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A hydrophobic and 2-thiophen-2-yl-vinyl-conjugated ruthenium complex, cis-Ru(dhtbpy)(dcbpy)(NCS)2 [dhtbpy = 4,4'-di(hexylthienylvinyl)-2,2'-bipyridyl; dcbpy = 4,4'-dicarboxy-2,2'-bipyridyl], was newly designed, synthesized and applied successfully to sensitization of nanocrystalline TiO2-based solar cells, giving a conversion efficiency of 9.5% under irradiation with AM 1.5 solar light.

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We performed a 28-day repeated-dose toxicity study of ethynylestradiol (EE) and bisphenol A (BPA) based on the draft protocol of the "Enhanced OECD Test Guideline no. 407", and assessed the sensitivity of a list of parameters for detecting endocrine-related effects of endocrine disruption. Doses of EE at 0, 10, 50 or 200 microg/kg per day, or BPA at 0, 40, 200 or 1000 mg/kg per day were orally administered to Sprague-Dawley rats. The highest dose of BPA was decreased to 600 mg/kg per day from the second week of administration because a male rat given 1000 mg/kg BPA had died within 1 week with toxic clinical signs. In the assay using EE, the decrease of prostate, seminal vesicle and pituitary weights, increase of the testis weight, atrophic changes of the prostate, seminal vesicle and mammary gland, and degenerative changes in the testes were detected in male rats in the 50 and/or 200 microg/kg groups. In females of the 200 microg/kg group, decrease of the ovary weight, increase of the uterine weight, atrophy of the ovary, hypertrophy or squamous metaplasia of the uterine epithelial cells and mucification in the vagina were observed. Furthermore, diestrous, estrous or the unknown stage was prolonged in the 50 and 200 microg/kg groups of rats. Endocrine-mediated effects of EE were not detected in general observations, hematology, serum biochemistry, or hormonal or spermatological examinations. In the assay using BPA, the diestrous stages were prolonged at the highest dose, but changes related to endocrine effects were not detected in other examinations. Thus, among the parameters tested, the weight of endocrine-linked organs and their histopathological assessment and estrous cycle stage allowed the detection of the endocrine-related effect of EE, whereas the estrous cycle stage was only a useful parameter to detect the effect of BPA.

The object of this study was to enhance the solubility, dissolution rate, and oral bioavailability of rutin by complexation with 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CyD). The interaction of rutin with cyclodextrins (CyDs) was evaluated by the solubility, and ultraviolet (UV) and circular dichroism (CD) spectrophotometries. The chemical and enzymatic stability of rutin was examined in an alkaline buffer solution and in rat small intestinal homogenates, respectively. Dissolution rates of rutin and its CyD complexes were measured by the dispersed amount method. In vivo absorption studies of rutin after oral administration via conventional tablet containing rutin alone or its beta-CyD complexes was performed on beagle dogs. The stability constants calculated from the phase solubility method increased in the order of HP-gamma-CyD < G2-beta-CyD < beta-CyD < HP-beta-CyD. Spectroscopic studies also revealed that HP-beta-CyD and beta-CyD formed a relatively more stable inclusion complex with rutin. The dissolution rates of rutin increased by the complexation with CyDs in the order of rutin alone < HP-beta-CyD < or = beta-CyD. HP-beta-CyD inhibited the hydrolysis of rutin in the alkaline buffer solution and the small intestinal homogenates of rats, suggesting that HP-beta-CyD may stabilize rutin in a gastrointestinal tract after oral administration. When the tablet containing rutin or its beta-CyD complexes was administered to beagle dogs, the plasma levels of homovanillic acid (HVA) (a major stable metabolite of rutin) after oral administration of HP-beta-CyD complex were much higher than in either that of rutin alone or in its beta-CyD complex. The in vivo absorption study suggests that HP-beta-CyD increased the oral bioavailability of rutin from the gastrointestinal tracts of beagle dogs because of the increase in solubility, faster dissolution rate, and gastrointestinal stability. HP-beta-CyD has a significant advantage with respect to providing high aqueous solubility while maintaining a lack of toxicity in oral pharmaceutical preparations of rutin.