ABSTRACT
In the framework of the Italian TOP-IMPLART project (Regione Lazio), ENEA-Frascati, ISS and IFO are developing and constructing the first proton linear accelerator based on an actively scanned beam for tumor radiotherapy with final energy of 150 MeV. An important feature of this accelerator is modularity: an exploitable beam can be delivered at any stage of its construction, which allows for immediate characterization and virtually continuous improvement of its performance. Currently, a sequence of 3 GHz accelerating modules combined with a commercial injector operating at 425 MHz delivers protons up to 35 MeV. Several dosimetry systems were used to obtain preliminary characteristics of the 35-MeV beam in terms of stability and homogeneity. Short-term stability and homogeneity better than 3% and 2.6%, respectively, were demonstrated; for stability an improvement with respect to the respective value obtained for the previous 27 MeV beam.
Subject(s)
Particle Accelerators/instrumentation , Protons , Radiometry/instrumentation , Radiometry/methods , Equipment Design , Radiation DosageABSTRACT
The first proton linear accelerator for tumor therapy based on an actively scanned beam up to the energy of 150 MeV, is under development and construction by ENEA-Frascati, ISS and IFO, under the Italian TOP-IMPLART project. Protons up to the energy of 7 MeV are generated by a customized commercial injector operating at 425 MHz; currently three accelerating modules allow proton delivery with energy up to 27 MeV. Beam homogeneity and reproducibility were studied using a 2D ionizing chamber, EBT3 films, a silicon diode, MOSFETs, LiF crystals and alanine dosimetry systems. Measurements were taken in air with the detectors at ~1 m from the beam line exit window. The maximum energy impinging on the detectors surface was 24.1 MeV, an energy suitable for radiobiological studies. Results showed beam reproducibility within 5% and homogeneity within 4%, on a circular surface of 16 mm in diameter.
Subject(s)
Film Dosimetry/instrumentation , Film Dosimetry/methods , Particle Accelerators/instrumentation , Protons , Fluorides/chemistry , Linear Energy Transfer , Lithium Compounds/chemistry , Silicon/chemistryABSTRACT
A sinvastatina, pertencente à classe das estatinas, é um importante fármaco redutor do colesterol e é encontrada comercialmente como medicamentos referência, genéricos e similares em diferentes dosagens, sendo a de 10 mg a mais comum. Este trabalho tem como objetivo avaliar a qualidade e a equivalência entre comprimidos de sinvastatina 10 mg comercializados no mercado brasileiro. Foram selecionados dois medicamentos similares, um genérico e referência. Os ensaios de controle de qualidade aplicados foram: determinação do peso médio, dureza, friabilidade, desintegração, teor de princípio ativo, uniformidade de conteúdo e dissolução in vitro. Para tanto, foi necessário desenvolvimento e validação de metodologia por espectrofotometria na região do ultravioleta (UV). As formulações apresentaram-se dentro dos limites preconizados para todas as análises. No entanto, quando analisou-se estatisticamente os perfis de dissolução, verificou-se a não equivalência entre os medicamentos similares e o de referência. Porém, através dos resultados obtidos, podemos evidenciar a equivalência entre o genérico e o de referência, sugerindo sua intercambialidade...
Simvastatin, a well-known medicine of the statin class, is used therapeutically for the reduction of cholesterol and is commercially available in reference, similar and generic forms, in various doses, the tablet of 10 mg being the commonest in prescriptions. The purpose of this study was to test the quality and the pharmaceutical equivalence of tablets containing 10 mg of simvastatin available on the Brazilian market. One generic, one reference and two similar dosage forms were selected. The quality-control variables used were: weight variation, hardness, friability, disintegration, content of the active principle, content uniformity and dissolution in vitro. A UV-spectrophotometric method was developed and validated. All formulations were approved in the quality analysis. By using mathematical and statistical models, it was observed that the dissolution profiles of the similar dosage forms were not equivalent to that of the reference. On the other hand, when the generic medicine was compared with the reference, their interchangeability was confirmed...
