Tissue culture of Digitalis mertonensis I. Effect of certain steroids on the callus growth and formation of baljet positive substances in D. mertonensis
✍ Scribed by R. S. Medora; D. P. N. Tsao; L. S. Albert
- Publisher
- John Wiley and Sons
- Year
- 1967
- Tongue
- English
- Weight
- 624 KB
- Volume
- 56
- Category
- Article
- ISSN
- 0022-3549
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✦ Synopsis
No general relationship between the chemistry methodology is satisfactory for testing a variety of of colorants and stability has been found. How-pharmaceutical products. A ranking of colorant ever, the indigoid, pyrazolone, and quinoline types stabilities in tablets is given which is intended to rank high in stability. Xanthenc, fluoran, and provide a guide for selecting a stable color for triphenylmethane dyes rank low. Monoazo and related formulations. anthraquinone colorants generally are intermediate. Functional groups and their positions no doubt are REFERENCES important factors in coloran; stability.
Tablets of R3 were run in duplicate in order to obtain an estimate of reproduciblity. The data for the various color differences and two concentrations of the colorant are summarized in Table 11. Color differences for each concentration are of different magnitudes as was noted previously. However, an inverse correlation between color difference and lightness, Y, is seen. For the lower concentration, tablet 1 has a lightness of 73.2 wersus 74.4 for tablet 2. Tablet 2 shows a smaller degree of fading in all instances, an effect related to the change in concentration. Even though the tablets contained the same amount of colorant, the compression of the powder gave tablets of variable lightness, a factor that alters stability to some extent. The same correlation can be seen for the higher concentration where tablet 1 is lighter than tablet 2.
SUMMARY AND CONCLUSIONS
A method of testing color stability using a colori-The same metric procedure has been described.