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Properties of spherical pellets produced by a hot-melt extrusion and spheronization processYoung, Christopher Ryan 28 August 2008 (has links)
Not available / text
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NMR and MRI studies of controlled release drug delivery systemsZhang, Qilei January 2012 (has links)
No description available.
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In vitro and in vivo testing of a gastric retention device : development and evaluation of a new colonic delivery systemAhmed, Iman Saad 04 September 2002 (has links)
This thesis describes evaluation of a gastric retention device (GRD)
developed at Oregon State University. The device was originally fabricated from
Xanthan gum and Locust bean gum. A modified gastric retention device
containing other additives was developed and investigated in this work. The
modified device was evaluated in vitro for swelling and dissolution properties using
riboflavin as a model drug. Different shapes and sizes of GRDs were tested in dogs
to study the gastric retention potential of these devices. The effect of the device on
food emptying from the stomach in dogs was also investigated. Endoscopic studies
in dogs also showed that the device swells rapidly and considerably in gastric fluid.
The bioavailability of riboflavin from three different size GRDs was
determined in six fasted human volunteers and compared to an immediate release
formulation. The biostudy indicated that the bioavailability of riboflavin from a
large size GRD was more than triple that measured after administration of the
immediate release formulation. Deconvolution was used to determine gastric
residence time of the different size GRDs.
A new colonic delivery system made of acetaminophen loaded beads
produced by extrusion and spheronization and coated with different ratios of pectin
and ethylcellulose coating solutions in a spray coating apparatus was also
developed in this work. Such beads release their drug content in the colon due to
susceptibility of pectin in the outer coat to enzymatic action of colonic bacteria.
The new delivery system was evaluated in vitro by conducting release studies in
different dissolution media to mimic transit times, pH and enzyme conditions in the
gastrointestinal tract. The gastrointestinal transit behavior of drug beads was also
assessed by conducting gamma-scintigraphic studies in dogs.
The bioavailability and pharmacokinetic parameters of acetaminophen from
several colonic delivery system formulations were determined in human volunteers
and compared to the immediate release commercial product Tylenol®. A selected
pectin-ethylcellulose coat formulation in the ratio 1:3 was further evaluated in six
volunteers under both fed and fasting conditions and was found to be effective and
to provide sustained drug release in the colon over a period of 12 hours. / Graduation date: 2003
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1) Development and in vivo testing of a gastric retention device (GRD) in dogs : 2) product formulations and in vitro-in vivo evaluation of a) immediate release formulation of itraconazole, b) controlled-release formulation of ketoprofen in adultsKapsi, Shivakumar G. 24 November 1998 (has links)
This thesis describes 1) development of a gastric retention device (GRD) to
increase gastric retention time of certain drugs, 2) product formulations of an immediate
release itraconazole and controlled-release ketoprofen. GRD was fabricated from crosslinked
carbohydrate polymers. Rate and extent of hydration of the film in water and in
simulated gastric fluid, compressibility of film, shape of the film, and in vivo gastric
transit time in the stomach of dog were used as tools to evaluate gastric retention
properties. Hydration studies were carried out at 37��C. Evaluation of the device
containing radio-opaque agents, in dogs for gastric retention was carried out with the help
of X-rays. The device was found to stay in the stomach of dogs for at least 10 hours.
GRD containing amoxicillin trihydrate caplets were evaluated in a human. The area
under the excretion rate curve was found to increase by 30% when compared to without
the device.
A successful development of a formulation of water insoluble itraconazole,
without the use of organic solvents, was achieved with modifications from eutectic
mixture techniques. Solubilization of the drug was achieved in polyethylene glycol of
higher molecular weight. A series of formulations made by varying the amounts
ingredients therein, were evaluated for dissolution profile in comparison with the
reference, Sporanox��. Effect of molecular weights of PEG and types of PEG were
evaluated for desired drug dissolution. Preliminary study from 6 subjects under the
conditions of fasting and fed indicated that bioavailability from the new formulation was
increased slightly when compared to the reference. This may be correlated to difference
in the rate of in vitro dissolution, where the new formulation has initial faster dissolution.
A controlled-release formulation of ketoprofen was also developed using a
diffusion-controlled polymer, which was coated onto the drug beads. Release of drugs
from such beads is controlled by the thickness of the coat. Thickness of the coat was
evaluated by SEM and was correlated to the desired in vitro drug release in comparison
to the reference Oruvail��. A three-way cross over study involving the new formulation
and two marketed products in 12 subjects under fasting conditions indicated that there
was a significant difference between the new product and marketed products, so as to be
considered non-bioequivalent. Use of In Vitro-In Vivo Correlations and Convolution-
Deconvolution relations predicted desired in vitro drug dissolution in a subsequent
modification of the formulation. / Graduation date: 1999
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Development and evaluation of an oral controlled release and a transdermal delivery system, for melatonin in human subjectsLee, Beom-jin 08 December 1992 (has links)
Graduation date: 1993
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Physicochemical and mechanical characterization of hot-melt extruded dosage formsCrowley, Michael McDonald 28 August 2008 (has links)
Not available / text
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Properties of polymeric drug delivery systems prepared by hot-melt extrusionZhu, Yucun 28 August 2008 (has links)
Not available / text
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Lightly crosslinked poly(ethylene glycol)-tethered, pH-responsive biomaterialsThomas, Joshua Brock 28 August 2008 (has links)
Not available / text
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Investigation of cellulose ether polymers in controlled drug deliveryMahaguna, Vorapann 28 March 2011 (has links)
Not available / text
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Application of Silk Fibroin In Controlled-Release of Theophylline/Özgarip, Yarkın. Bayraktar, Oğuz January 2004 (has links) (PDF)
Thesis (Master)--İzmir Institute of Technology, İzmir, 2004. / Includes bibliographical references (leaves. 55-58).
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