ABSTRACT
The study focused on the in vitro release of Buyanghuanwu (BYHW) elementary osmotic pump sustained release tablets. Its band similarity was calculated by the total quantum statistical moment. Meanwhile, in vitro release characteristics were analyzed to discuss the existence of supramolecular imprinting templates. The results show that the same imprint templates may exist in different structures of traditional Chinese medicine(TCM)'s multi-components. The BYHW sustained release tablets prepared by elementary osmotic pump can meet the objectives of "overall control, synchronous release". However, the supramolecular imprinting templates in TCM compound prescriptions should be further explored, the overall and synchronous release of different components was controlled through imprinting templates, so as to seek the more suitable sustained release preparation technology for multiple components of TCM, and make it in line with the characteristics of TCM.
ABSTRACT
We synthesized a novel (18)F-labeled dopamine D(4) receptor antagonist (Ki=4.3 nM), 3-(4-[(18)F]fluorobenzyl)-8-methoxy-1,2,3,4-tetrahydrochromeno[3,4-c]pyridin-5-one ([(18)F]FMTP), which has exhibited high affinity and selectivity. Radiosyntheses were accomplished by the reaction of fluorine-18-labeled intermediate with 8-methoxy-1,2,3,4-tetrahydrochromeno[3,4-c]pyridin-5-one (1) followed by HPLC purification. The overall radiochemical yield of the radiosynthesis was 19.5% (decay corrected), the specific radioactivity was about 110 GBq/micromol and the radiochemical purity was greater than 99%, the time of synthesis and purification was approximately 110 min. Tissue distribution studies of the [(18)F]FMTP in rats showed that the radioactivity in the brain was concentrated in frontal cortex and medulla, the region that has a high density of D(4) receptors. Pre-treatment with nonradioactive FMTP (1.0mg/kg) produced a significant reduction of radioactivity in all the regions. About 40% of total radioactivity in plasma and 100% in rat brain extract represented unchanged radioligand at 60 min after injection as determined by HPLC. These results indicate that [(18)F]FMTP have some specific binding to the D(4) receptor.
