Anticholinesterase activity of some degradation products of physostigmine

✍ Scribed by B. A. Hemsworth; G. B. West

• Publisher: John Wiley and Sons
• Year: 1970
• Tongue: English
• Weight: 347 KB
• Volume: 59
• Category: Article
• ISSN: 0022-3549
• DOI: 10.1002/jps.2600590128

✦ Synopsis

which is capable of spreading. The spreading test may also be applied in certain cases to the detection of solid contaminants, such as detergents which are leached by solvents. The recent report of silicones present in disposable syringes (10) suggests another possible application. Silicones are surface active; if spread on water, as little as 0.01 mg. can easily be determined (1 1).

Although the spreading method is very sensitive, it is limited to those impurities which are not very volatile and which have some affinity for the surface. Included in this category are surfactants, lipids, most polymers, and some other materials such as steroids and antibiotics. The method is incapable of detecting, for example, the presence of low boiling homologs or isomers in hexane. Therefore it should not be considered a substitute for other methods of checking purity. Nevertheless, if it is necessary to determine trace quantities of surface-active impurities, the spreading method represents a convenient and efficient tool.