Oriented Crystallization on Organic Monolayers to Control Concomitant Polymorphism |
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Authors: | Pranita Bora Dr Basanta Saikia Dr Bipul Sarma |
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Institution: | Department of Chemical Sciences, Tezpur University, Tezpur, 784028, Assam India |
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Abstract: | Nucleation events and crystal growth can be guided by molecular recognition at interfaces through intermolecular interactions. The short-acting antimicrobial sulfa drug sulfathiazole is known for its concomitant crystallization, which has five known polymorphs, due to conformational flexibility and hydrogen-bond synthon variation. In its development stage of a drug the issue of concomitant crystallization needs to be addressed with respect to patent litigation, including legal actions to protect patents against infringement. A functional self-assembled monolayer (SAM) of organic thiol on a gold surface has been employed as an efficient approach to control concomitant nucleation of such flexible drugs. The crystallization on a SAM surface is mostly kinetically driven and often leads to the nucleation of novel metastable forms. Spectroscopic, thermal analysis and X-ray diffraction studies reveal that a previously unknown, sixth form of the drug nucleates on the designed SAM surface. |
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Keywords: | crystal engineering crystal growth monolayers polymorphism self-assembly |
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