Thesis (Ph. D.)--Rutgers University, 2009. / "Graduate Program in Food Science." Includes bibliographical references (p. 122-130).

Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains xxii, 220 p.; also includes graphics (some col.). Includes bibliographical references (p. 202-220). Available online via OhioLINK's ETD Center.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1987. / Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 159-183).

Στην παρούσα διπλωματική εργασία μελετήθηκε η αποδέσμευση τριών βιοδραστικών ουσιών με διαφορετική διαλυτότητα στο νερό, από υδρόφιλες μήτρες αποτελούμενες από άλατα του φωσφορικού ασβεστίου. Οι υδρόφιλες μήτρες κυρίως πολυμερών, χρησιμοποιούνται ευρύτατα στην ελεγχόμενη αποδέσμευση βιοδραστικών ουσιών από στερεές φαρμακοτεχνικές μορφές διότι μπορούν να παρέχουν τα απαιτούμενα χαρακτηριστικά αποδέσμευσης (ρυθμός και ποσοστό αποδέσμευσης έναντι χρόνου). Σημαντικά πλεονεκτήματα των αλάτων του φωσφορικού ασβεστίου είναι το χαμηλό κόστος παραγωγής των και το γεγονός ότι πρόκειται για βιοσυμβατά και βιοδιασπώμενα υλικά. Οι βιοδραστικές ενώσεις που μελετήθηκαν ήταν η καφεϊνη, η θεοφυλλίνη και η θεοβρωμίνη που έχουν την ίδια βασική χημική δομή και ανήκουν στην κατηγορία των μεθυλοξανθινών, αλλά έχουν διαφορετική διαλυτότητα στο νερό. Οι υδρόφιλες μήτρες των αλάτων του φωσφορικού ασβεστίου που μελετήθηκαν στην παρούσα εργασία ήταν α) δισκία τα οποία παρασκευάσθηκαν με συμπίεση μιγμάτων των αλάτων του φωσφορικού ασβεστίου και της βιοδραστικής ένωσης με ορισμένη σύσταση και β) οστικά τσιμέντα τα οποία παρασκευάσθηκαν με επεξεργασία μίγματος αλάτων του φωσφορικού ασβεστίου και της βιοδραστικής ένωσης με φωσφορικό οξύ. Μελετήθηκε η μεταβολή του ρυθμού και του ποσοστού αποδέσμευσης των βιοδραστικών ουσιών έναντι του χρόνου α) για διαφορετικές συστάσεις της υδρόφιλης μήτρας, β) με την υδατοδιαλυτότητα της βιοδραστικής ένωσης, γ) με την ταχύτητα ανάδευσης του μέσου διαλυτοποίησης και δ) με την σύσταση του μέσου διαλυτοποίησης. Επίσης τα κινητικά δεδομένα (ποσοστό αποδέσμευσης έναντι του χρόνου) αναλύθηκαν με βάση ορισμένα κινητικά πρότυπα προκειμένου να προσδιορισθεί το κινητικό πρότυπο ή πρότυπα που καθορίζουν την αποδέσμευση των παραπάνω βιοδραστικών ενώσεων από τα δισκία και τα οστικά τσιμέντα αλάτων του φωσφορικού ασβεστίου. / -

No description available.

The therapeutic effect of pulmonary drug delivery systems is limited by its rapid clearance from the lungs by robust clearance mechanisms. By controlling the release of drugs, the therapeutic effect of pulmonary drug delivery systems, as well as patient convenience and compliance could be improved by reducing the number of times drugs need to be administered. In this study, two controlled pulmonary drug delivery systems for drugs of different solubilities were investigated and they were characterised for their viability as effective controlled release pulmonary drug delivery systems, particularly in areas of aerosol performance and dissolution profile. A hybrid protein-polymer controlled release pulmonary drug delivery system was developed to sustain the release of a water-soluble anti-asthma drug, cromolyn sodium (CS). Two excipients with complementary characteristics – a protein, bovine serum albumin, and a polymer, polyvinyl alcohol – were formulated together with CS via co-spray drying, with varying protein-polymer ratios and drug loadings. The hybrid particles showed promise in combining the positive attributes of each excipient, with respirable particles shown to sustain the release of CS with a fine particle fraction of 30%. Combining the two excipients was complex, with further optimisation of the hybrid formulations possible. A commercially available polymer, Soluplus® was spray-dried with a poorly-water soluble corticosteroid, beclomethasone dipropionate (BDP). The resultant respirable powders were shown to have potential for use as a controlled release pulmonary drug delivery system with up to 7-fold improvement in the amount of BDP released compared to spray-dried BDP. The spray-dried BDP-Soluplus® powders were found to be amorphous, and physically stable against re-crystallisation for up to 9 months at accelerated stress test conditions with drug loadings of up to 15 % (w/w). Although it provided a platform to compare between formulations, the USP 4 flow-through cell dissolution apparatus was found to be inadequate to accurately study the dissolution profiles of the pulmonary drug delivery systems due to the formation of a gel in the apparatus. Preliminary work on the use of a novel technique to predict the crystallisation of amorphous formulations with terahertz time-domain spectroscopy was also conducted. The system confirmed the re-crystallisation tendencies of several hybrid CS/BSA/PVA formulations. Modification to the experimental setup to probe the formulations at different relative humidities instead of temperatures could yield improved results.

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Master of Science / Department of Journalism and Mass Communications / Louise Benjamin / The video news release (VNR) has been a source of controversy since its first inclusion into newscasts in the early 1980s. This third-party (not produced by a news station) public relations and marketing-friendly content, when included alongside normally produced news stories, can make it difficult for the public to discern what is news and what is not. Problems specifically arise when news operations fail to disclose to their audience the source or provider of VNR content, and prevent news consumers from evaluating the legitimacy or intent of a VNR. A 4 (source disclosure cue: audio, video, combination of the two, and none) x 2 (source agent type: biased or neutral) experiment was implemented within this study to better understand audience evaluations, post exposure to a source disclosure cue, of the credibility of a news operation that implements VNRs within their broadcast. Disclosure cues were also evaluated for their effectiveness in raising awareness to the persuasive aspects of a VNR, and the impact of differing source agent types on participants' credibility assessment of a news operation. Results demonstrated 75% of participants (n=238) failed to correctly identify the source of the VNR when a disclosure cue was given. However, the audio and video combination condition was found to instigate the most awareness to the use of VNR. Overall, disclosure of a VNR's source could not be linked to changes in participants' evaluation of a news operation's credibility, with results demonstrating uniformly average means throughout. In addition, source disclosure could not be associated to a change in participants' awareness to the persuasive context of the VNR, with similar means exhibited. Because of the lack of an overall effect concerning credibility or knowledge of persuasive content within the study, greater media transparency is needed as are more media literacy opportunities for the public to best understand and navigate today’s complicated broadcast media reality.

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