Analysis of factors affecting dissolution of digoxin from tablets.

Abstract

Factors affecting dissolution of digoxin from the tablets were investigated on the basis of the measurement on physical characteristics and the amount of digoxin released from 10 lots of tablets prepared by different procedures and formulations. While the hardness, friability and basket disintegration time (by U. S. P. dissolution apparatus) were influenced by the content of magnesium stearate, the disintegration time (by J. P. disintegration test method) was neither affected by the content of magnesium stearate nor the preparative procedure. Concerning the dissolution test by the U.S.P. dissolution apparatus, it was found that the dissolution rate had a tendency to increase with an increase in the rotation speed of basket. The dissolution of the tablets prepared by the powder dilution method was influenced significantly by the difference in mean particle size of digoxin powders, while the release of digoxin from the tablets produced by solvent deposition method showed a fast dissolution profile compared with the case by powder dilution method without depending on the difference in batch. Therefore, it was found that one of the predominant factors affecting the release of digoxin from digoxin tablets was either the formulation or the preparative procedure. Additionally, it was proposed that the dissolution test should be necessary for a quality test of digoxin tablets because the present J. P. disintegration test alone could not guarantee the quality of the tablets.