Search

The activity of eight chemical preservatives and one hundred and twenty-six different proportions of twenty-six different mixtures of two, three, four, and five esters of p-hydroxybenzoic acid was tested against four microorganisms isolated from pharmaceutical syrups. Storage tests were conducted in syrup, U. S. P., and diluted syrup (42.5% sucrose w/v) under two different storage conditions for 60 days. o-Phenylphenol was most effective against the mold fungi and the yeast and benzyl p-hydroxybenzoate was the most effective against the bacterium. The following preservatives appeared to be the most effective for syrup, U. S. P.: o-phenylphenol at 1:15,000; propyl p-hydroxybenzoate at 1:5000; methyl, ethyl, propyl, butyl, and benzyl esters of p-hydroxybenzoic acid in the proportion 15:15:15:15:40 w/w at 1:7500. Mixtures of the p-hydroxybenzoates exhibited a potentizing effect in both the antimicrobial tests and storage studies. Antimicrobial studies using the FD&C colors showed that FD&C Red No. 3 was effective against the bacterium at 1:20,000, and FD&C Orange No. 1 was effective against the bacterium at 1:4700 and against the yeast at 1:3000.

Publisher Summary This chapter describes the methods used for detecting antitumour activity and selecting drugs for clinical trial, and outlines the chemistry and pharmacology of compounds derived from plants, which possess antitumour activity. It discusses active compounds isolated from the higher plants and ferns where appropriate, substances obtained from fungi and bacteria are considered. Compounds are classified according to the functionality responsible for the activity rather than according to the classes of natural products, such as alkaloids and steroids. The chapter reviews number of methods that have been developed for detecting antitumour activity, all of which are a compromise between the desirable and the practicable such as Transplantable tumours, spontaneous tumours, induced tumours, heteroplanted human tumours, and tissue culture techniques and antimicrobial tests. The main test system employed is the transplanted animal tumour. Other tests, such as spontaneous and induced tumour systems, tissue culture techniques, and anti-microbial and biochemical tests, are used to a lesser extent.