Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.

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Thesis (Ph.D.) - University of Queensland, 2004. / Includes bibliography.

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: mass balance approach; bioavailability; drug delivery; dynamic modeling; partial differential equations; sensitivity analysis; dynamic simulations. Includes bibliographical references (p. 62-67).

Objective: Medication safety is always having great concern in healthcare. Giving oral medication through enteral feeding tubes is not uncommon and is a well-known area that prone to error happening. These errors may lead to inadequate treatment or adverse drug reaction resulting in unnecessary health care cost and wastage of public health resources. This systematic review aims to identify contributing factors on medication errors associated with administration of oral medication via enteral feeding tubes. With better understanding of the factors, improvement measures applicable to Hong Kong situations will be suggested. Methods: Pubmed, Medline and Embase databases were searched up to February 2014 by using relevant keywords. Prospective studies with researcher analyzing the drug administration process to observe the occurrence of errors and evaluate the contributing factors and case reports on medical error with review of the place of errors and their potential root causes were considered to be potential relevant literature. Studies meeting the inclusion criteria were included and evaluated in this review. Studies were excluded based on the exclusion criteria. Results and Discussion: An initial search of medical literature by searching engines identified 682 references. After appraisal for inclusion, 11 of them were included in this systematic review. For the findings, lack of knowledge, lack of the presence or the awareness of protocol, environmental factors, inter-disciplinary communication among healthcare professionals and the ability of inadvertent connection of both IV catheter and enteral feeding system had been identified to be key contributing factors to drug administration error. Taken account with the findings, measures to improve the existing local practice through educational reinforcement, establishing guideline and inter-disciplinary communication were suggested. Conclusion: With consideration of the local situation in Hong Kong and the findings identified in this review, suggestions of improvement measures on different aspects have been made in this review. Involvement of government policy, institutional management and the collaboration of multi-disciplinary healthcare professional are essential for the success of these improvement measures. Besides, this review also revealed the lack of research on medication safety issue concerning feeding tube, further research in this area is required. / published_or_final_version / Public Health / Master / Master of Public Health

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Thesis (Ph. D.)--University of Texas at Austin, 2004. / Supervisor: Nicholas A. Peppas. Vita. Includes bibliographical references. Also available from UMI.

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

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

No description available.