation study of five PET system designs in clinical conditions.

    PubMed

    Robert, Charlotte; Fourrier, Nicolas; Sarrut, David; Stute, Simon; Gueth, Pierre; Grevillot, Loïc; Buvat, Irène

    2013-10-07

    PET is a promising technique for in vivo treatment verification in hadrontherapy. Three main PET geometries dedicated to in-beam treatment monitoring have been proposed in the literature: the dual-head PET geometry, the OpenPET geometry and the slanted-closed ring geometry. The aim of this work is to characterize the performance of two of these dedicated PET detectors in realistic clinical conditions. Several configurations of the dual-head PET and OpenPET systems were simulated using GATE v6.2. For the dual-head configuration, two aperture angles (15° and 45°) were studied. For the OpenPET system, two gaps between rings were investigated (110 and 160 mm). A full-ring PET system was also simulated as a reference. After preliminary evaluation of the sensitivity and spatial resolution using a Derenzo phantom, a real small-field head and neck treatment plan was simulated, with and without introducing patient displacements. No wash-out was taken into account. 3D maps of the annihilation photon locations were deduced from the PET data acquired right after the treatment session (5 min acquisition) using a dedicated OS-EM reconstruction algorithm. Detection sensitivity at the center of the field-of-view (FOV) varied from 5.2% (45° dual-head system) to 7.0% (full-ring PET). The dual-head systems had a more uniform efficiency within the FOV than the OpenPET systems. The spatial resolution strongly depended on the location within the FOV for the ϕ = 45° dual-head system and for the two OpenPET systems. All investigated architectures identified the magnitude of mispositioning introduced in the simulations within a 1.5 mm accuracy. The variability on the estimated mispositionings was less than 2 mm for all PET systems.

  8. PET-based dose delivery verification in proton therapy: a GATE based simulation study of five PET system designs in clinical conditions

    NASA Astrophysics Data System (ADS)

    Robert, Charlotte; Fourrier, Nicolas; Sarrut, David; Stute, Simon; Gueth, Pierre; Grevillot, Loïc; Buvat, Irène

    2013-10-01

    PET is a promising technique for in vivo treatment verification in hadrontherapy. Three main PET geometries dedicated to in-beam treatment monitoring have been proposed in the literature: the dual-head PET geometry, the OpenPET geometry and the slanted-closed ring geometry. The aim of this work is to characterize the performance of two of these dedicated PET detectors in realistic clinical conditions. Several configurations of the dual-head PET and OpenPET systems were simulated using GATE v6.2. For the dual-head configuration, two aperture angles (15° and 45°) were studied. For the OpenPET system, two gaps between rings were investigated (110 and 160 mm). A full-ring PET system was also simulated as a reference. After preliminary evaluation of the sensitivity and spatial resolution using a Derenzo phantom, a real small-field head and neck treatment plan was simulated, with and without introducing patient displacements. No wash-out was taken into account. 3D maps of the annihilation photon locations were deduced from the PET data acquired right after the treatment session (5 min acquisition) using a dedicated OS-EM reconstruction algorithm. Detection sensitivity at the center of the field-of-view (FOV) varied from 5.2% (45° dual-head system) to 7.0% (full-ring PET). The dual-head systems had a more uniform efficiency within the FOV than the OpenPET systems. The spatial resolution strongly depended on the location within the FOV for the ϕ = 45° dual-head system and for the two OpenPET systems. All investigated architectures identified the magnitude of mispositioning introduced in the simulations within a 1.5 mm accuracy. The variability on the estimated mispositionings was less than 2 mm for all PET systems.

  9. Diagnosing delivery problems in the White House Information Distribution System

    SciTech Connect

    Nahabedian, M.; Shrobe, H.

    1996-12-31

    As part of a collaboration with the White House Office of Media Affairs, members of the MIT Artificial Intelligence Laboratory designed a system, called COMLINK, which distributes a daily stream of documents released by the Office of Media Affairs. Approximately 4000 direct subscribers receive information from this service but more than 100,000 people receive the information through redistribution channels. The information is distributed via Email and the World Wide Web. In such a large scale distribution scheme, there is a constant problem of subscriptions becoming invalid because the user`s Email account has terminated. This causes a backwash of hundreds of {open_quotes}bounced mail{close_quotes} messages per day which must be processed by the operators of the COMLINK system. To manage this annoying but necessary task, an expert system named BMES was developed to diagnose the failures of information delivery.

  10. Designing polymers with sugar-based advantages for bioactive delivery applications.

    PubMed

    Zhang, Yingyue; Chan, Jennifer W; Moretti, Alysha; Uhrich, Kathryn E

    2015-12-10

    Sugar-based polymers have been extensively explored as a means to increase drug delivery systems' biocompatibility and biodegradation. Here,we review he use of sugar-based polymers for drug delivery applications, with a particular focus on the utility of the sugar component(s) to provide benefits for drug targeting and stimuli responsive systems. Specifically, numerous synthetic methods have been developed to reliably modify naturally-occurring polysaccharides, conjugate sugar moieties to synthetic polymer scaffolds to generate glycopolymers, and utilize sugars as a multifunctional building block to develop sugar-linked polymers. The design of sugar-based polymer systems has tremendous implications on both the physiological and biological properties imparted by the saccharide units and are unique from synthetic polymers. These features include the ability of glycopolymers to preferentially target various cell types and tissues through receptor interactions, exhibit bioadhesion for prolonged residence time, and be rapidly recognized and internalized by cancer cells. Also discussed are the distinct stimuli-sensitive properties of saccharide-modified polymers to mediate drug release under desired conditions. Saccharide-based systems with inherent pH- and temperature-sensitive properties, as well as enzyme-cleavable polysaccharides for targeted bioactive delivery, are covered. Overall, this work emphasizes inherent benefits of sugar-containing polymer systems for bioactive delivery.

  11. Quantitative analysis of the brain-targeted delivery of drugs and model compounds using nano-delivery systems.

    PubMed

    Kozlovskaya, Luba; Stepensky, David

    2013-10-10

    The blood-brain barrier (BBB) prevents drugs' permeability into the brain and limits management of brain diseases. Specialized drug delivery systems (DDSs) are utterly required to overcome this barrier and to achieve efficient delivery of therapeutic agents to the brain. For this purpose, drug-encapsulating nanoparticles or vesicles, drug conjugates and other types of DDSs are being developed by many research groups worldwide. However, efficiency of the brain drug/DDS delivery and targeting is usually presented in indirect and vague form and it is hard to quantitatively estimate it based on the reported data. We searched for the scientific papers that were published in 1970-2012 that reported delivery of drugs or model compounds to the brain following systemic administration of DDSs via parenteral routes and contained quantitative data on brain drug/DDS delivery and targeting efficiency. We identified 123 publications that matched the search criteria and analyzed their experimental settings, formulation types, analytical methods, and the claimed efficiencies of drug/DDS brain targeting (brain/plasma or brain/tissue concentration ratios) and brain accumulation (% of the administered dose that accumulated in the brain). Based on the outcomes of this analysis, we describe the major research trends, discuss the efficiencies of the different drug/DDS brain targeting approaches, and provide recommendations for quantitative assessment of brain-targeting DDSs in the appropriately designed studies. © 2013.

  12. Design, fabrication, testing, and delivery of improved beam steering devices

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The development, manufacture, and testing of an optical steerer intended for use in spaceborne optical radar systems are described. Included are design principles and design modifications made to harden the device against launch and space environments, the quality program and procedures developed to insure consistent product quality throughout the manufacturing phase, and engineering qualification model testing and evaluation. The delivered hardware design is considered conditionally qualified pending action on further recommended design modifications.

  13. Mucoadhesive in situ nasal gelling drug delivery systems for modulated drug delivery.

    PubMed

    Singh, Reena M P; Kumar, Anil; Pathak, Kamla

    2013-01-01

    The nasal route is an attractive target for administration of the drug of choice, particularly in overcoming disadvantages such as high first-pass metabolism and drug degradation in the gastrointestinal environment that are associated with the oral and other modes of administration. The major limitation associated is of rapid mucociliary clearance in the nasal delivery that results in low absorption and hence poor bioavailability. In order to overcome this, mucoadhesive in situ nasal gelling drug delivery systems have been explored to develop sustained/controlled delivery via nasal route. The present review critically evaluates the importance of in situ gel for the nasal delivery of drugs, and the polymers used in the formulation of in situ gel along with their mechanism of gelation. It also encompasses the research reports made in this arena of delivery system. The challenges of drug delivery through nose has led to development of in situ nasal gelling systems using a myriad of polymers to deliver the drugs, proteins, amino acids, hormones, vaccines and plasmid DNA for the local, systemic and central nervous system effects. Though a range of preclinical reports are available, clinical intricacies need to be critically worked out.

  14. Recent advancements in erythrocytes, platelets, and albumin as delivery systems

    PubMed Central

    Xu, Peipei; Wang, Ruju; Wang, Xiaohui; Ouyang, Jian

    2016-01-01

    In the past few years, nanomaterial-based drug delivery systems have been applied to enhance the efficacy of therapeutics and to alleviate negative effects through the controlled delivery of targeting and releasing agents. However, few drug carriers can achieve high targeting efficacy, even when targeting modalities and surface markers are introduced. Immunological problems have also limited their wide applications. Biological drug delivery systems, such as erythrocytes, platelets, and albumin, have been extensively investigated because of their unique properties. In this review, erythrocytes, platelets, and albumin are described as efficient drug delivery systems. Their properties, applications, advantages, and limitations in disease treatment are explained. This review confirms that these systems can be used to facilitate a specific, biocompatible, and smart drug delivery. PMID:27274282

  15. NANOPARTICLE DELIVERY SYSTEMS IN CANCER VACCINES

    PubMed Central

    Krishnamachari, Yogita; Geary, Sean M.; Lemke, Caitlin D.; Salem, Aliasger K.

    2013-01-01

    Therapeutic strategies that involve the manipulation of the host’s immune system are gaining momentum in cancer research. Antigen-loaded nanocarriers are capable of being actively taken up by antigen presenting cells (APCs) and have shown promising potential in cancer immunotherapy by initiating a strong immunostimulatory cascade that results in potent antigen-specific immune responses against the cancer. Such carrier systems offer versatility in that they can simultaneously co-deliver adjuvants with the antigens to enhance APC activation and maturation. Furthermore, modifying the surface properties of these nanocarriers affords active targeting properties to APCs and/or enhanced accumulation in solid tumors. Here we review some recent advances in these colloidal and particulate nanoscale systems designed for cancer immunotherapy and the potential for these systems to translate into clinical cancer vaccines. PMID:20721603

  16. Production of nanoparticle drug delivery systems with microfluidics tools.

    PubMed

    Khan, Ikram Ullah; Serra, Christophe A; Anton, Nicolas; Vandamme, Thierry F

    2015-04-01

    Nowadays the development of composite nano- and microparticles is an extensively studied area of research. This interest is growing because of the potential use of such particles in drug delivery systems. Indeed they can be used in various medical disciplines depending upon their sizes and their size distribution, which determine their final biomedical applications. Amongst the different techniques to produce nanoparticles, microfluidic techniques allow preparing particles having a specific size, a narrow size distribution and high encapsulation efficiency with ease. This review covers the general description of microfluidics, its techniques, advantages and disadvantages with focus on the encapsulation of active principles in polymeric nanoparticles as well as on pure drug nanoparticles. Polymeric nanoparticles constitute the majority of the examples reported; however lipid nanoparticulate systems (DNA, SiRNA nanocarriers) are very comparable and their formulation processes are in most cases exactly similar. Accordingly this review focuses also on active ingredient nanoparticles formulated by nanoprecipitation processes in microfluidic devices in general. It also provides detailed description of the different geometries of most common microfluidic devices and the crucial parameters involved in techniques designed to obtain the desired properties. Although the classical fabrication of nanoparticles drug delivery systems in batch is extremely well-described and developed, their production with microfluidic tools arises today as an emerging field with much more potential. In this review we present and discuss these new possibilities for biomedical applications through the current emerging developments.

  17. A Universal Delivery System for Percutaneous Heart Valve Implantation.

    PubMed

    Bartosch, Marco; Peters, Heiner; Spriestersbach, Hendrik; O H-Ici, Darach; Berger, Felix; Schmitt, Boris

    2016-09-01

    Transcatheter heart valve implantation is an emerging technology and an alternative to surgical valve replacement. Most existing systems consist of valves sewn into balloon-expandable stents with a delivery catheter functioning with the specific valve only. The aim of this study was to develop a universally applicable delivery system (DS) for plane stents, valves sewn into both balloon-expandable and self-expandable stents and feasible for use with different access routes. A DS was designed and manufactured in five different diameters. The requirements were derived from the implants, the implantation technique and the cardiovascular geometry of the experimental sheep. The combination of a self-expandable Nitinol stent and a jugular access point represented the major challenge as both flexibility and rigidity of the DS were required. To fulfill these contradicting mechanical properties the sheaths were comprised of a soft outer polymer tube with a stainless steel coiled spring inside. Tissue-engineered and pericardial pulmonary valves were implanted. Also polymeric and balloon-expandable stents were delivered to various positions in the vascular system. The initial success rate was 70.5%. After refinement of the DS, a success rate of 83.3% was achieved with the remaining failed implantations resulting from inadequate sizes of the prostheses.

  18. Application of three-dimensional printing for colon targeted drug delivery systems

    PubMed Central

    Charbe, Nitin B.; McCarron, Paul A.; Lane, Majella E.; Tambuwala, Murtaza M.

    2017-01-01

    Orally administered solid dosage forms currently dominate over all other dosage forms and routes of administrations. However, human gastrointestinal tract (GIT) poses a number of obstacles to delivery of the drugs to the site of interest and absorption in the GIT. Pharmaceutical scientists worldwide have been interested in colon drug delivery for several decades, not only for the delivery of the drugs for the treatment of colonic diseases such as ulcerative colitis and colon cancer but also for delivery of therapeutic proteins and peptides for systemic absorption. Despite extensive research in the area of colon targeted drug delivery, we have not been able to come up with an effective way of delivering drugs to the colon. The current tablets designed for colon drug release depend on either pH-dependent or time-delayed release formulations. During ulcerative colitis the gastric transit time and colon pH-levels is constantly changing depending on whether the patient is having a relapse or under remission. Hence, the current drug delivery system to the colon is based on one-size-fits-all. Fails to effectively deliver the drugs locally to the colon for colonic diseases and delivery of therapeutic proteins and peptides for systemic absorption from the colon. Hence, to overcome the current issues associated with colon drug delivery, we need to provide the patients with personalized tablets which are specifically designed to match the individual's gastric transit time depending on the disease state. Three-dimensional (3D) printing (3DP) technology is getting cheaper by the day and bespoke manufacturing of 3D-printed tablets could provide the solutions in the form of personalized colon drug delivery system. This review provides a bird's eye view of applications and current advances in pharmaceutical 3DP with emphasis on the development of colon targeted drug delivery systems. PMID:28929046

  19. Design of polymeric nanoparticles for biomedical delivery applications**

    PubMed Central

    Elsabahy, Mahmoud; Wooley, Karen L.

    2012-01-01

    Polymeric nanoparticles-based therapeutics show great promise in the treatment of a wide range of diseases, due to the flexibility in which their structures can be modified, with intricate definition over their compositions, structures and properties. Advances in polymerization chemistries and the application of reactive, efficient and orthogonal chemical modification reactions have enabled the engineering of multifunctional polymeric nanoparticles with precise control over the architectures of the individual polymer components, to direct their assembly and subsequent transformations into nanoparticles of selective overall shapes, sizes, internal morphologies, external surface charges and functionalizations. In addition, incorporation of certain functionalities can modulate the responsiveness of these nanostructures to specific stimuli through the use of remote activation. Furthermore, they can be equipped with smart components to allow their delivery beyond certain biological barriers, such as, skin, mucus, blood, extracellular matrix, cellular and subcellular organelles. This tutorial review highlights the importance of well-defined chemistries, with detailed ties to specific biological hurdles and opportunities, in the design of nanostructures for various biomedical delivery applications. PMID:22334259

  20. The development of a parachute system for aerial delivery from high speed cargo aircraft

    SciTech Connect

    Behr, V.L.

    1992-01-01

    Supply of military personnel on the ground with cargo has long been accomplished with parachute delivery systems from aircraft. Structural limits of aircraft have typically limited these operations to no more than 150 KCAS. A desire for increased survivability of cargo delivery aircraft has led to the development and fielding of aircraft capable of delivering cargo at substantially higher speeds. This paper describes efforts undertaken to design develop and test a cargo delivery system for use at speeds compatible with those high speed cargo aircraft.

  1. The development of a parachute system for aerial delivery from high speed cargo aircraft

    SciTech Connect

    Behr, V.L.

    1992-12-31

    Supply of military personnel on the ground with cargo has long been accomplished with parachute delivery systems from aircraft. Structural limits of aircraft have typically limited these operations to no more than 150 KCAS. A desire for increased survivability of cargo delivery aircraft has led to the development and fielding of aircraft capable of delivering cargo at substantially higher speeds. This paper describes efforts undertaken to design develop and test a cargo delivery system for use at speeds compatible with those high speed cargo aircraft.

  2. Designing automatic resupply systems.

    PubMed

    Harding, M L

    1999-02-01

    This article outlines the process for designing and implementing autoresupply systems. The planning process includes determination of goals and appropriate participation. Different types of autoresupply mechanisms include kanban, breadman, consignment, systems contracts, and direct shipping from an MRP schedule.

  3. Optical diagnostics integrated with laser spark delivery system

    DOEpatents

    Yalin, Azer; Willson, Bryan; Defoort, Morgan; Joshi, Sachin; Reynolds, Adam

    2008-09-02

    A spark delivery system for generating a spark using a laser beam is provided, and includes a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. The laser delivery assembly further includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. Other embodiments use a fiber laser to generate a spark. Embodiments of the present invention may be used to create a spark in an engine. Yet other embodiments include collecting light from the spark or a flame resulting from the spark and conveying the light for diagnostics. Methods of using the spark delivery systems and diagnostic systems are provided.

  4. Particle designs for the stabilization and controlled-delivery of protein drugs by biopolymers: a case study on insulin.

    PubMed

    Lim, Hui-Peng; Tey, Beng-Ti; Chan, Eng-Seng

    2014-07-28

    Natural biopolymers have attracted considerable interest for the development of delivery systems for protein drugs owing to their biocompatibility, non-toxicity, renewability and mild processing conditions. This paper offers an overview of the current status and future perspectives of particle designs using biopolymers for the stabilization and controlled-delivery of a model protein drug--insulin. We first describe the design criteria for polymeric encapsulation and subsequently classify the basic principles of particle fabrication as well as the existing particle designs for oral insulin encapsulation. The performances of these existing particle designs in terms of insulin stability and in vitro release behavior in acidic and alkaline media, as well as their in vivo performance are compared and reviewed. This review forms the basis for future works on the optimization of particle design and material formulation for the development of an improved oral delivery system for protein drugs. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Nanoparticulate fingolimod delivery system based on biodegradable poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV): design, optimization, characterization and in-vitro evaluation.

    PubMed

    Rezaie Shirmard, Leila; Bahari Javan, Nika; Khoshayand, Mohammad Reza; Kebriaee-Zadeh, Abbas; Dinarvand, Rassoul; Dorkoosh, Farid A

    2015-11-11

    This study was focused on the fabrication, statistical optimization and in vitro characterization of poly (hydroxybutyrate-co-hydroxyvalerate) (PHBV) nanoparticles loaded with fingolimod. PHBV-based fingolimod nanoparticles were prepared by single and double evaporation methods; the incorporation efficiency of fingolimod was higher with the single emulsion evaporation method in the nanosize range particles. Fingolimod HCL was neutralized with NaOH in order to slow down the release of the highly soluble fingolimod. The encapsulation efficiency of neutralized fingolimod was much higher (53-73%) due to the insoluble form of the drug used in encapsulation. It was found that the amount of fingolimod, concentration of PHBV and polyvinyl alcohol (PVA) would influence the encapsulation efficiency significantly. The effect of these parameters on the Particle size, PdI, loading capacity and loading efficacy was studied. The optimum conditions were 1.32% PHBV, 0.42% PVA and 5 mg fingolimod. The average size of optimized nanoparticles which measured with the aid of the Box-Behnken experimental design was 250 nm and entrapment efficiency of 73(%). Drug-release from the nanospheres over a four-week period has shown a characteristic triphasic release pattern with an initial burst effect.

  6. A Benefit Cost Analysis of Alternative Library Delivery Systems.

    ERIC Educational Resources Information Center

    Hu, Teh-Wei; And Others

    The application of cost-benefit analysis to two library delivery systems--bookmobiles and books-by-mail (BBM)--is described. The study surveyed 36 bookmobiles and the mail order delivery (MOD) of books in Pennsylvania. The analyses are intended to provide decision-makers with guidance in determining (1) the kinds of information which must be…

  7. Drug delivery by red blood cells: vascular carriers designed by Mother Nature

    PubMed Central

    Muzykantov, Vladimir R.

    2010-01-01

    Importance of the field Vascular delivery of several classes of therapeutic agents may benefit from carriage by red blood cells (RBC), for example, drugs that require delivery into phagocytic cells and those that must act within the vascular lumen. The fact that several protocols of infusion of RBC-encapsulated drugs are been currently explored in patients illustrates a high biomedical importance for the field. Areas covered by this review Two strategies for RBC drug delivery are discussed: encapsulation into isolated RBC ex vivo followed by infusion in compatible recipients and coupling therapeutics to surface of RBC. Studies of pharmacokinetics and effects in animal models and in human studies of diverse therapeutic enzymes, antibiotics and other drugs encapsulated in RBC are described and critically analyzed. Coupling to RBC surface of compounds regulating immune response and complement, affinity ligands, polyethylene glycol alleviating immune response to donor RBC and fibrinolytic plasminogen activators is d escribed. Also described is a novel, translation-prone approach for RBC drug delivery by injecting of therapeutics conjugated with fragments of antibodies providing safe anchoring of cargoes to circulating RBC, without need for ex vivo modification and infusion of RBC. What the reader will gain The readers will gain historical perspective, current status, challenges and perspectives of medical applications of RBC for drug delivery. Take home message RBC represent naturally designed carriers for intravascular drug delivery, characterized by unique longevity in the bloodstream, biocompatibility and safe physiological mechanisms for metabolism. Novel approaches for encapsulating drugs into RBC and coupling to RBC surface provide promising avenues for safe and widely useful improvement of drug delivery in the vascular system. PMID:20192900

  8. Thiolated polymers as mucoadhesive drug delivery systems.

    PubMed

    Duggan, Sarah; Cummins, Wayne; O' Donovan, Orla; Hughes, Helen; Owens, Eleanor

    2017-03-30

    Mucoadhesion is the process of binding a material to the mucosal layer of the body. Utilising both natural and synthetic polymers, mucoadhesive drug delivery is a method of controlled drug release which allows for intimate contact between the polymer and a target tissue. It has the potential to increase bioavailability, decrease potential side effects and offer protection to more sensitive drugs such as proteins and peptide based drugs. The thiolation of polymers has, in the last number of years, come to the fore of mucoadhesive drug delivery, markedly improving mucoadhesion due to the introduction of free thiol groups onto the polymer backbone while also offering a more cohesive polymeric matrix for the slower and more controlled release of drug. This review explores the concept of mucoadhesion and the recent advances in both the polymers and the methods of thiolation used in the synthesis of mucoadhesive drug delivery devices.

  9. Characterization of particulate drug delivery systems for oral delivery of Peptide and protein drugs.

    PubMed

    Christophersen, Philip Carsten; Fano, Mathias; Saaby, Lasse; Yang, Mingshi; Nielsen, Hanne Mørck; Mu, Huiling

    2015-01-01

    Oral drug delivery is a preferred route because of good patient compliance. However, most peptide/ protein drugs are delivered via parenteral routes because of the absorption barriers in the gastrointestinal (GI) tract such as enzymatic degradation by proteases and low permeability acrossthe biological membranes. To overcome these barriers, different formulation strategies for oral delivery of biomacromolecules have been proposed, including lipid based formulations and polymer-based particulate drug delivery systems (DDS). The aim of this review is to summarize the existing knowledge about oral delivery of peptide/protein drugs and to provide an overview of formulationand characterization strategies. For a better understanding of the challenges in oral delivery of peptide/protein drugs, the composition of GI fluids and the digestion processes of different kinds of excipients in the GI tract are summarized. Additionally, the paper provides an overview of recent studies on characterization of solid drug carriers for peptide/protein drugs, drug distribution in particles, drug release and stability in simulated GI fluids, as well as the absorption of peptide/protein drugs in cell-based models. The use of biorelevant media when applicable can increase the knowledge about the quality of DDS for oral protein delivery. Hopefully, the knowledge provided in this review will aid the establishment of improved biorelevant models capable of forecasting the performance of particulate DDS for oral peptide/protein delivery.

  10. Potential of nanoparticulate drug delivery systems by intranasal administration.

    PubMed

    Ali, Javed; Ali, Mushir; Baboota, Sanjula; Sahani, Jasjeet Kaur; Ramassamy, Charles; Dao, Lé; Bhavna

    2010-05-01

    Due to number of problems related with oral, parenteral, rectal and other routes of drug administration, the interest of pharmaceutical scientists has increased towards exploring the possibilities of intranasal delivery of various drugs. Nasal drug delivery system is commonly known for the treatment of local ailments like cold, cough, rhinitis, etc. Efforts have been made to deliver various drugs, especially peptides and proteins, through nasal route for systemic use; utilizing the principles and concepts of various nanoparticulate drug delivery systems using various polymers and absorption promoters. The incorporation of drugs into nanoparticles might be a promising approach, since colloidal formulations have been shown to protect them from the degrading milieu in the nasal cavity and facilitate their transport across the mucosal barriers. The use of nanoparticles for vaccine delivery provides beneficial effect, by achieving good immune responses. This could be due to the fact that small particles can be transported preferentially by the lymphoid tissue of the nasal cavity (NALT). The brain gets benefited through the intranasal delivery as direct olfactory transport bypasses the blood brain barrier and nanoparticles are taken up and conveyed along cell processes of olfactory neurons through the cribriform plate to synaptic junctions with neurons of the olfactory bulb. The intranasal delivery is aimed at optimizing drug bioavailability for systemic drugs, as absorption decreases with increasing molecular weight, and for drugs, which are susceptible to enzymatic degradation such as proteins and polypeptides. This review discusses the potential benefits of using nanoparticles for nasal delivery of drugs and vaccines for brain, systemic and topical delivery. The article aims at giving an insight into nasal cavity, consideration of factors affecting and strategies to improve drug absorption through nasal route, pharmaceutical dosage forms and delivery systems with

  11. Partnering for Quality under the Workforce Investment Act: A Tool Kit for One-Stop System Building. Module 4: Designing a System for the Delivery of Integrated Services. Trainer Manual with Participant Workbook.

    ERIC Educational Resources Information Center

    Kogan, Deborah; Koller, Vinz; Kozumplik, Richalene; Lawrence, Mary Ann

    This document is part of a five-module training package to help employment and training service providers comply with the Workforce Investment Act (WIA) of 1998 and develop a one-stop training and employment services system. It consists of the participant workbook, trainer manual, and activity worksheets for a module on designing a system for the…

  12. Rheological, mechanical and mucoadhesive properties of thermoresponsive, bioadhesive binary mixtures composed of poloxamer 407 and carbopol 974P designed as platforms for implantable drug delivery systems for use in the oral cavity.

    PubMed

    Jones, David S; Bruschi, Marcos Luciano; de Freitas, Osvaldo; Gremião, Maria Palmira Daflon; Lara, Elza Helena Guimarães; Andrews, Gavin P

    2009-05-08

    This study described the formulation and characterisation of the viscoelastic, mechanical and mucoadhesive properties of thermoresponsive, binary polymeric systems composed of poloxamer (P407) and poly(acrylic acid, C974P) that were designed for use as a drug delivery platform within the oral cavity. Monopolymeric and binary polymeric formulations were prepared containing 10, 15 and 20% (w/w) poloxamer (407) and 0.10-0.25% (w/w) poly(acrylic acid, 934P). The flow rheological and viscoelastic properties of the formulations were determined using controlled stress and oscillatory rheometry, respectively, the latter as a function of temperature. The mechanical and mucoadhesive properties (namely the force required to break the bond between the formulation and a pre-hydrated mucin disc) were determined using compression and tensile analysis, respectively. Binary systems composed of 10% (w/w) P407 and C934P were elastoviscous, were easily deformed under stress and did not exhibit mucoadhesion. Formulations containing 15 or 20% (w/w) Pluronic P407 and C934P exhibited a sol-gel temperature T(sol/gel), were viscoelastic and offered high elasticity and resistance to deformation at 37 degrees C. Conversely these formulations were elastoviscous and easily deformed at temperatures below the sol-gel transition temperature. The sol-gel transition temperatures of systems containing 15% (w/w) P407 were unaffected by the presence of C934P; however, increasing the concentration of C934P decreased the T(sol/gel) in formulations containing 20% (w/w) P407. Rheological synergy between P407 and C934P at 37 degrees C was observed and was accredited to secondary interactions between these polymers, in addition to hydrophobic interactions between P407 micelles. Importantly, formulations composed of 20% (w/w) P407 and C934P exhibited pronounced mucoadhesive properties. The ease of administration (below the T(sol/gel)) in conjunction with the viscoelastic (notably high elasticity) and

  13. Light-switchable systems for remotely controlled drug delivery.

    PubMed

    Shim, Gayong; Ko, Seungbeom; Kim, Dongyoon; Le, Quoc-Viet; Park, Gyu Thae; Lee, Jaiwoo; Kwon, Taekhyun; Choi, Han-Gon; Kim, Young Bong; Oh, Yu-Kyoung

    2017-09-06

    Light-switchable systems have recently received attention as a new mode of remotely controlled drug delivery. In the past, a multitude of nanomedicine studies have sought to enhance the specificity of drug delivery to target sites by focusing on receptors overexpressed on malignant cells or environmental features of diseases sites. Despite these immense efforts, however, there are few clinically available nanomedicines. We need a paradigm shift in drug delivery. One strategy that may overcome the limitations of pathophysiology-based drug delivery is the use of remotely controlled delivery technology. Unlike pathophysiology-based active drug targeting strategies, light-switchable systems are not affected by the heterogeneity of cells, tissue types, and/or microenvironments. Instead, they are triggered by remote light (i.e., near-infrared) stimuli, which are absorbed by photoresponsive molecules or three-dimensional nanostructures. The sequential conversion of light to heat or reactive oxygen species can activate drug release and allow it to be spatio-temporally controlled. Light-switchable systems have been used to activate endosomal drug escape, modulate the release of chemical and biological drugs, and alter nanoparticle structures to control the release rates of drugs. This review will address the limitations of pathophysiology-based drug delivery systems, the current status of light-based remote-switch systems, and future directions in the application of light-switchable systems for remotely controlled drug delivery. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. New Beam Delivery System Optics: BDS9901(LCC-0020)

    SciTech Connect

    Tenenbaum, P

    2004-04-14

    We describe in detail the optics and XSIF decks for the NLC Beam Delivery System in its present version, BDS9901. In this Note, we describe the present optics design of the NLC Beam Delivery System, which has been somewhat revised for 1999. Most important optical changes include: (1) Organization of BPMs into quad-style (BPMQ), BPMs in feedback loops (BPMFB), BPMs which provide sub-train/multibunch information (BPMMB), and BPMs used to measure beam-beam detections (BPMIP); (2) Addition of a number of small quad, skew-quad, sextupole, and skew-sextupole tuning magnets; (3) Addition of actuators for the feedbacks; (4) A 6-quadrupole final telescope, which allows all of the linear degrees of freedom to be optimized; (5) Replacement of the low-energy final quads Q1A and Q1B with a single magnet; (6) An improved IP Switch which increases the x distance between the beamlines; and (7) Optimized final focus bandwidth. In addition to optical refinements, there have been a number of organizational improvements to the decks, and the treaty points in the decks have been made identical to the treaty points in the WBS.

  15. Updates on smart polymeric carrier systems for protein delivery.

    PubMed

    El-Sherbiny, Ibrahim; Khalil, Islam; Ali, Isra; Yacoub, Magdi

    2017-10-01

    Smart materials are those materials that are responsive to chemical (organic molecules, chemical agents or specific agents), biochemical (protein, enzymes, growth factors, substrates or ligands), physical (electric field, magnetic field, temperature, pH, ionic strength or radiation) or mechanical (pressure or mechanical stress) signals. These responsive materials interact with the stimuli by changing their properties or conformational structures in a predictable manner. Recently, smart polymers have been utilized in various biomedical applications. Particularly, they have been used as a platform to synthesize stimuli-responsive systems that could deliver therapeutics to a specific site for a specific period with minimal adverse effects. For instance, stimuli-responsive polymers-based systems have been recently reported to deliver different bioactive molecules such as carbohydrates (heparin), chemotherapeutic agents (doxorubicin), small organic molecules (anti-coagulants), nucleic acids (siRNA), and proteins (growth factors and hormones). Protein therapeutics played a fundamental role in treatment of various chronic and some autoimmune diseases. For instance insulin has been used in treatment of diabetes. However, being a protein in nature, insulin delivery is limited by its instability, short half-life, and easy denaturation when administered orally. To overcome these challenges, and as highlighted in this review article, much research efforts have been recently devoted to design and develop convenient smart controlled nanosystems for protein therapeutics delivery.

  16. Optimizing light delivery for a photoacoustic surgical system

    NASA Astrophysics Data System (ADS)

    Eddins, Blackberrie; Lediju Bell, Muyinatu A.

    2017-03-01

    This work explores light delivery optimization for a photoacoustic surgical system previously proposed to provide real-time, intraoperative visualization of the internal carotid arteries hidden by bone during minimally invasive neurosurgeries. Monte Carlo simulations were employed to study 3D light propagation in tissue. For a 2.4 mm diameter drill shaft and 2.9 mm spherical drill tip, the optimal fiber distance from the drill shaft was 2 mm, determined from the maximum normalized fluence seen by the artery. A single fiber was insufficient to deliver light to arteries separated by a minimum of 8 mm. Using similar drill geometry and the optimal 2 mm fiber-to-drill shaft distance, Zemax ray tracing simulations were employed to propagate a 950 nm wavelength Gaussian beam through one or more 600 μm core diameter optical fibers, and the resulting optical beam profile was detected on the representative bone surface. For equally spaced fibers, a single merged optical profile formed with 7 or more fibers, determined by thresholding the resulting light profile images at 1/e times the maximum intensity. The corresponding spot size was larger than that of a single fiber transmitting the same input energy, thus reducing the fluence delivered to the sphenoid bone and enabling higher energies within safety limits. A prototype was designed and built based on these optimization parameters. The methodology we used to optimize our light delivery system to surround surgical tools is generalizable to multiple interventional photoacoustic applications.

  17. Delivery system for molten salt oxidation of solid waste

    DOEpatents

    Brummond, William A.; Squire, Dwight V.; Robinson, Jeffrey A.; House, Palmer A.

    2002-01-01

    The present invention is a delivery system for safety injecting solid waste particles, including mixed wastes, into a molten salt bath for destruction by the process of molten salt oxidation. The delivery system includes a feeder system and an injector that allow the solid waste stream to be accurately metered, evenly dispersed in the oxidant gas, and maintained at a temperature below incineration temperature while entering the molten salt reactor.

  18. Modern prodrug design for targeted oral drug delivery.

    PubMed

    Dahan, Arik; Zimmermann, Ellen M; Ben-Shabat, Shimon

    2014-10-14

    The molecular information that became available over the past two decades significantly influenced the field of drug design and delivery at large, and the prodrug approach in particular. While the traditional prodrug approach was aimed at altering various physiochemical parameters, e.g., lipophilicity and charge state, the modern approach to prodrug design considers molecular/cellular factors, e.g., membrane influx/efflux transporters and cellular protein expression and distribution. This novel targeted-prodrug approach is aimed to exploit carrier-mediated transport for enhanced intestinal permeability, as well as specific enzymes to promote activation of the prodrug and liberation of the free parent drug. The purpose of this article is to provide a concise overview of this modern prodrug approach, with useful successful examples for its utilization. In the past the prodrug approach used to be viewed as a last option strategy, after all other possible solutions were exhausted; nowadays this is no longer the case, and in fact, the prodrug approach should be considered already in the very earliest development stages. Indeed, the prodrug approach becomes more and more popular and successful. A mechanistic prodrug design that aims to allow intestinal permeability by specific transporters, as well as activation by specific enzymes, may greatly improve the prodrug efficiency, and allow for novel oral treatment options.

  19. Electronic nicotine delivery systems: is there a need for regulation?

    PubMed

    Trtchounian, Anna; Talbot, Prue

    2011-01-01

    Electronic nicotine delivery systems (ENDS) purport to deliver nicotine to the lungs of smokers. Five brands of ENDS were evaluated for design features, accuracy and clarity of labelling and quality of instruction manuals and associated print material supplied with products or on manufacturers' websites. ENDS were purchased from online vendors and analysed for various parameters. While the basic design of ENDS was similar across brands, specific design features varied significantly. Fluid contained in cartridge reservoirs readily leaked out of most brands, and it was difficult to assemble or disassemble ENDS without touching nicotine-containing fluid. Two brands had designs that helped lessen this problem. Labelling of cartridges was very poor; labelling of some cartridge wrappers was better than labelling of cartridges. In general, packs of replacement cartridges were better labelled than the wrappers or cartridges, but most packs lacked cartridge content and warning information, and sometimes packs had confusing information. Used cartridges contained fluid, and disposal of nicotine-containing cartridges was not adequately addressed on websites or in manuals. Orders were sometimes filled incorrectly, and safety features did not always function properly. Print and internet material often contained information or made claims for which there is currently no scientific support. Design flaws, lack of adequate labelling and concerns about quality control and health issues indicate that regulators should consider removing ENDS from the market until their safety can be adequately evaluated.

  20. Biomimetics in drug delivery systems: A critical review.

    PubMed

    Sheikhpour, Mojgan; Barani, Leila; Kasaeian, Alibakhsh

    2017-03-18

    Today, the advanced drug delivery systems have been focused on targeted drug delivery fields. The novel drug delivery is involved with the improvement of the capacity of drug loading in drug carriers, cellular uptake of drug carriers, and the sustained release of drugs within target cells. In this review, six groups of therapeutic drug carriers including biomimetic hydrogels, biomimetic micelles, biomimetic liposomes, biomimetic dendrimers, biomimetic polymeric carriers and biomimetic nanostructures, are studied. The subject takes advantage of the biomimetic methods of productions or the biomimetic techniques for the surface modifications, similar to what accrues in natural cells. Moreover, the effects of these biomimetic approaches for promoting the drug efficiency in targeted drug delivery are visible. The study demonstrates that the fabrication of biomimetic nanocomposite drug carriers could noticeably promote the efficiency of drugs in targeted drug delivery systems.

  1. Convection-enhanced delivery to the central nervous system.

    PubMed

    Lonser, Russell R; Sarntinoranont, Malisa; Morrison, Paul F; Oldfield, Edward H

    2015-03-01

    Convection-enhanced delivery (CED) is a bulk flow-driven process. Its properties permit direct, homogeneous, targeted perfusion of CNS regions with putative therapeutics while bypassing the blood-brain barrier. Development of surrogate imaging tracers that are co-infused during drug delivery now permit accurate, noninvasive real-time tracking of convective infusate flow in nervous system tissues. The potential advantages of CED in the CNS over other currently available drug delivery techniques, including systemic delivery, intrathecal and/or intraventricular distribution, and polymer implantation, have led to its application in research studies and clinical trials. The authors review the biophysical principles of convective flow and the technology, properties, and clinical applications of convective delivery in the CNS.

  2. Cellulose based polymeric systems in drug delivery

    USDA-ARS?s Scientific Manuscript database

    The pharmaceutical industry requires the development of biodegradable, biocompatible, non toxic, site specific drug delivery polymers, which can be easily coupled with drugs to be delivered orally, topically, locally, or parenterally. The use of the most abundant biopolymer, cellulose along with its...

  3. CHAPTER 11. DELIVERY AND DISTRIBUTION SYSTEMS

    USDA-ARS?s Scientific Manuscript database

    Water delivery through canals or pipelines usually implies that several farms must somehow share access to the water in terms of flow rate, duration of access, and the return time to access the flow again, called an irrigation schedule, which can be rigid or flexible regarding the rate, duration and...

  4. Information Delivery Systems: The Future Is Here.

    ERIC Educational Resources Information Center

    O'Malley, Penelope Grenoble

    1993-01-01

    Looks at developments in information delivery (including new interactive media formats, vastly increased channel capacity for standard cable television, and the development of wireless cable and other distribution technologies) that are revolutionizing the communications industry. Raises questions about the role technical communicators are being…

  5. Information Delivery Systems: The Future Is Here.

    ERIC Educational Resources Information Center

    O'Malley, Penelope Grenoble

    1993-01-01

    Looks at developments in information delivery (including new interactive media formats, vastly increased channel capacity for standard cable television, and the development of wireless cable and other distribution technologies) that are revolutionizing the communications industry. Raises questions about the role technical communicators are being…

  6. 78 FR 55731 - Notice of Service Delivery Area Designation for the Wilton Rancheria

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-11

    ... HUMAN SERVICES Indian Health Service Notice of Service Delivery Area Designation for the Wilton... Indian Health Service (IHS) proposes the geographic boundaries of the Service Delivery Area (SDA) for the... Contract Health Service Delivery Area (CHSDA), for the purpose of operating a Contract Health Service...

  7. 77 FR 56652 - Notice of Service Delivery Area Designation for the Mashpee Wampanoag Indian Tribe

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-13

    ... Service Delivery Area Designation for the Mashpee Wampanoag Indian Tribe AGENCY: Indian Health Service...) established the geographic boundaries of the Service Delivery Area (SDA) for the newly recognized Mashpee... administratively as the SDA, to function as a Contract Health Service Delivery Area (CHSDA), for the purposes...

  8. 78 FR 55743 - Notice of Service Delivery Area Designation for the Shinnecock Indian Nation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-11

    ... HUMAN SERVICES Indian Health Service Notice of Service Delivery Area Designation for the Shinnecock... boundaries of the Service Delivery Area (SDA) for the newly recognized Shinnecock Indian Nation. The... Delivery Area (CHSDA), for the purposes of operating a Contract Health Service (CHS) program pursuant...

  9. 78 FR 55737 - Notice of Service Delivery Area Designation for the Tejon Indian Tribe

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-11

    ... HUMAN SERVICES Indian Health Service Notice of Service Delivery Area Designation for the Tejon Indian... of the Service Delivery Area (SDA) for the Tejon Indian Tribe. The Tribe's federal recognition was... administratively as the SDA, to function as a Contract Health Service Delivery Area (CHSDA), for the purpose...

  10. Nanotechnologies in delivery of mRNA therapeutics using nonviral vector-based delivery systems.

    PubMed

    Guan, S; Rosenecker, J

    2017-02-02

    Because of its safe and effective protein expression profile, in vitro transcribed messenger RNA (IVT-mRNA) represents a promising candidate in the development of novel therapeutics for genetic diseases, vaccines or gene editing strategies, especially when its inherent shortcomings (for example, instability and immunogenicity) have been partially addressed via structural modifications. However, numerous unsolved technical difficulties in successful in vivo delivery of IVT-mRNA have greatly hindered the applications of IVT-mRNA in clinical development. Recent advances in nanotechnology and material science have yielded many promising nonviral delivery systems, some of which were able to efficiently facilitate targeted in vivo delivery of IVT-mRNA in safe and noninvasive manners. The diversity and flexibility of these delivery systems highlight the recent progress of IVT-mRNA-based therapy using nonviral vectors. In this review, we summarize recent advances of existing and emerging nonviral vector-based nanotechnologies for IVT-mRNA delivery and briefly summarize the interesting but rarely discussed applications on simultaneous delivery of IVT-mRNA with DNA.Gene Therapy advance online publication, 2 February 2017; doi:10.1038/gt.2017.5.

  11. Solubility enhancement and delivery systems of curcumin a herbal medicine: a review.

    PubMed

    Hani, Umme; Shivakumar, H G

    2014-01-01

    Curcumin diferuloylmethane is a main yellow bioactive component of turmeric, possess wide spectrum of biological actions. It was found to have anti-inflammatory, antioxidant, anticarcinogenic, antimutagenic, anticoagulant, antifertility, antidiabetic, antibacterial, antifungal, antiprotozoal, antiviral, antifibrotic, antivenom, antiulcer, hypotensive and hypocholesteremic activities. However, the benefits are curtailed by its extremely poor aqueous solubility, which subsequently limits the bioavailability and therapeutic effects of curcumin. Nanotechnology is the available approach in solving these issues. Therapeutic efficacy of curcumin can be utilized effectively by doing improvement in formulation properties or delivery systems. Numerous attempts have been made to design a delivery system of curcumin. Currently, nanosuspensions, micelles, nanoparticles, nano-emulsions, etc. are used to improve the in vitro dissolution velocity and in vivo efficiency of curcumin. This review focuses on the methods to increase solubility of curcumin and various nanotechnologies based delivery systems and other delivery systems of curcumin.

  12. Biophysics and Thermodynamics: The Scientific Building Blocks of Bio-inspired Drug Delivery Nano Systems.

    PubMed

    Demetzos, Costas

    2015-06-01

    Biophysics and thermodynamics are considered as the scientific milestones for investigating the properties of materials. The relationship between the changes of temperature with the biophysical variables of biomaterials is important in the process of the development of drug delivery systems. Biophysics is a challenge sector of physics and should be used complementary with the biochemistry in order to discover new and promising technological platforms (i.e., drug delivery systems) and to disclose the 'silence functionality' of bio-inspired biological and artificial membranes. Thermal analysis and biophysical approaches in pharmaceuticals present reliable and versatile tools for their characterization and for the successful development of pharmaceutical products. The metastable phases of self-assembled nanostructures such as liposomes should be taken into consideration because they represent the thermal events can affect the functionality of advanced drug delivery nano systems. In conclusion, biophysics and thermodynamics are characterized as the building blocks for design and development of bio-inspired drug delivery systems.

  13. Designing Online Learning. Knowledge Series: A Topical, Start-Up Guide to Distance Education Practice and Delivery.

    ERIC Educational Resources Information Center

    Mishra, Sanjaya

    The term "online learning" refers to an Internet- or intranet-based teaching and learning system designed for World Wide Web-based delivery without face-to-face contact between teacher and learner. The Internet is the backbone of online learning. The following media are available to designers of online courses: text; graphics and images;…

  14. Intelligent Systems Design

    DTIC Science & Technology

    2008-12-01

    1Krasnow Institute for Advanced Studies -- George Mason University Intelligent Systems Design James Albus Senior NIST Fellow – Retired Intelligent ...REPORT DATE DEC 2008 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Intelligent Systems Design 5a. CONTRACT NUMBER 5b. GRANT...ADDRESS(ES) Intelligent Systems Division National Institute of Standards and Technology 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING

  15. Iontophoresis: A Potential Emergence of a Transdermal Drug Delivery System

    PubMed Central

    Dhote, Vinod; Bhatnagar, Punit; Mishra, Pradyumna K.; Mahajan, Suresh C.; Mishra, Dinesh K.

    2012-01-01

    The delivery of drugs into systemic circulation via skin has generated much attention during the last decade. Transdermal therapeutic systems propound controlled release of active ingredients through the skin and into the systemic circulation in a predictive manner. Drugs administered through these systems escape first-pass metabolism and maintain a steady state scenario similar to a continuous intravenous infusion for up to several days. However, the excellent impervious nature of the skin offers the greatest challenge for successful delivery of drug molecules by utilizing the concepts of iontophoresis. The present review deals with the principles and the recent innovations in the field of iontophoretic drug delivery system together with factors affecting the system. This delivery system utilizes electric current as a driving force for permeation of ionic and non-ionic medications. The rationale behind using this technique is to reversibly alter the barrier properties of skin, which could possibly improve the penetration of drugs such as proteins, peptides and other macromolecules to increase the systemic delivery of high molecular weight compounds with controlled input kinetics and minimum inter-subject variability. Although iontophoresis seems to be an ideal candidate to overcome the limitations associated with the delivery of ionic drugs, further extrapolation of this technique is imperative for translational utility and mass human application. PMID:22396901

  16. Microneedles As a Delivery System for Gene Therapy

    PubMed Central

    Chen, Wei; Li, Hui; Shi, De; Liu, Zhenguo; Yuan, Weien

    2016-01-01

    Gene delivery systems can be divided to two major types: vector-based (either viral vector or non-viral vector) and physical delivery technologies. Many physical carriers, such as electroporation, gene gun, ultrasound start to be proved to have the potential to enable gene therapy. A relatively new physical delivery technology for gene delivery consists of microneedles (MNs), which has been studied in many fields and for many molecule types and indications. Microneedles can penetrate the stratum corneum, which is the main barrier for drug delivery through the skin with ease of administration and without significant pain. Many different kinds of MNs, such as metal MNs, coated MNs, dissolving MNs have turned out to be promising in gene delivery. In this review, we discussed the potential as well as the challenges of utilizing MNs to deliver nucleic acids for gene therapy. We also proposed that a combination of MNs and other gene delivery approaches may lead to a better delivery system for gene therapy. PMID:27303298

  17. Residential photovoltaic system designs

    SciTech Connect

    Russell, M. C.

    1981-01-01

    A project to develop Residential Photovoltaic Systems has begun at Massachusetts Institute of Technology Lincoln Laboratory with the construction and testing of five Prototype Systems. All of these systems utilize a roof-mounted photovoltaic array and allow excess solar-generated electric energy to be fed back to the local utility grid, eliminating the need for on-site storage. Residential photovoltaic system design issues are discussed and specific features of the five Prototype Systems now under test are presented.

  18. User engagement in the delivery and design of maternity services.

    PubMed

    Patel, Nashita; Rajasingam, Daghni

    2013-08-01

    User engagement is defined as a mutual exchange of information between the patient and the health professional, which has shown to improve patient experience as well as outcomes. Engaging the patient is vital for the healthcare system to remain sustainable. The National Health Service has attempted to incorporate and enhance patient engagement in the delivery of maternity services for the last decade. The financial crisis, changing socio-demographic status, increase in birth rate and public expectations-engaging the patient to take responsibility of their own health has not been achieved. Through in-depth examinations of these barriers we are able to draw conclusions as to why current policies have failed and recommend potential solutions.

  19. Educational and Career Guidance for Adults: Delivery System Alternatives.

    ERIC Educational Resources Information Center

    Darkenwald, Gordon G.

    1980-01-01

    Discusses the need for guidance and information services to help adults make educational and career choices, from an organizational and administrative perspective. Major innovations are needed in educational delivery systems for the adult public. Federal legislation can help. (JAC)

  20. Optical Systems For High Power Laser Beam Delivery

    NASA Astrophysics Data System (ADS)

    Durville, Frederic M.; Cilia, D.

    1989-03-01

    During the pst fifteen years, pwerful lasers have been developed for industrial applications such as cutting, piercing, welding, engraving, etc... Convenient and reliable delivery systems are still needed to widen their field of application.