A presença de sais no petróleo ocasiona grandes problemas operacionais relacionados à corrosão, uma vez que estes acabam formando ácido clorídrico no processo de separação do óleo bruto. Com o intuito de amenizar os efeitos de corrosão ácida, aminas podem ser adicionadas no topo das colunas para agir como neutralizantes. Porém, dependendo das condições operacionais e da quantidade de amina adicionada, pode ocorrer a deposição de cloridratos de aminas, promovendo a corrosão sob depósito. Assim, o conhecimento da pressão de sublimação desses sólidos é de extrema importância para especificar as condições de operação e o melhor desempenho destes aditivos no processo. Dentro desse contexto, o objetivo deste trabalho é determinar as pressões e entalpias de sublimação de cloridratos de aminas com a técnica termogravimétrica. Devido às dificuldades encontradas para obtenção de dados precisos de pressão em baixas temperaturas, uma extensão ao método termogravimétrico foi proposta, tornando possível medir pressões na ordem de 1 0,5 Pa. As substâncias estudadas foram: brometo de amônio, cloreto de amônio, cloridrato de etanolamina, cloridrato de metilamina, cloridrato de piridina, cloridrato de trimetilamina e dicloridrato de n-(1- naftil)etilenodiamina. Resultados de pressão e entalpia de sublimação alcançados com ácido benzoico, brometo de amônio e cloreto de amônio foram validados com dados da literatura Para os demais sólidos estudados, não há muitos dados disponíveis na literatura. No entanto, como a reação de sublimação do cloreto de amônio é análoga à dos demais cloridratos de amina, as entalpias de sublimação puderam ser comparadas e os resultados encontrados foram satisfatórios. Por fim, para uma melhor aplicabilidade dos resultados obtidos, uma equação de Clausius-Clapeyron modificada foi utilizada para correlacionar os dados medidos. Uma ótima correlação foi possível para todos os sais estudados, com coeficiente de correlação sempre superior a 0,97. / The presence of salts in petroleum causes operational problems related to corrosion, due to the fact that they end up forming hydrochloric acid in the crude oil separation process. In order to mitigate the effects of acid corrosion, amines can be added at the top of the columns to act as neutralizers. However, depending on the operational conditions and the amount of amine added, a deposition of amine hydrochlorides may occur, promoting under-deposit corrosion. Thus, the knowledge of the sublimation pressure of these salts has an extreme importance in trying to predict and to optimize the performance of the additives in the process. Within this context, the purpose of this study is to determine pressure and enthalpy of sublimation of amine hydrochlorides with the thermogravimetric technique. Due to the difficulties encountered to obtain precise pressure data at low temperatures, an extension of the thermogravimetric method was proposed, enabling to measure sublimation pressures in the order of 1 0,5 Pa. The substances studied were: ammonium bromide, ammonium chloride, ethanolamine hydrochloride, methylamine hydrochloride, pyridine hydrochloride, trimethylamine hydrochloride and n-(1-naphthyl)ethylenediamine dihydrochloride. Results of pressure and enthalpy of sublimation obtained with benzoic acid, ammonium bromide and ammonium chloride were validated using literature data. For other solids investigated in this study, experimental data is scarce in the literature. However, as the sublimation reaction of ammonium chloride is analogous to the others amine hydrochlorides, enthalpies of sublimation could be compared with the results found. Since similar values were observed, the results were considered satisfactory. Finally, the measured data were correlated using a modified Clausius-Clapeyron equation. A good correlation was possible for all salts studied, with correlation coefficient always higher than 0.97.

Methadone treatment continues to be the most widely used treatment modality for heroin addiction despite continued controversy. The efficacy of methadone treatment has been determined primarily by statistical research of program outcomes. This study explored heroin addicts' perceptions of methadone treatment.

Tho present thesis represents a summary or research done by the author (and others) that was conducted with heroin addicts and drug abusers undergoing behavioral and pharmacological therapy at Stockton State Hospital, Stockton, California. From June 1970 to December 1970 the Research Department of Stockton State Hospital, in conjunction with the Drug Abuse Program at Stockton State Hospital, conducted research investigating a number of difference facets relating to inpatient programs for heroin addicts undergoing methadone maintenance and drug abusers. These facets included the investigation and evaluation of (a) motivational factors; affecting the voluntary participation of inpatient heroin addicts and drug abusers in behavioral and pharmacological therapy, (b) the effectiveness of the synthetic narcotic methadone hydrocloride as a primary reinforcing technique for appropriate behavior, (c) the effectiveness of various therapeutic approaches used in conjunction with behavioral modification techniques, and (d) the effect of methadone on perceptual and motor functioning in the heroin addict under-going methadone maintenance. The present thesis is a compilation cf these research projects.

In this study, 14 typical South African feedlot bulls received no beta-adrenergic agonist for the last 30 days of the finishing period (C), 14 received 120 mg R-salbutamol per animal per day for the last 30 days of the finishing period (S30), 13 received 120 mg Rsalbutamol per animal per day for the last 40 days of the finishing period (S40) and the last group of 13 bulls received 60 mg zilpaterol hydrochloride per animal per day for the last 30 days of the finishing period (Zh). All animals were slaughtered after a 3-day withdrawal period. Parameters included weight gain, feed intake, feed conversion rate, warm and cold carcass mass, dressing %, subcutaneous fat thickness, hide yield %, internal carcass fat distribution, % bone, % fat and % muscle of the prime rib-cut, carcass classification code, conformation, compactness, post-mortem carcass pH profiles, cooking loss, shear force, blood urea nitrogen, creatinine and residue levels of the beta-adrenergic agonists. No differences were observed between any of the four treatment groups concerning live feedlot performance. Bulls receiving the S30 and Zh treatments had lower internal carcass fat distribution compared to C bulls (P <0.05). Bulls receiving the S40 treatment had a lower % fat in the prime rib-cut compared to Zh bulls (P <0.05). Carcasses from S30 bulls had higher pH values 24 hours post mortem compared to carcasses from Zh bulls (P <0.01). Meat samples from Zh bulls had higher shear force, which indicates less tender meat, compared to samples from S40 bulls (P <0.05). Change in serum creatinine levels increased only in Zh treated bulls from the start to the end of treatment and may reflect a higher protein turnover in Zh bulls. The results of this study indicate that R-salbutamol has a more pronounced effect on fat metabolism in feedlot bulls compared to zilpaterol hydrochloride, while zilpaterol hydrochloride has a more pronounced effect on protein metabolism. The residue levels in samples of the liver, kidney, muscle and feaces from zilpaterol hydrochloride and R-salbutamol treated bulls were well below acceptable limits. / Dissertation MSc(Agric)--University of Pretoria, 2014 / gm2015 / Animal and Wildlife Sciences / MSc(Agric) / Unrestricted

Thesis (M. Pharm. (Pharmaceutics)) -- University of Limpopo, 2019 / Various approaches have been developed to retain dosage forms in the gastrointestinal tract. One of the commonly used approaches is the use of microspheres. Due to their intrinsic low density and small size, they are distributed throughout the gastrointestinal tract which improves drug absorption thus improving bioavailability. Ranitidine hydrochloride, an antiulcer drug is poorly absorbed from the lower gastrointestinal tract and has a short half-life of 2.5-3 hours. The aim of this study was to formulate and evaluate gastroretentive microspheres of ranitidine hydrochloride in order to extend gastric retention in the upper gastrointestinal tract, which may result in enhanced absorption and thus improved bioavailability. Pre-formulation studies were conducted to develop and validate the analytical method to identify and quantify ranitidine hydrochloride; to select the suitable polymers for further formulation development and; to determine the compatibility of the chosen polymers with ranitidine hydrochloride. The analytical method was validated and found to be sensitive, linear, precise and accurate. Preliminary formulations lead to the selection of ethyl cellulose and PEG 4000 as polymers and solvent evaporation as the method of manufacture. Compatibility studies were determined by DSC/TGA, FTIR and short-term accelerated studies and no incompatibilities were observed. Two prototype formulations of the preliminary formulations F24 and F26 were manufactured comprised of varying drug: polymer concentration. The microspheres were evaluated for morphology, particle size, flow properties, percentage yield, buoyancy and in vitro drug release. Both formulations resulted in spherical microspheres with good flow properties, high yield and buoyancy studies revealed that the microspheres would float immediately upon contact with the dissolution media and floating would continue for more than 8 hours. In vitro drug release studies revealed that polymer concentration greatly affected drug release. Dissolution kinetic studies revealed that formulation F24 and v F26 were best described by the Korsmeyer-Peppas and Higuchi kinetic models respectively. Formulation F26 was considered the best formulation, which comprised of a drug: PEG 4000 ratio of 1:2 w/w, as it yielded better in better drug encapsulation, better buoyancy results and had complete drug release.

No description available.

No description available.

Schizophrenia is a debilitating neuropsychiatric disorder that affects approximately one percent of the global population. Aberrant N-methyl-D-aspartate receptors and endoplasmic reticulum stress have been implicated in the pathogenesis of schizophrenia. Despite a century of extensive research, outcomes from best-practice treatments remain dismal. Lurasidone hydrochloride is a novel atypical antipsychotic drug with a unique receptor binding profile that can potentially treat the heterogeneous symptomology of schizophrenia. However, discrepancies in experimental design (i.e. animal models used, symptoms assessed etc.) have yielded conflicting results surrounding the procognitive and antidepressant properties of lurasidone. Furthermore, the limited aqueous solubility of lurasidone poses a considerable challenge for improving antipsychotic drug delivery to the brain and limiting the prevalence of adverse side effects. These obstacles coupled with the elusive pathophysiology of schizophrenia and its incurable nature, highlight the importance of investigating novel therapeutic targets and their underlying mechanisms to improve treatment and enhance the quality of life of patients with schizophrenia. This thesis sought to accomplish three primary objectives: (1) validate the behavioural efficacy of lurasidone hydrochloride; (2) investigate the role of mesencephalic astrocyte-derived neurotrophic factor as a potential therapeutic target of lurasidone; and (3) evaluate the therapeutic potential of intranasal lurasidone administration as a novel method for antipsychotic drug delivery. The data presented within this thesis suggest that repeated lurasidone treatment may be effective at treating the positive, negative, and cognitive symptoms of schizophrenia, but not sensorimotor gating deficits. Furthermore, sub-chronic lurasidone treatment in rats significantly increased the relative expression of mesencephalic astrocyte-derived neurotrophic factor in the rat prefrontal cortex, a primary site of impairment observed in schizophrenia. Lastly, we conclude that lurasidone administered via the nasal route using a novel poly(oligo ethylene glycol methacrylate)-based nanogel formulation required four times less drug to achieve a therapeutic response comparable to traditional intraperitoneal routes. The findings presented within this thesis suggest that lurasidone might be a favourable atypical antipsychotic drug that exerts its therapeutic effects through the modulation of neurotrophic factor expression in the brain regions affected by schizophrenia. This thesis offers new insight that can help guide future studies toward improving the prognosis of patients suffering from schizophrenia. / Thesis / Master of Science (MSc)

Naked mole-rats are eusocial rodents that live in subterranean colonies with a strict reproductive and social hierarchy. Breeders are socially dominant and other colony members are non-reproductive subordinates. The effects of manipulating the serotonergic system on aggression are well studied in many species, but not in eusocial rodents like the naked mole-rat. For the current study, the effects of fluoxetine hydrochloride (FLX) on status-specific behaviours of subordinates (Experiment 1) and queens (Experiment 2) were evaluated both in-colony and in a social-pairing paradigm to investigate how the serotonergic system influences aggression in this species. In accordance with our main hypothesis, chronic treatment of FLX attenuated the frequency and duration of aggression in queens, but not subordinates, when paired with an unfamiliar conspecific. Further exploration of pharmacological manipulation on status-specific behaviours of this eusocial species may elucidate the neurobiological mechanisms underlying their unique and rigid social hierarchy.

Master of Science / Department of Animal Sciences and Industry / Michael E. Dikeman / The longissimus lumborum (LL) muscle from 117 steers and the LL, gluteus medius (GM), and triceps brachii (TB) from 132 heifers were obtained to evaluate the effects of feeding zilpaterol hydrochloride (Zilmax®; ZH) (7.56g/907kg on a 100% DM basis) on tenderness. Both genders were blocked by initial weight into 6 blocks of 4 pens. Pens were assigned to treatments of either 0, 20, 30 or 40 d on ZH, with a 3 d withdrawal. One steak was removed from each muscle for proximate analysis and three 2.54 cm thick steaks were vacuum aged for either 7, 14 or 21 d. Steaks were cooked to 70 ˚C and six 1.27 cm diameter cores were removed for Warner-Bratzler shear force (WBSF) determinations. All muscles from steers and heifers fed 30 and 40 d with ZH, had higher (P < 0.05) WBSF compared with controls. The WBSF of steer LL and heifer TB from the 20 d treatment was higher (P < 0.05) than controls. There were no treatment by aging interactions (P > 0.05) for WBSF of steaks from steer LL, heifer LL or heifer TB, but there was a treatment by aging interaction (P < 0.05) for WBSF of steaks from heifer GM. There were no differences (P > 0.05) in percent intramuscular fat for any muscle due to treatment. When using percent intramuscular fat as a covariate, differences in WBSF of steer LL and heifer TB were not altered, but there were slight differences in heifer LL and GM WBSF due to treatment when compared with not using percent fat as a covariate. Percentages of steaks with WBSF ≥ 5 kg increased as days on ZH increased and decreased as days of aging increased. Warner-Bratzler shear force values among the three aging times for steer LL control, 20 and 40 d treatments; all heifer LL treatments, and heifer TB 20 d were all positively correlated (P < 0.01) with each other. Feeding ZH for 20 d generally increased WBSF values, but means were still acceptable. Feeding ZH for 40 d was very detrimental to tenderness.