ANYL 202 |
| Crystals of a chemical compound can be exist in more than one structure, which is known as polymorphism. Polymorph screening, in which discovering and characterizing all possible solid forms that a target compound can have, is required in the early stage of the drug development process. In this work, a novel technology for generating different crystal forms concomitantly is described. Arrays of small solution droplets on the nano- and pico liter scale are generated using patterned substrates of SAM's1. As the solvent evaporates from the droplets, the crystals are formed within each droplet. The solid state form of each crystal produced is characterized using Raman and optical microscopy. With mefenamic acid and sulfathiazole as model drug compounds, two and four different polymorphic forms of mefenamic acid and sulfathiazole, respectively, were observed under identical conditions. Furthermore, it is established the polymorphic distribution of crystals obtained is highly dependent on the evaporation rate of solvent and the concentration of solution. These results imply that the different polymorphic forms competitively nucleate in a solution, and the probability of each polymorph form nucleating is strongly dependent on the supersaturation of the solution. In addition, the size of the crystals obtained can be controlled through control of the domain size. |
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Characterization of Polymorphic Compounds and Mixtures
1:30 PM-4:55 PM, Monday, 11 September 2006 Moscone Center -- Room 130, Oral
Division of Analytical Chemistry |