Topical preparations, stability testing

There are a number of informative reviews on anodes for SOFCs [1-5], providing details on processing, fabrication, characterization, and electrochemical behavior of anode materials, especially the nickel-yttria stabilized zirconia (Ni-YSZ) cermet anodes. There are also several reviews dedicated to specific topics such as oxide anode materials [6], carbon-tolerant anode materials [7-9], sulfur-tolerant anode materials [10], and the redox cycling behavior of Ni-YSZ cermet anodes [11], In this chapter, we do not attempt to offer a comprehensive survey of the literature on SOFC anode research instead, we focus primarily on some critical issues in the preparation and testing of SOFC anodes, including the processing-property relationships that are well accepted in the SOFC community as well as some apparently contradictory observations reported in the literature. We will also briefly review some recent advancement in the development of alternative anode materials for improved tolerance to sulfur poisoning and carbon deposition. 

Accelerated stability tests provide a means of comparing alternative formulations, packaging materials, and/or manufacturing processes in short-term experiments. As soon as the final formulation and manufacturing process have been established, the manufacturer carries out a series of accelerated stability tests which will enable the stability of the drug product to be predicted and its shelf-life and storage conditions determined. Real-time studies must be started at the same time for confirmation purposes. Suitable measures should be taken to establish the utilization period for preparations in muitidose containers, especially for topical use. 

Environmental analytical association Ecoanalytica produce standai d samples during last 12 years. Two topics will be discussed. The first is the principles of development of staictures and maintenance of quality of standai d samples. The organization of manufacture and maintenance of their stability ai e considered too in the report. Besides them authors consider scientifically-methodical aspects of preparation of samples for experimental check of technical competence of analytical laboratories and also samples for interlaboratory tests. 

Part ICl contains an expert report on the chemical, pharmaceutical, and biological documentation. Topics presented include composition, method of preparation, control of starting materials, control tests on intermediate products, control tests on hnished product, stability, and information on the pharmaceutical expert. An example is given in Exhibit 8.5. 

In a variation of this theme, the stabilizer used is albumin. This technology results in an amorphous nanoparticle form of the drug coated by albumin, and having a size of about 100-200 nm. Drugs prepared by this technology have been tested by intravenous, intra-arterial, inhalational, oral, and topical administration. In the case of i.v. paclitaxel, the albumin is said to result in an increased and prolonged intracellular availability of the drug. ... 

Many problems occur in Se-speciation analysis, owing e.g. to risks of adsorption on container walls, instability of species or contamination, insufficient separation efficiency of the chromatographic techniques, problems of conversion yield of selenite to selenate etc. Prior to conducting an interlaboratory project on this topic, it was hence decided to assess the stability of selenite and selenate according to various factors (effects of container materials, additives, temperature and light). The study focused on tests of effects of physicochemical parameters on solutions stored in polyethylene and PTFE containers. Container volumes were 100 and 500 mL for polyethylene and 500 and 1000 mL for PTFE. Stock and initial working solutions were prepared in 1 and 5 L polyethylene containers previously cleaned with nitric acid (at pH 2) and rinsed with Milli-Q water. The stock solutions were prepared with sodium selenite and sodium selenate (purity >98%). 

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