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Kinetics of the reactions of amoxycillin sodium and potassium clavulanate alone and in combination were investigated in the liquid and frozen states at selected pH values of 2.0, 4.6 and 7.0. A stability indicating HPLC assay was developed to perform simultaneous quantification of these compounds validated under stressed conditions.Amoxycillin and clavulanate degradation obeyed first-order kinetics under all conditions of this study. The effect of temperature, buffer, concentrations and complexation were investigated. Both compounds showed acceleration in rates due to general acid catalysis from buffer species. The buffer catalysis rate constants due to total phosphate and total acetate at 55 degrees celsius were 5.84x10(subscript)-1 (mol dm(subscript)-3)(subscript)-1 h(subscript)-1 and 1.53 X10(subscript)-1 (mol dm(subscript)-3)(subscript)-1 h(subscript)-1 for amoxycillin, 2.33 (mol dm(subscript)-3)(subscript)-1 h(subscript)-1 and 4.4x10(subscript)-1 mol dm(subscript)-3)(subscript)-1 h(subscript)-1 for clavulanate respectively. The buffer independent rate constant values were obtained and interpreted according to the available literature data. Increase in the initial concentration of amoxycillin or clavulanate did not change the first-order rate constant values of these antibiotics significantly at liquid state temperatures. However in the buffer systems, the rate of hydrolysis of amoxycillin in the combination was significantly subject to clavulanate catalysis. This novel finding was influenced by phosphate buffer concentration. A kinetic model was proposed and the second-order catalytic rate constant values at pH 7.0 and 55 degrees celsius were estimated for clavulanate catalysis of amoxycillin (k(subscript)cvc) to be k(subscript)cvc = 1.75 X10(subscript)2 (mol dm(subscript)-3)(subscript)-1 h(subscript)-1 and for phosphate catalyzed of clavulanate catalysis of ++ / amoxycillin (k(subscript)phccv) as k(subscript)phccv = 2.87 (mol dm(subscript)-3)(subscript)-1 h(subscript)-1.The temperature dependence of the rate of amoxycillin sodium degradation over the pH range evaluated did not change significantly. However the E(subscript)a values of potassium clavulanate decreased slightly with increase in pH. Both the compounds showed similar E(subscript)a values at pH 4.6 in acetate system. Hence 71.2 kJ mol(subscript)-1 for amoxycillin and 75.1 kJ mol(subscript)-1 for clavulanate.The investigation on complexation effects by HPbetaCD on the rate of hydrolysis of amoxycillin and clavulanate indicated no significant change in the rate of reaction of amoxycillin in the acetate buffer system. But the rate of clavulanate hydrolysis in combination was decreased by approximately 10%. The rate constant within the cyclodextrin complex and the stability constant of the complex obtained for clavulanate at pH 4.6 and 55 degrees celsius were k(subscript)c = 1.54x 10(subscript)-1 h(subscript)-1 and K(subscript)c = 74.2 (mol dm(subscript)-3)(subscript)-1.Extrapolation of the rate constant values to the frozen state from the liquid state data indicated marked acceleration of the rate of amoxycillin and clavulanate in all the pH values investigated. The highest acceleration in rate recorded was 15.0 fold for clavulanate in the hydrochloric acid system and the lowest value was 4.4 fold for amoxycillin at -7.3 degrees celsius. The rate constant values obtained were interpreted in terms of the concentration model (Pincock and Kiovsky 1966), phase-temperature relationship of the solutes, buffer catalysis, pH change and polymerization reactions.In the hydrochloric acid system a kinetic model was deduced providing adequate explanation of the experimental results. The stabilizing effect of sodium chloride used for maintaining constant ionic strength (mu=0.5) was ++ / enormous in this system. The shelf-life of amoxycillin was increased from 2.2 h to 58.3 h at -7.3 degrees celsius when sodium chloride was included in the system. It also stabilized the rates of the reactions significantly in the buffer systems.The buffer systems used in this study stabilized the rates of the reaction of both the drug compounds considerably. The shelf-life of amoxycillin in phosphate buffer was 621.3 h at -13.5 degrees celsius and in acetate buffer the shelf-life of clavulanate was 71.9 h at the same temperature. These are the highest shelf-life values recorded so far in the literature for amoxycillin and clavulanate at this frozen temperature.

Submitted by WILLIAN RICARDO PIRES null (willian_ricardo_p@hotmail.com) on 2016-03-08T18:17:47Z No. of bitstreams: 1 WILLIAN RICARDO PIRES - MESTRADO.pdf: 2268277 bytes, checksum: a2d3f70b98d0db4ee5e123e6c1a0451b (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-03-09T17:39:39Z (GMT) No. of bitstreams: 1 pires_wr_me_araca.pdf: 2268277 bytes, checksum: a2d3f70b98d0db4ee5e123e6c1a0451b (MD5) / Made available in DSpace on 2016-03-09T17:39:39Z (GMT). No. of bitstreams: 1 pires_wr_me_araca.pdf: 2268277 bytes, checksum: a2d3f70b98d0db4ee5e123e6c1a0451b (MD5) Previous issue date: 2016-03-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A luxação extrusiva é uma injúria do ligamento periodontal caracterizada pelo deslocamento parcial do dente do seu alvéolo sendo que o tratamento preconizado consiste no reposicionamento, contenção e alguns autores recomendam a antibioticoterapia sistêmica (ATS). No entanto, não há nenhuma evidência para a utilização da ATS no reparo tecidual após a injúria de luxação extrusiva. O objetivo da pesquisa foi avaliar o efeito da ATS com Amoxicilina e Tetraciclina no processo de reparo da injúria de luxação extrusiva. Noventa ratos (Rattus norvegicus albinus), adultos, machos tiveram seus incisivos superiores direito luxados, deslocados 3mm no sentido axial e após 5 minutos reposicionados. Os animais foram aleatoriamente divididos em três grupos: Soro, Amoxicilina (25mg/Kg) e Tetraciclina (2,5mg/Kg). A medicação foi administrada de 12/12h por gavagem por um período de 7 dias. Os animais sofreram eutanásia nos períodos de 7, 15 e 30 dias após a luxação. A análise estatística foi realizada por meio dos testes de Kruskal-Wallis e pós-teste de Dunn's de múltipla comparação ao nível de 5%. O tecido conjuntivo subjacente à inserção epitelial apresentou um infiltrado inflamatório agudo que foi de menor intensidade e extensão no grupo Amoxicilina nos três períodos pós-operatório analisados. Em todos os grupos o ligamento periodontal estava organizado e o infiltrado inflamatório agudo só apresentou diferença significante aos 7 e 15 dias com melhor resultado para o grupo Amoxicilina. Com relação ao infiltrado inflamatório crônico, tanto na intensidade quanto na extensão, foi maior no grupo Soro. Ocorreram poucas áreas de reabsorção radicular em todos os grupos sem diferença significante. O tecido pulpar na maioria dos espécimes em todos os grupos apresentou calcificações. Pode-se concluir que a antibioticoterapia sistêmica tem um efeito positivo no processo de reparo da luxação extrusiva e que a amoxicilina é uma boa opção. / The extrusive luxation is a periodontal ligament injury characterized by partial dislocation of the tooth its alveolus and that the recommended treatment consists of repositioning, contain and some authors recommend systemic antibiotic therapy (SAT). However, there is no evidence for the use of SAT in tissue repair after injury extrusive luxation. The objective is to evaluate the effect of SAT with Amoxicillin and Tetracycline in the repair process of the injury of extrusive luxation. Ninety rats (Rattus norvegicus albinus), adult male had his dislocated right incisor, moved 3 mm in the axial direction and after 5 minutes repositioned. The animals were randomly divided into three groups: Saline, Amoxycillin (25mg/kg) and Tetracycline (2,5mg/kg). The drug is administered of 12/12h by gavage for a period of 7 days. The animals were euthanized at 7, 15 and 30 days after the dislocation. Statistical analysis was performed using the Kruskal-Wallis test and Dunn's post-test for multiple comparison to the level of 5%. The underlying connective tissue to the epithelial attachment presented an acute inflammatory infiltrate that was less intensity and extent in the Amoxicillin group in the three postoperative periods analyzed. In all groups the periodontal ligament was organized and acute inflammatory infiltrate showed only significant difference at 7 and 15 days with best result for the amoxicillin group. In relation to the chronic inflammatory infiltrate in both the intensity and the extent was greater in the Saline group. There have been few areas of root resorption in all groups with no significant difference. The pulp tissue in most specimens in all groups had calcifications. It can be concluded that systemic antibiotic therapy has a positive effect on the extrusive luxation repair process and that amoxicillin is an good option.

Orientador: Maria Stella Gonçalves Raddi / Banca: Lourdes Botelho Garcia / Banca: Hérida Regina Nunes Salgado / Banca: Fernando de Sá Del Fiol / Banca: Luiz Marcos da Fonseca / Resumo: O efeito de amoxicilina e ciprofloxacino, agentes antimicrobianos com diferentes mecanismos de ação, sobre alguns fatores relacionados à sua virulência em Staphylococcus aureus ATCC 25923 foi comparado. Efeito pós-antimicrobiano, atividade hemolítica para hemácias de carneiro, atividade de citolisinas extracelulares para células McCoy, susceptibilidade à fagocitose dependente e não dependente de opsonização, por neutrófilos de Rattus albinus norvegicus, foram avaliados em bactérias crescidas na presença de concentração subinibitória (½ CIM) do antimicrobiano e a capacidade de induzir estresse oxidativo foi determinada diretamente sobre as células bacterianas através da detecção da produção de ânion superóxido. Amoxicilina e ciprofloxacino demonstraram efeito sobre o crescimento de S. aureus estatisticamente significativo em relação ao controle, sendo maior para amoxicilina. A atividade hemolítica foi diminuída na presença de amoxicilina e ambos antimicrobianos induziram aumento na atividade de citolisinas extracelulares. A técnica de quimiluminescência dependente de luminol, utilizada para avaliar susceptibilidade à fagocitose através do burst oxidativo de polimorfonucleares neutrófilos, demonstrou que amoxicilina influenciou positivamente a fagocitose dependente de opsoninas e ciprofloxacino estimulou a fagocitose não opsonizada. Visto o burst oxidativo ser um método indireto para a demonstração de fagocitose, a confirmação de células bacterianas fagocitadas/aderidas foi realizada através da observação de esfregaços corados em microscopia ótica comum (1000 x). Apesar de ambos antimicrobianos induzirem aumento de ânion superóxido intracelular, detectado em ensaios de redução de nitroblue tetrazolium (NBT), o ciprofloxacino induziu maior quantidade que a amoxicilina. A demonstração de que diferentes antimicrobianos possam atuar sobre...( Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Amoxycillin and ciprofloxacin are antimicrobials with dissimilar mechanisms of action against bacteria. This is a comparative study of how each of these agents affects some of the factors related to the virulence of the pathogenic strain of Staphylococcus aureus ATCC 25923. The post-antibiotic effect, hemolytic activity against sheep erythrocytes, cytolysin activity against McCoy cells and susceptibility to opsonin-dependent and independent phagocytosis by neutrophils from Rattus albinus norvegicus were assessed in bacteria grown in a subinhibitory concentration (½ MIC) of each agent. Induction of oxidative stress was observed directly by detecting superoxide production in response to the bacteria. Both the antimicrobials exerted effect on the growth of S. aureus, which was significantly different from the growth of controls, though amoxycillin had the stronger effect. Hemolytic activity was diminished in the presence of amoxycillin, but both agents induced an increase in the activity of secreted cytolysins. By employing luminol-dependent chemiluminescence to assess the susceptibility of the bacteria to phagocytosis by detecting the respiratory burst in polymorphonuclear neutrophils, it was shown that amoxycillin had a positive effect on opsonin-dependent phagocytosis, while ciprofloxacin stimulated non-opsonized phagocytosis. Since detection of the respiratory burst is an indirect demonstration of phagocytosis, direct observation of stained slides under the light microscope at 1000 × magnification was used to confirm the presence of bacteria ingested by and adhering to neutrophils. While both agents induced a rise in the intracellular level of superoxide, assayed by nitroblue tetrazolium reduction, ciprofloxacin produced the stronger response. The demonstration that distinct antimicrobials... (Complete abstract click electronic access below) / Doutor

Made available in DSpace on 2014-06-11T19:32:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-11-17Bitstream added on 2014-06-13T20:24:17Z : No. of bitstreams: 1 aoki_ee_dr_arafcf.pdf: 506585 bytes, checksum: 218b2c8e86bf9f798b9b0d4d716e2401 (MD5) / Universidade Estadual Paulista (UNESP) / O efeito de amoxicilina e ciprofloxacino, agentes antimicrobianos com diferentes mecanismos de ação, sobre alguns fatores relacionados à sua virulência em Staphylococcus aureus ATCC 25923 foi comparado. Efeito pós-antimicrobiano, atividade hemolítica para hemácias de carneiro, atividade de citolisinas extracelulares para células McCoy, susceptibilidade à fagocitose dependente e não dependente de opsonização, por neutrófilos de Rattus albinus norvegicus, foram avaliados em bactérias crescidas na presença de concentração subinibitória (½ CIM) do antimicrobiano e a capacidade de induzir estresse oxidativo foi determinada diretamente sobre as células bacterianas através da detecção da produção de ânion superóxido. Amoxicilina e ciprofloxacino demonstraram efeito sobre o crescimento de S. aureus estatisticamente significativo em relação ao controle, sendo maior para amoxicilina. A atividade hemolítica foi diminuída na presença de amoxicilina e ambos antimicrobianos induziram aumento na atividade de citolisinas extracelulares. A técnica de quimiluminescência dependente de luminol, utilizada para avaliar susceptibilidade à fagocitose através do burst oxidativo de polimorfonucleares neutrófilos, demonstrou que amoxicilina influenciou positivamente a fagocitose dependente de opsoninas e ciprofloxacino estimulou a fagocitose não opsonizada. Visto o burst oxidativo ser um método indireto para a demonstração de fagocitose, a confirmação de células bacterianas fagocitadas/aderidas foi realizada através da observação de esfregaços corados em microscopia ótica comum (1000 x). Apesar de ambos antimicrobianos induzirem aumento de ânion superóxido intracelular, detectado em ensaios de redução de nitroblue tetrazolium (NBT), o ciprofloxacino induziu maior quantidade que a amoxicilina. A demonstração de que diferentes antimicrobianos possam atuar sobre...( Resumo completo, clicar acesso eletrônico abaixo) / Amoxycillin and ciprofloxacin are antimicrobials with dissimilar mechanisms of action against bacteria. This is a comparative study of how each of these agents affects some of the factors related to the virulence of the pathogenic strain of Staphylococcus aureus ATCC 25923. The post-antibiotic effect, hemolytic activity against sheep erythrocytes, cytolysin activity against McCoy cells and susceptibility to opsonin-dependent and independent phagocytosis by neutrophils from Rattus albinus norvegicus were assessed in bacteria grown in a subinhibitory concentration (½ MIC) of each agent. Induction of oxidative stress was observed directly by detecting superoxide production in response to the bacteria. Both the antimicrobials exerted effect on the growth of S. aureus, which was significantly different from the growth of controls, though amoxycillin had the stronger effect. Hemolytic activity was diminished in the presence of amoxycillin, but both agents induced an increase in the activity of secreted cytolysins. By employing luminol-dependent chemiluminescence to assess the susceptibility of the bacteria to phagocytosis by detecting the respiratory burst in polymorphonuclear neutrophils, it was shown that amoxycillin had a positive effect on opsonin-dependent phagocytosis, while ciprofloxacin stimulated non-opsonized phagocytosis. Since detection of the respiratory burst is an indirect demonstration of phagocytosis, direct observation of stained slides under the light microscope at 1000 × magnification was used to confirm the presence of bacteria ingested by and adhering to neutrophils. While both agents induced a rise in the intracellular level of superoxide, assayed by nitroblue tetrazolium reduction, ciprofloxacin produced the stronger response. The demonstration that distinct antimicrobials... (Complete abstract click electronic access below)