A. Salari et Re. Young, APPLICATION OF ATTENUATED TOTAL REFLECTANCE FTIR SPECTROSCOPY TO THE ANALYSIS OF MIXTURES OF PHARMACEUTICAL POLYMORPHS, International journal of pharmaceutics, 163(1-2), 1998, pp. 157-166
Full characterization of the polymorphic content of bulk drug chemical
s has become increasingly important in the pharmaceutical industry. A
multitude of analytical techniques are commonly employed in this proce
ss. In this work the feasibility of the Attenuated Total Reflectance F
ourier Transform Infrared Spectroscopy (ATR-FTIR) to the qualitative a
nd quantitative analysis of mixtures of polymorphs is investigated usi
ng three known polymorphs of ganciclovir as model compounds. Definitiv
e identification of all three polymorphs is achieved from their ATR-FT
IR spectra obtained from the sample in their native state (no sample p
reparation). Quantitation of polymorphic mixtures is carried out using
a partial least-squares procedure. Quantitative results obtained with
validation samples for both binary and ternary crystal form mixtures
clearly demonstrate the strong potential of ATR-FTIR technique for use
in quantitative analysis of polymorphic content of bulk pharmaceutica
l materials. (C) 1998 Elsevier Science B.V. All rights reserved.