Bazı H2 reseptör antagonisti ilaçlar üzerine çalışmala

Bu tezin, veri tabanı üzerinden yayınlanma izni bulunmamaktadır. Yayınlanma izni olmayan tezlerin basılı kopyalarına Üniversite kütüphaneniz aracılığıyla (TÜBESS üzerinden) erişebilirsiniz.[Abstarct Not Available

Nitrendipinin stabilitesi üzerinde çalışmalar

Bu tezin, veri tabanı üzerinden yayınlanma izni bulunmamaktadır. Yayınlanma izni olmayan tezlerin basılı kopyalarına Üniversite kütüphaneniz aracılığıyla (TÜBESS üzerinden) erişebilirsiniz.124 SUMMARY Nitrendipine was characterized as one of the more potent calcium channel blockers of the dihydropyridine class. The development of nitrendipine began at 1978 in West Germany. There has been scanty of knowledge in literature on its stability. So temperature and pH effect on the stability of nitrendipine for the first time were investigated in our study. First of all, the different pH values (pH 1.5 - 3.5 - 5.5 - 8.0 - 9.0) of nitrendipine solutions were prepared and these solutions were kept at 40°, 60°, 80° C and the accelerated stability tests were carried out to determine their shelf-lives and t1/2 at room temperature. The most suitable pH which has been found for the nitrendipine solutions is pH 5.5 prepared by using Mc Ilvaine buffer solution. Its shelf life was 2.37 year and t1/2 was 15.66 year at room temperature. In the second part of the study the degradation products in acidic and alkaline pH at 100 °C were investigated. One of the acidic degradation product was separated by TLC and its structure was illuminated by spectroscopic methods such as UV, IR, NMR, Mass and it has been proved to be 2,6 -dimethyl-4- (3'-nitrophenyl) pyridine-3,4-dicarboxylic acid ethyl methyl ester. The effect of the different sterilization conditions on nitrendipine solutions at pH 5-7-9 also were investigated. It has been found that the steril filtration is the most suitable125 sterilization method for the nitrendipine solutions. In addition we investigated the stability of pure nitrendipine and its commercial tablet form in simulated gastric and intestinal media with or without enzyme. The degradation of nitrendipine in commercial tablet form is slower than pure nitrendipine in the same media.123 ÖZET Nitrendipin antihipertansif etkili, dihidropiridin türevi bir ilaçtır. Yapılan literatür araştırmasında, nitrendipinin alkollü çözeltisinin ışığa karşı duyarlı olduğu belirtilmiştir. Ancak ısı ve pH nın etkisine ait bir çalışmaya rastlanmamıştır. Bu nedenle araştırmamız bu konularda yoğunlaştırılmıştır. Hazırlanan pH 1.5 - 3.5 - 5.5 - 8.0 ve 9.0 daki nitrendipin çözeltileri 40°, 60° ve 80°C gibi üç farklı sıcaklıkta renkli ampuller içerisinde bekletilmiş ve miktar tayinleri yapılarak nitrendipinin en dayanıklı olduğu pH bulunmuştur. Mc Ilvaine tamponu ile hazırlanan pH 5.5 daki nitrendipin çözeltisinin diğerlerine göre daha dayanıklı olduğu saptanmıştır. Bu pH daki nitrendipin çözeltisinin oda sıcaklığındaki raf ömrü 2.37 yıl olarak bulunmuştur. 1. dereceden kinetiğe uyduğu belirlenen bozunma reaksiyonu 100°C deki asit ve alkali hidroliz sonucuyla da paralellik göstermiştir. Asit hidrolizi sonucu elde edilen parçalanma ürünlerinden birisinin yapısı aydınlatılmıştır. Bu madde 2,6 - dimetil - 4 - (3- nitrofenil) piridin - 3,4 - dikarboksilik asidin etil ve metil esteri olarak bulunmuştur. Farklı pH daki çözeltilere steril filtrasyon, 100°C de 30 dakika su banyosu sterili- zasyonu ve 110°C de 0.5 atmosferde 30 dakika otaklav sterilizasyonu uygulanmış, değişik sterilizasyon koşullanın nitrendipin üzerine stabilite açısından etkisi incelenmiştir. En uygun sterilizasyon koşulunun steril filtrasyon olduğu bulunmuştur. Piyasada nitrendipinin tablet şeklinde bulunması nedeniyle hem bu maddenin hem de tabletlerinin 37°C de suni mide ve suni barsak vasatındaki dayanıklılığı da incelenmiş ve nitrendipin miktarında kayıp saptanmıştır. Bu kayıp, bozunma ürünlerinin bu ortamlarda oluştuğunu düşündürmektedir. Nitekim nitrendipinin bozunması sonucu oluşan ve dehidronitrendipin olarak yapısını aydınlattığımız bozunma ürünü nitrendipinin metabolizması sırasında bir ara basamak olarak meydana gelmektedir ve literatürde toksik olduğuna dair herhangi bir kayıt yoktur (32:48

The Adaptation of the Mathematics Anxiety Rating Scale-Elementary Form into Turkish, Language Validity, and Preliminary Psychometric Investigation

The purpose of the present study was to adapt the Mathematics Anxiety Rating Scale-Elementary Form (MARS-E, Suinn, 1988) into Turkish by first doing the translation of its items and then the preliminary psychometric investigation of the Turkish form. The study included four different samples: 30 bilingual language experts, 50 Turkish language experts, 50 mathematics subject matter experts, 21 school counselors, and 336 elementary school students. After each item was independently translated into Turkish by three experts, the accuracy of the translation was investigated. Next, the Turkish form was studied in terms of understandability. In order to study, the Turkish form's preliminary properties, the scale was administered to 336 elementary school students. Results showed evidence for language validity, structural validity, content validity, and concurrent validity. In addition, the Turkish form's items were found to have acceptable internal consistency reliabilities. Results were discussed in relation to previous mathematics anxiety literature. It is concluded that the Turkish MARS-E appears to be a valid and reliable instrument in measuring mathematics anxiety levels of Turkish elementary school children

A COMPARATIVE STUDY OF EDUCATIONAL ADMINISTRATORS' THINKING STYLES IN RELATION TO DIFFERENT VARIABLES

In recent years, there has been a relative increase in the number of studies on thinking styles as an integrated dimension of individual differences. The scarcity of the studies in the literature focusing on educational administrators and their thinking styles increases the importance of the present study. The present study is a descriptive investigation of the thinking styles of educational administrators in Tokat province of Turkey. Thinking styles are compared in relation to different variables such as age, gender, tenure, and school type. The sample of the study is 241 voluntary school administrators who were selected conveniently. The Thinking Styles Inventory and a personal data form were used to collect the data. Results showed that the most preferred thinking styles are Hierarchical, Legislative, and External: whereas the least preferred ones are Conservative. Oligarchic, and Local thinking styles. Significant differences across the independent variables of the study were found. These differences were interpreted and suggestions were given

A Multivariate Investigation of Coping Strategies among School Administrators

A multivariate investigation and comparison of the coping strategies used in dealing with stress and psycho-social factors among school administrators is the purpose of the current study. Personal and environmental independent variables were studied across 13 dependent variables. The participants were 214 school administrators who voluntarily responded to the Turkish version of the Coping Strategies Scales and a set of demographic questions. Results showed significant differences between men and women; among four age groups; and school type. Female administrators showed significantly higher preference for behavioral detachment; older administrators showed more preference for religion, whereas younger administrators preferred active coping and planning strategies. Those administrators who worked in middle schools scored higher on seeking instrumental and emotional social support compared to their colleagues who worked in elementary schools. Results are discussed in the light of current literature and suggestions were provided

Development and validation of an RP-HPLC method for simultaneous determination of curcumin and metronidazole in combined dosage form

Background and Aims: The present study aimed to develop and validate a simple reverse phase-high pressure liquid chro-matography (RP-HPLC) method for simultaneous determination of natural compound curcumin and metronidazole in bulk and its combined dosage form.Methods: In situ gel formulation containing curcumin and metronidazole was prepared as a model combined system. The chromatographic separation was accomplished isocratically on Eclipse XDB-C18 (150 mm x 4.6 mm, 5 pm particle size) col-umn using UV-detection at 254 nm. The optimized mobile phase contained a mixture of Phosphate Buffer pH4.5-Acetonitrile (50:50, v/v), and the flow rate was set to 1.0 mL/min with 10 pL injection volume. The method was validated in compliance with International Council for Harmonisation (ICH) standards, and it was successfully used for quality control assays for their combined drug productResults: The results for retention times were 8.60 and 1.40 min for curcumin and metronidazole, respectively. The method indicated linear responses within the concentration ranges of 3.0-80 and 4.8-128 pg/mL with LOD values of 0.62; 1.03 pg/mL and LOQ values of 1.88; 3.13 pg/mL for curcumin and metronidazole, respectively. Precision results were within acceptable limits (RSD2%), and the determination of the two active substances was not interfered with by any formulation components.Conclusion: The proposed validated RP-HPLC method was successfully applied to determine the total contents of curcumin and metronidazole in situ gel formulation. The validation results showed that the proposed method was simple, specific, and precise, and that it could be used for routine quality control for their combined pharmaceutical application

BIOADHESIVE AND MECHANICAL PROPERTIES OF TRIAMCINOLONE ACETONIDE BUCCAL GELS

Bioadhesive drug delivery systems are the most widely used approach which aims to provide high drug concentrations in the oral cavity for a long period of time. A formulation which has been designed for buccal application must exhibit acceptable mechanical characteristics. Texture profile analysis is a method which determines the mechanical properties of polymeric systems. The aim of this study was to develop different buccal gel formulations with several bioadhesive polymers for oral mucosal ulcerations as an alternative to commercial product and to compare the effect of bioadhesive polymers on the mechanical and textural properties of the gel formulations. For these purposes, the gel formulations containing Triamcinolone acetonide were prepared by using Polaxamer 407, Carbopol 934, chitosan and HPMC. All the developed formulations were compared with commercial product which is containing 0.1% triamcinolone acetonide (Kenacort-A Orabese®). According to the results, it was observed that the bioadhesive properties of the formulations depends on the bioadhesive polymer concentration and molecular weight of chitosan. It was also noted that, the bioadhesive performance of the chitosan based formulations was improved with HPMC. Texture profile analysis (TPA) results indicated that mechanical properties of the developed gels are more suitable than the commercial produc

Evaluation of chitosan based vaginal bioadhesive gel formulations for antifungal drugs

The aim of the present study was to evaluate chitosan as a vaginal mucoadhesive gel base for econazole nitrate and miconazole nitrate. To this aim, different types of chitosan with different molecular masses and viscosity properties [low molecular mass chitosan (viscosity: 20,000 mPa s), medium molecular mass chitosan (viscosity: 200,000 mPa s), high molecular mass chitosan (viscosity: 800,000 mPa s)] have been used. First, rheological studies were conducted on chitosan gels. Mechanical, syringeability and mucoadhesive properties of chitosan gels were determined. Release profiles of econazole nitrate and miconazole nitrate from chitosan gels were obtained and evaluated kinetically. In addition, anticandidal activities of formulations were determined. Finally, vaginal retention of chitosan gels in rats was evaluated by in vivo distribution studies. Based on the results, it can be concluded that gels prepared with medium molecular mass chitosan might be effectively used for different antifungal agents in the treatment of vaginal candidiosis, since it has high mucoadhesiveness, suitable mechanical and release properties with good vaginal retentio