PREDICTING THE DISSOLUTION RATE OF IBUPROFEN-ACIDIC EXCIPIENT COMPRESSED MIXTURES IN REACTIVE MEDIA

Acid excipients suppressed the dissolution rate of ibuprofen from mixed discs causing the drug's dissolution profile to curve positively while the excipient profile curved negatively. The release of ibuprofen into a buffered medium from compressed discs containing adipic acid, succinic acid, L-(+)-tartaric acid or citric acid monohydrate indicated that the extent of suppression and curvature depends on the proportion of excipient in the disc, its pK(a) and solubility. Good predictions for the solubility of ibuprofen in acid excipient solutions were made using EQUIL(R). A modified non-interacting model which uses these solubility predictions to calculate limiting rates gave the most accurate predictions in the case of the less soluble excipients.