@article {46372, title = {Supramolecular synthon hierarchy in bumetanide cocrystals}, journal = {Acta Crystallographica A-Foundation and Advances}, volume = {70}, year = {2014}, month = {FEB}, pages = {C721}, type = {Meeting Abstract}, keywords = {Novel cocrystals of sulfonamide drug Bumetanide with carboxamides are developed based on supramolecular synthons approach}, issn = {2053-2733}, author = {Allu, Suryanarayana and Bolla, Geetha and Tothadi, Srinu and Nangia, Ashwini} } @article {43818, title = {Supramolecular synthons in bumetanide cocrystals and ternary products}, journal = {Crystal Growth \& Design}, volume = {17}, year = {2017}, month = {AUG}, pages = {4225-4236}, type = {Article}, abstract = {A novel design strategy for cocrystals of the diuretic sulfonamide drug bumetanide (BUM) with carboxamides is reported based on reliable supramolecular synthons. Binary cocrystals of BUM with pyridine carboxamides, pyridones, and cytosine were obtained by solvent assisted grinding followed by solution crystallization. All cocrystal structures exhibit hydrogen bonding of the coformer with the carboxylic acid group of BUM via heterosynthons which replace the acid homodimer in the drug crystal structure. Pyridones are inserted as N-H center dot center dot center dot O dimers which are in turn bonded to the acid group of BUM, while the pyridine amide coformers interact via the acid amide heterosynthon. Cocrystal polymorphs were obtained for bumetanide isonicotinamide cocrystal structure with the sulfonamide pyridine and sulfonamide acid synthons. Careful crystal packing analysis of BUM structure and nine new binary adducts gave an idea for the design ternary cocrystals, and subsequently four new ternary crystalline products were crystallized. Whereas the binary cocrystal structures were confirmed by single crystal diffraction, the ternary combinations were chatacterized by their unique powder X-ray diffraction patterns as well as by thermal and spectroscopic techniques.}, doi = {10.1021/acs.cgd.7b00531}, author = {Allu, Suryanarayana and Bolla, Geetha and Tothadi, Srinu and Nangia, Ashwini} } @article {46804, title = {Salts and cocrystal of etodolac: advantage of solubility, dissolution, and permeability}, journal = {Crystal Growth \& Design}, volume = {20}, year = {2020}, month = {JUL }, pages = {4512-4522}, type = {Article}, abstract = {

{Etodolac (ETD) is a nonsteroidal anti-inflammatory drug (NSAID) approved by the United States Food and Drug Administration (US-FDA) in 1991 for the treatment of rheumatoid arthritis. Because of its poor aqueous solubility and high permeability, ETD falls under Biopharmaceutics Classification System (BCS) Class II drug. The present study was aimed to screen stable salts and cocrystals of ETD using Generally Recognized as Safe (GRAS) and a few non-GRAS coformers. Crystallization of five salts (i.e.

}, issn = {1528-7483}, doi = {10.1021/acs.cgd.0c00313}, author = {Rai, Sunil K. and Allu, Suryanarayana and Nangia, Ashwini K.} } @article {48432, title = {Synthesis of ternary cocrystals, salts, and hydrates of acefylline with enhanced dissolution and high permeability}, journal = {Crystal Growth \& Design}, volume = {22}, year = {2022}, month = {JUN}, pages = {4165{\textendash}4181}, abstract = {

Acefylline (ACF) is a stimulant xanthine derivative drug, which is formulated as a piperazine salt for the treatment of bronchial asthma. ACF falls under BCS class IV category of low solubility and poor permeability, which together limit the bioavailability and efficacy of the drug. In this work, ACF binary and ternary cocrystals, salts{\textendash}cocrystals, and their polymorphs are synthesized by cocrystallization with several coformers. Two different methods were adopted for the supramolecular assembly of the ternary systems A.B.C: (1) first, binary adducts A.B or A.C were crystallized by grinding a slurry of the components in a suitable solvent and then C was added and grinding was continued; and (2) all three components were taken in a solvent slurry and ground together. The former method was found to be superior in affording the ternary salt/cocrystal. The role of laboratory seeding is implicated to explain the variation in crystallization results at different stages of the project. Crystal structures of the product{\textquoteright}s binary and ternary systems were solved by single-crystal X-ray diffraction and powder X-ray diffraction data for structure solution. The crystal structures show the recurrence of carboxylate{\textendash}pyridinium and imidazole{\textendash}acid heterosynthons in the binary and ternary adducts. The intermolecular interactions between ACF and the coformer are analyzed by Hirshfeld surfaces, 2D fingerprint plots, and an energy framework. The permeability of ACF increases in binary and ternary systems with selected coformers. The fast dissolution and high permeability of ACF-PIP make this salt an improved crystalline formulation of acefylline.

}, doi = {10.1021/acs.cgd.2c00184}, author = {Allu, Suryanarayana and Garai, Abhijit and Chernyshev, Vladimir V. and Nangia, Ashwini K.} }