The Relation Between in Vitro Disintegration Time of Sugar-Coated Tablets and Physiological Availability of Riboflavin*

Abstract

Many in vitro disintegration procedures have been suggested, but no attempt appears to have been made to assess their physiological validity in a uantitative manner. In the present stud the U. S. P. XIV disintegration test was modified for application to sugar-coated taglets. Simulated gastric and alkaline juices and a form of rubbing action with a rubber disk were found to be essential. The validity of the modified procedure was evaluated by a comparison with measurements of the physiological availability of riboflavin in the tablets as determined by a human bioassay technique. Results showed that tablets which did not disintegrate in vitro in sixty minutes were not completely available to the human subject as judged by urinary excretion of riboflavin. An eight-hour urinary excretion test was found, in most cases, to be as reliable as the twenty-four hour test. Satisfactory bioassay results were obtained without the use of special diets.