507 research outputs found
Bioequivalence of Oral Products and the Biopharmaceutics Classification System: Science, Regulation, and Public Policy
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109935/1/cptclpt2011109.pd
The interplay of university and industry through the FP5 network
To improve the quality of life in a modern society it is essential to reduce
the distance between basic research and applications, whose crucial roles in
shaping today's society prompt us to seek their understanding. Existing studies
on this subject, however, have neglected the network character of the
interaction between university and industry. Here we use state-of-the-art
network theory methods to analyze this interplay in the so-called Framework
Programme--an initiative which sets out the priorities for the European Union's
research and technological development. In particular we study in the 5th
Framework Programme (FP5) the role played by companies and scientific
institutions and how they contribute to enhance the relationship between
research and industry. Our approach provides quantitative evidence that while
firms are size hierarchically organized, universities and research
organizations keep the network from falling into pieces, paving the way for an
effective knowledge transfer.Comment: 21 pages (including Appendix), 8 figures. Published online at
http://stacks.iop.org/1367-2630/9/18
Permeability and clearance views of drug absorption: A commentary
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45051/1/10928_2006_Article_BF02354289.pd
Biowaiver monographs for immediate release solid oral dosage forms: acetaminophen (paracetamol).
Literature data are reviewed on the properties of acetaminophen (paracetamol) related to the biopharmaceutics classification system (BCS). According to the current BCS criteria, acetaminophen is BCS Class III compound. Differences in composition seldom, if ever, have an effect on the extent of absorption. However, some studies show differences in rate of absorption between brands and formulations. In particular, sodium bicarbonate, present in some drug products, was reported to give an increase in the rate of absorption, probably caused by an effect on gastric emptying. In view of Marketing Authorizations (MAs) given in a number of countries to acetaminophen drug products with rapid onset of action, it is concluded that differences in rate of absorption were considered therapeutically not relevant by the Health Authorities. Moreover, in view of its therapeutic use, its wide therapeutic index and its uncomplicated pharmacokinetic properties, in vitro dissolution data collected according to the relevant Guidances can be safely used for declaring bioequivalence (BE) of two acetaminophen formulations. Therefore, accepting a biowaiver for immediate release (IR) acetaminophen solid oral drug products is considered scientifically justified, if the test product contains only those excipients reported in this paper in their usual amounts and the test product is rapidly dissolving, as well as the test product fulfils the criterion of similarity of dissolution profiles to the reference product
Persistent elastic behavior above a megathrust rupture patch: Nias island, West Sumatra
We quantify fore-arc deformation using fossil reefs to test the assumption commonly made in seismic cycle models that anelastic deformation of the fore arc is negligible. Elevated coral microatolls, paleoreef flats, and chenier plains show that the Sumatran outer arc island of Nias has experienced a complex pattern of relatively slow long-term uplift and subsidence during the Holocene epoch. This same island rose up to 2.9 m during the Mw 8.7 Sunda megathrust rupture in 2005. The mismatch between the 2005 and Holocene uplift patterns, along with the overall low rates of Holocene deformation, reflects the dominance of elastic strain accumulation and release along this section of the Sunda outer arc high and the relatively subordinate role of upper plate deformation in accommodating long-term plate convergence. The fraction of 2005 uplift that will be retained permanently is generally <4% for sites that experienced more than 0.25 m of coseismic uplift. Average uplift rates since the mid-Holocene range from 1.5 to −0.2 mm/a and are highest on the eastern coast of Nias, where coseismic uplift was nearly zero in 2005. The pattern of long-term uplift and subsidence is consistent with slow deformation of Nias along closely spaced folds in the north and trenchward dipping back thrusts in the southeast. Low Holocene tectonic uplift rates provide for excellent geomorphic and stratigraphic preservation of the mid-Holocene relative sea level high, which was under way by ∼7.3 ka and persisted until ∼2 ka
A method to predict infinity values for biexponential processes
An equation is presented which allows infinity values for biexponential processes to be predicted in the early nonlinear phase when samples are taken at equal time intervals. This equation is independent of the value or ratio of the rate constants involved in the process. However, this method is very sensitive to noise normally associated with urine data.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45077/1/10928_2005_Article_BF01062539.pd
Advanced Technologies for Oral Controlled Release: Cyclodextrins for oral controlled release
Cyclodextrins (CDs) are used in oral pharmaceutical formulations, by means of inclusion complexes formation, with the following advantages for the drugs: (1) solubility, dissolution rate, stability and bioavailability enhancement; (2) to modify the drug release site and/or time profile; and (3) to reduce or prevent gastrointestinal side effects and unpleasant smell or taste, to prevent drug-drug or drug-additive interactions, or even to convert oil and liquid drugs into microcrystalline or amorphous powders. A more recent trend focuses on the use of CDs as nanocarriers, a strategy that aims to design versatile delivery systems that can encapsulate drugs with better physicochemical properties for oral delivery. Thus, the aim of this work was to review the applications of the CDs and their hydrophilic derivatives on the solubility enhancement of poorly water soluble drugs in order to increase their dissolution rate and get immediate release, as well as their ability to control (to prolong or to delay) the release of drugs from solid dosage forms, either as complexes with the hydrophilic (e.g. as osmotic pumps) and/ or hydrophobic CDs. New controlled delivery systems based on nanotechonology carriers (nanoparticles and conjugates) have also been reviewed
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