Detection of nanostructures in solutions of Zincum metallicum and the vehicle lactose

Background: Nanoparticles (NP), because of their size (< 1μm) and high relative surface area, are highly reactive forms of their source material with biological, chemical, optical, electromagnetic, and thermal properties different from larger bulk forms of the same material. It has been speculated that NPs can occur in homeopathic products as a function of trituration and shaking into glass containers. Moreover, the presence of sugars additives like lactose and of silicates leaked from the glassware are reported to stabilize the nanoparticles. 1 Up to now some authors observed nanoparticles in highly diluted samples2, 3, but further studies are needed to know the nature of the NPs. Actually, nanostructures in the solutions may derive from the source materials but also from stuff contaminations and also may be constituted by nano-bubbles. 4, 5 Moreover, the mechanism by which the nanostructures can be formed and the effect of serial dilution/succussions of the NPs suspension should be studied. 6 Many tools are available to analyze the nanostructures both in solutions or in dried samples and these give complementary information about the concentration, stability, structure and chemical nature of the NPs. In the present report we describe preliminary observations obtained by the nanoparticle tracking analysis (NTA) in Zincum metallicum (Zinc met.) solutions at low-grade dilution/dynamization and their lactose controls. This study is part of a formal Brazilian-Italian inter-university collaboration. Materials and methods: Zinc met./lactose triturated powder (1cH) and the corresponding vehicle lactose was prepared at the Pharmacy Faculty of Rio de Janeiro UFRJ (BR) following the Brazilian Homeopathic pharmacopoeia guidelines. Before the analysis, the Zinc met. powder or lactose (1cH) were dissolved in ultrapure water (1% w/v) (Sigma), transferred into clean sterile soda-lime glass tubes and succussed with a DinaA mechanical shaker for 7.5 sec (150 strokes) to obtain the centesimal dilution 2cH. The final assay mixture was