Stereochemical aspects of the molecular pharmaceutics of ibuprofen.
Thermal analysis, thermodynamics of solution and molecular modelling of (+)-ibuprofen and (+/-)-ibuprofen gave information on how heterochiral or homochiral interactions would affect the processing of ibuprofen. The study confirmed that (+/-)-ibuprofen exists as a true racemate with a 10% eutectic pure enantiomer composition. Both the racemate and the (+)-isomer crystal unit cells include four molecules and crystallize in the P2(1/c) and P2(1) space groups, respectively. Thus the intermolecular forces were different in each crystal. As a consequence the (+)-enantiomer lattice was more fragile but only slightly more soluble than the racemate in aqueous media. The solid-state structure contributions to solubility were different for the two crystals (delta H (+) = 51.1 and delta H(+/-) = 32.2 kJ mol-1) but the standard free energies of the solutions were comparable for both compounds.
Romero
A J
AJ
University of Rhode Island, Department of Pharmaceutics, Kingston 02881.
Rhodes
C T
CT
D003460:Crystallization; D007052:Ibuprofen / Q000737:chemistry* / Q000493:pharmacokinetics; D008958:Models, Molecular; D015394:Molecular Structure; D012995:Solubility; D013237:Stereoisomerism; D013816:Thermodynamics; D014961:X-Ray Diffraction
D007052:Ibuprofen