EFFECT OF COLORANTS ON SOLUBILITY OF MODIFIED CELLULOSE POLYMERS

The effect of colorants on the solubility characteristics of cellulose polymers was studied. The work was conducted because of earlier findings that FD & C Red No. 3 dye altered the solubility of hydroxypropyl methylcellulose to the extent that dried films were insoluble in media below approximately pH 5.5. A total of 28 dyes was screened in combination with hydroxypropyl methylcellulose, hydroxypropyl cellulose, and sodium ethylcellulose sulfate. Free film solubility disclosed that six dyes significantly altered the solubility of the polymers tested. Coatings containing FD & C Red No. 3, FD & C Red No. 4, D & C Red No. 17, D & C Red No. 18, D & C Red No. 21, and D & C Red No. 22 dyes were shown to have a retardation effect on tablet disintegration and riboflavin dissolution rate. Riboflavin urine excretion studies confirmed that these dyes may adversely affect in vivo product performance. The effects of the insoluble films on in vitro and in vivo product performance will depend upon the thickness and strength of the film as well as the disintegrating characteristics of the tablet. Copyright © 1969 Wiley‐Liss, Inc., A Wiley Company