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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Chitosan-Cellulose Nanocrystal Polyelectrolyte Complex Particles: Preparation, Characterization, and In Vitro Drug Release Properties

Wang, Hezhong 01 December 2009 (has links)
Polyelectrolyte complexes (PECs) between chitosan, a mucoadhesive, intestinal mucosal permeability-enhancing polysaccharide, and cellulose nanocrystals, rod-like cellulose nanoparticles with sulfate groups on their surface, have potential applications in oral drug delivery. The purpose of this research was to develop an understanding of the formation and properties of chitosan–cellulose nanocrystal PECs and determine their in vitro drug release properties, using caffeine and ibuprofen as model drugs. Cellulose nanocrystals were prepared by sulfuric acid hydrolysis of bleached wood pulp. Chitosans with three different molecular weights (81, 3·103, 6·103 kDa) and four different degrees of deacetylation (77, 80, 85, 89%) were used. PEC formation was studied by turbidimetric titration. PEC particles were characterized by FT-IR spectroscopy, scanning electron microscopy, dynamic light scattering, and laser Doppler electrophoresis. The formation and properties of chitosan–cellulose nanocrystal PEC particles were governed by the strong mismatch in the densities of the ionizable groups. The particles were composed primarily of cellulose nanocrystals. Particle shape and size strongly depended on the mixing ratio and pH of the surrounding medium. The ionic strength of the surrounding medium, and the molecular weight and degree of deacetylation of chitosan had a minor effect. Release of caffeine from the chitosan–cellulose nanocrystal PEC particles was rapid and uncontrolled. Ibuprofen-loaded PEC particles showed no release in simulated gastric fluid and rapid release in simulated intestinal fluid. Further evaluation studies should focus on the expected mucoadhesive and permeability-enhancing properties of chitosan–cellulose nanocrystal PEC particles. / Ph. D.
62

Mechanism of hydrogen-bonded complex formation between ibuprofen and nanocrystalline hydroxyapatite

Ryabenkova, Yulia, Jadav, Niten B., Conte, M., Hippler, M.F.A., Reeves-McLaren, N., Coates, Philip D., Twigg, Peter C., Paradkar, Anant R 07 March 2017 (has links)
Yes / Nanocrystalline hydroxyapatite (nanoHA) is the main hard component of bone and has potential to be used to promote osseointegration of implants and to treat bone defects. Here, using active pharmaceutical ingredients (APIs) like ibuprofen, we report on the prospects of combining nanoHA with biologically active compounds to improve the clinical performance of these treatments. In this study we designed and investigated the possibility of API attachment to the surface of nano-HA crystals via the formation of a hydrogen-bonded complex. The mechanistic studies of an ibuprofen/nanoHA complex formation have been performed using a holistic approach encompassing spectroscopic (FT-IR and Raman) and X-ray diffraction techniques as well as quantum chemistry calculations (DFT), while comparing the behaviour of the ibuprofen/nanoHA complex with that of a physical mixture of the two components. Whereas ibuprofen exists in dimeric form both in solid and liquid state, our study showed that the formation of the ibuprofen/nanoHA complex most likely occurs via the dissociation of the ibuprofen dimer into monomeric species promoted by ethanol, with subsequent attachment of a monomer to the HA surface. An adsorption mode for this process is proposed; this includes hydrogen bonding of the hydroxyl group of ibuprofen to the hydroxyl group of the apatite, together with the interaction of the ibuprofen carbonyl group to an HA calcium centre. Overall, this mechanistic study provides new insights into the molecular interactions between APIs and the surfaces of bioactive inorganic solids and sheds light on the relation between the non-covalent bonding and drug release properties. / Authors would like to acknowledge funding support from EPSRC (EP/L027011/1, EP/K029592/1). This research was performed in part at the MIDAS Facility, at the University of Sheffield, which was established with support from the Department of Energy and Climate Change.
63

Exploring Microstructural Changes in Structural Analogues of Ibuprofen-Hosted In Situ Gelling System and Its Influence on Pharmaceutical Performance

Patil, S.S., Venugopal, E., Bhat, S., Mahadik, K.R., Paradkar, Anant R 26 February 2015 (has links)
No / The present work explores inner structuration of in situ gelling system consisting of glyceryl monooleate (GMO) and oleic acid (OA). The system under study involves investigation of microstructural changes which are believed to govern the pharmaceutical performance of final formulation. The changes which are often termed mesophasic transformation were analysed by small angle X-ray scattering (SAXS), differential scanning calorimetry (DSC), rheology and plane polarised light (PPL) microscopy. The current work revealed transformation of blank system from W/O emulsion to reverse hexagonal structure upon addition of structural analogues of ibuprofen. Such transformations are believed to occur due to increased hydrophobic volume within system as probed by SAXS analysis. The findings of SAXS studies were well supported by DSC, rheology and PPL microscopy. The study established inverse relationship between log P value of structural analogues of ibuprofen and the degree of binding of water molecules to surfactant chains. Such relationship had pronounced effect on sol-gel transformation process. The prepared in situ gelling system showed sustained drug release which followed Higuchi model.
64

The effect of prophylactic use of oral ketorolac and ibuprofen in the control of endodontic post treatment pain a thesis submitted in partial fulfillment ... for the degree of Master of Science in Endodontics ... /

Olazabal-Bello, Angelita C. January 1993 (has links)
Thesis (M.S.)--University of Michigan, 1993.
65

Icke-steroida anti-inflammatoriska läkemedels inverkan på skelettmuskulaturen i samband med styrketräning / Effects of Non-Steroidal Anti-Inflammatory Drugs on Skeletal Muscle in Strength Training

Engdahl, Alexander January 2020 (has links)
Bakgrund: För att bibehålla ett liv med en hög livskvalité är det viktigt att ha en tillräcklig muskelstyrka för att klara av vardagen och minska skador. Styrketräning kan utveckla skelettmuskulaturen och anses vara ett populärt träningssätt. Användningen av icke-steroida antiinflammatoriska läkemedel (NSAID) har ökat inom idrotten. Forskningsläget var sparsamt bland den yngre befolkningen, men mer forskning fanns inom området på den äldre befolkningen. Dock saknades forskning kring påverkan av olika doser under en längre användningsperiod. Syfte: Litteraturöversiktens syfte var att granska användandet av preparaten (NSAID) och tydliggöra vilken effekt dessa hade på styrkeutveckling, skelettmuskeltillväxt och signaler i skelettmuskulaturen i samband med styrketräning. Metod: Den systematiska litteraturöversikten skapades med publikationer från databaserna Pubmed och SPORT Discus där 86 studier identifierades. För att kunna besvara frågeställningen resulterade det i nio studier totalt. De valda studiernas validitet bedömdes och samtliga var av god kvalité. Resultat: Äldre runt 65 år undersöktes i fem av nio studier då alla förutom en inte påvisade någon skillnad i skelettmuskulaturen medan en påvisade en signifikant positiv effekt i muskelmassa vid intag av icke-steroida antiinflammatoriska läkemedel i jämförelse med placebo. De resterande fyra studierna var gjorda på yngre individer runt 25 år och spretade åt olika håll. Där de visade på att ingen skillnad fanns i att det blev en minskad styrkeutveckling och skelettmuskeltillväxt och att det hämmar signaler men att individerna även orkar utföra ett större arbete med läkemedlen. Slutsats: För yngre individer visade preparaten ha en hämmande effekt på muskeltillväxten men för äldre individer verkade inte muskeltillväxten påverkas. / Background: To maintain a life with a high quality of life, it is important to have sufficient muscle strength to cope with everyday life and reduce injuries. Strength training can develop skeletal muscle and is considered a popular exercise method. The use of non-steroidal anti-inflammatory drugs (NSAIDs) has increased in sports. The research situation was sparse among the younger population, but more research was found in the field of the older population. However, there was no research on the effect of different doses over a longer period of use. Purpose: The purpose of the literature review was to examine the use of the preparations (NSAIDs) and to clarify their effect on strength development, skeletal muscle growth and signals in the skeletal muscle in connection with strength training. Method: The systematic literature review was created with publications from the Pubmed and SPORT Discus databases, where 86 studies were identified. In order to answer the question, it resulted in nine studies in total. The validity of the selected studies was assessed, and all were of good quality. Results: Elderly people around the age of 65 were examined in five of nine studies, all except one showing no difference in skeletal muscle, while one showed a significant positive effect in muscle mass when taking non-steroidal anti-inflammatory drugs compared to placebo. The remaining four studies were done on younger individuals around 25 years of age and spread in different directions. Where they showed that there was no difference in the fact that there was a decrease in strength development and skeletal muscle growth and that it inhibited signals but that the individuals also can do a greater work on the drugs. Conclusion: For younger individuals, the preparations were shown to have an inhibitory effect on muscle growth, but for older individuals, muscle growth did not appear to be affected.
66

The relative effectiveness of cervical spine manipulation and a nonsteroidal anti-inflammatory drug (Ibuprofen) in the treatment of episodic tension-type headaches

Legoete, Kgosietsile January 2010 (has links)
Dissertation submitted in partial compliance with the requirements for the Masters Degree in Technology: Chiropractic, Durban University of Technology, 2010. / The 1 year overall prevalence of Episodic Tension-Type Headache (ETTH) is 38.3%; with lifetime prevalence at 46% for TTH. Little literature exists to support the effectiveness of spinal manipulation in the treatment of ETTH. Therefore aim of this study was to determine the relative effectiveness of cervical spine manipulation and a Nonsteroidal Anti-inflammatory drug (NSAID) (Ibuprofen®) in the treatment of ETTH. Method: This study was a prospective randomised clinical trial with two intervention groups (N=32, n1=16 and n2=16). The allocation of participants to the two groups was completed by means of simple randomization. Group one were treated using cervical spine manipulation. Group two were treated using Ibuprofen. Subjective measurements included the Numerical Rating Scale 101 Questionnaire (NRS-101), Short Form McGill Pain Questionnaire (SF-MPQ), CMCC Neck Disability Index (CMCC) and Headache Diary. A p value <0.05 was considered as statistically significant. Results: The subjective measurements of the NRS-101, SF-MPQ and CMCC showed a significant time effect in both treatment groups. Several of the subjective Headaches Diary outcomes followed this trend with significant time effect in both groups. There was a significant treatment effect for the NRS-101. Several subject outcomes from the Headache Diary showed a significant treatment effect in favour of manipulation, namely frequency and duration of headaches. Conclusion: The findings in this study have shown that cervical spine manipulation is more effective than Ibuprofen® for the treatment of ETTH in terms of several subjective outcomes namely: pain intensity (NRS-101), and the frequency and the duration of headache per day.
67

Role of amyloid beta protein modulation in Alzheimer's disease / Rolle der Beta-Amyloid Protein Modulierung in der Alzheimer-Krankheit

Hillmann, Antje 04 July 2012 (has links)
No description available.
68

Which COX-inhibitor to which patient; an analysis of contemporary evidence including pharmacology and medicinal chemistry / Vilken COX-hämmare till vilken patient; en analys av kontemporär evidens inklusive farmakologi och läkemedelskemi

Persson, Jakob January 2018 (has links)
NSAIDs are among the most used drugs in the world. It is estimated that 30 million people take NSAIDs daily world-wide, without including drugs sold over the counter. They are effective in alleviating pain and inflammation. Even though they are very common there does not appear to be any clear-cut guidelines to when which NSAID should be used. It has therefore been the purpose of this thesis to analyze if there is a need to differentiate between different NSAIDs according to contemporary evidence. Since the withdrawal of rofecoxib in 2004 there has been a general idea that coxibs as a group are cardiotoxic, recent evidence suggests that this holds true for all NSAIDs however. As such this work included 5 drugs, three common over the counter non-selective NSAIDs; naproxen, ibuprofen and diclofenac as well as the two coxibs currently on the Swedish market; celecoxib and etoricoxib. Pubmed and google scholar were searched for relevant studies on the subject. The results showed that there is a need to differentiate between NSAIDs, however the clinical setting is complex and a one-size fits all solution is difficult to come by. Naproxen and moderate doses of celecoxib (100 mg b.i.d.) show the best cardiovascular profiles whilst etoricoxib, celecoxib and diclofenac show the best gastrointestinal profiles. Coxibs show similar upper GI-profiles as tNSAIDs if combined with PPI however PPI are not without adverse events and the lower GI is not affected by PPI. Longer half-life is in general the better option in situations with lasting pain since it has been shown that lower dosing intervals increase adherence. In terms of pain management there does not appear to be any differences in efficacy amongst different NSAIDs
69

HISTOLOGICAL AND BEHAVIORAL CONSEQUENCES OF REPEATED MILD TRAUMATIC BRAIN INJURY IN MICE

Bolton Hall, Amanda Nicholle 01 January 2016 (has links)
The majority of the estimated three million traumatic brain injuries that occur each year are classified as “mild” and do not require surgical intervention. However, debilitating symptoms such as difficulties focusing on tasks, anxiety, depression, and visual deficits can persist chronically after a mild traumatic brain injury (TBI) even if an individual appears “fine”. These symptoms have been observed to worsen or be prolonged when an individual has suffered multiple mild TBIs. To test the hypothesis that increasing the amount of time between head injuries can reduce the histopathological and behavioral consequences of repeated mild TBI, a mouse model of closed head injury (CHI) was developed. A pneumatically controlled device with a silicone tip was used to deliver a diffuse, midline impact directly onto the mouse skull. A 2.0mm intended depth of injury caused a brief period of apnea and increased righting reflex response with minimal astrogliosis and axonal injury bilaterally in the entorhinal cortex, optic tract, and cerebellum. When five CHIs were repeated at 24h inter-injury intervals, astrogliosis was exacerbated acutely in the hippocampus and entorhinal cortex compared to a single mild TBI. Additionally, in the entorhinal cortex, hemorrhagic lesions developed along with increased neurodegeneration and microgliosis. Axonal injury was observed bilaterally in the white matter tracts of the cerebellum and brainstem. When the inter-injury interval was extended to 48h, the extent of inflammation and cell death was similar to that caused by a single CHI suggesting that, in our mouse model, extending the inter-injury interval from 24h to 48h reduced the acute effects of repeated head injuries. The behavioral consequences of repeated CHI at 24h or 48h inter-injury intervals were evaluated in a ten week longitudinal study followed by histological analyses. Five CHI repeated at 24h inter-injury intervals produced motor and cognitive deficits that persisted throughout the ten week study period. Based upon histological analyses, the acute inflammation, axonal injury, and cell death observed acutely in the entorhinal cortex had resolved by ten weeks after injury. However, axonal degeneration and gliosis were present in the optic tract, optic nerve, and corticospinal tract. Extending the inter-injury interval to 48h did not significantly reduce motor and cognitive deficits, nor did it protect against chronic microgliosis and neurodegeneration in the visual pathway. Together these data suggested that some white matter areas may be more susceptible to our model of repeated mild TBI causing persistent neuropathology and behavioral deficits which were not substantially reduced with a 48h inter-injury interval. In many forms of TBI, microgliosis persists chronically and is believed to contribute to the cascade of neurodegeneration. To test the hypothesis that post-traumatic microgliosis contributes to mild TBI-related neuropathology, mice deficient in the growth factor progranulin (Grn-/-) received repeated CHI and were compared to wildtype, C57BL/6 mice. Penetrating head injury was previously reported to amplify the acute microglial response in Grn-/- mice. In our studies, repeated CHI induced an increased microglial response in Grn-/- mice compared to C57BL/6 mice at 48h, 7d, and 7mo after injury. However, no differences were observed between Grn-/- and WT mice with respect to their behavioral responses or amount of axonal injury or ongoing neurodegeneration at 7 months despite the robust differences in microgliosis. Dietary administration of ibuprofen initiated after the first injury reduced microglial activation within the optic tract of WT mice 7d after repeated mild TBI. However, a two week ibuprofen treatment regimen failed to affect the extent of behavioral dysfunction over 7mo or decrease chronic neurodegeneration, axon loss, or microgliosis in brain-injured Grn-.- mice when compared to standard diet. Together these studies underscore that mild TBIs, when repeated, can result in long lasting behavioral deficits accompanied by neurodegeneration within vulnerable brain regions. Our studies on the time interval between repeated head injuries suggest that a 48h inter-injury interval is within the window of mouse brain vulnerability to chronic motor and cognitive dysfunction and white matter injury. Data from our microglia modulation studies suggest that a chronically heightened microglial response following repeated mild TBI in progranulin deficient mice does not worsen chronic behavioral dysfunction or neurodegeneration. In addition, a two week ibuprofen treatment is not effective in reducing the microglial response, chronic behavioral dysfunction, or chronic neurodegeneration in progranulin deficient mice. Our data suggests that microglia are not a favorable target for the treatment of TBI.
70

Pharmaceutical co-crystals : combining thermal microscopy and phase space considerations to facilitate the growth of novel phases

Berry, David J. January 2009 (has links)
The crystalline solid state is invaluable to both the pharmaceutical and fine chemical sectors. The advantages primarily relate to reducibility criteria required during processing of stable solid state materials and delivering purification, which is inherently performed by the crystal growth process. A major challenge is achieving control through crystallising solids with the desired physico-chemical properties. If this can be achieved the crystalline solid is of great financial and practical benefit. One emerging methodology for manipulating the solid crystalline form is the application of co-crystals. This work relates to key steps in the understanding of rational design of co-crystals utilizing crystal engineering concepts to determine systems before then applying screening criteria to the selected sub-set. Co-crystal screening is routinely undertaken using high-throughput solution growth. We report a low- to medium-throughput approach, encompassing both a melt and solution crystallization step as a route to the identification of co-crystals. Prior to solution studies, a melt growth step was included utilizing the Kofler mixed fusion method. This method allowed elucidation of the thermodynamic landscape within the binary phase diagram and was found to increase overall screening efficiency. This led to the discovery of a number of co-crystal systems with the co-former nicotinamide, with the single crystal structures determined for the following systems; R/S ibuprofen: nicotinamide, S ibuprofen: nicotinamide, R/S flurbiprofen: nicotinamide and salicylic acid: nicotinamide. To assess the crystallization and phase behaviours of determined co-crystals the R/S ibuprofennicotinamide system was selected and successful studies were undertaken determining the aqueous ternary phase behavior and the pre-nucleation speciation in methanol. There have, as yet, been a limited number of published examples which are concerned with pharmaceutical property enhancement by co-crystals, as vast proportion of the literature concerns the growth and isolation of these novel phases. To elucidate further the pharmaceutical relevance of co-crystals the properties of the R/S ibuprofen- nicotinamide system were then assessed showing a positive profile for this material.

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