The Incompatibilities Between Chlorhexidine Diacetate and Some Tablet Excipients

The incompatibilities in a powder mixture for the manufacture of a chewable direct compression antiplague tablet preparate, were studied. The degree of loss of chlorhexi-dine diacetate in the presence of some common tablet exci-pients was studied under high relative humidity (80 % RH) and in water solution.

The most significant losses in water solution were observed with lubricants magnesium stearate and sodium lauryl sulphate. Under high relative humidity the greatest losses were, on the contrary, observed with the materials having a great water absorption capacity, such as sodium carboxy-methylcellulose and sodium starch glycolate.     

Biosensor recognition of thyroid-disrupting chemicals using transport proteins

Novel surface plasmon resonance-based biosensor assays for the bioeffect-related screening of chemicals with thyroid-disrupting activity are described. Two thyroid transport proteins (TPs), thyroxine binding globulin (TBG) and recombinant transthyretin (rTTR), were applied in an inhibition assay format in a Biacore 3000 using CM5 biosensor chips coated with l-thyroxine (T4), the main hormone of the thyroid system. Assay conditions were optimized for the natural thyroid hormones, and known thyroid disruptors and structurally related compounds were selected as model compounds to be tested in both assays for their relative potency (RP) compared to T4. The chosen compounds were halogenated phenols, halogenated bisphenols, bisphenol A, 3,5-dichlorobiphenyl, and its hydroxylated metabolite 4-hydroxy-3,5-dichlorobiphenyl (4-OH PCB 14). The TBG-based assay was highly specific for T4, and the rTTR-based assay was sensitive toward several compounds, the highest sensitivity (RP = 4.4) being obtained with 4-OH PCB 14, followed by tetrabromobisphenol A (RP = 1.5) and tetrachlorobisphenol A (RP = 0.75). For the bioeffect-related screening of known and identification of possible new thyroid disruptors, the TPs-based biosensor assays were more sensitive (IC(50) of 13.7 +/- 1.3 and 8.6 +/- 0.7 nM for the rTTR and the TBG-based assay, respectively), easier to perform, and faster alternatives (10 min/sample) than the currently used methods such as radioligand binding assays and immunoprecipitation-HPLC.     

实验室危险化学品的分类与管理

介绍了危险化学品的分类及安全管理。危险化学试剂的管理和存放是个很严谨的问题,实验室管理人员熟知大多数化学试剂的习性,便于在存放和使用化学试剂时,采取一些防范措施,避免由于存放和使用不当造成对实验人员及实验设备的危害。     

Hazard evaluation of chemicals for bulk marine shipment

For economic reasons most chemicals used in large quantities by industry are transported in tank vessels. These chemicals range in properties from essentially harmless to highly dangerous. Although the United States and IMCO require certain minimum data before classifying a new chemical to be transported in bulk, no formal system exists to correlate these data with specific shipboard requirements such as the location of the tank within the vessel, gauging and venting systems, or cargo overfill protection.Developing guidelines for the evaluation of chemicals is a two part problem. First, the inherent hazards of a chemical (the hazards of a product when it is released, without regard to its cargo containment system) must be investigated. In the second part of the evaluation, these hazards are then correlated with specific shipboards requirements as mentioned above. This paper outlines the essential elements for developing a comprehensive system of hazard evaluation for bulk liquid chemicals.