ABSTRACT
The objective of this study was to investigate the bone regeneration of a "gold standard" (autograft) from iliac crest associated with cellular therapy in rabbits. A bone defect was created with 10x5x5mm in 28 rabbit mandibles. The control group animals (n=14) were repaired with autograft of iliac crest and the experimental group animals (n=14) received iliac crest autograft in association with mononuclear cells from the bone marrow of the femur. Weekly radiographs were taken of the surgery region and histological analyses was performed in seven animals in each group at 15 days and in seven animals of each group at 30 days after the surgery. A gradual increase of bone density was observed and the experimental animals presented the bone bridge in 85.7 percent (6/7) of the cases, while only 42.8 percent (3/7) of the animals in the control group presented this structure 28 days after the surgery. The histopathological parameters analyzed did not show any statistical difference between the control and experimental group in 15 and 30 days of analysis. The results suggest that the mononuclear cells from the marrow bone can better support the autograft regeneration in mandible defects in rabbits.
Avaliou-se a regeneração óssea de auto-enxerto, considerado "padrão ouro" da crista ilíaca associado à terapia celular da medula óssea em coelhos. Foi criado um defeito ósseo de 10x5x5mm na mandíbula de 28 coelhos, distribuídos em grupo-controle com, 14 animais, reparados com auto-enxerto de crista ilíaca, e grupo experimental com, 14 animais, em que o auto-enxerto foi associado a células mononucleares da medula óssea autógena do fêmur. Foram realizadas radiografias semanais da região operada e análise histológica em sete animais de cada grupo aos 15 e em sete de cada grupo aos 30 dias do pós-operatório. Houve aumento gradativo da densidade óssea, e 85,7 por cento (6/7) dos animais do grupo experimental e 42,8 por cento (3/7) do grupo-controle apresentaram formação de ponte óssea 28 dias após a cirurgia. Na análise histopatológica aos 15 dias, os enxertos foram facilmente visualizados e a atividade das células fagocitárias foi intensa. Já aos 30 dias, a visualização foi mais difícil e, quando possível, apenas um resquício foi visualizado. Os resultados sugerem que a adição de células mononucleares da medula óssea favorece a regeneração do auto-enxerto em defeitos mandibulares de coelhos.
Subject(s)
Animals , Male , Bone Marrow Cells , Bone Regeneration , Ilium/transplantation , Mandible , Rabbits , Transplantation, Autologous/veterinary , Bone Transplantation/veterinary , Bone Density , Cell Separation , Deglutition , MasticationABSTRACT
Compararam-se duas técnicas cirúrgicas de redução e estabilização da articulação coxofemoral experimentalmente luxada em cães. Dois grupos de animais, submetidos às respectivas técnicas após a indução cirúrgica da luxação, foram acompanhados clínica e radiograficamente por um período de 60 dias, findos os quais, realizaram-se avaliações macroscópica e histológica e teste de tensiometria das articulações. Cada grupo foi constituído por oito animais, clinicamente sadios, com pesos entre 5 e 20kg. Os animais submetidos ao implante de fáscia apresentaram, ao exame físico, evolução da deambulação significativamente precoce em relação aos do grupo submetido ao implante de pino de Steinmann, além de menor grau de atrofia muscular. Os testes de tensiometria, as avaliações macroscópicas e radiográficas e os exames histológicos não diferiram entre os grupos, evidenciando também que ambas as técnicas não geraram alterações deletérias à articulação operada. Conclui-se que a técnica de estabilização da articulação coxofemoral com implante de fascia lata foi clinicamente eficaz e vantajosa quando comparada à técnica do pino transarticular.
It was compared both surgical techniques of reduction and stabilization of experimentally luxated coxofemoral join in dog. Two groups were submitted to the techniques after surgical induction of the luxation. All animals were clinically and radiografically observed during 60 days. After that, a macroscopic study, an histological exam, and a tensiometry test in the articulations were performed. Each group had eight healthy animals, weighting from 5 to 20kg. The most important advantage was related to the deambulation, which the animals submited to the facia lata implant showed a faster evolution after the surgery at the physical exam, and muscular atrophy in a smaller degree. The tensiometry tests, the radiographic and the histological exams did not present important differences between both groups, but they were useful to show that the two techniques did not cause alterations in the studied articulation. It can be concluded that the stabilization of the coxofemoral articulation using bubaline fascia lata implant was clinically efficient and more advantageous compared to the transarticular pin technique.
ABSTRACT
Pantoprazole sodium is a proton pump inhibitor, used in acid-related disorders, like peptic ulcers and gastroesophageal reflux. This drug is unstable in acid solution and in the presence of salts. The aim of this work was to study the photostability under UVC radiation of pantoprazole and to determine its kinetics. A methanol solution and the solid pantoprazole were evaluated by HPLC within 120 min and 10 days, respectively. The work was also dedicated to evaluate and compare the ability of microencapsulation in stabilizing pantoprazole after UVC radiation. Pantoprazole-loaded microparticles prepared by emulsification/solvent evaporation or spray drying were compared. Pantoprazole was encapsulated using Eudragit S100 or its blend with poly(epsilon-caprolactone) or HPMC. In methanol solution, pantoprazole was completely degraded after 120 min and presented zero-order kinetics with t1/2 of 6.48 min. In the solid form, after 10 days, pantoprazole concentration was reduced to 27% following zero-order kinetic. The microparticles prepared only with Eudragit S100 demonstrated an increase of the drug photostability. After 10 days of irradiation, 56 and 44% of the drug was stable when encapsulated by emulsification/solvent evaporation and spray drying, respectively. The use of polymer blends did not improve the pantoprazole photostability.
Subject(s)
2-Pyridinylmethylsulfinylbenzimidazoles/administration & dosage , 2-Pyridinylmethylsulfinylbenzimidazoles/chemistry , Proton Pump Inhibitors/administration & dosage , Proton Pump Inhibitors/chemistry , Chromatography, High Pressure Liquid , Desiccation , Drug Compounding , Drug Stability , Emulsions , Excipients , Light , Methanol , Nanoparticles , Pantoprazole , Particle Size , Photochemistry , Polymers , Solutions , Solvents , Ultraviolet RaysABSTRACT
Pantoprazole is used in the treatment of acid related disorders and Helicobacter pylori infections. It is activated inside gastric parietal cells binding irreversibly to the H+/K(+)-ATPase. In this way, pantoprazole must be absorbed intact in gastro-intestinal tract, indicating that enteric delivery systems are required. The purpose of this study was to prepare pantoprazole-loaded microparticles by spray-drying using a blend of Eudragit S100 and HPMC, which can provide gastro-resistance and controlled release. Microparticles presented acceptable drug loading (120.4 mgg(-1)), encapsulation efficiency (92.3%), surface area (49.0 m2g(-1)), and particle size (11.3 microm). DSC analyses showed that the drug is molecularly dispersed in the microparticles, and in vivo anti-ulcer evaluation demonstrated that microparticles were effective in protecting stomach against ulceration. Microparticles were successfully tabletted using magnesium stearate. In vitro gastro-resistance study showed that microparticles stabilized pantoprazole in 62.0% and tablets in 97.5% and provided a controlled release of the drug.
Subject(s)
2-Pyridinylmethylsulfinylbenzimidazoles/administration & dosage , Acrylic Resins/chemistry , Anti-Ulcer Agents/administration & dosage , Methylcellulose/analogs & derivatives , 2-Pyridinylmethylsulfinylbenzimidazoles/chemistry , 2-Pyridinylmethylsulfinylbenzimidazoles/pharmacology , Animals , Anti-Ulcer Agents/chemistry , Anti-Ulcer Agents/pharmacology , Calorimetry, Differential Scanning , Chemistry, Pharmaceutical , Chromatography, High Pressure Liquid , Delayed-Action Preparations , Desiccation , Drug Compounding , Ethanol , Excipients , Hypromellose Derivatives , Methylcellulose/chemistry , Microscopy, Electron, Scanning , Nanoparticles , Pantoprazole , Particle Size , Porosity , Rats , Solvents , Stomach Ulcer/chemically induced , Stomach Ulcer/pathology , Stomach Ulcer/prevention & control , Surface PropertiesABSTRACT
Pantoprazole is an important drug in the treatment of acid-related disorders. This work concerns the preparation and characterization of gastro-resistant pantoprazole-loaded microparticles prepared using an O/O emulsification/solvent evaporation technique. The in vivo activity of the pantoprazole-loaded Eudragit S100 microparticles was carried out in rats. Furthermore, tablets containing the microparticles were also investigated. Microparticles presented spherical and smooth morphologies (SEM) and they remained intact in the inner surface of tablets. DSC and IR analyses showed that pantoprazole was physically and molecularly dispersed in the polymer. In vivo anti-ulcer evaluation showed that the microparticles were able to protect rat stomachs against ulcer formation, while the drug aqueous solution did not present activity. Drug dissolution profiles from tablets demonstrated slower release than untabletted microparticles. Weibull equation was the best model for describing the drug release profiles from microparticles and tablets. As regards the acid protection, tablets showed a satisfactory drug protection in acid medium (61.05 +/- 8.09% after 30 min).
