The solubilities of the pharmacopœial organic acids and their salts / by Atherton Seidell.

  • Seidell, Atherton, 1878-1961.
Date:
[1910]
Catalogue details

Licence: In copyright

Credit: The solubilities of the pharmacopœial organic acids and their salts / by Atherton Seidell. Source: Wellcome Collection.

    72/104 (page 70)
    saponifying in a closed flask and titrating the excess of alkali used. The results showed the material to be of practically 100 per cent purity. Only one series of solubility determinations was made, the time of shaking being two days. The amount of phenyl salicylate was deter- mined by evaporation of the solvents at 55-60° and drying the residues to constant weight in a vacuum desiccator. The results are given in Table No. XXXIII and the curve in figure 6. The amount dissolved by water according to the present deter- mination is only about one-third that reported by the pharmacopada. The actual amount, however, in both cases is verv small and the state- ment of most of the other reference books that salol is almost insoluble in water is perhaps suflicient for all practical purposes. In regard to the figures ipioted for alcohol very great variations exist in the litera- ture. Thus it is given as 1 part in 5 by the IT. S. Pharmaco])a'ia, as 1 part in 10 by most of the German authorities, and as 1 jiart in 20 by Sc[uire’s Companion to the British Pharmacopoeia. The present results show that the value cjiioted by the U. S. Pharmacopada is very near the correct figure. Table No. XXXIII.—Solubility of phenyl salicylate in aqueous alcohol at 25° C. EXPERIMENTAL DETERMINATIONS. Solvent. Specific grav- ity of saturated solution at 25° C. C6II4OII- Specific grav- ity at 15°. Per cent by weight of C2II5OH. COOCoIls per 100 grams sat- urated solution. Dist. H2O 0.0 0.999 Grams. 0.015 0.986 8.9 0.985 0.018 0.954 32.0 0.950 0.067 0.916 51.0 0.912 0.861 0.872 70.2 0.877 4.44 0.828 88.0 0.863 11.91 0.805 96.3 0.878 26.68 0.794 99.8 0.897 34.73 CALCULATED DETERMINATIONS. The above results plotted on cross-section paper yielded a curve from which the following results were read: Per cent by weight of CcIIsOII in solvent. Specific gravity sat- urated solu- tion at 25° C. CelLOIICOOCsIIt, per 100 grams. Solvent to dissolve 1 gram CUL- OlICOOCcIR. Saturated solution. Solvent. Per cent. Grams. Grams. Grams. 0 0.999 0.015 0.015 6665.00 20 0.967 0.020 0.020 5tKK). 00 40 0.934 0.220 0.220 453.50 50 0.914 0.760 0.770 130.60 60 0.895 2.100 2.150 46.62 70 0.877 4.400 4.000 21.73 80 0.863 7.700 8.340 11.99 90 0.865 14.000 16.280 6.14 0 92.3 0.868 17.700 21.510 4.65 100 0.898 35.000 53.860 1.86 “U. S. Pharmacopoeia strength.