99 research outputs found

    Synthetic Geopolymers for Controlled Delivery of Oxycodone: Adjustable and Nanostructured Porosity Enables Tunable and Sustained Drug Release

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    In this article we for the first time present a fully synthetic mesoporous geopolymer drug carrier for controlled release of opioids. Nanoparticulate precursor powders with different Al/Si-ratios were synthesized by a sol-gel route and used in the preparation of different geopolymers, which could be structurally tailored by adjusting the Al/Si-ratio and the curing temperatures. In particular, it was shown that the pore sizes of the geopolymers decreased with increasing Al/Si ratio and that completely mesoporous geopolymers could be produced from precursor particles with the Al/Si ratio 2∶1. The mesoporosity was shown to be associated with a sustained and linear in vitro release profile of the opioid oxycodone. A clinically relevant release period of about 12 h was obtained by adjusting the size of the pellets. The easily fabricated and tunable geopolymers presented in this study constitute a novel approach in the development of controlled release formulations, not only for opioids, but whenever the clinical indication is best treated with a constant supply of drugs and when the mechanical stability of the delivery vehicle is crucial

    The FOAM study : Is Hysterosalpingo foam sonography (HyFoSy) a cost-effective alternative for hysterosalpingography (HSG) in assessing tubal patency in subfertile women? Study protocol for a randomized controlled trial

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    This is an investigator initiated trial, VU medical center Amsterdam is the sponsor, contact information: prof. CJM de Groot, Department of Obstetrics and Gynaecology, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands, Tel: + 31-204444444. This study is funded by ZonMw, a Dutch organization for Health Research and Development, project number 837001504. ZonMW gives financial support for the whole project. IQ Medical Ventures provides the ExEm FOAM® kits. The funding bodies have no role in the design of the study; collection, analysis, and interpretation of data; and in writing the manuscript.Peer reviewedPublisher PD

    Spectral properties of myeloperoxidase compounds II and III

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    In order to resolve the confusion about the spectral properties of myeloperoxidase Compound II and Compound III (myeloperoxidase is donor:hydrogen-peroxide oxidoreductase, EC 1.11.1.7), the absorbance spectra in the visible and ultraviolet regions were measured under conditions where either Compound II or Compound III was present. Peak positions, isosbestic points and absorption coefficients are presented. We conclude that in most studies on Compound II or Compound III, mixtures of these compounds had been present. Our data indicate that the relative contributions of Compound II and Compound III in a sample can be determined from the absorbance ratio A625nm/A456nm. The optical absorbance spectrum of myeloperoxidase compound III was not affected by pH (pH 3-8). The absorbance spectrum of Compound II, however, was dependent on pH. The absorbance spectrum of Compound II at high pH is describe
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