THE QUALITATIVE AND QUANTITATIVE-ANALYSIS OF CHLORPROPAMIDE POLYMORPHIC MIXTURES BY NEAR-INFRARED FOURIER-TRANSFORM RAMAN-SPECTROSCOPY

We analyzed binary mixtures of polymorphs A and B of chlorpropamide (( 1-[4-chlorobenzenesulphonyl]-3-propyl urea)) by near-infrared Fourier transform Raman spectroscopy (FTRS). The individual polymorphs were pr epared and characterized by differential scanning calorimetry (DSC), F ourier transform infrared (FT-IR) microscopy, and physical appearance. The FTR spectra of the two polymorphs showed distinct differences whi ch result from ''crystal splitting'' effects. A series of 13 different mixtures of polymorph A and B was prepared by geometric mixing and th eir FTR spectra statistically analysed by factor analysis programming. Predictions of the A/B polymorphic composition of mixtures were made and compared with the theoretical values. The results demonstrate that FTRS combined with factor analysis programming may be successfully ap plied to the in situ monitoring of the A/B polymorphic nature of a chl orpropamide sample.