<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Thorat, Shridhar H.</style></author><author><style face="normal" font="default" size="100%">Sahu, Sanjay Kumar</style></author><author><style face="normal" font="default" size="100%">Gonnade, Rajesh G.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Crystal structures of the pyrazinamide-p-aminobenzoic acid (1/1) cocrystal and the transamidation reaction product 4-(pyrazine-2-carboxamido)-benzoic acid in the molten state</style></title><secondary-title><style face="normal" font="default" size="100%">Acta Crystallographica Section C-Structural Chemistry</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">acid-amide hetero-synthon</style></keyword><keyword><style  face="normal" font="default" size="100%">active pharmaceutical ingredient (API)</style></keyword><keyword><style  face="normal" font="default" size="100%">cocrystal</style></keyword><keyword><style  face="normal" font="default" size="100%">crystal structure</style></keyword><keyword><style  face="normal" font="default" size="100%">hydrogen bonding</style></keyword><keyword><style  face="normal" font="default" size="100%">molten-state reaction</style></keyword><keyword><style  face="normal" font="default" size="100%">powder diffraction</style></keyword><keyword><style  face="normal" font="default" size="100%">transamidation reaction</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2015</style></year><pub-dates><date><style  face="normal" font="default" size="100%">NOV</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">11</style></number><publisher><style face="normal" font="default" size="100%">INT UNION CRYSTALLOGRAPHY</style></publisher><pub-location><style face="normal" font="default" size="100%">2 ABBEY SQ, CHESTER, CH1 2HU, ENGLAND</style></pub-location><volume><style face="normal" font="default" size="100%">71</style></volume><pages><style face="normal" font="default" size="100%">1010-U276</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;The synthesis of pharmaceutical cocrystals is a strategy to enhance the performance of active pharmaceutical ingredients (APIs) without affecting their therapeutic efficiency. The 1: 1 pharmaceutical cocrystal of the antituberculosis drug pyrazinamide (PZA) and the cocrystal former p-aminobenzoic acid (p-ABA), C7H7NO2- C5H5N3O, (1), was synthesized successfully and characterized by relevant solid-state characterization methods. The cocrystal crystallizes in the monoclinic space group P21/n containing one molecule of each component. Both molecules associate via intermolecular O-H center dot center dot center dot O and NH center dot center dot center dot O hydrogen bonds [O center dot center dot center dot O = 2.6102 (15)angstrom and O-H center dot center dot center dot O = 168.3 (19)degrees; N center dot center dot center dot O = 2.9259 (18) angstrom and N-H center dot center dot center dot O = 167.7 (16)degrees] to generate a dimeric acidamide synthon. Neighbouring dimers are linked centrosymmetrically through N-H center dot center dot center dot O interactions [N center dot center dot center dot O = 3.1201 (18) angstrom and N-H center dot center dot center dot O = 136.9 (14)degrees] to form a tetrameric assembly supplemented by C-H center dot center dot center dot N interactions [C center dot center dot center dot N = 3.5277 (19) angstrom and C-H center dot center dot center dot N = 147 degrees]. Linking of these tetrameric assemblies through N-H center dot center dot center dot O [N center dot center dot center dot O = 3.3026 (19) angstrom and N-H center dot center dot center dot O = 143.1 (17)degrees], NH center dot center dot center dot N [N center dot center dot center dot N = 3.221 (2) angstrom and N-H center dot center dot center dot N = 177.9 (17)degrees] and C-H center dot center dot center dot O [C center dot center dot center dot O = 3.5354 (18) angstrom and C-H center dot center dot center dot O = 152 degrees] interactions creates the twodimensional packing. Recrystallization of the cocrystals from the molten state revealed the formation of 4-(pyrazine-2-carboxamido) benzoic acid, C12H9N3O3, (2), through a transamidation reaction between PZA and p-ABA. Carboxamide (2) crystallizes in the triclinic space group P1 with one molecule in the asymmetric unit. Molecules of (2) form a centrosymmetric dimeric homosynthon through an acid-acid O-H center dot center dot center dot O hydrogen bond [O center dot center dot center dot O = 2.666 (3) angstrom and O-H center dot center dot center dot O = 178 (4) degrees]. Neighbouring assemblies are connected centrosymmetrically via a C-H center dot center dot center dot N interaction [C center dot center dot center dot N = 3.365 (3) angstrom and C-H center dot center dot center dot N = 142 degrees] engaging the pyrazine groups to generate a linear chain. Adjacent chains are connected loosely via C-H center dot center dot center dot O interactions [C center dot center dot center dot O = 3.212 (3) angstrom and CH center dot center dot center dot O = 149 degrees] to generate a two-dimensional sheet structure. Closely associated two-dimensional sheets in both compounds are stacked via aromatic pi-stacking interactions engaging the pyrazine and benzene rings to create a threedimensional multi-stack structure.&lt;/p&gt;</style></abstract><custom3><style face="normal" font="default" size="100%">&lt;p&gt;Foreign&lt;/p&gt;</style></custom3><custom4><style face="normal" font="default" size="100%">0.479</style></custom4></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Thorat, Shridhar H.</style></author><author><style face="normal" font="default" size="100%">Sahu, Sanjay Kumar</style></author><author><style face="normal" font="default" size="100%">Patwadkar, Manjusha V.</style></author><author><style face="normal" font="default" size="100%">Badiger, Manohar V.</style></author><author><style face="normal" font="default" size="100%">Gonnade, Rajesh G.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Drug-drug molecular salt hydrate of an anticancer drug gefitinib and a loop diuretic drug furosemide: an alternative for multidrug treatment</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Pharmaceutical Sciences</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">cancer chemotherapy</style></keyword><keyword><style  face="normal" font="default" size="100%">cocrystals</style></keyword><keyword><style  face="normal" font="default" size="100%">crystal engineering</style></keyword><keyword><style  face="normal" font="default" size="100%">crystal structure</style></keyword><keyword><style  face="normal" font="default" size="100%">dissolution rate</style></keyword><keyword><style  face="normal" font="default" size="100%">hydrate</style></keyword><keyword><style  face="normal" font="default" size="100%">phase transition</style></keyword><keyword><style  face="normal" font="default" size="100%">solubility</style></keyword><keyword><style  face="normal" font="default" size="100%">stability</style></keyword><keyword><style  face="normal" font="default" size="100%">thermal analysis</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2015</style></year><pub-dates><date><style  face="normal" font="default" size="100%">DEC</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">12</style></number><publisher><style face="normal" font="default" size="100%">WILEY-BLACKWELL</style></publisher><pub-location><style face="normal" font="default" size="100%">111 RIVER ST, HOBOKEN 07030-5774, NJ USA</style></pub-location><volume><style face="normal" font="default" size="100%">104</style></volume><pages><style face="normal" font="default" size="100%">4207-4216</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;A 1:1 monohydrate salt containing gefitinib, an orally administrated chemotherapy treatment for lung and breast cancers and furosemide, a loop diuretic drug, commonly used in the treatment of hypertension and edema, has been prepared. The molecular salt crystallized in triclinic P-1 space group. The CO bond lengths (similar to 1.26 angstrom) in the COOH group show that proton transfer has occurred from furosemide to morpholine moiety of the gefitinib suggesting cocrystal to be ionic. The morpholine moiety of the gefitinib showed significant conformational change because of its involvement in conformation dictating the strong N-H center dot center dot center dot O hydrogen bonding interaction. The strong hydrogen bonding interaction between gefitinib and furosemide places their benzene rings in stacking mode to facilitate the generation of pi-stack dimers. The neighboring dimers are bridged to each other via water molecule through N-H center dot center dot center dot O, C-H center dot center dot center dot O, O-H center dot center dot center dot N, and O-H center dot center dot center dot O interactions. The remarkable stability of the salt hydrate could be attributed to the strong hydrogen bonding interactions in the crystal structure. Interestingly, release of water from the lattice at 140 degrees C produced new anhydrous salt that has better solubility and dissolution rate than salt hydrate. The drug-drug molecular salt may have some bearing on the treatment of patient suffering from anticancer and hypertension. (C) 2015 Wiley Periodicals, Inc. and the American Pharmacists Association&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">12</style></issue><custom3><style face="normal" font="default" size="100%">&lt;p&gt;Foreign&lt;/p&gt;</style></custom3><custom4><style face="normal" font="default" size="100%">2.641</style></custom4></record></records></xml>