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Study On Slow Release Of Novel Materials For Use In Intrauterine Devices

Posted on:2007-06-05Degree:MasterType:Thesis
Country:ChinaCandidate:H XiangFull Text:PDF
GTID:2144360242461165Subject:Materials science
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Among the various contraceptive methods, intrauterine devices (IUDs), especially the copper-containing intrauterine devices (Cu-IUDs), have become one of the most popular methods for birth control throughout the world, especially in the developing countries, due to their advantages of long-lasting and high efficacy, economy, safety and reversibility. However, the existing Cu-IUDs have some side effects such as pain, intermenstrual bleeding and so on which are relevant to the burst release of cupric ions, direct contact of the copper with endometrium, low transformation ratio of the copper and stiff deposits deposited on the copper surface et al. To solve these problems, a series of novel Cu-IUDs materials have been developed in our research and, the specific release rate of cupric ion of these novel Cu-IUDs materials in simulated uterine solution was systemically investigated in this thesis.We prepared Copper/Silicon rubber composite by the process of mixing and heat-vulcanizing. The release rate of Cu2+ of this composite was investigated by absorbance measurement. The composite was determined by using X-ray diffraction (XRD) technique after incubation. The results show that, both Copper/LDPE microcomposite and Copper/LDPE nanocomposite have the identical feature of Cu2+ on slow release in simulated uterine solution. The steady release rate of Cu2+ is 5μg /dayafter a burst release phase. The Copper/LDPE nanocomposite has the shorter burst release phase of Cu2+ than Copper/LDPE microcomposite.Copper/LDPE composite was prepared successfully by mixing and hot process forming methods. We investigated the Cu2+ release behavior controlled by Copper/LDPE microcomposite and nanocomposite in simulated uterine solution during 270 days. The results show that: both Copper/LDPE microcomposite and Copper/LDPE nanocomposite have the burst release phenomenon of Cu2+ in the first few day after incubation, and then the Cu2+ release behavior will tend to stable. The Cu2+ burst release phase has persisted for 50 days and 10 days of Copper/LDPE microcomposite and Copper/LDPE nanocomposite, respectively. The steady release rate of Cu2+ is about 20μg/day both Copper/LDPE microcomposite and Copper/LDPE nanocomposite.We prepared Indomethacin/copper/low density polyethylene composites with various mass fractions of copper particles and indomethacin powder by process forming and investigated a series of subjects listed as follows: the Cu2+ release behavior, the interference between Cu2+ and indomethacin, the effects between the dimension of copper particle and the release behavior of indomethacin, the interference between Human Serum albumin (HSA) and the release behavior of Cu2+/indomethacin. In the end, the composite was determined by using X-ray diffraction (XRD) technique before/after incubation. The results show that: first, the release behavior tended to identical feature both Cu2+ and indomethacin; second, Cu2+ release rate was accelerated due to the existence of indomethacin and the more mass fractions of indomethacin resulted the higher release rate of Cu2+; third, the mass fractions of indomethacin was irrelevant to release rate of Cu2+ when the release rate of Cu2+ was kept stable; finally, It is found that no obvious interference caused by the HSA in the experiment even though the HSA can both accelerate the release rate of Cu2+ and complex with indomethacin.In this thesis, we have made some surface treatments to the Copper/LDPE composites by flame thermal spraying, ultraviolet radiation andγ-ray radiation, respectively before incubation experiment. The results show that: the Cu2+ release rate of Copper/LDPE composites treated by surface treatment is 1 3 ~1 2 times than which not treated. This result seems very importance to slow down or eliminate the side-effect and, promote it's industrialization.As the chitosan is an excellent hydrophilic biomaterial, we prepared indomethacin/polyethylene alcohol/chitosan complex film and, investigated its controlled release behavior of indomethacin and absorbance of Cu2+, respectively. The results show that: the indomethacin has released out in five days by this complex film method.
Keywords/Search Tags:Intrauterine Device (IUD), Cupric ion (Cu2+), Indomethacin, Chitosan, Low density polyethylene (LDPE), Surface treatment, Controlled release, Burst release phenomenon
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