In conclusion we prepared DS

In conclusion, we prepared DS enteric-coated capsules, and developed an analysis method for the quantification and in vitro release study of DS. The results showed this assay method had highly convenience and reliability for the rapid quantitative determination of DS concentration in high-throughput release characteristic studies. Furthermore, the drugs could be well released from enteric-coated capsules in release medium within the specified time limit, and the release characteristics of the developed formulation and commercial samples were quite consistent with each other.

Acknowledgments
This work was financially supported by the Plan for Scientific Innovation Talent of the Henan University of Technology (No: 2014CXRC07), and the Natural Science Research Program of the Education Department of Henan Province (15A350006).

Introduction
In recent years, constant social and economic development results in people’s accelerating pace of life. Meanwhile, environmental problems deteriorate (He et al., 2008). As a result, global cancer incidence and mortality rates stay a high level, posing a serious threat to people’s health, wherein, liver cancer, stomach cancer, esophageal cancer and colorectal cancer and other gastrointestinal cancers have a high incidence (Chao and Zhang, 2012). Currently, chemotherapy is one of the primary means for treatment of cancer, but its treatment effect is subject to drug side effects and drug resistance. In recent years, with the blend of molecular biology, molecular pharmacology, gingerol materials, thermal chemistry and other subjects, the researchers have developed controlled release preparations and targeting preparation which can be intelligently controlled according to tumor site characteristics (Wang et al., 2010; Li et al., 2012a,b; He et al., 2011). Chitosan (shown as Fig. 1) (CS), the product of deacetylation of chitin, is the only alkaline polysaccharide in nature. With broad range of sources, good biodegradability, biocompatibility and low toxicity, it is widely used in such aspects as pharmaceutical, textile, environmental monitoring and tissue repair. But intermolecular and intramolecular hydrogen-bond interaction reduces its solubility, only partially soluble in acid, such as acetic acid, hydrochloric acid, methane sulfonic acid. In order to make excellent the properties of chitosan that are benefit for more cancer patients, chitosan must be modified. 5-Fluorouracil (shown as Fig. 2) (5-Fu) is an anticancer drug of DNA synthesis cycle. As its cells enjoy relatively strong destruction characteristics, it is widely used in the treatment of a variety of solid tumors such as colorectal cancer, stomach cancer, breast cancer in clinics. However, metabolic rate of the drug is relatively fast, which easily leads to problems such as gastrointestinal reactions and poor selectivity, so these drugs are not very widespread in practice. To enhance anti-cancer effect and reduce toxicity, over the years, people have done a lot of chemical modification work on 5-FU, to effectively reduce side effects of these drugs (Xu et al., 2014). Nanoparticles (NP) is ultra fine particle decentralized administration system formed by aggregate, poly charge of natural or synthetic polymer materials, which belongs to colloid administration system; its shape is mostly solid colloidal particles with diameter of 10–1000nm (Li et al., 2012a,b). Nanoparticles have significant medicinal property transport advantages, so preparation of nanoparticles has always been the focus of research questions. With constant progress and development of chemical preparation level, preparation mode of nanoparticles demonstrates significant diversification characteristics. In this paper, preparation effect of fluorouracil–chitosan nanoparticles with ion gel method is deeply analyzed, and its inhibitory effect for cancer tumors is explored.

Materials and methods