Nanoemulsion as potential vehicles for transdermal delivery of pure phytopharmaceuticals and poorly soluble drug

Nanoemulsion (NE) is defined as an O/W or W/O emulsion producing a transparent product that has a droplet size from 20-200nm and does not have the tendency to coalesce. It is promising for transdermal delivery of drugs as an efficient route of drug administration. Several mechanisms have been proposed to explain the advantages of nanoemulsions for the transdermal delivery of drugs. In transdermal delivery, the goal of dosage design is to maximize the flux through the skin into systemic circulation. A useful strategy for improving percutaneous flux is to improve the concentration of drug or choose an appropriate vehicle for the transdermal delivery. The nanoemulsions system should be a promising vehicle due to powerful ability to deliver drug through skins. With these approaches, the aim of this present study is to review the potential of nanoemulsion formulation for transdermal delivery of pure phytopharmaceuticals and poorly soluble drugs. Some nanoemulsions have however exhibited sufficiently high level of stability for them to be proposed as vehicle for drug delivery. Using the transdermal route eliminates the side effects, increases patient compliance, avoids first-pass metabolism, enhance bioavailability and maintains the plasma drug level for a longer period of time.Keywords: Transdernmal, poorly soluble drug, phytopharmaceuticals, nanoemulsion

A Survey of Quality of Service Differentiation Mechanisms for Optical Burst Switching Networks

Cataloged from PDF version of article.This paper presents an overview of Quality of Service (QoS) differentiation mechanisms proposed for Optical Burst Switching (OBS) networks. OBS has been proposed to couple the benefits of both circuit and packet switching for the ‘‘on demand’’ use of capacity in the future optical Internet. In such a case, QoS support imposes some important challenges before this technology is deployed. This paper takes a broader view on QoS, including QoS differentiation not only at the burst but also at the transport levels for OBS networks. A classification of existing QoS differentiation mechanisms for OBS is given and their efficiency and complexity are comparatively discussed. We provide numerical examples on how QoS differentiation with respect to burst loss rate and transport layer throughput can be achieved in OBS networks. © 2009 Elsevier B.V. All rights reserved

FORMULATION AND EVALUATION OF ORAL FLOATABLE IN-SITU GEL OF RANITEDINE HYDROCHLORIDE

Objective: The present investigation deals with the formulation, optimization and evaluation of sodium alginate based floating oral In situ gel of Ranitedine HCl. Sodium alginate used as a polymer and CaCO3 was used as a cross-linking agent. In-situ forming polymeric formulation drug delivery systems is in sol form before administration in the body, but once administered, undergoes gelation in-situ to form a gel. The formulation of gel depends upon factors like temperature modulation, pH changes, presence of ions and ultraviolet irradiation from which drug gets released in sustained and controlled manner. Methods: The objective of this study was to develop a novel in- situ gel system for sustained drug delivery using natural biodegradable polymers. The system utilizes polymers that exhibit sol-to-gel phase transition due to change in specific physicochemical parameters. Results: In-situ gel was formed at a gastric pH from designed set of experiments, it was evident that formulation containing 2 % of sodium alginate control the release of drug for longer duration. The in-situ gel exhibited the expected, viscosity, drug content, pH, in vitro gelling capacity, in vitro floating ability and sustained drug release. Conclusion: The formulated in situ gel for Ranitedine Hydrochloride was found to be stable in situ gel. It was found to have better floating efficacy and in vitro release profile characteristics. Better efficiency and results of batch F-6 gives newer alternative use of natural biodegradable polymers in situ gel formulation. Key Words: Oral In-situ gel, Sustained Release. Sodium alginate, Calcium Carbonate, Ranitedine HCl

Human Fibroblast Sheet Promotes Human Pancreatic Islet Survival and Function In Vitro

In previous work, we engineered functional cell sheets using bone marrow-derived mesenchymal stem cells (BM-MSCs) to promote islet graft survival. In the present study, we hypothesized that a cell sheet using dermal fibroblasts could be an alternative to MSCs, and then we aimed to evaluate the effects of this cell sheet on the functional viability of human islets. Fibroblast sheets were fabricated using temperature-responsive culture dishes. Human islets were seeded onto fibroblast sheets. The efficacy of the fibroblast sheets was evaluated by dividing islets into three groups: the islets-alone group, the coculture with fibroblasts group, and the islet culture on fibroblast sheet group. The ultrastructure of the islets cultured on each fibroblast sheet was examined by electron microscopy. The fibroblast sheet expression of fibronectin (as a component of the extracellular matrix) was quantified by Western blotting. After 3 days of culture, islet viabilities were 70.2 ± 9.8%, 87.4 ± 5.8%, and 88.6 ± 4.5%, and survival rates were 60.3 ± 6.8%, 65.3 ± 3.0%, and 75.8 ± 5.6%, respectively. Insulin secretions in response to high-glucose stimulation were 5.1 ± 1.6, 9.4 ± 3.8, and 23.5 ± 12.4 μIU/islet, and interleukin-6 (IL-6) secretions were 3.0 ± 0.7, 5.1 ± 1.2, and 7.3 ± 1.0 ng/day, respectively. Islets were found to incorporate into the fibroblast sheets while maintaining a three-dimensional structure and well-preserved extracellular matrix. The fibroblast sheets exhibited a higher expression of fibronectin compared to fibroblasts alone. In conclusion, human dermal fibroblast sheets fabricated by tissue-engineering techniques could provide an optimal substrate for human islets, as a source of cytokines and extracellular matrix

Reconstructing 3D Building Models with the 2D Cadastre for Semantic Enhancement

International audienceVirtual city models are increasingly used in urban land management processes, which involve the use of different sources of spatial information. This heterogeneous data is, however, often complementary and it may be necessary to give the possibility to join information provided by different sources. This paper presents a method to enhance 3D buildings by using usual 2D vectorial polygon database. These polygons may represent districts, building footprints, or any seg-mentation of the urban area that adds information to the city model. The enhancement consists in using this polygon database to split the 3D buildings into a set of city objects where each element possesses a 3D geometry and the semantic information of the polygon it is linked to. In this paper, for an illustration purpose, we will present how to create this link between 3D buildings and the cadastre map, in order to create a set of semantically rich 3D building models

Comparative standardization of a polyherbal Ayurvedic formulation <i>Talishadi Churna</i>

608-611India is a land mark for traditional system of medicine from the past few centuries. Most of the traditional systems of medicine are effective but only one major drawback is lack of standardization. So, there is a need to develop a standardization technique to mingle this system of medicine in the main stream of health sciences. Central Council for Research in Ayurveda and Siddha (CCRAS) has given preliminary guidelines for standardizing these conventional formulations. The present paper reports on standardization of Talishadi churna, an Ayurvedic formulation. Three marketed samples and in-house preparation were subjected to organoleptic study, physical characteristics, physiochemical screening and High Performance Thin Layer Chromatography (HPTLC) chromatogram. It was observed that all commercial samples and standard are similar in their organoleptic and qualitative chemical analysis but physical characteristic, fluorescence analysis and High Performance Thin Layer Chromatography (HPTLC) chromatogram of various formulations are not matching with each other, and it may be due to the raw material collection time, geographical variation, etc. Which can be further investigated for its pharmacological activity. This study provides ready reference for the selection of an appropriate formulation in the clinical practice and hence effective rational therapy, the overall theme of health sciences