Monte Carlo simulation of whole body dose distribution in patients with total body X (γ) ray irradiation / 中华放射肿瘤学杂志

Objective To explore the feasibility of application of the Monte Carlo method to simulate the whole body dose distribution in patients with total body X (γ) ray irradiation by comparing the actual measurement results.Methods A Monte Carlo model of a 6 MV Elekta Synergy Clinical linear accelerator was established by MCNPX.According to the relationship between the CT value and the density of the material,the CT of the ATOM physical phantom was converted into a voxel phantom for MCNPX calculation.The dose distribution of the whole body was simulated in the total body X (γ) ray irradiation.The simulated results were compared with the measurement values of the thermoluminescence dosimetry at different positions in the ATOM physical phantom to analyze the differences.Results The difference between the depth dose curve and the off-axis dose curve and the actual measurement values calculated by the 6 MV accelerator treatment head model in the water tank was less than 2％,with the maximum dose depth of approximately 1.5 cm and field size of 10 cm× 10 cm,which were consistent with the actual measurement values.The maximum difference between the simulated results at different locations in the body and the thermoluminescence dosimeter was approximately 4％,and the simulated results of MCNPX were almost in good agreement with the results of thermoluminescence.Conclusions The whole body dose distribution in patient with total body X (γ) ray irradiation can be accurately simulated by MCNPX.Monte Carlo simulation makes it possible to optimize the uniformity of the total body dose during the total body irradiation process.

Validation of impregnation process for homeopathic globules by spectrophotometric-UV method

We compared the impregnation techniques for globules according to the Manual of Technical Norms for Homeopathic Pharmacies (MNTFH) of the Association of Homeopathic Pharmacists (ABFH), Brazilian Homeopathic Pharmacopoeia (FHB) and variations of these techniques. The variables were evaluated in this procedure, three different sizes of globules (N o . 3, 5 and 7), the hydroalcoholic solution of 70% (v/v) Minoxidil 2% (w/v) was used to impregnate the globules in concentrations of 2, 3, 4, 5% (v/w) and the impregnation at 10 %(v/w) was used hydroalcoholic solutions at 70, 80 and 90% (v/v), and four impregnation techniques various ( A -glass, B -paper, C -cup and D -FHB). As the results of content uniformity did not demonstrate a normal distribution, the one way ANOVA and a nonparametric statistical model were used for evaluation. Considering the average, the standard deviation (SD), the individual variance of each group and the principal components analysis graphs (PCA), it was observed that the “A” impregnation of globules technique, with 5% (v/w) of the impregnation concentrations and the No.5 globule presented the best uniformity of dose. As to the drying, there was a need to use a heat source.

Compararam-se as técnicas de impregnação para glóbulos segundo o Manual de Normas Técnicas para Farmácias Homeopáticas (MNTFH) da Associação Brasileira de Farmacêuticos Homeopatas (ABFH), Farmacopeia Homeopática Brasileira (FHB) e variações destas técnicas. As variáveis avaliadas neste processo foram: três tamanhos diferentes de glóbulos (n.º 3, 5 e 7); a solução hidroalcóolica a 70% (v/v) de minoxidil a 2% (p/v) foi utilizada para impregnar os glóbulos nas concentrações de 2, 3, 4, 5% (v/p) e na impregnação a 10% (v/p) utilizaram-se as soluções hidroalcóolicas a 70, 80 e 90% (v/v); e quatro técnicas de impregnação diferentes ( A -vidro, B -papel, C -copo e D -FHB). A impregnação foi validada através da uniformidade de dose por conteúdo, sendo o minoxidil a substância quantificada. Como os resultados da uniformidade de dose por conteúdo não demonstraram distribuição normal, utilizaram-se o One way ANOVA e um modelo estatístico não paramétrico para sua avaliação. Considerando-se a média, o desvio padrão (DP), a variância individual de cada grupo e os gráficos de análise de componentes principais (ACP), observou-se que a impregnação que utilizou o glóbulo nº5, a concentração para impregnação de 5% (v/p), graduação alcoólica de 70% (v/v) e técnica “A” apresentou a melhor uniformidade de dose. Quanto à secagem, verificou-se a necessidade do uso de uma fonte de calor.

An aerosol formulation of R-salbutamol sulfate for pulmonary inhalation

An aerosol formulation containing 7.5 mg of R-salbutamol sulfate was developed. The aerosol was nebulized with an air-jet nebulizer, and further assessed according to the new European Medicines Agency (EMA) guidelines. A breath simulator was used for studies of delivery rate and total amount of the active ingredient at volume of 3 mL. A next generation impactor (NGI) with a cooler was used for analysis of the particle size and in vitro lung deposition rate of the active ingredient at 5 °C. The anti-asthmatic efficacy of the aerosol formulation was assessed in guinea pigs with asthma evoked by intravenous injection of histamine compared with racemic salbutamol. Our results show that this aerosol formulation of R-salbutamol sulfate met all the requirements of the new EMA guidelines for nebulizer. The efficacy of a half-dose of R-salbutamol equaled that of a normal dose of racemic salbutamol.