[Changes of the spectrum on thyroid disease after the ten-year implementation of universal salt iodization in Guangxi Zhuang Autonomous Region].

OBJECTIVE: To reveal the relationship between iodine nutrition and the change of spectrum on thyroid diseases through comparing the different iodine environments pre- and post- the universal salt iodization(USI)campaign. METHODS: To compare the urinary iodine concentration between 1000 normal people and 5998 patients with thyroid disease who had undergone surgical operations, from 4 major cities, including iodine deficient and rich areas of Guangxi Zhuang Autonomous Region. RESULTS: After USI was put into practice, the urinary iodine concentration of patients with thyroid appeared higher than those of normal people(324.3 µg/L vs. 238.5 µg/L, P < 0.05). The urinary iodine concentrations of nodular goiter,Graves disease, toxic nodular goiter, thyroid papillary carcinoma and Hashimoto's thyroiditis were higher than those before the USI was taken(263.8 µg/L vs. 69.75 µg/L, 289.7 µg/L vs. 228.3 µg/L, 346.8 µg/L vs. 268.4 µg/L, 350.3 µg/L vs. 316.2 µg/L and 378.5 µg/L vs. 305.8 µg/L). The proportions of toxic nodular goiter, thyroid papillary carcinoma and Hashimoto's thyroiditis appeared as 7.59% vs. 4.80%, 5.85% vs. 4.02% and 3.88% vs. 2.46%, all higher than those before the implementation of USI, except the nodular goiter which showed a reduction (63.56% vs. 69.75%). CONCLUSION: The spectrum of thyroid diseases appeared an obvious change in Guangxi within the last 10-year implementation of USI. However, the excessive intake of iodine might serve as a risk factor for toxic nodular goiter, thyroid papillary carcinoma and Hashimoto's thyroiditis.

[Determination of vitexin-rhamnoside in Beagle dog plasma and preliminary pharmacokinetics of Yixintong sustained release tablets].

OBJECTIVE: To develop an HPLC method to determine vitexin-rhamnoside in plasma of Beagle dogs and study the pharmacokinetics and bioavailability of Yixintong sustained release tablets in Beagle dogs. METHOD: A newly-developed HPLC method using C18 column and methanol-acetonitrile-tetrahydrogenfuran-0.5% acetic acid (1:1:19.4:78.6) as mobile phase was validated, and then was employed to determine vitexin-rhamnoside in plasma of Beagle dogs after oral administration of Yixintong sustained release tablets and general tablets. The main pharmacokinetic parameters were estimated by pharmacokinetic program 3p87. The non-compartmental pharmacokinetic parameters were also calculated on basis of the statistic moment theory. RESULT: The pharmacokinetic profiles of Yixintong sustained release tablets and the general tablets were fitted to a one-and two-compartment open model, respectively. The T1/2, Tmax, AUC0-infinity and MRT for Yixintong sustained release tablets were 5.22 h, 4.0 h, 6,792.75 ng x h x mL(-1) and 8.4 h, respectively, compared with 8.94 h, 1.0 h, 5,880.4 ng x h x mL(-1) and 6.1 h for the general tablets. The relative bioavailability of the Yixintong sustained release tablets was 115.5% in Beagle dogs. CONCLUSION: The sustained-release characteristic of Yixintong sustained release tablets were confirmed by pharmacokinetic study.

Release-controlling absorption enhancement of enterally administered Ophiopogon japonicus polysaccharide by sodium caprate in rats.

The aim of this study was to improve the intestinal absorption of Ophiopogon japonicus polysaccharide (OJP) by incorporating it together with sodium caprate (SC) into erodible matrices, designed to release OJP and SC at various rates over different periods of time. OJP, a graminan type fructosan with an average molecular weight in number of 3400 Da has been demonstrated to have anti-myocardial ischemic activity. The determination of OJP blood levels was carried out by the fluorescein isothiocyanate (FITC) prelabeling method. Matrix tablets, possessing different erosion rates, were prepared by changing the amounts of sodium alginate and using the two-layer tableting technique. Formulation effectiveness was evaluated by monitoring OJP plasma levels after intra-intestinal administration of each of the tablets to anesthetized rats. The findings indicate that all the SC containing formulations can significantly improve FITC-OJP bioavailability. Compared with the formulations not containing SC, the increase varied from 5.6- to 20.8-fold for the worst and best SC containing formulations studied, respectively. Moreover, there were no statistically significant differences between the C(max) and AUC(0-4) values obtained for three optimized formulations, which synchronously or nonsynchronously released both FITC-OJP and SC within 1-2 h. Their absorption enhancement effects were 2.1- to 3.6-fold higher than those of faster and slower release formulations studied. Fast delivery of the drug and its absorption adjuvant(s) contributes to their high concentrations at the absorption sites. However, at the same time, it leads to their short residence times and fast dilution by intestinal fluids. The better the balance between the two opposite effects for drug absorption, the more effective absorption enhancement would be obtained.