Effect of solvent on crystal habit and dissolution behavior of tolbutamide by initial solvent screening

Abstract

By an initial solvent screening of 18 solvents, 14 pure good solvents were selected for the crystallization of tolbutamide. Solid generation by the solvent-change method was carried out using the pure good solvents. Crystals were generated in only 10 of the 14 solvents. Different crystal forms of tolbutamide were obtained. Crystals were subjected to evaluation tests such as differential scanning calorimetry, optical microscopy, and in vitro dissolution. All crystals were determined as isomorphic by differential scanning calorimetry. Dissolution rate was influenced by crystal form. Thus, the choice of suitable crystal habit and proper selection of solvent is important in manufacturing the drug tolbutamide.