The energy barrier of excited state proton transfer (ESPT) process in 3-hydroxyflavone (3HF) was studied considering the solvent effects. It was found that the ESPT energy barrier increased with the increase of solvent polarity. But the ESPT energy barrier of 3HF in methanol is lower than in vacuum, n-hexane and acetonitrile. It was found that methanol molecule lowers the ESPT energy barrier by forming a seven-membered-ring 3HF-methanol complex.

The prescription of sofosbuvir tablets was screened to select the best prescription proportions. Methods: According to the prescription technology of foreign listed tablets “sovaldi^®”, experiments of diluents, disintegrating agents, binders, lubricants and coating process were investigated, including the stability study of self-made samples and reference tablets under the conditions of high temperature, high humidity and illumination. We aimed to screen a reasonable prescription process. Results: Prescription process was ultimately determined including: sofosbuvir 400 mg, mannitol 360 mg, microcrystalline cellulose 360 mg, cross-linked sodium carboxymethyl cellulose 60 mg, magnesium stearate 14 mg, gum arabic 6 mg, opadry film coating powder 36 mg, and chose purified water as a binder. Conclusion: The determined prescription process was stable, and the production process was not harsh, it was suitable for scale-up production. The results of stability study and the dissolution behavior in vitro were similar to those of commercial products, so the prescription is design reasonably.

Based on density functional theory (DFT), the adsorption of atomic and molecular hydrogen and nitrogen on pyrite ${\rm FeS}_2 $ (100) surface was studied. Both atomic ${\rm N}$ and ${\rm N}_2$ molecule prefer to adsorb on the top Fe site. The adsorption of atomic ${\rm N}$ on the surface of ${\rm FeS}_2$ (100) is more stable than ${\rm N}_2.$ Adsorption energy calculation shows that the adsorption stability weakens with the increase of the ${\rm N}$ atom coverage. Hydrogen adsorption differs quite a lot with that of nitrogen adsorption. It is found that atomic ${\rm H}$ could stably adsorbs on ${\rm FeS}_2$ (100) surface at the top Fe site, while ${\rm H}_2$ molecule is quite difficult to adsorb on pyrite ${\rm FeS}_2$ (100) surfaces. The adsorption stability of atomic hydrogen sharply weakens as the ${\rm H}$ coverage increases.

Clone the Harvoni$^{\rm TM}$(Sofosbuvir/Ledipasvir) tablet manufactured by Gilead Sciences, Inc. and screen out the best formula of prescription, to make the pesticide effect of prepared tablet was equal to the original tablet. Methods: Based on the prescription of Harvoni^TM manufactured by Gilead Sciences, Inc., the compatibility test of the excipient with the active ingredient was carried out. The stability of self-made samples and reference preparations were investigated, which includes high temperature, high humidity and light conditions. According to the above test, the most reasonable prescription process was chosen. Results: The determined prescription process contained sofosbuvir (400mg), ledipasvir (90mg), copovidone (97.5mg), croscarmellose sodium (50mg), microcrystalline cellulose (115mg), lactose monohydrate (230mg), magnesium stearate (7.5mg), gum arabic(10mg), opadry film coating powder, and purified water. Conclusion: The determined prescription process was stable and the pesticide effect of prepared tablet was equal to the original tablet, so the prescription design was reasonable.