A Comparison of the Caries-preventive Effects of Fluoride Mouthrinsing, Fluoride Tablets, and Both Procedures Combined: Final Results after Eight Years

This paper presents final results of an eight-year clinical trial designed to compare the caries-preventive benefits of two self-administered fluoride procedures when used separately and in combination with one another. Children in kindergarten and first grade residing in Springfield, Ohio, a nonfluoridated community, were assigned randomly within school to one of three groups that either (a) rinsed once a week in school with a 0.2 percent neutral NaF solution; (b) chewed, rinsed with, and then swallowed daily in school a neutral 2.2 mg NaF tablet; or (c) carried out both procedures. At baseline (1981), 1,640 participants were examined clinically using the DMF surface index. Findings for 640 children remaining after eight years show that subjects in the combination group experienced a mean caries increment of 2.40 DMFS, 15.2 percent lower than the mean score of 2.83 DMFS for children in the tablet group and 32.8 percent lower than the 3.57 DMFS for those in the rinse group. Only the difference in incremental caries scores between the combined fluoride procedure and the fluoride rinse was statistically significant (P less than .05). The pattern of these findings is similar to that found on the two interim examinations. Even though the combined regimen showed an additional caries-preventive benefit compared with the rinse, considerations of cost effectiveness and feasibility do not support changing an ongoing rinse program to one that employs both procedures. For new programs the best choice appears to be the tablet procedure alone.     

Mechanism of ionophore A23187 induction of plasma protein leakage and of its inhibition by indomethacin

Calcium ionophore A23187 produced a dose-dependent increase in plasma protein leakage on intradermal injection in rats. Studies with mepyramine and cyproheptadine indicated that histamine and 5-hydroxytryptamine (5-HT) partially contribute to the ionophore action and experiments with compound 48/80 supported these findings. Depletion of plasma kininogen levels with cellulose sulphate administered indomethacin inhibited the ionophore response in a dose-dependent manner. The inhibition was not reversed by intradermally injected prostaglandin E2 (PGE2) in doses up to 50 ng/site, suggesting that PGE2 also may not be an important mediator. It is proposed that the ionophore produces plasma protein leakage by an indirect (through histamine and 5-HT release) and a direct action on vascular endothelial cells and that indomethacin antagonises both actions by inhibiting calcium transport processes.     

线性变温法测定氨酚待因片中磷酸可待因稳定性的研究

应用双波长扫描法和动力学线性变温法测定了纯品磷酸可待因和氨酚待因片中磷酸可待因的化学稳定性,测得氧化分解活化能 E 分别为106.789及119.547 kJ·mol~(-1);25℃时贮存期 t_(0.9)分别为3.75及9.85年。     

西药片剂对大肠杆菌存活影响的研究

本文根据卫生部《药品卫生检验方法》，研究了１８种西药片剂对大肠杆菌存活的影响。结果表明：有１７种片剂不利于大肠杆菌的存活。建议对西药制剂应该有选择地进行卫生学限度检查。     

苯妥英钠缓释片的研制

参照美国药典收载的“延效苯妥英钠胶囊”的体外释放速率,筛选处方,制成苯妥英钠缓释片,并进行体外释放度测定。根据测定结果表明,能达到延效目的,因此,每天只需服药1～2次。     

三波长分光光度法测定常药降压片中氢氯噻嗪的含量

本文介绍了三波长分光光度法的基本原理和实验方法,以及应用该法在751G 型分光光度计上测定常药降压片中氢氯噻嗪含量的结果。其平均回收率为99.79±0.64%(95%置信率)。     

感冒欣片中扑热息痛的差示紫外分光光度测定

采用差示紫外分光光度法测定感冒欣片中扑热息痛的含量。方法简便准确，平均回收率为１００．４％，ＲＳＤ为０．２２％。     

对心律平片卫生学检验方法的探索

作者进行了心律平片对五种不同菌的最低抑菌浓度(MIC)的测定,然后就心律平片和具抑菌作用的甲硝唑片对大肠杆菌最低抑菌浓度(MIC)做了比较,在此基础上对心律平片的卫生学检验方法进行了探索。结果表明:心律平片也有较强的抑菌作用,需经去除其抑菌成份,方可行大肠杆菌的检出。     

The Influence of Polymer Glass Transition Temperature and Molecular Weight on Drug Release from Tablets Containing Poly(DL-lactic Acid)

Five molecular weight grades of poly(DL-lactic acid) were characterized using gel permeation chro-matography, differential scanning calorimetry, and viscometry to determine the effect of molecular weight on the glass transition temperature and the intrinsic viscosity. In addition, dynamic mechanical thermal analysis was used to assess the dynamic storage modulus and the damping factor of the polymer samples by detecting motional and structural transitions over a wide temperature range. Significant relationships were found between the molecular weight and these polymer properties. The five grades of poly(DL-lactic acid) were also incorporated as binders into matrix tablet formulations containing the model drug theophylline and microcrystalline cellulose. Dissolution studies showed significant correlations between the properties of the polymer and the matrix release profiles of the tablets. The release of theophylline slowed down progressively as the polymer molecular weight increased. The differences in release became less significant and reached a limiting asymptotic value as the molecular weight increased to 138,000. Further, tablet index testing was utilized to determine the compaction properties of the polymer granulations. Although there was no correlation with the molecular weight of PL A, brittle fracture index testing indicated very low brittleness for all granulations tested. However, bonding index determinations correlated very well with both the physical-mechanical properties of the polymer and drug release profiles.