INFLUENCE OF CRYSTALLIZATION SOLVENT AND DISSOLUTION BEHAVIOR FOR A DICLOFENAC SALT

11 samples of diclofenac/N-(2-hydroxyethyl)pyrrolidine salt obtained by crystallization from alcohol-type solvents or mixtures with triacetin were analyzed by scanning electron microscopy and differential scanning calorimetry. Few differences were found concerning the size parameters of particles obtained from different solvents, while the shape parameters displayed major differences depending on the crystallization solvent. Most of the samples showed simple thermograms while in the case of those obtained from isopropanol and 1,3-butanediol, the presence of the solvent inside the mass of the crystals was recorded. Dissolution profiles were found to be different for all the samples (due also to different sizes of the dissolving particles). An interesting linear relationship was found between the efficiency of dissolution and the shape factor of the dissolving particles, suggesting the relevant importance of shape irregularity in affecting dissolution rate differences.