Improved dissolution of ibuprofen after crystallization from polymeric solution: Correlation with crystal parameter

The objective of the present work was to investigate the effect of various hydrophilic polymers like hydroxypropylmethyl cellulose, methyl cellulose, carboxymethyl cellulose and poly vinyl alcohol on the in vitro dissolution property of ibuprofen (IBU) crystallized from aqueous polymeric solutions. By using solvent-change technique, IBU crystal products were produced in presence of the selected polymers. Results showed that in presence of polymers; crystallization yield of IBU was higher than that of pure drug crystal (absence of polymer). SEM photographs revealed visible changes in the crystal morphology in the presence of polymers. The FTIR spectra of the crystallized IBU (polymer-treated) showed a shifting of the acid-dimer peak from 1718 cm-1 to 1721 cm-1 but absence of specific peaks for polymers. XRD study further confirmed absence of polymers in the crystallized IBU as no specific peaks were observed for the polymers. A higher percentage of cumulative drug release was reported for the polymeric-treated IBU crystals than that of plain IBU. Further in vivo studies are warranted to establish the in vitro-in vivo correlation for the future technology transfer of the formulation.

X-ray diffraction properties of curved crystal diffractors

Since Du Mond and Kirkpatrick first discussed the principle of a bent crystal spectrograph in 1930, curved single crystals have been widely utilized as spectrometric monochromators as well as diffractors for focusing x rays diverging from a point. Curved crystal diffraction theory predicts that the diffraction parameters - the rocking curve width w, and the peak reflection coefficient r of curved crystals will certainly deviate from those of their flat form. Due to a lack of curved crystal parameter data in current literature and the need for optimizing the choice of diffraction geometry and crystal materials for various applications, we have continued the investigation of our technique presented at the last conference. In the present abstract, we describe a more rigorous and quantitative procedure for measuring the parameters of curved crystals.The diffraction image of a singly bent crystal under study can be obtained by using the Johann geometry with an x-ray point source.