Solubility and dissolution rate studies of ergotamine tartrate

The solubility of ergotamine tartrate in aqueous solutions of tartaric acid, citric acid, hydrochloric acid, and caffeine and the dissolution rate of ergotamine tartrate in aqueous mixtures containing hydrochloric acid, caffeine, citric acid, or sodium acetate were studied. The Noyes-Whitney model of dissolution is useful for predicting the dissolution rate of ergotamine tartrate in most of the dissolution media. The relative slowness with which ergotamine chloride (a substance with low water solubility) precipitated when ergotamine tartrate was dissolved in 0.1 M HCl resulted in the solid dissolving faster in this medium than was predicted using the Noyes-Whitney equation.