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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.

Biodegradation of bisphenol a and ibuprofen by ammonia oxidizing bacteria

Subramanya, Nethra T. 17 September 2007 (has links)
Bisphenol A (BPA) is a compound that is commonly used in the manufacture of epoxy resins and plastics. Because of large scale production and widespread usages, BPA is released into the atmosphere through air, land, and water. BPA is weakly estrogenic in animals and has acute aquatic toxicity even at low concentrations of 1- 10μg/L. Ibuprofen is a widely used analgesic and antipyretic. Ibuprofen and its metabolites are mainly released into the environment by human urinary excretion. Ibuprofen has been detected at low concentrations in surface and waste waters. The environmental and health effects at such concentrations are unclear. The high removal of BPA and ibuprofen in the wastewater treatment plants (WWTPs), suggest that biodegradation might be responsible for the removal of these compounds. Several bacterial strains, isolated from waste water, are known to degrade BPA and ibuprofen. No studies, however, have reported using ammonia oxidizing bacteria for this purpose. Ammonia oxidizing bacteria (AOB) are an important group of microorganisms in nitrifying activated sludge of WWTPs. AOB are known to express ammonia monooxygenase (AMO) to degrade many different aromatic and aliphatic organics via cometobolic degradation (non beneficial mechanism). Nitrosomonas europaea is a widely studied AOB found to degrade synthetic estrogen by a study. This study aims to characterize the biodegradation of BPA and ibuprofen by AOB. The biodegradation ability of N.europaea with respect to BPA and ibuprofen was examined. Experiments were conducted in the presence/absence of the AMO inhibitor (allylthiourea), an external reducing energy source (sodium formate) and different primary substrate (ammonia) concentrations. The second part of the study comprises of biodegradation tests on BPA and ibuprofen using activated sludge from two WWTPs, one with one-sludge activated sludge system and the other one with two-sludge nitrification system. From the experiments conducted BPA at a concentration of 1.6 mg/L was degraded to 0.12 mg/L by N.europaea. BPA at concentrations of 1.0 mg/L and 0.75 mg/L was completely degraded by the cells. Resting cells of N.europaea were, however, unable to degrade BPA. Also ibuprofen of two concentrations, 0.42 mg/L and 0.8 mg/L, were not degraded by the culture. BPA at a concentration of 1 mg/L was degraded to 0.2 mg/L and ibuprofen at 0.5 mg/L was completely degraded by the activated sludge from the combined reactor. The activated sludge from the nitrification tank degraded BPA of concentration 1 mg/L and ibuprofen of concentration 0.5 mg/L completely. Hence, it can be summarized that Bisphenol A was degraded by N.europaea and also by the activated sludge obtained from the WWTPs. Ibuprofen was found incapable of inhibiting ammonia oxidizing bacteria in the case of the pure culture while it was successfully degraded by the mixed culture.

Formulation of a fast-acting ibuprofen suspension by using nicotinamide as hydrotropic agent-application of DSC, spectroscopy and microscopy in assessment of the type of interaction /

Oberoi, Lalit Mohan. January 2004 (has links)
Thesis (M.S.P.)--University of Toledo, 2004. / Typescript. "A thesis [submitted] as partial fulfillment of the requirements of the Master of Science degree in Pharmaceutical Sciences." Bibliography: leaves 94-112.

Statistically designed spheronization and scale-up of ibuprofen microparticulates using the rotor disk fluid-bed technology coating for prolonged release and hard gelatin encapuslation of microparticulates /

Chukwumezie, Beatrice Nkem. January 2003 (has links)
Thesis (Ph. D.)--Duquesne University, 2003. / Title from document title page. Abstract included in electronic submission form. Includes bibliographical references (p. 260-290) and index.

Novel systems for transdermal drug delivery

Campbell, K. C. January 2001 (has links)
No description available.

In vitro passage of ibuprofen through synthetic and biological membranes

Purdon, Carryn Hamilton January 2001 (has links)
Ibuprofen is a non-steroidal anti-inflammatory drug with three major types of effect: anti-inflammatory, analgesic and antipyretic. Ibuprofen may be administered in a number of different forms via the oral as well as the topical route. Published evidence suggests that topical, unlike oral, non-steroidal anti-inflammatory drugs are associated with few systemic side effects as plasma concentrations are low compared to oral therapy. In some countries it is particularly difficult to obtain human skin for in vitro experimentation and it is therefore important to have alternate biological or synthetic membranes which mimic human skin for diffusion experiments. Synthetic membranes serve as predictive models for topical drug release and in South Africa, shed snake skin is easily obtainable from the many snake parks present in the country. The FDA guidelines were considered when choosing the apparatus to be used in the comparative diffusion study on proprietary ibuprofen-containing topical preparations from three countries and the verification of the usefulness, or otherwise, of shed snake skin as a biological membrane for the assessment of the permeation of ibuprofen. Two diffusion techniques were considered appropriate for the measurement of the amount of ibuprofen released from a topical formulation during in vitro testing. One was the Franz diffusion cell, as modified by Keshary and Chien (88,169) and the other was the European Pharmacopoeia diffusion cell (187). High performance liquid chromatography was used as the analytical technique for the analysis of ibuprofen in aqueous solution using ultraviolet detection at 222 nm. The validated method was applied to the determination of the diffusion of ibuprofen from topical ibuprofen-containing formulations (gels, creams and mousse) through synthetic silicone membrane and shed snake skin biological membrane from four different species. In a study of fifteen topical ibuprofen-containing formulations (gels, creams and mousse) from three countries (South Africa, United Kingdom and France) it was found that there was a trend of products from two countries consistently exhibiting superior diffusion characteristics as well as products from the same two countries consistently exhibiting the lowest diffusion of ibuprofen. Interpretation of the results of these studies demonstrated the importance of employing a combination of statistical analyses and peak integration values when drawing conclusions regarding comparative diffusion characteristics. Shed snake skin has been described as a 'model' membrane, i.e. a membrane which shows similar permeability to human stratum corneum. The results reported here show clearly that, for ibuprofen, the four species of snake produce shed skin with completely different diffusion characteristics when all other conditions are identical. It may well be that there is one particular species of snake which produces shed skin of identical permeability to human stratum corneum, but to describe shed snake skin in general as a model membrane seems incorrect. It is therefore important that if shed snake skin is used as a membrane, the species, skin site and orientation should be reported. The European Pharmacopoeia diffusion apparatus was judged to be the better of the two diffusion techniques assessed for the measurement of the amount of ibuprofen released from a topical formulation during in vitro testing using silicone membranes and for the measurement of the amount of ibuprofen diffusing across the ventral outside orientation of shed skin during in vitro testing, whereas the Franz diffusion apparatus was judged to be better for the measurement of the amount of ibuprofen diffusing across the dorsal outside orientation of shed skin during in vitro testing. However, the choice of this diffusion apparatus must be weighed against the relatively poor reproducibility as compared with the European Pharmacopoeia diffusion apparatus.

Ibuprofen, paracetamol and tilidine; their role in post tonsillectomy pain at Dr George Mukhari Hospital

Makhafula, Lebone D. January 2011 (has links)
Thesis (M Med(Otorhinolaryngology)) -- University of Limpopo, 2011. / Background: Tonsillectomy is one of the commonest operations performed by ENT surgeons. Pain, haemorrhage, delayed feeding and resumption of normal activities are common morbidities. Different groups of analgesics are used to reduce these morbidities. Objective: We examined the effectiveness of the use of three analgesics, some in combinations in reducing these morbidities. The primary outcome measures were pain, resumption of normal diet, resumption of normal physical activities and secondary haemorrhage. The secondary outcome was comparison of pain profile of children and adults. Methods: A prospective randomized double blind controlled study. Subjects were recruited and randomized into three study groups; group A (Paracetamol & Ibuprofen), group B (Ibuprofen) and group C (Paracetamol, Ibuprofen & Tilidine). A diathermy dissection technique was used on all patients in removing tonsils. Pain was measured using a patient morbidity scoring form (PMS) as well as the Smiley scale. The care givers for children and adult patients recorded all other events. Results: Sixty five patients were recruited, 30 were in group A, 20 in group B and 15 in group C. There were 36 females and 29 males. The youngest patient was 4 years of age and the oldest was 38 years. The mean number of days prior to resuming normal daily activities for groups A, B and C was 9.27, 10.60 and 7.67 respectively. Group C patients started their daily activities earlier than those in group B (p≤0.05). The average number of days to stop analgesic use was 12.3, 13.3 and 10.6 for groups A, B and C respectively. Patients in group C stopped using analgesics earlier than group B patients (p≤0.05). There was no statistically significant difference in PMS scores, resumption of normal diet, post-tonsillectomy haemorrhage as well as pain profiles of adults and children. Conclusion: Paracetamol-ibuprofen-tilidine combination appears to be more effective than either paracetamol-ibuprofen combination or ibuprofen in the first two weeks in the treatment of post tonsillectomy pain (p>0.05), however, further studies will have to be carried out to confirm this. Patients treated with a paracetamol-ibuprofen-tilidine combination appear to stop medication and return to their normal daily activities much earlier (p ≤ 0.05). Minor haemorrhage from the use of ibuprofen following tonsillectomy was not a cause for concern.

An evaluation of directly compressible tablet bases on the performance of ibuprofen tablets

Vawda, Naseem 02 February 2001 (has links)
A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand , in partial fulfilment of the requirements for the degree of Master of Science in Medicine (Pharmaceutical affairs) / Ibuprofen is a phenylpropionic acid derivative, which has analgesic, antiinflammatory and antipyretic actions. It is used in the management of mild to moderate pain, inflammatory conditions, peri-articular disorders, musculoskeletal disorders and joint disorders. Tablets, like ibuprofen, can be manufactured by three different processes viz. wet granulation, dry granulation and direct compression. With direct compression, the directly compressible base, along with the active ingredient (ibuprofen) and other suitable excipients, can be compressed directly. / IT2018

A novel tablet design for zero-order sustained-release

Sundy, Erica 28 January 2002 (has links)
Dissertation submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in Medicine in the branch of Pharmacy / A coated doughnut-shaped tablet is evaluated as its ability to release model drugs at a zero-order rate for 8 to 12 hours. The doughnut-shape tablets were compressed using special designed punches.Automated technology is thus feasible for this system. The coating material , 10% w /w gelatin in HPMC K15M was directly compressed and adhered to the tablet core . / IT2018

Influence of crystallisation conditions on the morphology of ibuprofen crystals.

Shariare, Mohammad H., Blagden, Nicholas, de Matas, Marcel, York, Peter January 2010 (has links)
no / Crystallisation is a widely used technique for purification and manipulation of the final crystal form of therapeutic agents. In particular, potential exists to control the mechanical properties of ibuprofen through control of crystal habit. The aim of this study was therefore to understand the influence of crystallisation conditions on the morphology of ibuprofen to enable production of crystals with different habits.

Molekulare Mechanismen der antikarzinogenen Wirkung von Ibuprofen-Enantiomeren

Janssen, Astrid. Unknown Date (has links) (PDF)
Frankfurt (Main), Universiẗat, Diss., 2007.

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