Co-Crystal Polymorphs from a Solvent-Mediated Transformation

2008 ◽  
Vol 8 (7) ◽  
pp. 2537-2542 ◽  
Author(s):  
Joop H. ter Horst ◽  
Peter W. Cains
Keyword(s):  
Solvent Mediated Transformation

scholarly journals Synthesis and Characterization of a New Norfloxacin/Resorcinol Cocrystal with Enhanced Solubility and Dissolution Profile

Pharmaceutics ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 49
Author(s):  
Hanan Fael ◽  
Rafael Barbas ◽  
Rafel Prohens ◽  
Clara Ràfols ◽  
Elisabet Fuguet
Keyword(s):  
Dissolution Rate ◽  
Shake Flask ◽  
Ph Value ◽  
Dissolution Profile ◽  
Ph Values ◽  
Enhanced Solubility ◽  
Poorly Soluble ◽  
Transformation Experiment ◽  
Solvent Mediated Transformation

A new cocrystal of Norfloxacin, a poorly soluble fluoroquinolone antibiotic, has been synthetized by a solvent-mediated transformation experiment in toluene, using resorcinol as a coformer. The new cocrystal exists in both anhydrous and monohydrate forms with the same (1:1) Norfloxacin/resorcinol stoichiometry. The solubility of Norfloxacin and the hydrated cocrystal were determined by the shake-flask method. While Norfloxacin has a solubility of 0.32 ± 0.02 mg/mL, the cocrystal has a solubility of 2.64 ± 0.39 mg/mL, approximately 10-fold higher. The dissolution rate was tested at four biorelevant pH levels of the gastrointestinal tract: 2.0, 4.0, 5.5, and 7.4. In a first set of comparative tests, the dissolution rate of Norfloxacin and the cocrystal was determined separately at each pH value. Both solid forms showed the highest dissolution rate at pH 2.0, where Norfloxacin is totally protonated. Then, the dissolution rate decreases as pH increases. In a second set of experiments, the dissolution of the cocrystal was evaluated by a unique dissolution test, in which the pH dynamically changed from 2.0 to 7.4, stepping 30 min at each of the four biorelevant pH values. Results were quite different in this case, since dissolution at pH 2 affects the behavior of Norfloxacin at the rest of the pH values.

Crystal Structures and Solvent-Mediated Transformation of the Enantiotropic Polymorphs of 2,3,5-Trimethyl-1,4-diacetoxybenzene

2013 ◽  
Vol 52 (49) ◽  
pp. 17667-17675 ◽  
Author(s):  
Liqiang Yang ◽  
Hongxun Hao ◽  
Lina Zhou ◽  
Wei Chen ◽  
Baohong Hou ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Solvent Mediated Transformation

2D to 3D solvent mediated transformation of a photoreactive lanthanum MOF: a case of three parallel photo-cycloaddition reactions

CrystEngComm ◽  
2019 ◽  
Vol 21 (7) ◽  
pp. 1137-1142 ◽  
Author(s):  
Stavroula Skoulika ◽  
Michael G. Siskos ◽  
Adonis Michaelides
Keyword(s):  
Reaction Scheme ◽  
Layered Compound ◽  
Cycloaddition Reactions ◽  
Parallel Reaction ◽  
Solvent Mediated Transformation ◽  
2D To 3D

Irradiation of the 3D MOF [La2(hex)3(H2O)4]3H2O, obtained upon dehydration of the layered compound [La2(hex)3(H2O)6]9H2O, gives two [2 + 2] and one [4 + 4] photocycloaddition reactions occurring in the parallel reaction scheme.

In Situ Monitoring of the Solvent-Mediated Transformation of Cefadroxil DMF Solvate into Monohydrate

2013 ◽  
Vol 17 (9) ◽  
pp. 1110-1116 ◽  
Author(s):  
Xuemei Wang ◽  
Songgu Wu ◽  
Weibing Dong ◽  
Junbo Gong
Keyword(s):  
In Situ Monitoring ◽  
Solvent Mediated Transformation
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