Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Asymmetric Membrane Tablet Coatings for Controlled-Release of Drugs(Izmir Institute of Technology, 2002) Yenal, Hacer; Alsoy Altınkaya, SacideMost of the controlled release systems developed for drug delivery applications dependon membrane technology. The dense structure of the membrane in conventional controlled release systems prolongs the release of drug. To eliminate this disadvantage while maintaining the benefits of dense membrane systems, an asymmetric type of coating was applied on tablets. Coatings were prepared from cellulose acetate, acetone, water solution by phase inversion technique. To determine the release rate of drug, dissolution studies on tablets were performed according to United States of Pharmacopeia (USP). In these studies, the effects of composition of the polymer/solvent/nonsolvent, coating time, number of coating layers, evaporation conditions and the nonsolvent type on the release rate of the drug and the structure of membrane were investigated. Experiments were designed using commercial software package Design-Expert and a quadratic model equation was obtained to predict the effect of composition of cellulose acetate, acetone and water on the release rate of drug. The advantage of asymmetric type coating over the conventional dense type coating was further demonstrated by measuring the permeabilities of both type of coatings. In addition, the structures of membranes were analyzed using scanning electron microscope (SEM) micrographs.Master Thesis Synthesis of Silica Nano Particles With Custom-Made Morphology for Controlled Drug Delivery(Izmir Institute of Technology, 2012) Siretli, Çağrı; Polat, MehmetThe purpose was to have nanosized particles with low energy perimeters which function as non-reacting transporters for targeted delivery along with high energy sites inside the pores to achieve controlled release of specialized chemicals. Surfactants were used in combination with both base and acid catalyzed methods to achive desired structural properties and the characterization studies such as SEM, TEM, FTIR, BET surface area, pore size, size and zeta potential measurements were conducted. The effect of surfactants on mesoporous silica production changed depending on the type of methods. In the case of base catalysed method in alcohol, formation of stabilized emulsions with different sizes and their effect on the size and shape of silica particles was proposed. The effect of surfactants was attributed to their effect on a) the emulsification process and b) silica-silica and silica-surfactant interactions involved. In the case of base catalysed silica production in water, however, surfactant micelles were used as templates to produce pores. The effect of surfactant type and concentration was attributed to their effect on the CMC, micelle shape and size. Rod-like (~400 nm) at high and spherical (~200 nm) particles at low concentrations were synthesized. Here the surface area of ~1000 m2/g and average pore size of ~3 nm were obtained. Carbonization of these materials were performed to obtain nanosized silica particles with low energy perimeters successfully. Acid catalysed silica production in water was similar. Rod-like (600-800 nm) and cubic (800-1000 nm) nanoparticles were produced. These particles exhibited lower surface area of ~700 m2/g and larger pore size of ~5 nm.Master Thesis Application of Silk Fibroin in Controlled-Release of Theophylline(Izmir Institute of Technology, 2004) Özgarip, Yarkın; Bayraktar, OğuzPolimerik malzemeler kullanılarak ilaç salınım proseslerini modellemek amacı ile çalımalar yapılmaktadır. Organik bazlı polimerik çözeltiler ile ilaçların kaplanması hala çok yaygın olmasına ramen ,organik bazlı polimerik çözeltilerin toksik ve çevreye zaralı olması nedeni ile ilaç endüstrisi farklı kaplama malzemeleri üzerine çalımaya balamıtır. Su bazlı kaplama teknikleri, organik polimerik çözeltilerin neden olduğu toksik özellikleri ortadan kaldırmak amacı ile kullanılmaktadır. Bu çalımada kontrollü ilaç salınım mekanizmasını elde etmek için kaplama malzemesi olarak su bazlı fibroin çözeltisi ve model ilaç olarak da teophylline kullanılmıtır. laç tabletleri ısıl işlem görmü silk fibroin, polietilenglikol (PEG) ve fibroin çözeltisi karıımı ile kaplanmıtır. Ek olarak EDC ile kroslink edilmi fibroin çözeltisiden elde edilen kaplamanın ilaç salınımına etkisi aratırılmıtır. Bütün örneklerin ilaç salınım profilleri UVspectrofotometre kullanılarak dissolusyon testi ile yapılmıtır. Ayrıca PEG konsantrasyonunun ve film kaplama kalınlıının etkileri aratırılmıtır. Taramalı elektron mikroskobu kullanılarak filmlerin morfolojisi ve film kaplama kalınlıkları bulunmutur. PEG in plastikletirici etkisinin ve fibroinin EDC ile kroslink edilmesinin, ilacın kontrollü bir ekilde salınmasını saladıı gözlemlenmitir. Hedef profile göre %17 PEG içeren fibroin çözeltisi ile kaplanan tabletlerin %70 salınım profilinde çözünme süresi 345 dakika olarak bulunmutur. laç salınım hızı ve tablet kaplama kalınlıı arasında bir baıntı elde edilmitir. EDC ile kroslink edilen fibroin çözeltisiyle kaplanan tabletlerde , kaplama kalınlıı arttıkça ilaç salınımı azalmıtır. Film kaplama kalınlıını 7.68 mm.ye getirilerek istenen ilaç salınımı elde edilmitir.