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Journal ArticleDOI

Release characteristics of diclofenac sodium from poly(vinyl alcohol)/sodium alginate and poly(vinyl alcohol)-grafted-poly(acrylamide)/sodium alginate blend beads.

01 Feb 2007-European Journal of Pharmaceutics and Biopharmaceutics (Elsevier)-Vol. 65, Iss: 2, pp 204-214
TL;DR: It was observed that, DS release from the beads decreased with increasing PVA/NaAlg (m/m) ratio, drug/polymer ratio (d/p) and extent of cross-linking, but release increased with increasing acrylamide content of the PVA-g-PAAm polymer.
About: This article is published in European Journal of Pharmaceutics and Biopharmaceutics.The article was published on 2007-02-01. It has received 150 citations till now. The article focuses on the topics: Controlled release & Polyvinyl alcohol.
Citations
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Journal ArticleDOI
TL;DR: The state of the art of crosslinked ionic polysaccharides as components of delivery systems that can regulate drug release as a function of changes in pH, ion nature and concentration, electric and magnetic field intensity, light wavelength, temperature, redox potential, and certain molecules are analyzed.

418 citations

Journal ArticleDOI
TL;DR: In vitro drug release evaluations showed that both the kind of polymer and the amount of drug loaded greatly affected the degree of swelling, weight loss, and initial burst and rate of drug release, and the thickness of the blend nanofiber mats strongly influenced the initial release and rateof drug release.
Abstract: The aim of this study was to develop novel biomedicated nanofiber electrospun mats for controlled drug release, especially drug release directly to an injury site to accelerate wound healing. Nanofibers of poly(vinyl alcohol) (PVA), poly(vinyl acetate) (PVAc), and a 50:50 composite blend, loaded with ciprofloxacin HCl (CipHCl), were successfully prepared by an electrospinning technique for the first time. The morphology and average diameter of the electrospun nanofibers were investigated by scanning electron microscopy. X-ray diffraction studies indicated an amorphous distribution of the drug inside the nanofiber blend. Introducing the drug into polymeric solutions significantly decreased solution viscosities as well as nanofiber diameter. In vitro drug release evaluations showed that both the kind of polymer and the amount of drug loaded greatly affected the degree of swelling, weight loss, and initial burst and rate of drug release. Blending PVA and PVAc exhibited a useful and convenient method for electrospinning in order to control the rate and period of drug release in wound healing applications. Also, the thickness of the blend nanofiber mats strongly influenced the initial release and rate of drug release.

349 citations


Cites background from "Release characteristics of diclofen..."

  • ...Because of its flexibility and swelling capability in an aqueous medium, PVA has been much studied as a wound dressing;(2) however, its poor stability in water has limited its use in aqueous systems, particularly for drug-delivery applications.(18,22) To overcome this problem, PVA has been made insoluble by grafting,(18) copolymerizing,(22) and cross-linking,(23) which require some additional and sometimes complicated and time-consuming processes....

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Journal ArticleDOI
TL;DR: The newly developed TSP-alginate composite beads are suitable for controlled delivery of diclofenac sodium for prolonged period and their observed responses were coincided well with the predicted values by the experimental design.

211 citations

Journal ArticleDOI
TL;DR: Solution pH, crosslinker concentration and monomer to SA weight ratio of the hydrogels were found to have a strong effect on adsorption and in vitro release profile of the drug from the gel matrix.

206 citations

Journal ArticleDOI
TL;DR: In this work, the nanocomposite beads prepared under optimum condition could prolong the release of DS for 8h more compared with the pristine SA hydrogel beads and the entrapment efficiency and release rate of DS was improved, and the burst release ofDS was overcome.

201 citations

References
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Book
01 Jan 1956
TL;DR: Though it incorporates much new material, this new edition preserves the general character of the book in providing a collection of solutions of the equations of diffusion and describing how these solutions may be obtained.
Abstract: Though it incorporates much new material, this new edition preserves the general character of the book in providing a collection of solutions of the equations of diffusion and describing how these solutions may be obtained

20,495 citations

Journal ArticleDOI
TL;DR: In this paper, an exponential relation M t /M ∞ = kt n may be used to describe the Fickian and non-Fickian release behavior of release systems which are prepared by incorporation of a drug in a hydrophilic, initially glassy polymer.

3,522 citations

Journal ArticleDOI
TL;DR: Kevin Shakesheff investigates new methods of engineering polymer surfaces and the application of these engineered materials in drug delivery and tissue engineering.
Abstract: s, and 360 patents, and edited 12 books. He has also received over 80 major awards including the Gairdner Foundation International Award, Lemelson-MIT prize, ACS’s Applied Polymer Science and Polymer Chemistry Awards, AICHE’s Professional Progress, Bioengineering, Walker and Stine Materials Science and Engineering Awards. In 1989, Dr. Langer was elected to the Institute of Medicine of the National Academy of Sciences, and in 1992 he was elected to both the National Academy of Engineering and the National Academy of Sciences. He is the only active member of all three National Academies. Kevin Shakesheff was born in Ashington, Northumberland, U.K., in 1969. He received his Bacheclor of Pharmacy degree from the University of Nottingham in 1991 and a Ph.D. from the same institution in 1995. In 1996 he became a NATO Postdoctoral Fellow at MIT, Department of Chemical Engineering. He is currently an EPSRC Advanced Fellow at the School of Pharmaceutical Sciences, The University of Nottingham. His research group investigates new methods of engineering polymer surfaces and the application of these engineered materials in drug delivery and tissue engineering. 3182 Chemical Reviews, 1999, Vol. 99, No. 11 Uhrich et al.

2,532 citations

Journal ArticleDOI
01 Jul 1987-Drugs
TL;DR: Pentoxifylline offers a well-tolerated and effective alternative to the treatment options available for patients with peripheral vascular disease and in isolated studies proved to be superior to drugs such as co-dergocrine mesylate, adenosine and pyrithioxine.
Abstract: Pentoxifylline (oxpentifylline) is an orally active haemorheological agent for the treatment of peripheral vascular disease, cerebrovascular disease and a number of other conditions involving a defective regional microcirculation. Pentoxifylline acts primarily by increasing red blood cell deformability, by reducing blood viscosity and by decreasing the potential for platelet aggregation and thrombus formation. Extensive open and placebo-controlled studies have shown that pentoxifylline 600 to 1200 mg/day for at least 6 weeks is associated with subjective and objective improvements in 60 to 100% of patients with peripheral vascular disease. The most commonly assessed clinical parameter, walking distance, is usually improved by about 100%, although much greater improvements have also been documented. Other parameters which have been clearly improved include lower limb rest pain, paraesthesia, muscle blood flow, cramps and leg ulcers. Pentoxifylline has produced consistently better results than placebo, and in those studies using comparative drugs, better results than nylidrin, adenosine and naftidrofuryl. In patients with cerebrovascular disorders, open studies with pentoxifylline, usually at a dosage of 600 to 1200 mg/day (300 to 600 mg/day in Japan), have shown marked overall clinical improvements in about 85% of patients. Symptomatic improvements in rehabilitation psychometric tests, neuromotor and speech deficits and other subjective symptoms have accompanied increased cerebral blood flow, particularly to ischaemic areas. Pentoxifylline would appear to be useful in most types of cerebrovascular disease including transient ischaemic attacks, sequelae of cerebral thrombosis and haemorrhage, and chronic ischaemic disorders. In patients with chronic cerebrovascular disease pentoxifylline 600 to 1200 mg/day conferred significant clinical benefit compared with placebo and in isolated studies proved to be superior to drugs such as co-dergocrine mesylate, adenosine and pyrithioxine. Preliminary studies indicate that pentoxifylline may also prove useful in vaso-occlusive crises of sickle cell disease, some hearing disorders, disorders of eye circulation, high altitude sickness and asthenozoospermia. Pentoxifylline is usually well tolerated when administered as the conventional controlled release formulation, gastrointestinal symptoms (about 3%) being the most common complaint, although these and other adverse effects have not occurred to a significantly greater extent than with placebo. Thus, pentoxifylline offers a well-tolerated and effective alternative to the treatment options available for patients with peripheral vascular disease.(ABSTRACT TRUNCATED AT 400 WORDS)

1,788 citations